Maximising the use of recycled and secondary aggregates: examples from Hampshire

Transcription

1 Maximising the use of recycled and secondary aggregates: examples from Hampshire Prepared for Partners in Innovation Programme, Department of Trade and Industry J M Reid, J Pittman, C R Sowerby and J Hibbert TRL Report TRL651

2 First Published 2006 ISSN ISBN Copyright TRL Limited This report has been produced by TRL Limited, under/as part of a contract placed by the Department of Trade and Industry. Any views expressed in it are not necessarily those of the Department. TRL is committed to optimising energy efficiency, reducing waste and promoting recycling and re-use. In support of these environmental goals, this report has been printed on recycled paper, comprising 100% post-consumer waste, manufactured using a TCF (totally chlorine free) process. ii

3 CONTENTS Page Executive Summary 1 1 Introduction Sustainability and local authorities Who should read this report? Project aims and objectives Structure of the report 4 2 Implementing sustainability in Hampshire Highway maintenance in Hampshire Minerals and waste in Hampshire: an integrated approach 5 3 Availability of recycled and secondary aggregates in Hampshire Current use of aggregates in Hampshire Potential future use of recycled and secondary aggregates Actions required to achieve the stretching best practice scenario targets Infrastructure Market development Standards and specifications 10 4 Use of recycled and secondary aggregates in Hampshire: demonstration projects Demonstration projects Demonstration Project 1: Embankment stabilisation on the A325 at Alice Holt Demonstration Project 2: Recycled asphalt in footway works, B3047 at Martyr Worthy Demonstration Project 3: Recycled surface dressing sweepings at sites across Hampshire Demonstration Project 4: Bar End Household Waste Recycling Centre (HWRC) Demonstration Project 5: A3 Bus Priority Corridor, Portsmouth to Clanfield Demonstration Project 6: North Popley development, Basingstoke Factors influencing the use of recycled and secondary aggregates in the demonstration projects Benefits from the use of recycled and secondary aggregates in the demonstration projects 15 iii

4 Page 5 Planning: minerals and waste development framework Principles Policies Provision of recycling capacity Supply of minerals Conclusion 22 6 Issues, guidance and actions: Recycling in transport infrastructure revisited Issues Specifications Test methods Reliability and quality control Environmental concerns Waste management regulations Conditions of contract Planning Supply and demand Economics Lack of awareness Summary: progress and the way forward 31 7 Conclusions 31 8 Acknowledgements 32 9 References 32 Abstract 34 Related publications 34 Appendix A: Summary versions of demonstration Appendix A 1 projects Appendix B: Demonstration projects: full case Appendix B 1 studies iv

5 Executive Summary One of the ways in which sustainable construction can be achieved is by the use of recycled and secondary aggregates instead of primary aggregates. This has advantages in terms of preservation of natural resources and protection of the environment, two of the pillars that underlie the concept of sustainability. There have been many developments in recent years in terms of standards, specifications and protocols that permit the use of recycled and secondary aggregates, but experience has shown that the critical factor is often the active involvement of the client. Local authorities are major construction clients, particularly in areas such as highways, and hence are able to exert a considerable influence on the use of construction materials in their area. They are also responsible for a number of related activities, such as waste management and planning, that can have a significant effect on the extent to which recycling of all kinds takes place. This report describes the experience of Hampshire County Council, and shows how a local authority that is committed to sustainability and prepared to take action to implement its principles can achieve considerable success in maximising the use of recycled and secondary aggregates. Hampshire County Council has a firm commitment to sustainability, embodied in Aim 2 of its corporate strategy, which is to protect the environment by promoting the principles of environmental sustainability. These principles are embodied in formal council policies that directly affect the activities of its departments, including the Highways Group. The delivery of highway maintenance services in Hampshire is achieved through a partnership between the County Council, Raynesway Construction Southern Ltd (RCS) and Foster Yeoman Limited. Other sustainability-related initiatives include Project Integra, Hampshire s integrated household waste strategy and the Hampshire Natural Resources Initiative, which aims to achieve a step change in the way natural resources are perceived and used in Hampshire. Bringing all these initiatives together is the Material Resources Strategy (MRS), a stakeholder process involving community and industry representatives working in partnership with Hampshire County Council, Portsmouth and Southampton City Councils and Project Integra. This integrated approach aims to change the way material resources are used to maximise efficiency and minimise waste. As part of the MRS process, estimates had to be made of current levels of recycling for a range of materials, including aggregates, and potential levels estimated for 2010 and 2020 under two scenarios: business as usual; and stretching best practice. TRL Limited carried out assessments for a number of recycled and secondary aggregates that were relevant for Hampshire, and compared this with the expected production of primary aggregates and overall demand for aggregates. The materials considered were:! Recycled aggregates from inert construction demolition and excavation waste (CD&EW).! Highway maintenance and new construction.! Spent railway ballast.! Incinerator bottom ash aggregate from three waste-toenergy plants in Hampshire.! Recycled glass, plastic and tyres. Current (2004) use of recycled and secondary aggregates in Hampshire was estimated to be 686,000 tonnes per year, approximately 13.4% of the total aggregate use. Most of this was recycled aggregates from inert CD&EW, with significant contributions from spent railway ballast and highway works, and most of it was used as relatively low value unbound granular fill. Under the stretching best practice scenario of the MRS this could rise to 1,104,530 tonnes per year by 2020, 21.6% of total aggregate use. This arises from greater use of recycled aggregates from inert CD&EW, more recycling in highway works and use of incinerator bottom ash aggregate. Up to 20% of the aggregates should be used in high value applications such as concrete and asphalt. These figures were fed into the MRS process. In order to achieve these targets, a number of actions will be required. Additional infrastructure will be required to process the recycled and secondary materials into acceptable aggregates; quality protocols and specifications will need to be enforced to ensure the materials are used appropriately; education and market development will be required; and the planning system will need to encourage recycling through tools such as the Demolition Protocol and the Sustainable Building Code of Practice. Hampshire County Council and other major clients can set an example by maximising recycling in their operations and encouraging it in others. Six demonstration projects were developed to illustrate how the use of recycled and secondary aggregates can be maximised in Hampshire:! Demonstration Project 1: Embankment Stabilisation on A325 at Alice Holt.! Demonstration Project 2: Recycled Asphalt in Footway Works on B3047 at Martyr Worthy.! Demonstration Project 3: Recycled Surface Dressing Sweepings.! Demonstration Project 4: Bar End Household Waste Recycling Centre.! Demonstration Project 5: A3 Bus Priority Corridor, Portsmouth to Clanfield.! Demonstration Project 6: North Popley Development, Basingstoke. A wide range of applications were covered, from general and selected granular fill, capping and unbound sub-base, through to cement stabilised sub-base, cold recycled bitumen bound material, surface dressing and structural concrete. The demonstration projects cover many of the potential applications for recycled and secondary aggregates in Hampshire. 1

6 A number of factors were critical for the success of recycled and secondary aggregate use in Hampshire:! There was a clear lead from the client and coordination with other recycling initiatives.! There was early involvement of contractors and other relevant stakeholders.! Logistical arrangements were put in place, e.g. storage depots and recycling plants.! Locally available materials were used.! Modern specifications, design guides and quality protocols were used and new ones were developed where necessary. The use of recycled and secondary aggregates not only resulted in environmental gains, such as reduced use of primary aggregates, reduced disposal of materials to landfill and reduced emissions of CO 2, but also reduced costs in most cases. The experience of Hampshire County Council is thus an example for other local authorities of how to tackle sustainability issues in an integrated way that will yield benefits for local residents and the country as a whole. A number of issues were identified as key to increased use of recycled and secondary aggregates in a TRL publication Recycling in transport infrastructure in These issues were reviewed and it was found that there had been considerable progress on a number of the issues, particularly in the greater use of partnering and early contractor involvement, updating of specifications, standards and quality protocols, resolution of conflicts with the Waste Management Licensing regime and addressing the lack of awareness among construction professionals and major clients. The WRAP Aggregates Programme has made a very significant contribution to this, particularly through their web site A number of areas remain where obstacles to recycling could still occur, such as obtaining planning permission for recycling facilities, developing protocols for secondary aggregates and addressing the lack of awareness issue for the Small to Medium Enterprises (SME) sector. It is important that use of recycled and secondary aggregates is seen as part of an overall programme on sustainability and co-ordinated with other activities. The MRS approach adopted by Hampshire County Council, Portsmouth and Southampton City Councils provides a good example of how this can be achieved. 2

7 1 Introduction 1.1 Sustainability and local authorities Sustainability has become a key concept world-wide in recent years, and has been incorporated in UK government policy through a number of documents (DETR, 1999; 2000). It was originally defined in the Brundtland Report as development which meets the needs of the present without compromising the ability of future generations to meet their own needs (World Commission on Environmental Development, 1987). It covers a wide range of activities which are inter-related and should not be addressed in isolation, including resource use, waste production and disposal, energy, emissions and social and economic issues. In the UK they have been grouped into four objectives (DETR, 1999):! Social progress which recognises the needs of everyone.! Effective protection of the environment.! Prudent use of natural resources.! Maintenance of high and stable levels of economic growth and employment. One of the ways in which sustainability can be implemented in construction is by the use of recycled and secondary aggregates in place of primary aggregates. This is consistent with the objectives of prudent use of natural resources and effective protection of the environment. One of the major uses of aggregates in the UK is in road construction and maintenance, and this area offers many opportunities for use of recycled and secondary aggregates (Sherwood, 1995; Reid and Chandler, 2001). Local authorities have been at the forefront of interpreting what this new philosophy is about and implementing it in their activities. In England and Wales, county councils, unitary authorities and metropolitan boroughs have a wide range of responsibilities where sustainability issues are relevant, including waste collection and disposal and construction-related activities such as highway maintenance, schools and housing. They are also planning authorities with responsibilities including deciding applications for new mineral workings, waste disposal and recycling facilities or extensions to existing facilities, new developments and redevelopment of existing sites and making provision to meet central government targets for mineral production and waste disposal. They thus have a very large influence on activities in their area, both as client and enforcing authority, and can affect the extent to which the principles of sustainability are implemented. Most local authorities have some reference to sustainability in their high level strategic objectives. Success in delivery of these objectives relies on establishing a link between these strategic goals and what happens on the ground. This requires a clear lead from the top and the establishment of policies that translate the objectives into action. It also requires a major change in culture and attitude on the part of the staff of the council and those of organisations working for them. If these conditions are met, major advances in sustainability can be achieved. By being proactive in increasing the use of recycled and secondary aggregates, Hampshire County Council and other local authorities are responding to community concerns about the impact of mineral working and waste disposal and community desire for a more sustainable approach to use of material resources. The role of local authorities and the public sector generally in responding to community concerns and desires closing the loop is a key driver for change. This involves linking functions such as minerals and waste, procurement and highways to create market demand for products such as recycled and secondary aggregates. This forms part of the broader agenda for sustainable consumption and production, in which local authorities are heavily involved. 1.2 Who should read this report? This report deals with the activities of Hampshire County Council and the neighbouring City Councils of Southampton and Portsmouth, their partners, contractors, suppliers and other relevant stakeholders and their efforts to implement sustainability in their activities, particularly in increasing the use of recycled and secondary aggregates in place of primary aggregates. The emphasis is mainly on highway maintenance, new construction and related activities, but these are dealt with in the wider context of overall waste and material use. It illustrates how the integrated approach adopted by Hampshire, Southampton and Portsmouth can lead to significant increases in the use of recycled and secondary aggregates. The report should be read by local authority personnel who are interested in implementing the principles of sustainability in their operations, particularly those involved in highway maintenance and construction. It will also be of interest to contractors, designers and suppliers working for local authority highways departments and planners and waste management officers in local authorities. 1.3 Project aims and objectives The work described in this report was carried out by TRL Limited under a Partners in Innovation project funded by the Department of Trade and Industry, with in-kind contributions from a range of individuals and organisations including Hampshire County Council, Raynesway Construction Southern, Foster Yeoman, the Environment Agency, Dean & Dyball and the Institution of Civil Engineers. The aim of the project was to provide technical information to enable the maximum use to be made of recycled and secondary aggregates (RSA) in the County of Hampshire 1 and the associated urban areas of Southampton and Portsmouth. It was a linked research, development and demonstration project which proceeded in two stages:! Stage 1: A review of information on current and potential use of recycled and secondary aggregates and the technical and regulatory mechanisms by which these are controlled, leading to identification of requirements 1 In this report, Hampshire is used to denote the county of Hampshire and the urban areas of Portsmouth and Southampton. 3

8 for processing and other infrastructure to enable the maximum potential use to be achieved.! Stage 2: A series of research and demonstration projects involving the use of recycled and secondary aggregates in a variety of applications that will illustrate how the potential can be achieved and how obstacles can be overcome. This is the final report for the project and summarises the work carried out in both stages of the project. The work carried out in Stage 1 is described in detail by Sowerby et al. (2005). 1.4 Structure of the report In Chapter 2 the integrated approach to sustainability adopted by Hampshire County Council is described, with particular emphasis on highway maintenance and mineral and waste policy. The current and potential future availability of recycled and secondary aggregates in Hampshire, and the contribution they can make to the overall aggregate requirements of the county are described in Chapter 3. The ways in which these aggregates can be used are described by means of a number of demonstration projects in Chapter 4, and the effect on the minerals and waste development framework are described in Chapter 5. In Chapter 6 a number of potential drivers and obstacles to greater use of recycled and secondary aggregates are discussed and conclusions are given in Chapter 7. Summary and full versions of the demonstration projects are give in Appendices A and B respectively. 2 Implementing sustainability in Hampshire 2.1 Highway maintenance in Hampshire Hampshire is a county on the south coast of England, roughly half way between the east and west ends of the country. It has a population of 1,240,000 and covers an area of 367,680 hectares, making it one of the largest nonmetropolitan or shire counties in England ( Most of the county is within 1-2 hours of London by main-line rail services or motorways. The major cities of Southampton and Portsmouth, on the south coast, are not part of the county but are covered by the respective city councils. The county is partly rural but many areas are heavily developed, particularly around Basingstoke and the towns of urban south Hampshire (Eastleigh, Fareham, Gosport, Havant). In England and Wales, county councils are responsible for the maintenance of public highways with the exception of trunk roads and motorways. This covers a wide range of situations, from lightly trafficked roads in rural areas and housing estates to major principal roads ( A roads) that are very heavily trafficked and connect with the trunk road and motorway network. Highway maintenance covers a wide range of operations, from patching and surface dressing to complete reconstruction of life-expired carriageways. The county councils are also involved in new construction, from ensuring that new roads in housing and industrial estates are constructed in accordance with the local authorities adoption specifications to major schemes such as bypasses. County councils are thus in a very powerful position to influence the amount of recycling and the use of recycled and secondary aggregates in highway maintenance and new construction in their areas. Hampshire County Council is responsible for maintaining more than 6,000 miles of road and a similar length of footways. The maintenance of Hampshire s road network is carried out to ensure that the highways are safe and that the public can use them without obstruction. The Hampshire Highways Group, a branch of the County Council s Environment Department, carries this out in accordance with set policies. Hampshire has been at the forefront of developing a systematic approach to the maintenance and management of the highway network and was influential in the development of the local authorities association s Code of Practice for Highway Maintenance (Anon, 2005). Hampshire County Council has a firm commitment to sustainability. Aim 2 of the council s corporate strategy is to protect the environment by promoting the principles of environmental sustainability. Sustainable development implies the following principles which can be adopted for highway maintenance operations:! A reduction in the consumption of natural resources, including energy. Non-renewable resources should be substituted with renewable resources.! Waste should be reduced.! Waste should be reused or recycled.! Biodiversity should be preserved or enhanced.! Valuable natural and physical assets and amenities should be preserved and protected. These principles are embodied in a formal council policy which states that Hampshire County Council, as the highway authority, shall consider environmental factors whenever designing a maintenance scheme or planning a maintenance operation. The choice of materials and processes that preserve or enhance the environment should have due regard to the health and safety of the road user. This policy drives the actions of the Hampshire Environment Department and clearly favours recycling and the use of recycled and secondary aggregates, provided this does not adversely affect the performance or safety of the highway network. As part of its commitment to sustainability, Hampshire County Council signed a Public Service Agreement (PSA) with the Government in April 2002 covering the period up to March The Public Service Agreement requires Hampshire County Council to achieve more demanding performance targets than would otherwise be expected. One of the targets was to recycle an additional 40,000 tonnes per annum of household, commercial and industrial waste through development of a natural resource management approach. Highway maintenance and new construction were identified as key areas which could contribute significantly to meeting this target. 4

9 The delivery of highway maintenance services in Hampshire is achieved through a partnership between the County Council, Raynesway Construction Southern Ltd (RCS) and Foster Yeoman Limited. The partnership has a number of benefits including a shared feeling of project ownership, agreed priorities and common goals by all the stakeholders. Stable relationships are developed between the partners, which generates and stimulates strategic thinking. The arrangement allows efficiencies in programming by linking project clusters to project partners. It enables the development of new materials and specifications, with input and advice from the Environment Agency where necessary. The project has the following sustainability related objectives:! Identify opportunities for changing working practices on highway maintenance to optimise reuse and recycling of construction waste.! Reduce construction waste and use recycled and secondary aggregates.! Draw on each others strengths for the mutual benefit of the partners and the people of Hampshire. The partnership covers routine highway maintenance work. Large capital projects, such as major maintenance schemes, are let by competitive tender. 2.2 Minerals and waste in Hampshire: an integrated approach The Hampshire, Portsmouth and Southampton Minerals and Waste Local Plan was adopted by the three councils in December The plan period was to December 2001 with provision for a seven year land bank for sand and gravel to A review of the Plan commenced, and the three authorities reconsidered the approach to the review in the light of comments arising from the stakeholder dialogue and the implications of the Planning and Compulsory Purchase Bill. They agreed that a review of waste policies should be urgently progressed and that an integrated Hampshire Minerals and Waste Development Framework (HMWDF) be prepared. As part of the process of producing a context for the HMWDF, the joint municipal waste management strategy and work through the Natural Resources Initiative on societal change, the councils instigated a stakeholder consultation process called the Material Resources Strategy (MRS). This involved community and industry representatives working in partnership with Hampshire County Council, Portsmouth and Southampton City Councils and Project Integra (Hampshire s integrated household waste strategy) and the Hampshire Natural Resources Initiative (HNRI), which aims to achieve a step change in the way natural resources are perceived and used in Hampshire. Details of Project Integra and HNRI can be found at the web sites and respectively. The MRS addressed the use of all material resources, including municipal, construction, commercial and agricultural waste in Hampshire. The philosophy was to regard arisings of all materials as a resource rather than a waste, to maximise reuse, recycling and recovery, minimise arisings of waste and minimise the amount going to landfill. A key part of the strategy was to minimise extraction of primary resources, such as aggregates, by better process and product design and by maximising the use of recycled and secondary aggregates. The MRS proceeded by means of a series of stakeholder workshops, in parallel with which a review was undertaken of all the main material and waste streams arising in Hampshire. For each material stream, estimates were made of the current level of arisings and recycling, and potential levels in 2010 and 2020 under two scenarios:! A business as usual scenario that had regard to essential change, e.g. the requirements of existing and new legislation, regulations and statutory targets.! A stretching best practice scenario that set out the best that could reasonably be achieved with a concerted effort, having regard to state of the art approaches overseas and in the UK. The estimates for each material were reviewed by an independent panel of interested stakeholders and subjected to an independent validation review before being incorporated into the MRS. TRL was already preparing estimates for a range of recycled and secondary aggregates under the PII project (see 1.4 above), and the form in which the information was collected was adapted to comply with the requirements for the MRS. In addition to estimates of quantities under the two scenarios, issues such as collection and infrastructure requirements, market development, education, financial issues, risks and wider issues were addressed. A separate report on construction waste and soil was produced specifically for the MRS (Sowerby and Reid, 2005). The findings of these studies are discussed in Chapter 3. The outcome of the MRS process was published as More from Less in March 2005 on behalf of the community stakeholders by Hampshire County Council, Portsmouth and Southampton City Councils and Project Integra. It is intended as a primary reference point to guide and integrate three key work areas:! Production of the statutory joint minerals and waste development framework.! Development of plans for managing municipal waste under Project Integra.! Implementation of societal change objectives via the Hampshire Natural Resources Initiative. The document reviews a number of topics, including resource efficiency and reducing wastage, maximising reuse, recycling and composting, dealing with unavoidable wastes, meeting the need for minerals and the need for new infrastructure and sites. For each topic the current situation is reviewed, ways forward are suggested, actions listed and targets set. The overall vision of More from Less is that: we will change the way we use material resources to maximise efficiency and minimise wastage. To deliver this they have identified four aims:! To extract primary materials only where it can be shown that the need cannot be met in a more sustainable way. 5

10 ! To change minds and behaviours to use all resources efficiently and minimise wastage at all stages of production and consumption.! Where waste is produced to maximise opportunities for business and the community to reuse, recycle and compost such waste to produce sustainable products.! To recover value from and dispose of unavoidable waste using sustainable means, as far as possible avoiding the landfilling of biodegradable/recyclable waste. Clearly, increasing the use of recycled and secondary aggregates in activities such as highway maintenance is a crucial part of achieving these aims. Details of how this can be carried out are given in Chapter 4. It is important to remember that this is part of an overall strategy for dealing with minerals and waste, and not an end in itself. 3 Availability of recycled and secondary aggregates in Hampshire 3.1 Current use of aggregates in Hampshire Hampshire is a county with no reserves of hard rock, but with extensive deposits of sand and gravel which have been worked for many years. Marine dredged sand and gravel is available from the English Channel, and is landed at a number of wharves in Portsmouth and Southampton. Crushed rock is imported into the county through these wharves, and is also delivered by rail to several depots in the Southampton and Portsmouth area. Good quality data are available on the amounts of these primary aggregates produced each year. These are published in the annual Aggregates Monitoring (AM) reports produced by the South East England Regional Assembly. The data for 2002 are summarised in Table 1. The total arisings of primary aggregates were estimated to be 4,944,000 tonnes per annum, of which 4,434,500 tonnes (90%) was used in the county, with the balance exported to neighbouring counties and London. These primary aggregates are supplemented by recycled and secondary aggregates from a variety of sources. For Hampshire, the potentially significant materials were found to be:! Recycled aggregates from inert construction demolition and excavation waste (CD&EW).! Recycled aggregates and asphalt from highway maintenance and new works.! Spent railway ballast.! Incinerator bottom ash aggregate (IBAA) from processing of incinerator bottom ash (IBA). Data on the current use and potential availability of these materials was much less accurate than for the primary aggregates. Estimates of production of recycled aggregates from CD&EW are available at national and regional level from surveys carried out every two years for the Office of the Deputy Prime Minister (ODPM, 2002a and 2004). The data has large error margins and cannot be broken down to county level. Estimates of CD&EW recycled at licensed waste management sites in Hampshire were obtained from data collected by the Environment Agency. This data is subject to a number of uncertainties due to the way it is recorded by the site operators (Sowerby et al., 2005). It also underestimates the total amount of recycled CD&EW because it does not include recycling at sites exempt from the waste management licensing regulations. This category includes redevelopment projects where materials are produced, processed and reused on site. Discussions with suppliers of recycled aggregates and other stakeholders helped to provide estimates of the quantity of inert CD&EW potentially recyclable as aggregate and the amount actually Table 1 Current aggregate use in Hampshire (tonnes/year) Amount arising in Hampshire (produced in Hampshire Material or imported into the county) Amount used in Hampshire Primary Land based sand and gravel 2,193,000 2,010,500 Marine dredged sand and gravel 1,715,000 1,638,000 Rail import of crushed rock 600, ,000 Marine imports of crushed rock 436, ,000 Total sand and gravel 3,908,000 3,648,500 Total crushed rock 1,036, ,000 Total primary aggregates 4,944,000 4,434,500 Recycled and secondary aggregates Amount suitable for use as aggregates Amount used as aggregates Recycled aggregate from inert CD&EW 750, ,000 Highways new works and maintenance Not known 45,000 Spent railway ballast 140, ,000 Incinerator bottom ash aggregate (IBAA) 30,000 1,000 Recycled glass 36,500 0 Recycled plastics 33,500 0 Recycled tyres 10,400 0 Total recycled and secondary aggregates 1,000, ,000 Total aggregate use in Hampshire 5,119,500 Proportion of recycled and secondary aggregates 13.4% 6

11 recycled as aggregate. These were estimated as 750,000 and 500,000 tonnes per annum respectively. The figures are shown in Table 1. This is by far the largest source of recycled aggregates in Hampshire. The total amount of inert CD&EW produced in Hampshire was estimated to be about 1,540,000 tonnes per annum. Of this about half, 750,000 tonnes is estimated to be potentially recyclable as aggregate. The remainder is thought to consist of excavation waste, largely clay, silt and chalk which cannot be recycled as aggregate, or mixed waste in which potentially recyclable material is mixed with soil or excessive amounts of material such as timber, plasterboard, plastic or metal. About one third of the total inert CD&EW, 500,000 tonnes is currently recycled as aggregate. This is similar to a national survey which found an overall rate of recycling of inert CD&EW as aggregate of about 36% in the South East Region in 2001 (ODPM, 2002a). Highway maintenance works are a major potential source of recycled aggregates, in the form of asphalt planings, concrete kerbs, granular sub-base and subsoil. A number of techniques are available for recycling these materials (see Chapter 4) and these have been increasingly used in Hampshire in recent years; the proportion of highway maintenance arisings recycled by Hampshire County Council rose from 10% in 1997/98 to 66% in 2000/01 (Reid and Chandler, 2001). The estimate for the amount recycled in 2003/04 is 45,000 tonnes, and this is shown in Table 1. The total arisings were not known. These figures were supplied by Hampshire County Council Highways Group. Another major source of recycled aggregates in Hampshire is spent railway ballast. This comes in to the rail depots in South Hampshire from all over the South East of England and is predominantly primary aggregate such as granite mixed with soil and sub-ballast material. It is mainly used as capping material, sub-base and general fill. All the railway ballast is handled by Foster Yeoman Ltd; they provided the figure in Table 1 and indicated that the supply is fairly constant. The total arisings are about 140,000 tonnes per annum, and all of this is used as recycled aggregate. The only other material that is potentially significant as aggregate in Hampshire is incinerator bottom ash aggregate (IBAA). Hampshire has developed three Energy from Waste facilities as part of an integrated strategy to handle municipal waste; now that they are fully operational, they will produce a total of about 100,000 tonnes of incinerator bottom ash per year. This can be processed and used as aggregate (IBAA), otherwise it has to be disposed of to landfill. A trial was carried out in 2004 using 1,000 tonnes of IBAA in a road construction (see Chapter 4), and this figure is shown in Table 1. At the time only one Energy from Waste plant was operational, producing about 30,000 tonnes of incinerator bottom ash per year. Other materials that could potentially be used as aggregate include glass, plastic and tyres. Estimates for the amounts of these materials that are potentially suitable for recycling as aggregate are shown in Table 1. None of these materials are currently used as aggregates in Hampshire. Glass is collected by Midland Glass in Southampton and is recycled into new glass, which is a higher value application than use as aggregates, although the use of ground glass as bedding sand and as aggregate in asphalt is well established. Plastic and tyres can also be used as aggregates, but it is expensive to process them for these applications compared to other end uses, and compared to using other primary, recycled or secondary aggregates for the same applications. The figures indicate that the total use of aggregates in Hampshire is about 5,119,500 tonnes per annum of which 686,000 tonnes (13.4%) are recycled and secondary aggregates. Overall figures for aggregate use in England for 2001 (Barritt, 2003) suggest that recycled and secondary aggregates account for about 23% of total aggregate use. The reason for the discrepancy is not clear. The estimate of recycled aggregates produced from inert CD&EW for Hampshire may be an underestimate because it does not include material recycled at exempt sites, but it is thought that this could not account for all the difference. The figures should be viewed as indicative, with large margins of uncertainty, not as accurate estimates. This difference between the amounts predicted from national surveys and the amounts that were actually found to be available at county level has important implications when considering Hampshire s allocations of recycled and secondary aggregates in statutory minerals plans in the future (see Chapter 5). The end use of most recycled and secondary aggregates was found to be mainly as relatively low value unbound granular materials, with some being used as capping and sub-base but only very small amounts in higher value bound applications such as concrete and asphalt. This agrees with the findings of Barritt (2003) that recycled and secondary aggregates in England are mostly used in low value unbound applications. 3.2 Potential future use of recycled and secondary aggregates The survey of existing use found that there was considerable scope for increasing the quantities of recycled and secondary aggregates used in Hampshire, and also for using them in higher value applications. In conjunction with the development of the MRS, estimates for potential use in 2010 and 2020 were made under the stretching best practice and business as usual scenarios described in Chapter 2.2. The results are presented in Table 2. National demand for aggregates has been assumed to be effectively constant across the period to 2020, in line with ODPM guidance (ODPM, 2002b). The arisings of recycled and secondary aggregates are assumed to increase at a slow rate over the period to 2010 and 2020 in line with population estimates for Hampshire, Portsmouth and Southampton (ONS, 2003) except where specific information was available. An average increase of 2.5% was chosen for both the periods 2004 to 2010 and 2010 to Details of the calculations are given in Sowerby et al. (2005). Based on these estimates, the proportion of recycled and secondary aggregates used in Hampshire could rise to 19.6% by 2010 and 21.6% by 2020 under the stretching best practice scenario. 7

12 Table 2 Estimates of future use of recycled and secondary materials as aggregates in Hampshire Estimated amount Estimated amount Estimated amount recycled in 2004 recycled in 2010 recycled in 2020 Material (tonnes per year) Scenario (tonnes per year) (tonnes per year) Recycled aggregates (from inert CD&EW) 500,000 Stretching best practice 654, ,000 Business as usual 525, ,000 Highway new works and maintenance 45,000 Stretching best practice 100, ,000 Business as usual 47,500 50,000 Railway ballast 140,000 Stretching best practice 140, ,000 Business as usual 140, ,000 Incinerator bottom ash aggregate 1,000 Stretching best practice 90,000 90,000 Business as usual 2,000 5,000 Recycled glass 0 Stretching best practice 15,000 15,400 Business as usual 0 0 Recycled plastic 0 Stretching best practice 1,000 2,000 Business as usual 0 0 Recycled tyres 0 Stretching best practice 5,000 5,130 Business as usual 0 0 Totals 686,000 Stretching best practice 1,005,000 1,104,530 Business as usual 714, ,000 Total aggregate use in Hampshire 5,119,500 Zero growth in total aggregate use assumed 5,119,500 5,119,500 Proportion of recycled and secondary aggregates 13.4% Stretching best practice 19.6% 21.6% Business as usual 14.0% 14.6% The largest source of recycled aggregates remains the processing of inert CD&EW. Under the stretching best practice scenario, this would rise from the current level of about 66% of the potentially recyclable material to 95% by Estimates were also made of the amount that could be used in higher value applications (concrete, asphalt). This is currently effectively zero, but it estimated that 10% (65,400 tonnes) of the recycled aggregates from this source could be used in higher value applications by 2010 and 20% (150,000 tonnes) by For highway maintenance arisings, it is estimated that a rapid increase in recycling up to about 100,000 tonnes per annum could take place by 2010, building on initiatives that have already begun under the PSA and partnership with Raynesway Construction Southern and Foster Yeoman. This is considered to be about the maximum that can be achieved, and a slow growth in line with population is predicted from 2010 to The arisings of spent railway ballast are thought likely to remain relatively constant to This is all currently recycled, approximately 90,000 tonnes (64%) as unbound granular fill and 50,000 tonnes (36%) as capping. Potentially some of this material could be used as aggregate in concrete and asphalt, and more could be used as sub-base and less as general fill. The stretching best practice estimates therefore predict 10,000 tonnes (7%) in bound applications by 2010, rising to 25,000 tonnes (18%) by 2020, with the amount used as sub-base rising to 90,000 tonnes (64%) by 2010 and then remaining constant to The amount used as general fill will decrease proportionately. At the time of the survey, only one Energy from Waste plant was operational, at Chineham near Basingstoke. The other two plants, at Marchwood and Portsmouth, should be operational by the end of When all three plants are operational they will generate about 100,000 tonnes of incinerator bottom ash per annum. It is considered that about 90,000 tonnes (90%) will be suitable for processing to form incinerator bottom ash aggregate. This represents a valuable source of aggregate for Hampshire. It is likely that this will be used almost entirely in bound form, principally as coarse aggregate in asphalt or blocks, to avoid any concerns about environmental risks if it was used as unbound granular fill. Some allowance has been made for the use of recycled glass, plastic and tyres as aggregates or as substitutes for aggregates in the period to Expansion of collection schemes for glass, including flat glass, will result in more material becoming available, and some use in asphalt or as bedding sand is likely, particularly in urban South Hampshire. Recycled tyres may be used as rubber in asphalt, as aggregate in concrete, or as tyre bales in a variety of applications (Hylands and Shulman, 2003). Plastics are probably least likely to be used as aggregates. 3.3 Actions required to achieve the stretching best practice scenario targets The stretching best practice scenario implies that changes have to be made to existing practices to achieve the targets in Table 2. The increase in recycling under the business as usual scenario is much smaller and will not enable 8

13 Hampshire to meet its goals under the MRS. The overall philosophy is set out in More from Less (Hampshire County Council, 2005). The particular changes and actions that are required to achieve the targets for recycled and secondary aggregates are discussed here Infrastructure The proposed increase in recycled aggregates will require the development of additional CD&EW Recycling Centres to produce the material. The current distribution of CD&EW Recycling Centres shows them mainly around the periphery of the Southampton Portsmouth and Aldershot areas (Figure 1). Several areas appear under provided in relation to their population, such as Basingstoke, Andover and Winchester, though there are waste transfer stations in these areas that collect CD&EW and send it on to CD&EW Recycling Centres elsewhere. New CD&EW Recycling Centres will have to meet strict requirements on control of noise, dust, vibration, traffic and visual impact. They will also have to operate according to quality control protocols if they are to produce aggregates that are acceptable under modern specifications. CD&EW Recycling Centres should be located close to where the material arises and to the proposed market, in accordance with the proximity principle. Excessive transport distances will also make the materials uneconomic in relation to primary aggregates. There will also be a requirement for a site to enable the incinerator bottom ash from the three incinerators in Hampshire to be weathered and processed into aggregate. This should ideally be located centrally to the incinerators, so that the product would be available to all parts of the county without excessive transport distances. The site would need to be at least 4 ha in size and would need to have arrangements to contain the drainage water from the IBAA during the weathering phase. This would form part of a strategic network of recycling centres for Hampshire. This is discussed in more detail in Chapter Market development There is need for market development in several areas, particularly for the use of recycled and secondary aggregates in bound applications. The use of these materials can be encouraged by the use of targets in contracts and planning controls, but the most productive approach is likely to be the development of partnerships such as the existing one for highway maintenance, where all parties can feel ownership of the project and work towards common goals. This arrangement could usefully be extended to other areas. A tool that can be used by the planning system to increase the amount of recycling in redevelopment projects is the Demolition Protocol (EnviroCentre, 2004). Under the protocol, a pre-demolition audit is carried out and the quantity of material that can be recycled is calculated; this is called the Demolition Recovery Index (DRI). It applies not only to aggregates, but also to other recyclable materials such as metal, glass, plasterboard, timber and ornamental stone. These quantities are then carried forward into the design of the new development as the New Build Recovery Index (NBRI) and are itemised in the Bill of Quantities. The material does not have to be CD&EW Recycling Centres Figure 1 Location of CD&EW Recycling Centres in Hampshire 9

14 recycled on site; it can be sent to recycling centres at the time of demolition and replaced by equivalent quantities of recycled materials when the new structure is built. This does not put undue limitations on the developer in terms of the type of new structure or the timescale for redevelopment, but ensures a high level of recycled content in the new development. The protocol is intended to be used as part of the planning process, with its use being one of the conditions of planning permission for the new development. Another factor that will encourage greater recycling is the Code for Sustainable Building, which is expected to be launched by the UK Government (DTI) in It is likely that this will include a minimum value for recycled material content in new projects, possibly 10% of the material value. This will only apply for projects above a certain value, but the level has not been decided. Use of recycled aggregates is one way in which developers can rapidly increase the recycled content of their projects, particularly by their use in concrete blocks and structural concrete which are high value products. They can also be used in pipe bedding and backfill, general oversite, fill below floor slabs and in access roads. Education is a major requirement if the targets for Recycled and Secondary Aggregates use are to be met. This is partly a case of dissemination of information about specifications, quality control, regulations and what is possible with the materials, and partly making the business case for recycling. There is a need to target all sectors of the construction industry and the public with appropriate messages. Some of these may be best done on a national basis, but local initiatives will also be important. Table 3 Specifications and standards that permit the use of recycled and secondary aggregates! Specification for Highway Works (SHW), updated quarterly: Pipe bedding and filter material. Earthworks (general and selected granular fill, capping, etc). Unbound sub-base. Cement and other hydraulically bound materials. Asphalt base and binder course. Pavement quality concrete.! HD 35/04 Conservation and the use of secondary and recycled materials, 2004: Updated from original version of Volume 7 Part 1 Section 2 of the Design Manual for Roads and Bridges. Includes new materials including recycled glass and incinerator bottom ash. Extends potential use of materials beyond the current SHW.! BS 8500: Concrete 2002: Defines recycled aggregate (RA) and recycled concrete aggregate (RCA). Permits their use in various grades of concrete and in mixtures with primary aggregates. Permits use of blast furnace slag Standards and specifications Standards and specifications are not a barrier. Most national specifications have been updated in recent years to allow the use of recycled and secondary aggregates (see Table 3) and a protocol has been developed to ensure quality control. The problem is more often one of perception. People may equate the mixed rubble in a builder s skip with recycled aggregates, or may be working to outdated specifications that did not permit the use of recycled or secondary aggregates. There may also be environmental concerns about the use of some materials, such as incinerator bottom ash aggregate, especially in a county like Hampshire large parts of which are underlain by a major aquifer. Hence a programme of education is required, and one of the best ways of doing this is by demonstration projects that illustrate what can be achieved and the environmental and economic benefits that can be realised. This theme is taken up in Chapter 4. Another common perception is that recycled and secondary aggregates will be more expensive than primary aggregates. The reverse is more often the case, as the demonstration projects illustrate. There is considerable potential for increasing both the amount of recycled and secondary aggregates used in Hampshire and the value of the applications for which they are used. The targets should not be regarded as precise estimates but as goals to aim for, which should be reviewed! Specification for the Reinstatement of Openings in Highways, 2 nd edition 2002: Permits use of recycled and secondary aggregates. Provided meet defined performance characteristics. Local authority approval needed.! Civil Engineering Specification for the Water Industry, 6 th edition 2004: Extends use of recycled aggregates.! European harmonised standards for aggregates, 2004: Do not differentiate between primary, recycled and manufactured aggregates. Have to be called up by national specifications.! WRAP quality protocol for the production of recycled aggregates from inert waste: Framework document for producers of recycled aggregates. Quality control plan to meet specification requirements. If followed, demonstrates wastes have been fully recovered. Called up by the Specification for Highway Works. 10

15 periodically. Recycling should not be seen as an end in itself but as part of the overall process of developing a more sustainable construction industry, which will benefit industry and the general public. This is exemplified by the MRS process carried out by Hampshire County Council and the City Councils of Portsmouth and Southampton. 4 Use of recycled and secondary aggregates in Hampshire: demonstration projects 4.1 Demonstration projects The use of recycled and secondary aggregates has become much more widespread in recent years and applications have been described from a wide range of construction scenarios; see Reid and Chandler (2001) or the numerous case studies on the AggRegain web site ( As part of this project, a total of six demonstration projects were developed over the period July 2004 to June The projects are described briefly below, summary versions are given in Appendix A and the full case studies in Appendix B. The main points are summarised in Table 4, and the locations of the projects are shown in Figure 2. The case studies were numbered and are listed below:! Demonstration Project 1: Embankment Stabilisation on A325 at Alice Holt.! Demonstration Project 2: Recycled Asphalt in Footway Works on B3047 at Martyr Worthy.! Demonstration Project 3: Recycled Surface Dressing Sweepings.! Demonstration Project 4: Bar End Household Waste Recycling Centre.! Demonstration Project 5: A3 Bus Priority Corridor, Portsmouth to Clanfield.! Demonstration Project 6: North Popley Development, Basingstoke. The projects were chosen to give a good geographic spread across the county and represent the main areas of highway and infrastructure construction and maintenance where recycled and secondary aggregates can readily be used in Hampshire. Hampshire County Council was the client for all the projects, but they cover a wide range of situations and a number of different departments were involved Demonstration Project 1: Embankment stabilisation on the A325 at Alice Holt This project was a major maintenance scheme contracted out from Hampshire County Council (HCC). The project was a three phase operation with RCS being involved in phase two, which involved the stabilisation of the A325 near Alice Holt, over a distance of about 1.8km. The works are shown schematically on Figure 3. The embankment was made up of poor quality clay at a variable slope and had been suffering from instability. The excavated material was replaced with Class 6F5 selected granular fill. The embankment ranged from 0.8m to 5.0m in height and the works required a total of 29,000 tonnes of imported fill. Table 4 Summary table for demonstration projects No. Title Approximate Activity Applications Materials amount used 1 Embankment Stabilisation on A325 at Alice Holt Earthworks. Selected granular fill. Recycled aggregate. 29,000 tonnes 2 Recycled Asphalt in Footway Works, B3047 at Martyr Worthy Footways. Cold recycled bitumen bound material. Recycled asphalt. 300 tonnes 3 Recycled Surface Dressing Sweepings at sites across Hampshire Surface dressing. Reuse of surplus surface dressing material. Recycled asphalt. 4,000 tonnes 4 Bar End Household Waste Recycling Centre Access road. General granular fill. Recycled aggregate. 12,000 tonnes Footway. Selected granular fill. Recycled asphalt. Concrete base slab. Capping. Recycled railway ballast. Retaining walls. Unbound sub-base. Incinerator bottom ash aggregate. Cold recycled bitumen bound material. Structural concrete. 5 A3 Bus Priority Corridor, Portsmouth to Clanfield Road widening and reconstruction. General granular fill. Recycled asphalt. 4,000 tonnes Lower trench fill. Recycled concrete (crushed kerbs). Capping. Subsoil and topsoil. Unbound sub-base. 6 North Popley Development, Basingstoke Access road for new school on General granular fill. Chalk. 2,600 tonnes greenfield site. Cement bound sub-base and trench backfill. Recycled asphalt. Cold recycled bitumen bound material. 11

16 Note: The surface dressing project was carried out at a number of sites across Hampshire; these are not shown on the map. Figure 2 Locations of demonstration projects Embankment height varies from 0.8m to 5m high Existing soft clay fill removed New 1:3 slope being constructed ROAD Backfill of 6F5 material Existing slope Steps dug out from existing embankment Figure 3 Cross section of embankment works at Alice Holt The new embankment was built at a uniform slope of 1:3. The imported fill was supplied by recycled aggregates derived from processing construction and demolition material from Day Aggregates Ltd, TJ Transport from Selborne, and Wessex Construction Ltd (sited in Adsdean, Sussex), thus avoiding the use of primary aggregates Demonstration Project 2: Recycled asphalt in footway works, B3047 at Martyr Worthy This case study dealt with the use of cold recycled bitumen bound material in routine highway maintenance works, with a particular focus on one example of innovative use of the material in a footway renovation project. The particular form of cold recycled bitumen bound material used involved the use of foamed bitumen as the main binder, usually with asphalt planings from other highway works as the coarse aggregate. Foster Yeoman set up a mobile plant at their depot at Micheldever to produce this material (commonly known as Foamix ) and it has been widely used across the county. Use of a single layer of Foamix can replace separate layers of sub-base and base in road construction (Figure 4), resulting in a thinner pavement. The cold recycling technique also saves energy and emissions of CO 2 compared to conventional hot 12

17 Normal Classified road 40mm surface course 60mm binder Classified road using Foamix 40mm surface course 60mm binder 150mm road base 210mm Foamix 200mm sub-base Figure 4 The layers found in a normal classified road and a classified road using Foamix asphalt. In the particular example featured in the case study, cold recycled bitumen bound material was used to repair sub-base and as combined base and binder course in the renovation of some 700 m of footway. The use of this material meant that only a surface dressing was required on top, instead of a full surface course as would have been required under a conventional reinstatement Demonstration Project 3: Recycled surface dressing sweepings at sites across Hampshire In surface dressing operations on highways, there are always some surplus unused materials. After the surface dressing has been laid, further surplus material is generated as sweepings of loose material from the road surface. In Hampshire there are a number of remote sites where unused surface dressing chippings have been stockpiled for a number of years. These sites are now receiving post surface dressing sweepings as well as the unused material. The surface dressing sweepings would previously have been sent to landfill or used on farm tracks. In 2003 these stockpiles were estimated to be in excess of 4,000 tonnes. Hampshire County Council and their surfacing contractor Road Maintenance Service Ltd (RMS) wanted to find a use for the excess surface dressing chippings and sweepings. The material was dry screened, lightly coated with bitumen and used in new surface dressing operations. About 4,000 tonnes was successfully laid between May and August The material has been monitored and performance has been very satisfactory. This has saved the import of primary aggregates and also resulted in significant cost savings Demonstration Project 4: Bar End Household Waste Recycling Centre (HWRC) This was a capital project undertaken for the Waste Management Group of Hampshire County Council to build a new household waste recycling centre (HWRC) to serve the Winchester area. The project involved upgrading of some 300 m of access road to the site, construction of a base slab for the containers for recycled waste, retaining walls and a one-way road system round the slab, together with associated drainage and landscaping works. Sustainability was built into the design from the start, with maximum use of recycled aggregates and asphalt from existing buildings, access road and car park on the site. A sustainable urban drainage system (SUDS) was included in the design. Where additional aggregates were required, they were supplied by recycled aggregates and spent railway ballast from the local area. The base slab for the HWRC included recycled aggregate as 15% of the coarse aggregate. Cold recycled bitumen bound material from the Foster Yeoman plant at Micheldever was used for the base and binder course of the access road and perimeter road round the slab. The coarse aggregate was incinerator bottom ash aggregate from the Energy from Waste plant at Chineham. A cross section of the access road is shown on Figure 5, showing the use of recycled and secondary aggregates. The use of all the recycled and secondary aggregates was successful, and the project is intended to be an example of how sustainability can be maximised in future projects for this type of facility Demonstration Project 5: A3 Bus Priority Corridor, Portsmouth to Clanfield The A3 Bus Priority Corridor Project is included in Hampshire County Council s (HCC) Local Transport Plan It is managed under a partnership between HCC, Portsmouth City Council (PCC), Havant Borough Council (HBC), East Hampshire District Council (EHDC) and the bus operator First. It will provide high quality, reliable public transport by offering passengers a priority bus service along the A3 corridor from Gunwharf Quays, Portsmouth to Clanfield, a village north of Horndean. The works affect a 12km long stretch of road and involve road widening, carriageway and footway reconditioning, diversion of statutory undertakers utilities, drainage, replacement street lighting and new/upgraded pedestrian crossings (puffins and toucans). To ensure the project is delivered in a sustainable way a best practice checklist with supporting tools is under development. Currently only being used in-house on a few trial schemes, the checklist and tools are intended to be cascaded to other sections in the Environment Department at HCC. Specific aspects involving recycling include the use of recycled asphalt planings and crushed concrete kerbs as capping and subbase for the widened road and new footways and excavated subsoil as general fill and landscaping. 13

18 Rain Surface course 45mm Kerb and gully Footpath Foamix base and binder course mm Existing road structure 160mm Foamix Sub-base (recycled aggregates) 150mm SUDS Capping ~200mm Water table 0.9m-2.9m below ground level Figure 5 Cross section of access road to Bar End Household Waste Recycling Centre Demonstration Project 6: North Popley development, Basingstoke North Popley is a major new mixed use development on a green field site on the north side of Basingstoke. The site is owned by Hampshire County Council (HCC), who carried out preliminary infrastructure works to provide a spine road and services across the site. Preliminary works included provision of a 250 m access road for a new school. In accordance with HCC s corporate policies on sustainability, opportunities were sought to maximise recycling and the use of recycled and secondary aggregates in the construction. Any methods that were shown to work successfully could be extended to the much larger spine road and associated works. Two main techniques were used:! Cement stabilisation of in situ chalk to form a cement bound sub-base.! Cold recycled bitumen bound material as the base for the road pavement. HCCs specification was revised to include clauses on cement stabilisation and cold recycling, in particular to take advantage of new developments described in the recently published TRL Report TRL611 (Merrill et al., 2004). The cold recycled bitumen bound material used foamed bitumen as the binder and recycled asphalt from the A325 Alice Holt project as the coarse aggregate. It was supplied by Foster Yeoman from the plant at Micheldever. The project was very successful and resulted in over 2,000 tonnes of chalk being reused on site in a variety of applications, plus the use of about 600 tonnes of recycled asphalt in the cold recycled road pavement. 4.2 Factors influencing the use of recycled and secondary aggregates in the demonstration projects The demonstration projects illustrate how recycling and the use of recycled and secondary aggregates can be maximised in highway maintenance and new construction works. A number of factors are critical for the success of this in Hampshire:! There has to be a clear lead and commitment from the client. In this case it arises from Hampshire County Council s corporate objectives, which include an aim to protect the environment through the promotion of the principles of environmental sustainability. This has been worked through in the context of highway maintenance and drives the day-to-day activities in the county.! There has to be early involvement of all the key stakeholders, including contractors and suppliers. Hampshire County Council has enabled this through the partnership it has set up with Raynesway Construction Southern and Foster Yeoman for highway maintenance. However, it is possible to achieve this early input under other contractual arrangements.! All parties have to be fully committed to the project and work as a team sharing common goals. In this environment innovation can flourish and new methods and materials can be developed and trialed.! Logistical arrangements have to be made and facilities provided to enable arisings to be processed and reused in the highest value applications. In Hampshire, this involved setting up two segregation plants for highway arisings, establishing relationships with a recycling contractor and establishing a cold recycling plant.! Opportunities should be sought to take advantage of locally available recycled and secondary aggregates. In Hampshire this involved use of recycled aggregates, recycled asphalt and spent railway ballast and exploring the potential of a large material stream of incinerator bottom ash aggregate.! Most applications involving recycling and the use of recycled and secondary aggregates are already covered 14

19 by the UK Specification for Highway Works and design guides such as TRL Report TRL611 (Merrill et al., 2004). However, to take advantage of locally available materials it may be necessary to develop new methods and specifications, such as for the use of incinerator bottom ash aggregate in the base and binder course at Bar End and cement stabilisation at North Popley. The projects had an emphasis on sustainability in a number of ways, not just in the use of recycled and secondary aggregates. Examples of this include the provision of a sustainable drainage system at Bar End and the use of a long-life surface dressing on the A3 Bus Priority Corridor. The demonstration projects also show the use of innovative plant, such as a quiet kerb crusher on the A3 Bus Priority Corridor and the cold recycled bitumen bound material mixing plant at Micheldever, which supplied cold recycled bitumen bound material for the Martyr Worthy, Bar End and North Popley sites. Innovative design methods included the use of the recently published TRL Report TRL611 (Merrill et al., 2004), the development of a method statement for the use of incinerator bottom ash aggregate in cold recycled bitumen bound material and the use of cold recycled bitumen bound material in footways with only a surface dressing rather than a full surface course. Hampshire County Council adapted their specification to enable the use of TRL611 and the use of cement stabilisation of chalk at North Popley. Material Use Sheets are being introduced on projects to allow linking of surplus materials from one site to another and reduce the need for primary aggregates. The demonstration projects cover a wide range of applications and materials, but they do not cover all the uses of recycled and secondary aggregates that are possible. Other applications could include:! Processing and reuse of materials on demolition and redevelopment sites.! Use of recycled aggregate and recycled concrete aggregate in concrete.! Use of recycled aggregates and incinerator bottom ash aggregate in block manufacture.! Use of recycled aggregate in concrete haunch repairs.! Use of recycled asphalt in new hot asphalt materials.! Use of recycled glass in asphalt base and binder courses.! Use of recycled glass as bedding sand for pavers and pipes.! Use of tyre bales in roads over soft ground or flood defence applications.! Import of china clay sand for fill, pipe and paver bedding and concrete. Achieving the routine use of recycled and secondary aggregates in these applications as well as those illustrated by the demonstration projects, will be key to reaching the targets set for 2010 and 2020 under the stretching best practice scenario. 4.3 Benefits from the use of recycled and secondary aggregates in the demonstration projects The recycled and secondary aggregates in the demonstration projects performed as well as equivalent primary aggregates, so there was no technical disbenefit from their use. In a number of cases there were significant benefits, as it enabled the use of material generated on site that might otherwise have gone to landfill, such as the chalk arisings at North Popley. Reduced thicknesses of pavement layers can be achieved by the use of cold recycled bitumen bound material and stabilisation with cement and other materials. Significant cost savings can also be made by the use of recycled and secondary aggregates. The reuse of recycled surface dressing sweepings is estimated to have led to cost savings of over 28,000. There are also significant environmental benefits:! Reduced consumption of primary aggregates.! Reduced disposal of material to landfill.! Reduced haulage and associated fuel use.! Reduced energy use and CO 2 emissions by the use of cold recycled bitumen bound material rather than hot asphalt. The demonstration projects also made a significant contribution towards Hampshire s PSA targets. County councils are particularly well placed to drive increased recycling because the scale of their operations is sufficiently large to give them the opportunities to pursue these options and to justify the initial effort needed to set up the systems to make the approach work in practice. In this respect Hampshire is an exemplar local authority, and the approach Hampshire has adopted could usefully be followed by other local authorities in similar positions. The effort that has been put in has more than amply been repaid by cost savings and visible improvements in the sustainability of its highway operations, which in turn reflects the concerns of residents and government for a more sustainable future. 5 Planning: minerals and waste development framework 5.1 Principles The principles set out in More from Less are being taken forward in a number of ways by Hampshire County Council, Portsmouth and Southampton City Councils, Project Integra and the Hampshire Natural Resources Initiative. One of these is the statutory Hampshire Minerals and Waste Development Framework. The core planning strategy document (Hampshire County Council, 2005) for this was published for consultation at the end of September The strategy builds on the work described in this report in a number of ways. It is based on the overall vision of More from Less that We will change the way we use material resources to maximise efficiency and minimise wastage. 15

20 Demonstration Project 1: Compacting recycled aggregates as embankment fill at Alice Holt Demonstration Project 2: Footway at Martyr Worthy with surface dressing over cold recycled bitumen bound base 16

21 Demonstration Project 3: Screening surface dressing chippings for reuse Demonstration Project 3: Rural road with recycled surface dressing 17

22 Demonstration Project 4: Recycled aggregate sub-base in access road to Bar End Household Waste Recycling Centre Demonstration Project 4: Cold recycled bitumen bound base with incinerator bottom ash aggregate over recycled aggregate sub-base, Bar End Household Waste Recycling Centre 18

23 Demonstration Project 6: Chalk stabilised with cement in situ as sub-base for access road to new school, North Popley Development. Bituminous tack coat applied to project stabilised material Demonstration Project 6: Cold recycled bitumen bound base being placed and compacted, North Popley Development 19

24 This vision has three key elements relevant to the Plan:! Changing behaviour.! Resource efficiency.! Minimising waste. The preferred option developed from this vision includes, among other outcomes:! An overall recycling rate of 60% by 2020.! Materials and energy recovery maximised from unavoidable waste.! Use of landfill for all waste materials reduced to a minimum practicable level by 2020.! Demand for new minerals reduced to minimum practicable levels, with extraction of land-won sand and gravel reduced as far as practicable.! New sites and facilities provided to meet needs in a sustainable efficient way.! A supportive policy framework and all sectors of the community involved in delivering solutions and change. 5.2 Policies The strategy recognises that fundamental changes to existing practices and attitudes are required in order to meet the targets and achieve the vision. This includes suggestions that the following sustainable design elements should be reflected in city, district and borough councils Local Development Frameworks:! Using recycled or secondary materials in built development as far as possible, especially in associated road building and hard surfacing.! Where demolition needs to take place before construction, recovering or recycling the demolition waste as far as possible, preferably on-site. The North Popley demonstration project gives an example of how the first objective can be achieved, and the Demolition Protocol and forthcoming Code for Sustainable Building will be useful tools to help achieve the second. The strategy includes an overall recycling target of 60% for all waste by 2020, with specific targets for CD&EW of 50% for 2010 and 60% for The figures quoted in Chapter 3 indicate that in 2004 about 33% of all CD&EW was recycled as aggregate. Estimates under the stretching best practice scenario for recycling as aggregate were about 40% by 2010 and 50% by 2020, this being the maximum that is thought to be recyclable in this way. Achieving the overall recycling rate of 60% will therefore require recycling of other fractions of the CD&EW. This can be achieved by recycling excavation waste and other materials as soil, mixed with green waste compost, and by recovering other components of the waste stream such as timber, plasterboard, metal, glass and plastic. 5.3 Provision of recycling capacity Recycled and secondary materials require processing before they can be used as aggregates, and the provision of adequate facilities is essential if the targets for recycled and secondary aggregate use are to be met. Such facilities should be located so as to minimise the transport distances from where the materials arise and where they are to be used; these will not necessarily be the same, particularly with the development of several large areas of new housing on greenfield land. These developments offer many opportunities for the use of recycled and secondary aggregates. Long term development in Hampshire is to be met by large scale Major Development Areas (MDAs) in four areas: Waterlooville, Eastleigh, Basingstoke and Andover. The development areas are shown in Figure 6. These developments will incorporate housing, roads, and industrial and commercial development. In addition, large areas of MoD land in the Aldershot/Farnborough area are likely to be released for development in the near future. The MDAs provide particular opportunities for the use of recycled and secondary aggregates as they are to be developed according to sustainability principles. However, most CD&EW arises from the older urban areas of Portsmouth and Southampton, as shown by the location of existing recycling centres on Figure 1. The strategy states that siting issues have to be addressed for facilities for an additional 750,000 tonnes per year of strategic CD&EW recycling. Appropriate regional distribution is necessary, so that the recycled aggregates are available where they will be needed, not just in some parts of the county. A separate table gives a breakdown of indicative recycling capacity requirements for Hampshire, with the county split into three sub-county areas:! Urban South Hampshire (including Portsmouth and Southampton).! Forest and downland.! Hampshire s part of the western corridor (north Hampshire including Basingstoke). The bulk of the recycling capacity is indicated for Urban South Hampshire. Indicative capacities are given for 2010, 2015 and The overall indicative capacity for 2020 is a little over twice the target figure of an additional 750,000 tonnes per year. The strategy also recognises the need for facilities and capacity for 90,000 tonnes of incinerator bottom ash recycling, in line with the estimates for the amount of this material that will be available for recycling as aggregate in Table 2. Provision is also made for a soil hospital to treat 35,000 tonnes of contaminated soil; at least some of the treated material would potentially be available to use as recycled aggregates. The strategy does not identify particular sites for the recycling facilities, but lists criteria that should be applied when deciding on the suitability of individual sites, including the proximity principle and closeness to the Strategic Transport Network. Co-location of recycling facilities with other related activities, such as Resource Recovery Parks, is suggested as a way of identifying suitable sites. It is suggested that there should be several large strategic facilities for producing recycled aggregates from CD&EW to the standards required by the construction industry, with several smaller scale facilities such as skip waste transfer and recycling stations. It is suggested that the 20

25 Development area Figure 6 Proposed major development areas incinerator bottom ash recycling plant should be close to the Marchwood and Portsmouth facilities, as these produce more ash, offer connection to sustainable transport options such as rail, and be within 0.5 km of the road network linking the three plants. The soil hospital should be located in Urban South Hampshire, since this is where the contaminated soils predominantly arise. An important point that emerged during the MRS process was the need for permanent planning permission for CD&EW recycling facilities in order to attract sufficient investment from operators to install equipment to process materials to the standards required for high value applications. Often planning permissions for such sites are given on a temporary basis and are a disincentive to investment. The strategy recognises the need to address this issue. This is essential if the stretching best practice targets are to be met. The strategy also provides for safeguarding the existing wharves and rail depots that are used for importing aggregates into Hampshire. 5.4 Supply of minerals The strategy quotes the South East Plan which sets out the requirements for planning for minerals as follows: The supply of construction aggregates in the South East should be met from a significant increase in supplies of secondary and recycled materials, a reduced contribution from primary land-won resources and an increase in imports of marine-dredged aggregates. The South East Plan provides a sub-regional apportionment of 2.63 million tonnes per annum (mtpa) of land-won sand and gravel for Hampshire, Portsmouth and Southampton. This is higher than the current level of about 2.19 mtpa (Table 1). According to the strategy, the supply of land-won aggregate has shown a generally decreasing trend over the last decade despite increased economic growth. Although there has been a small increase from marine sources, the general trend in aggregate supply has been static. It is proposed to limit the amount of land-won sand and gravel by increased use of recycled and secondary aggregates. However, there are limitations to this. In most of the applications where recycled and secondary aggregates are used at present, they are substituting for crushed rock rather than sand and gravel, so the effect on demand for sand and gravel is limited. Sand is in particularly short supply in Hampshire, but most recycled and secondary aggregates are relatively coarse grained, and do not directly substitute for natural sand. At present (Table 2) recycled and secondary aggregates are thought to account for only about 13% of the aggregates used in Hampshire, and even under the stretching best practice scenario that only rises to about 22% by Recycled and secondary aggregates cannot completely replace primary aggregates. However, every effort should be made to increase the extent to which they are used, especially to increase their use in high value applications such as concrete, where they would directly replace sand and gravel. At present there is no sub-regional apportionment for recycled and secondary aggregates. However, there is a regional apportionment of 118 million tonnes for the South East to cover the period Assuming this is 21

26 apportioned sub-regionally by population, this would equate to a target of about 1.5 mtpa for Hampshire. This compares to present levels of about 0.69 mtpa and stretching best practice targets of 1.0 mtpa by 2010 and 1.1 mtpa by 2020 (Table 2). There is considerable uncertainty about all figures connected with recycled and secondary aggregates, but the discrepancy is too large to be explained purely by statistical uncertainty. It may be partly explained by the lack of information on material recycled on site during redevelopment. However, if increased use of recycled and secondary aggregates is to be relied on then the reasons for the discrepancy should be investigated. A further complication is that to date there has been no requirement for producers of recycled aggregate to record the quantities of materials they have sold, unlike primary aggregates. It is therefore very difficult to get accurate figures. This could make it difficult to tell whether targets for recycled and secondary aggregate use are being met. In the present project, estimates of amounts recycled were made from returns from operators of licensed waste management facilities to the Environment Agency; these were difficult to interpret, and were not designed to record recycling. New requirements for operators of exempt sites were introduced from July 2005, which should make it easier to obtain data on the amounts of material that are proposed to be recycled or deposited on these sites, but collating the information is likely to be a labour-intensive task. 5.5 Conclusion The strategy addresses the issues that are relevant if the proposed increases in recycled and secondary aggregate use are to be achieved. Further work will be required in some areas. The MRS has worked by getting all the stakeholders involved in the process and discussing the issues openly. If this approach is continued, it is likely that most of the obstacles can be overcome. 6 Issues, guidance and actions: Recycling in transport infrastructure revisited In October 2001, TRL published Recycling in transport infrastructure (Reid and Chandler, 2001), a guidance document on increasing the amount of recycling and use of alternative materials in transport infrastructure renewal works. The publication was the result of an extensive review of the topic by TRL, supported by a steering group with cross-industry representation. The report identified the main issues, summarised guidance that was already available and recommended actions for the main groups of stakeholders. The conclusions were summarised in a table, reproduced here as Table 5. It is instructive to look at these issues and recommended actions in the context of the present project, to see what progress has been made and whether any other issues have emerged as significant in recycling in construction. An updated version of the summary table is included as Table Issues Ten areas where there were potential obstacles to the use of recycled and secondary aggregates were identified. The issues, available guidance and recommended actions are reviewed briefly below Specifications At the time of Recycling in transport infrastructure, the May 2001 amendments to the Specification for Highway Works had just been issued. These greatly extended the scope for use of recycled and secondary aggregates and recycling techniques, but a number of other specifications still excluded them. Since then, most of these specifications have been updated (Table 3) and it is now possible to use most commonly available materials in most applications, provided they meet the requirements for engineering properties. Specifications are thus not a barrier to the use of recycled and secondary aggregates, provided up-to-date specifications are used Test methods The same test methods were being used for primary, recycled and secondary aggregates, although research showed that some of the test methods for primary aggregates were not appropriate for some recycled and secondary aggregates. This remains the case; harmonised European Standards for aggregates, introduced in the UK in 2004, cover all aggregates, whatever their origin, and require the same tests to be carried out on them. The advantages this has in placing recycled and secondary aggregates on the same level as primary aggregates outweighs any disadvantages in applying inappropriate test methods to a small number of materials. Work is underway in Europe towards producing bespoke test methods for recycled and secondary aggregates, particularly through the collaborative European research project SAMARIS (Sustainable and Advanced Materials for Road InfraStructure). Information on SAMARIS can be obtained from the web site Recycling in transport infrastructure also recommended that more performance-based test methods and specifications be developed. These take the focus away from the origin of a material and focus on its performance. Work has continued on development of performance-based test methods and specifications in the UK, Europe and elsewhere (Merrill et al., 2004; Nunn, 2004), but implementation on a large scale is likely to be several years ahead. Overall, test methods only provide a small barrier to particular uses of a few materials, and do not significantly inhibit their use Reliability and quality control This was identified as a key factor in determining the acceptability of recycled and secondary aggregates in The perception of recycled and secondary aggregates as highly variable and of low quality has changed somewhat, particularly with public sector clients 22

27 Table 5 Summary of issues relating to recycling in transport infrastructure, 2001 Issue Description Available guidance Recommended action required Specifications. Some materials and methods are A number of specifications for Update existing specifications to accommodate excluded from existing specifications. alternative materials and methods new developments more quickly, or write new are available. Specifications for particular applications. Test methods. Existing test methods developed for A number of tests have been assessed as Move to performance-based test methods natural materials are not suitable for suitable for alternative materials. and specifications. some alternative materials. Reliability and quality control. Alternative materials perceived as Utilise or adapt existing quality control Demonstrate quality of materials produced highly variable and of low quality. systems to produce a consistent, under a quality plan, upgrade processing fit-for-purpose material. plant to produce higher quality material. Environmental concerns. Potential long term leaching of Assess behaviour using leaching tests Agreement between environmental contaminants into controlled waters; dust and existing models where necessary; regulators and material producers on use of and noise during construction. CDM/COSHH legislation. materials in construction. Waste regulation including Unclear whether materials are waste or Use available guidance on waste Approach environmental regulators for advice at wastemanagement licensing covered by exemptions, potential long permitting system. early stage in design of project. DEFRA are and PPC regime. time scale required by waste permitting reviewing exemption system to ensure alternative processes. materials can be used in construction. Conditions of contract. Some forms of contract may create an Use appropriate forms of contract and Review standard conditions of contract to environment where there is no incentive adopt partnering. rectify any clauses discriminating against for innovation. innovative materials or methods. Planning. Difficulties getting planning permission Guidance for planners and applicants Ensure an adequate supply of recycling for recycling centres in or near urban areas. has been produced by DETR. centres is available to meet local needs. Supply and demand. Difficulty in matching supply and demand Plan in advance and stockpile material Develop long term partnering agreements to for some alternative materials. if necessary; use existing databases to enable better prediction of material source materials. requirements. Economics. Alternative materials and methods may be Ensure comparing like with like; use Adjust aggregates levy and landfill tax as more expensive than conventional ones. whole life costing to ensure best practical necessary to ensure alternative materials environmental option selected. remain competitive. Lack of awareness. Many individuals and organisations Disseminate existing information from Develop strategies to reach resistant sectors unaware of the possibilities, or only aware CIRIA, EA, TRL, BRE, AAS and others. of industry and infrastructure owners. of potential problems. 23

28 24 Table 6 Summary of issues relating to recycling in transport infrastructure, 2005 Issue Description Available guidance Recommended action required Specifications. Some materials and methods are excluded from Most specifications and standards now cover use Update specifications in line with new developments. existing specifications. of recycled and secondary aggregates (see 6.1.1). Test methods. Existing test methods developed for natural materials Some performance based test methods are available; Move to performance-based test methods and specifications. are not suitable for some alternative materials. test methods being developed via EC project SAMARIS (see 6.1.2). Reliability and quality control. Alternative materials perceived as highly WRAP quality protocol for production of aggregates Demonstrate quality of materials produced under a quality plan, variable and of low quality. from inert wastes (see 6.1.3). upgrade processing plant to produce higher quality material. Environmental concerns. Potential long term leaching of contaminants into Assess behaviour using leaching tests and existing Develop protocols for secondary aggregates. controlled waters; dust and noise during construction. models where necessary (see 6.1.4); CDM/COSHH legislation. Waste regulation including Unclear whether materials are waste or covered by Use guidance in waste management regulations Continued liaison between industry, WRAP, the Environment waste management licensing exemptions, potential long time scale required module on (see 6.1.5). Agency and DEFRA to avoid conflicts in the future. and PPC Regime. by waste permitting processes. Conditions of contract. Some forms of contract may create an environment Use appropriate forms of contract and adopt Monitor effectiveness of forms of contract and adapt where there is no incentive for innovation. partnering and early contractor involvement to where necessary. stimulate innovation (see 6.1.6). Planning. Difficulties getting planning permission for Include requirements for facilities in minerals and Ensure an adequate supply of recycling centres is available to aggregate recycling centres. waste development frameworks; use guidance in meet local needs; engage stakeholders in consultation at an early planning module on (see 6.1.7). stage. Supply and demand. Difficulty in matching supply and demand for Provide necessary facilities for storage and treatment Long term partnering agreements to enable better prediction of some alternative materials. of materials; divert recyclable material from exempt material requirements; divert recyclable material from exempt sites (see 6.1.8). sites. Economics. Alternative materials and methods may be more Use case studies on to Adjust aggregates levy and landfill tax as necessary to ensure expensive than conventional ones. demonstrate that recycled aggregates are often alternative materials remain competitive. cheaper than primary ones (see 6.1.9). Lack of awareness. Many individuals and organisations unaware of the Disseminate existing information from WRAP, Develop strategies to reach SME sector; continue to address possibilities, or only aware of potential problems. CIRIA, EA, TRL, BRE and others (see ). major clients and construction professionals.

29 such as local authorities, as a result of government initiatives on sustainability and increased experience of their satisfactory use. It remains a problem with many private clients and developers, particularly for the Small to Medium Enterprises (SME) sector. BR392 Quality control: the production of recycled aggregates was referenced in Recycling in transport infrastructure. This proved very successful in ensuring the quality of recycled aggregates, and was used successfully on major projects such as the widening of the M25 between J12 and 15 (see the case study on In 2004 BR 392 was superseded by the WRAP quality protocol for the production of aggregates from inert waste (Waste and Resources Action Programme, 2004), which incorporated the new harmonised European Standards for aggregates and included clarification on the issue of when materials ceased to be waste (see 6.1.5). The WRAP quality protocol has been very successful and provides a framework for producers to confirm that their products are fit for purpose and have been fully recovered. It is important for clients to insist that producers use this protocol. This will force up standards in the recycling industry and defeat the problem of cowboy recyclers who provide material of low quality and bring the industry into disrepute. The quality protocol was developed by WRAP through discussions with the Environment Agency and the Quarry Products Association. Following the successful production of this protocol, work started on similar protocols for pulverised fuel ash (PFA), steel slag and incinerator bottom ash aggregate. These secondary aggregates are extensively used in construction and there is considerable potential to increase their use, so protocols for these materials would be very valuable. However, we understand that there is little likelihood of these protocols being finalised in the near future. This is an important area and we would urge that higher priority should be given to agreeing protocols for these materials Environmental concerns This was raised as an area of potential concern, particularly for materials with potentially leachable constituents when used in sensitive areas such as major aquifers. The WRAP quality protocol has helped; as it is for the production of aggregates from inert waste, by definition they are unlikely to give rise to environmental problems. Consideration should always be given to specific circumstances however. Recycled concrete aggregate often has a high ph, for example, and should not be used below water near to sensitive groundwater or surface water receptors. Similar protocols for other secondary aggregates would be very helpful in defining where they could and could not be used, as noted in the previous section. Use of materials in bound form, such as asphalt or concrete, is likely to be much less contentious than use in unbound form, because the potential for release of contaminants is greatly reduced. Case study: use of incinerator bottom ash aggregate in bound form The use of incinerator bottom ash aggregate (IBAA) in bound form in the Bar End HWRC case study illustrates what can be achieved when all parties work together. The Environment Agency were very supportive of the use of IBAA in this application, as a constructive use of a material that would otherwise be landfilled, but they required a risk assessment and leaching tests to be carried out on the IBAA itself and on the asphalt containing the IBAA. The risk assessment concluded that the proposed use of IBAA in the base and binder of the path and roadway up to the waste transfer station was unlikely to have any adverse health or environmental effects. However, a programme of testing and monitoring was set up to provide reassurance on this point; this is reproduced in Figure 7. The BS EN 12457: Part 3 two-stage batch leaching test was carried out on the IBAA and the results compared to Waste Acceptance Criteria (WAC) for granular stable nonreactive hazardous waste (Statutory Instrument 2004 No. 1375). This was to ensure that the IBAA had been properly processed before incorporation into the asphalt. Fresh incinerator bottom ash (IBA) is strongly alkaline and produces leachate with very high concentrations of metals, sometimes in excess of the WAC for hazardous waste. Fresh IBA should not be used as aggregate, either in bound or unbound form. Weathering the material for at least six weeks allows hydration and carbonation reactions to occur, the ph drops and the solubility of metals and other contaminants is greatly reduced. The leaching test was a quality control test to ensure that the material had been weathered properly before being used in asphalt. 150 mm cube samples of the asphalt were taken at the time it was placed, cured for 28 days then subjected to a tank leaching test according to the Dutch Standard NEN 7345 as a check on the leachability of the final product. The cumulative release of all species from the cube samples was very low and did not give any cause for concern. The procedures adopted for the Bar End site confirmed that when used properly IBAA can be incorporated in asphalt pavement layers other than the surface course without any significant risk to the environment. Having established this principle, it should be possible to use this material widely without having to carry out all the leaching tests on each occasion. However, it is important to ensure that the materials are properly weathered before use, and a regular programme of batch leaching tests should be carried out by the producer to provide reassurance on this point. It is also important that the material is placed and compacted properly to ensure that there is no risk of release of contaminants. This can be demonstrated by standard engineering tests such as density and stiffness, which are carried out on the material to ensure it meets the engineering requirements for the application. Statutory Instrument 2004 No contains WAC for inert, granular stable non-reactive hazardous waste and hazardous waste, based on chemical analyses of a few parameters on the solid waste and the cumulative leaching results using the BS EN 12457: Part 3 two-stage batch 25

30 Tests on IBA Site Monitoring Carry out BS EN test on weathered IBA Take baseline samples from balancing pond and River Itchen Results below WAC for SNRHZW? Yes No Continue weathering material Use IBA in foamix: construct in accordance with Method Statement Confirm physical properties by engineering tests during construction Carry out tank tests on foamix in accordance with NEN 7345 Routine monitoring of balancing pond and River Itchen Results below WAC for SNRHZW for monolithic waste? Yes No Extract cores and carry out tank tests to NEN 7345: Increase frequency of monitoring of balancing pond and River Itchen Carry out quantitative risk analysis No Results within relevant water quality standards (to be defined) Yes Extract cores after one year and test according to NEN 7345 Monitoring of balancing pond and River Itchen after one year. Results below WAC for SNRHZW for monolithic waste? No Increase frequency of monitoring/core testing. Carry out quantitative risk analysis No Results below water quality standards (to be defined)? Yes Yes No further action unless monitoring of balancing pond or River Itchen indicates that some release of contaminants may have taken place Reduce frequency of monitoring. No further action unless results exceed water quality standards (to be defined). WAC = Waste Acceptance Criteria SNRHZW = Stable non-reactive hazardous waste Figure 7 Flow chart for environmental testing at Bar End 26

31 leaching test. These WAC values may provide a basis for risk assessments for the use of recycled and secondary aggregates, as the Environment Agency are familiar with them. As in all cases where there are potential environmental concerns, liaison with the Environment Agency should be undertaken from an early stage of the project to establish what the issues are and how they should be addressed Waste management regulations Few topics have generated so much controversy in recent years as the application of the Waste Management Licensing regime to the use of recycled and secondary aggregates. The interaction between regulatory regimes on waste management, driven by case law in the European Court and government driven initiatives on sustainability resulted in a situation where, under a strict interpretation of the law, recycled aggregates were regarded as waste until they had been placed in their final resting place, e.g. as capping materials or sub-base in a road construction. This meant that all sites using recycled aggregates had, in theory, to register an exemption from the Waste Management Licensing Regulations. The threat of this proved a significant disincentive to the use of recycled aggregates and, if it had been widely implemented, could have reversed the increase in use of recycled aggregates that had occurred in previous years. At the time of Recycling in transport infrastructure, the consensus was that recycled aggregates ceased to be waste once they had been processed so that they could be used in construction in the same way as primary aggregate. This meant that the point of recovery was at the recycling plant, and recycled aggregates were not regarded as waste when they left the plant to go to a construction site. Waste Management Regulation in the UK is governed by European Directives, and various cases in the European Court affected the position of the point of recovery, so that it was now on the construction site for recycled aggregates. The situation was resolved by negotiations between WRAP, the Quarry Products Association, the Highways Agency and the Environment Agency which resulted in the production of the WRAP quality protocol for the production of aggregates from inert waste. This included a list of wastes considered to be inert waste for the purpose of the protocol, provided there was no suspicion of contamination, which included most of the materials from which recycled aggregates are generally manufactured, including concrete, bricks, tiles, ceramics, soil and stones, road base and planings, track ballast and glass. The document was essentially an update of the earlier BR392 quality protocol. The purpose of the protocol was stated as to provide a uniform control process for producers by which they can reasonably state and demonstrate that their product has been fully recovered and is no longer a waste. The Environment Agency has circulated the protocol to their staff and advised them to also take account of it in their decision-making. The effect of the WRAP quality protocol is effectively that recycled aggregates produced in accordance with it will not be regarded as wastes, and sites which receive the recycled aggregates will not have to register exemptions from the Waste Management Licensing Regulations. The point of recovery has been effectively moved back to the recycling plant, for recycled aggregates produced in accordance with the protocol. It is therefore very important that the protocol is widely used, and that it is not abused, e.g. by using it to treat contaminated or organic materials. This could bring the protocol into disrepute, and lead to the Environment Agency changing their position on it. It is important for clients and designers to insist on the use of the protocol, not only to ensure the quality of the materials but also to avoid any disputes over whether the materials are waste or not. The subject of waste management regulation and its interaction with the use of recycled and secondary aggregates remains a complex one, and further developments may occur in the future. A useful guide to the current situation, including changes introduced in July 2005, is available in the Waste Management Regulation module of the AggRegain web site ( Conditions of contract Recycling in transport infrastructure concluded that, while some forms of contract could act as a discouragement to the use of recycled and secondary aggregates, the most important factor was not the particular form of contract but the spirit in which it was operated by all parties. Partnering was encouraged as a way to develop good relations between parties and encourage innovation. The success of the partnering approach adopted by Hampshire County Council for highways maintenance demonstrates the advantages of this approach. All parties feel involved and work towards common goals, there is a clear policy lead from the client towards more sustainable construction, early contractor involvement has resulted in a number of innovative approaches and development of new methods and materials, logistical arrangements have been made to enable the use of recycled materials, and techniques and specifications have been updated to enable recycling. The partnering approach is being adopted more widely in construction, including several county councils who have set up partnering arrangements for highway maintenance, including Essex, Surrey and Staffordshire. Details of ways in which conditions of contract can be used to increase the amount of recycling in local authority contracts for highway maintenance are given in the WRAP guidance document The Big Picture (Waste and Resources Action Programme, 2004b), which is available on the AggRegain web site ( procurement/quick_wins/index.html). While partnering is a good way to encourage recycling, it is not essential. With the right approach, recycling can be carried out under most forms of contract, including the traditional Institution of Civil Engineers (ICE) Conditions of Contract for Works of Civil Engineering Construction. What is essential, however, is a clear lead from the client and commitment from all parties. This is demonstrated by a series of supply chain case studies developed by TRL for WRAP, available at ( applications/aggregain/casestudysearch/index.rm). 27

32 6.1.7 Planning Recycling in transport infrastructure identified that there could be difficulties in obtaining planning permission for sites to produce recycled aggregates. This remains the case, although planning guidance for some regions recognises the need to provide for an adequate number of facilities and has widened the potential areas where such sites would be permitted (South East England Regional Assembly, 2004). Many local authorities are now looking to recycled and secondary aggregates as a way of reducing the amount of primary aggregate extraction they are required to make provision for, so the need for facilities to process the recycled and secondary aggregates to the standards needed for the construction industry e.g. the WRAP quality protocol is accepted. The approach adopted in Hampshire, to integrate the provision of facilities within an overall framework for minerals and waste development (Hampshire County Council, Portsmouth City Council and Southampton City Council, 2005), is described in Chapter 5. Information on applying for permission for an aggregate processing facility in England is available on the AggRegain web site at In practice, applications for new sites or extensions to existing sites may still be turned down, even if they are supported by the council officers, because of public concerns about traffic, noise, dust, environmental damage and visual intrusion. Conflicts of this sort are likely to continue, as nobody wants a recycling centre near them however much they agree with the principles of recycling. However, if applications for sites are submitted in line with planning guidance they are likely ultimately to be successful, even if they have to go to the Secretary of State on appeal. The provision for the Secretary of State to award costs against councils who turn down applications that are subsequently upheld on appeal ought to act as a deterrent to councils turning down applications that are in line with planning guidance. The consultation approach adopted by Hampshire, Portsmouth and Southampton should also help to reduce the number of objections to sites by involving all stakeholders in the selection process. If the targets for increased use of recycled and secondary aggregates under the stretching best practice scenario are to be met, there will need to be an increasing supply of quality materials. This in turn will require an adequate supply of reprocessing facilities to produce materials to the required standards. There is some debate as to whether these are best met by a few large, strategically located facilities or a network of smaller facilities closer to the sources of the materials (Hampshire County Council, Portsmouth City Council and Southampton City Council, 2005). This raises a number of issues. It may be easier to obtain planning permission for a few large sites, but is this in effect creating a monopoly for a small number of producers? There are clearly economies of scale with large facilities, but will this result in an overall increase in transport distances compared to a larger number of smaller sites located closer to the arisings? The proximity principle suggests that wastes should be dealt with as close as possible to their point of origin. These issues will have to be worked out and a satisfactory balance achieved between the various factors. Planning permission will continue to be an issue of critical importance for the use of recycled and secondary aggregates. As well as being a potential barrier to recycling, the planning system can also act as an enabling agent, particularly for redevelopment of existing sites through tools such as the Demolition Protocol (EnviroCentre, 2004) (see Chapter 3.3.2). The Demolition Protocol is available at It can also be accessed via the demolition module of the AggRegain web site Supply and demand Matching supply and demand remains one of the most difficult aspects of recycling, particularly ensuring a continuing supply of high quality materials. The issues relating to planning permission for recycling facilities have been discussed in the previous section. A supply of low quality materials does no good for the image of recycling, and can only depress the market for materials that are properly produced in accordance with protocols such as that developed by WRAP. There is an onus on clients, particularly in the public sector, to ensure that protocols, standards and specifications are included in contracts and their use is enforced. Over time this will force industry standards up and enlarge the market for recycled materials, as clients, contractors and suppliers gain more experience with them. A number of major producers are leading the way with provision of high-tech facilities to produce high quality recycled aggregates that can be used in applications such as concrete and asphalt. The plant set up in Brentford, London by Day Aggregates was highlighted in Recycling in transport infrastructure. More recently, FM Conway has set up a facility at Dartford for processing highway arisings that includes an aggregate washing plant, gully waste treatment plant and cold recycled bitumen bound material plant as well as the conventional crushers and screeners. The outputs include concrete up to C30 strength with 100% recycled aggregate and a variety of cold recycled bitumen bound products. Coleman and Co set up a similar urban quarry to process construction and demolition waste into high quality aggregates in Birmingham in 2005 (Anon, 2005). Partnering is one way of ensuring that supply and demand issues are addressed. The success of the partnering approach adopted by Hampshire County Council, Raynesway Construction Southern and Foster Yeoman for highway maintenance in Hampshire would not have been possible without the provision of adequate facilities for storing and processing materials. A network of storage sites for surface dressing materials was set up across the county, enabling the reuse of some 4,000 tonnes of this material (Chapter 4.1.3). Two segregation plants were set up, at Alton and Petersfield. These were waste transfer stations which were set up to receive arisings from highway works. The materials were sorted into categories such as concrete, asphalt, granular material and clay, so 28

33 that they could be reused for the highest value applications. The materials were stockpiled until sufficient volumes were available for reuse. They were then sent to nearby recycling centres for processing to meet the appropriate specification requirements and reused in further works. Two asphalt plants were also set up at Botley in the south of the county near the large urban areas of Portsmouth and Southampton, and at Micheldever in the centre of the county. Foster Yeoman set up a mobile Foamix plant at the Micheldever depot to process arisings from across the county. For example, asphalt planings from the A325 maintenance scheme at Alice Holt were sent to the Micheldever plant for processing into Foamix for use elsewhere in the county, including the North Popley Development (Chapter 4.1.6). As well as recycled asphalt, the plant can handle a number of other recycled and secondary aggregates. The IBAA used at Bar End (Chapter 4.1.4) was made into Foamix at the Micheldever plant. The provision of adequate sites, not only for reprocessing materials but also for storing them, is important for recycling in activities such as highway maintenance, where there is a continuous supply of arisings from different sites that require to be processed and are then used on other sites. This can be a particular problem in urban areas, where it can be difficult to provide sites with sufficient storage space because of high prices and pressure on land use. At the other end of the scale, there was considerable concern in 2001 about potentially recyclable materials being sent to exempt sites and deposited as low value fill. Changes to the Waste Management Regulations regarding exemptions to the waste management licensing process came into force in July 2005 (see waste management regulations module on AggRegain). These impose more stringent requirements for operators of exempt sites, including provision of information on the material being deposited, and the introduction of charges for exemptions. These new requirements should act as a disincentive to the dumping of material on exempt sites. Also, with increasing demand for recycled aggregates, it is increasingly more economic to process the material and sell it as recycled aggregate than to dump it. If the stretching best practice targets for Hampshire are to be met, it will be necessary to divert some CD&EW that is currently sent to exempt sites to recycling plants. On the demand side, there has been a lot of progress since Recycling in transport infrastructure in developing markets for recycled and secondary aggregates. Much of this has come about through public sector clients, such as local authorities, who have identified sustainability as an important guiding principle in their activities and put in place measures to achieve it. This also applies to other infrastructure owners such as the Highway Agency and British Airports Authority. The use of the Demolition Protocol and the inclusion of targets for recycled content in the forthcoming Code for Sustainable Building will also drive the demand side. There remains a need to stimulate demand among other private sector clients. This will be essential if the targets are to be met. This topic is addressed more fully in Chapter , Lack of awareness. With pressure to increase the use of recycled and secondary aggregates, the issue of matching supply and demand will continue to be important Economics The bottom line is always crucial, and the use of recycled and secondary aggregates will be limited if they are, or are perceived to be, more expensive than primary aggregates, however sustainable their use might be. The Aggregates Levy has helped to make recycled aggregates more competitive. However, recycled and secondary aggregates are often cheaper than primary aggregates, particularly in applications such as highway maintenance when the basic operations are generating a supply of materials that can be recycled and reused. Savings of over 28,000 were made by reusing surface dressing chippings in Hampshire (Chapter 4.1.3). A number of examples of cost savings by using recycling are given in The Big Picture (Waste and Resources Action Programme, 2005b) and in supply chain case studies on the AggRegain web site ( casestudysearch/index.rm), including:! Use of 750,000 tonnes of recycled aggregates on the M25 J12 to 15 widening contract was up to 4 per tonne cheaper than equivalent primary aggregates.! Use of road planings stabilised with PFA and lime in Staffordshire resulted in savings of 40% on the base and sub-base layers.! Cement and lime stabilisation of in situ soils led to cost savings of 20% compared to excavation and replacement with primary aggregate in haunching works in Staffordshire.! Use of locally available recycled and secondary aggregates in a household waste recycling centre in Devon was no more expensive than use of primary aggregates.! Use of in situ cold recycled bitumen bound material for repairs to a major road in Portsmouth, using arisings generated from the site, saved 25% to 30% on cost and time compared to conventional repairs. Increasingly, therefore, recycling is seen as a cost effective option as well as being environmentally friendly. Funding for capital infrastructure for the production of recycled and secondary aggregates has been available from WRAP under several programmes since This has helped to put in place the infrastructure necessary to deliver the quantity and quality of recycled aggregates that will be needed in the future. Increasingly WRAP are funding high quality facilities such as the urban quarry described in rather than basic crushing and screening plant, to drive the use of recycled and secondary aggregates to higher value products Lack of awareness In Recycling in transport infrastructure, this was identified as perhaps the biggest single factor inhibiting greater use of recycled and secondary aggregates. While 29

34 there were issues that needed to be resolved with some of the other topics, they were not insoluble provided there was a will to succeed. Overcoming the perceptional barriers and misconceptions about recycled materials was the key to enabling their greater use. Since 2001 there have been a number of initiatives in different ways in this area. Arising directly out of the experience of Recycling in transport infrastructure, TRL put together two roadshows under the heading Sustainable Construction in Practice (SCiP) with the aim of taking information on recycling to practising construction professionals across the UK. The roadshows were collaborative ventures involving presenters from industry (contractors, suppliers and designers), regulators (Environment Agency) and researcher organisations (TRL/ Viridis, CIRIA) and combined presentations on relevant topics and case studies with workshop sessions where the principles were worked out in the context of practical examples. SCiP roadshows were run in the winters of 2002/03 and 2004/05, visiting England, Scotland, Wales and Northern Ireland. A total of 19 events were held between the two roadshows. They proved very popular, attracting on average 50 delegates to each event, with very positive feedback from the delegates, who came from local authorities, contractors, designers and aggregate suppliers. Both SCiP roadshows were funded under the Partners in Innovation programme by the Department of Trade and Industry, with additional funding from the County Surveyors Society, Institution of Civil Engineers, Royal Institution of Chartered Surveyors, Tarmac, Aggregate Industries, Ballast Phoenix and the Waste and Resources Action Programme (WRAP). The Waste and Resources Action Programme (WRAP) WRAP is a major government programme established to promote sustainable waste management by tackling the barriers to waste minimisation and increased recycling. Aggregates were added to its portfolio in 2002, and the WRAP Aggregates Programme aims to promote sustainable use of aggregates through encouraging greater use of recycled and secondary aggregates by addressing the barriers to increased use. They have done this partly through providing economic support for the provision of recycling infrastructure (Chapter 6.1.9), partly through acting as an honest broker between industry and regulators to resolve the waste management licensing issue by production of the WRAP quality protocol (Chapter 6.1.5), but mainly through a range of promotional and dissemination activities. One of their first actions was to set up a web site, AggRegain ( to act as a one-stop shop for information on recycled and secondary aggregates. The site went live in February 2003 and been developed considerably since, most notably in July It now contains the following features:! The Specifier tool, which allows users to establish how recycled and secondary aggregates can be used in a range of construction applications under existing specifications.! A supplier directory.! A number of case studies demonstrating the use of recycled and secondary aggregates in a range of construction applications and demonstrating cost benefits and comparative performance compared to primary aggregates.! Access to the WRAP quality protocol and a number of other WRAP publications on recycled and secondary aggregates, including The Big Picture.! Modules on planning, recycling infrastructure, quality, waste management regulations, demolition, procurement and sustainability related to recycled and secondary aggregates.! Links to the WRAP web site and a number of other related sites. WRAP have also been very much involved in active dissemination, through launch events for AggRegain and publications like The Big Picture and through more structured programmes. In 2005 they ran a series of one day workshops for local authority highway engineers in England under the title Recycled Roads. This used the same format as SCiP and involved presenters from WRAP, TRL, BRE, Atkins and Capita Symonds. Ten events were held, with an average of 50 delegates attending and giving very positive feedback. The events also helped to establish a baseline of the level of recycling carried out by local authorities in highway maintenance in England. WRAP also held a series of events on the broader topic of recycling in construction, including building products, aimed more at clients, designers and influencers under the title ReConstruct. A series of workshops to disseminate the use of the Demolition Protocol is planned for early 2006, and a further series of Recycled Roads will also be held. There has therefore been considerable progress in addressing the problem of lack of information, certainly among construction professionals and major clients. Combined with continuing government initiatives on sustainability and work by other organisations such as CIRIA and BRE, and numerous articles in technical journals such as Surveyor, Highways, NCE, Construction News and the Contract Journal on recycling, most construction professionals are aware of the concept of sustainability, what it might mean in practice, and that using recycled and secondary aggregates is not only possible but positively desirable. Where progress has been less marked is in the SME sector. This is highly diverse and difficult to reach, but eventually the message will get through if only indirectly through escalating charges for sending material to landfill or increasing requirements from local authorities, either as clients or regulators (Planning and Building Control). There needs to be more of a focus on this area to encourage small clients and builders to adopt recycled materials, and to use materials that have been processed properly in accordance with the WRAP quality protocol rather than unsorted CD&EW passed off as recycled aggregates. 30

35 6.2 Summary: progress and the way forward There has been considerable progress since 2001 on a number of the issues highlighted in Recycling in transport infrastructure, particularly:! Updating a number of specifications to permit the use of recycled and secondary aggregates.! Development of the WRAP quality protocol.! Resolution of potential problems with the Waste Management Licensing regime.! Widespread development of partnering and early contractor involvement.! Increasing commitment of major clients to principles of sustainability and the working out of this in policies and activities.! Recognition of the need to provide adequate facilities for producing recycled and secondary aggregates and the development of a comprehensive planning framework for minerals and waste.! Increasing use of recycled and secondary aggregates in higher value applications and the establishment of plants to produce materials of the required quality.! Extensive programmes of dissemination have largely addressed the problem of lack of awareness among major clients and construction professionals.! The development of the WRAP Aggregates Programme has had a major effect on lack of awareness, capital support for recycling infrastructure and resolving conflicts with the Waste Management Licensing regime. Some areas of actual or potential difficulty remain if recycled and secondary aggregates are to fulfil the role, in terms of quantity and quality that is increasingly being expected of them. These are summarised in Table 6 and include:! Need to obtain planning permission for an adequate number of recycling facilities.! Need to develop quality protocols for secondary aggregates.! Need to stimulate more use of recycled and secondary aggregates in high value applications.! Need to divert more CD&EW from exempt sites to recycling centres.! Need to address lack of awareness in the SME sector of the construction industry.! Need to incorporate use of recycled and secondary aggregates in overall strategies for sustainability.! Need to use tools such as the Demolition Protocol and Code for Sustainable Building to increase the amount and level of recycling.! Need to continue to foster joint commitment to goals and capture innovation by early contractor involvement through partnering and other means.! Need for continued liaison with the Environment Agency to avoid future conflicts with the Waste Management Licensing regime.! Need for continued dissemination of good practice and research to address areas of uncertainty or difficulty. While these issues need to be addressed, the tide is now running firmly in favour of recycled and secondary aggregates. The fundamental principles are widely agreed, and it is the details that need attention to ensure that the potential is achieved. The work carried out by Hampshire County Council and their approach to the overall issues of minerals and waste, described in the earlier chapters of this report, illustrate what can be achieved if there is a clear commitment from the client. There is a need for this approach to be more widely adopted to maximise the potential use of recycled and secondary aggregates in highway maintenance and other construction activities. 7 Conclusions The actions of Hampshire County Council and Portsmouth and Southampton City Councils through the Material Resources Strategy (MRS) and the partnering arrangement with Raynesway Construction Southern and Foster Yeoman for highway maintenance has demonstrated how the use of recycled and secondary aggregates can be increased by a proactive approach as part of an overall strategy on sustainability. The demonstration projects illustrate some of the ways in which this can be achieved in practice, particularly in the context of local authority highway, waste and development activities. It also illustrates how planning for future needs can be undertaken through the statutory minerals and waste development framework, based on analysis of the materials available in the area and stretching but achievable targets for future use. Consultation with key stakeholders in the community has been given high priority through the MRS, and has enabled a consensus to be achieved on the overall strategy and the particular actions needed to turn it into reality. This approach may be a model for other local authorities to achieve increases in use of recycled and secondary aggregates as part of an overall strategy on sustainability. A number of factors were critical for the success of recycled and secondary aggregate use in Hampshire:! There was a clear lead from the client and coordination with other recycling initiatives.! There was early involvement of contractors and other relevant stakeholders.! Logistical arrangements were put in place, e.g. storage depots and recycling plant.! Locally available materials were used.! Modern specifications, design guides and quality protocols were used and new ones were developed where necessary. The use of recycled and secondary aggregates not only resulted in environmental gains, such as reduced use of primary aggregates, reduced disposal of material to landfill and reduced emissions of CO 2, but also reduced costs in most cases. 31

36 A number of issues were identified as key to increased use of recycled and secondary aggregates in a TRL publication Recycling in transport infrastructure in These were reviewed and it was found that there had been considerable progress on a number of the issues, particularly in the greater use of partnering and early contractor involvement, updating of specifications, standards and quality protocols, resolution of conflicts with the Waste Management Licensing regime and addressing the lack of awareness among construction professionals and major clients. The WRAP Aggregates Programme has made a very significant contribution to this, particularly in the provision of guidance through the web site A number of areas remain where obstacles to recycling could still occur, such as obtaining planning permission for recycling facilities, developing protocols for secondary aggregates and addressing the lack of awareness issue for the SME sector. These should be addressed, but it is felt that the principles of using recycled and secondary aggregates are firmly established and that most of the issues are concerned with the details of making it work in practice. Provided these issues are addressed, targets for increased use of recycled and secondary aggregates and use in higher value applications can be met. It is important that use of recycled and secondary aggregates is seen as part of an overall strategy on sustainability and co-ordinated with other activities, not seen as an end in itself. The MRS approach adopted by Hampshire County Council, Portsmouth and Southampton City Councils provides a good example of how this can be achieved. Local authorities are major construction clients and also have a large influence on activities in their area through the planning system and by the example they set, so it is important that they take the lead in implementing an agenda for sustainability that includes maximising the use of recycled and secondary aggregates. The role of local authorities in moving from strategy and policy to implementation through integration with their other functions is critical; joining up functions and using procurement to encourage a move to a closed loop system. The public sector as a whole has a key role to play in delivering sustainability, given the size of it s construction budget. 8 Acknowledgements The work described in this report was carried out in the Resource Management Group of TRL Limited. The authors are grateful to Dr John Lewis who carried out the quality review and auditing of this report. The project was funded by the Department of Trade and Industry through the Partners in Innovation Programme, Contract No. STBF/004/00090C, cc2504. The contract was awarded to Viridis, the waste and resource management arm of the Transport Research Foundation and sister company to TRL, and the work was subcontracted to TRL. The authors are also grateful to the members of the project Steering Group and their colleagues who provided information, advice and contacts in the preparation of this report. The members of the project Steering Group were: Julie Crouch Hampshire County Council, Waste Management Section. Emily Moon Hampshire County Council, Waste Management Section. Jeremy Smith Hampshire County Council, Minerals and Waste Planning. Terry Lomas Hampshire County Council, Technical Advisers Group. Terry Williams Hampshire County Council, Engineering Consultancy. Andy Harding Hampshire County Council, Highways Maintenance. Ian Avery Hampshire Natural Resources Initiative. Stewart Giddings Raynesway Construction. Southern Ltd. Lloyd Allen Raynesway Construction. Southern Ltd. Peter Cross Dean & Dyball Construction Ltd. /Institution of Civil Engineers. Martin Dudley Foster Yeoman Ltd. Peter Kelly Environment Agency. Russell Wolstenholme W S Atkins (Project Officer for DTI). 9 References Anon (2005). Well-maintained Highways: Code of Practice for Highway Maintenance. London: The Stationery Office. Anon (2005). Coleman opens urban quarry. Mining Quarrying & Recycling, 34 (3) May/June Barritt J (2003). Overcoming Barriers to Recycling - Addressing Government Sustainability and Recycling Targets for Construction and Related Industries. Paper presented at the 2 nd International Conference Liverpool John Moore University. Wednesday February 26 th British Standards Institution (2002). Characterisation of waste. Leaching. Compliance test for granular waste materials and sludges. Two stage batch test at a liquid to solid ratio of 2 l/kg and 8 l/kg for materials with a high solid content and with a particle size below 4 mm (without or with size reduction). BS EN 12457: Part 3. London: British Standards Institution. Department of the Environment, Transport and the Regions (1999). A better quality of life: a strategy for sustainable development in the UK. London: Department for Transport. 32

37 Department of the Environment, Transport and the Regions (2000). Building a better quality of life: a strategy for more sustainable development. London: Department for Transport. EnviroCentre Ltd (2004). Demolition Protocol Implementation Document. Retrieved: 2005, from icextra.ice.org.uk/tlml/demolition. Hampshire County Council (2005). More from Less: how to make better use of Hampshire s material resources. Winchester: Hampshire County Council. Retrieved: 2005, from Hampshire County Council, Portsmouth City Council and Southampton City Council (2005). Hampshire Minerals and Waste Development Framework - Strategy - Issues and Preferred Option. Winchester: Hampshire County Council. Retrieved: 2005, from Hylands K N and Shulman V (2003). Civil engineering applications of tyres. Viridis Report VR5. Wokingham: TRL Limited. Merrill D, Nunn M and Carswell I (2004). A guide to the use and specification of cold recycled materials for the maintenance of road pavements. TRL Report TRL611. Wokingham: TRL Limited. Nunn M (2004). Development of a more versatile approach to flexible and flexible composite pavement design. TRL Report TRL615. Wokingham: TRL Limited. Sowerby C R and Reid J M (2005). Hampshire County Council: material resources strategy - construction waste and soil. Published Project Report PPR058. Wokingham: TRL Limited. South East England Regional Assembly (SEERA) (2004). Proposed Alterations to Regional Planning Guidance, South East - Regional Minerals Strategy. Guildford: South East England Regional Assembly. Statutory Instrument 2004 No The Landfill (England and Wales) (Amendment) Regulations Retrieved: 2005, from htm. Waste and Resources Action Programme (WRAP) (2004). The quality protocol for the production of recycled aggregates from inert waste. Banbury: Waste and Resources Action Programme. Retrieved: 2005, from Waste and Resource Action Programme (WRAP) (2004b). The Big Picture: Specifying recycled in local authority contracts for highways maintenance: Good practice. Banbury: Waste and Resource Action Programme. Retrieved: 2005, from World Commission on Environment and Development (1987). Our common future. The Brundtland Report. Oxford: Oxford University Press. Office of the Deputy Prime Minister (2002a). Survey of arisings and use of construction and demolition waste in England and Wales London: Office of the Deputy Prime Minister. Office of the Deputy Prime Minister (2002b). Aggregates provision in England consultation paper. London: Office of the Deputy Prime Minister. Office of National Statistics (2003). Region in figures: South East. London: The Stationery Office. Reid J M and Chandler J W E (2001). Recycling in transport infrastructure. (MISC3). Wokingham: TRL Limited. South East England Regional Assembly (SEERA) (2003). Aggregates Monitoring Report Guildford: South East England Regional Assembly. Sherwood P T (1995). Alternative materials in road construction. London: Thomas Telford. Sowerby C R, Lovell J and Reid J M (2005). Optimising the use of recycled and secondary aggregates in Hampshire. Published Project Report PPR057. Wokingham: TRL Limited. 33

38 Abstract Local authorities are major construction clients, particularly in areas such as highways, and hence are able to exert a considerable influence on the use of construction materials in their area. They are also responsible for a number of related activities, such as waste management and planning, that can have a significant effect on the extent to which recycling of all kinds takes place. This report describes the experience of Hampshire County Council, and shows how a local authority that is committed to sustainability and prepared to take action to implement its principles can achieve considerable success in maximising the use of recycled and secondary aggregates. The current and potential use of recycled and secondary aggregates in Hampshire and the adjacent urban areas of Southampton and Portsmouth is described and targets are developed for 2010 and These include targets for materials used in high value applications such as asphalt and concrete as well as for total use of recycled and secondary aggregates. The actions that are necessary to achieve the targets are discussed, and six case studies are presented to illustrate how recycled and secondary aggregates can be used efficiently and effectively in a range of applications. The experience of Hampshire can be applied to other local authorities and construction clients in general. A range of issues that were highlighted in a 2001 TRL report, Recycling in transport infrastructure, are reviewed in the light of the experience of Hampshire and brought up to date. There has been considerable progress on a number of issues, but some potential barriers remain. Related publications TRL615 TRL611 PPR058 PPR057 CT89.3 CT36.3 Development of a more versatile approach to flexible and flexible composite pavement design by M Nunn (price 50, code HX) A guide to the use and specification of cold recycled materials for the maintenance of road pavements by D Merrill, M Nunn and I Carswell (price 50, code HX) Hampshire County Council: material resources strategy - construction waste and soil by C R Sowerby and J M Reid (price 30, code 2X) Optimising the use of recycled and secondary aggregates in Hampshire by C R Sowerby, J Lovell and J M Reid (price 35, code 3X) Recycling in transport infrastructure by J M Reid and J W E Chandler (price 35) (Ref: MISC3) Aggregates in road construction update ( ) Current Topics in Transport: selected abstracts from TRL Library s database (price 30) Recycling of road materials update ( ) Current Topics in Transport: selected abstracts from TRL Library s database (price 30) Prices current at February 2006 For further details of these and all other TRL publications, telephone Publication Sales on , publications@trl.co.uk, or visit TRL on the Internet at 34

39 Appendix A: Summary versions of demonstration projects Appendix A 1

40 Appendix A 2

41 Hampshire County Council Partners in Innovation (PII) Demonstration Project 1 Embankment Stabilisation on A325 Background This series of leaflets describes a number of projects demonstrating the technical, environmental and cost benefits that arise from the use of recycled and secondary aggregates in highway works in Hampshire. Working in partnership together, Hampshire County Council, Raynesway Construction Southern and Foster Yeoman adopted sustainable policies for highway maintenance works. A Partners in Innovation project, carried out by TRL and funded by the Department of Trade and Industry, enabled these practices to be captured in a number of demonstration projects. The material diverted from landfill as a result of the partnership is assisting Hampshire County Council with their Public Service Agreement (PSA) target to divert an additional 40,000 tonnes of material from landfill per annum by Activity: Repair of weak clay embankment on A325. Location: Application: Material: Amount used: A325 near Alice Holt, N E Hampshire. Selected granular fill. Recycled aggregate. 29,000 tonnes. Date: September 2004 to January Client: Contractor: Designer: Specification: Hampshire County Council. Raynesway Construction Southern Ltd (main contractor). Wessex. Construction Ltd (recycled aggregates) Day Aggregates (recycled aggregates). TJ Aggregates (recycled aggregates). Hampshire County Council. Specification for Highway Works.

42 Summary Embankment stabilisation was required on the A325 between the junction of the B3006 at Sleaford and north to the Hampshire county boundary at Holt Pond. The work covered a distance of about 1.8km. The embankment was previously made up of poor quality clay. The embankment was dug out in benches and the excavated material was replaced with Class 6F5 selected granular fill (see diagram). Recycled aggregate obtained from processing inert construction and demolition waste was used as the Class 6F5 material. The embankment ranged from 0.8 m to 5.0 m in height and the works required a total of 29,000 tonnes of imported fill. The new embankment was built at a uniform slope of 1:3. The imported fill was supplied by local suppliers Wessex Construction Ltd, Day Aggregates Ltd and TJ Transport from Selborne. Embankment height varies from 0.8m to 5m high Existing soft clay fill removed New 1:3 slope being constructed ROAD Backfill of 6F5 material Existing slope Steps dug out from existing embankment Technical benefits! The Specification called for Class 6F5 selected granular fill, which is normally used as a coarse grained capping layer imported to site. This was to ensure a well graded granular material with a high angle of internal friction was used.! Recycled aggregates performed as well as primary aggregates.! Reduced haulage costs compared to equivalent primary aggregates. Environmental benefits! Reduction in use of primary aggregates and reduced haulage distances.! Reduction in overall waste being disposed of to landfill within the county.! Savings in fuel and emissions of CO 2 by using a local supply of recycled aggregates. Benefits to local authorities The use of recycled aggregates in this project had double benefits for Hampshire County Council. It contributed to targets under the Public Service Agreement for diversion of materials from landfill and also led to cost savings compared to conventional methods. Recycling had direct tangible benefits for the local authority as well as broader environmental and technical benefits.

43 Hampshire County Council Partners in Innovation (PII) Demonstration Project 2 Recycled Asphalt in Footway works Background This series of leaflets describes a number of projects demonstrating the technical, environmental and cost benefits that arise from the use of recycled and secondary aggregates in highway works in Hampshire. Working in partnership together, Hampshire County Council, Raynesway Construction Southern and Foster Yeoman adopted sustainable policies for highway maintenance works. A Partners in Innovation project, carried out by TRL and funded by the Department of Trade and Industry, enabled these practices to be captured in a number of demonstration projects. The material diverted from landfill as a result of the partnership is assisting Hampshire County Council with their Public Service Agreement (PSA) target to divert an additional 40,000 tonnes of material from landfill per annum by Activity: Location: Application: Material: Footway renewal works. B3047 at Martyr Worthy. Cold recycled bitumen bound material with foamed bitumen binder (Foamix ). Recycled asphalt. Amount used: 150m 3 Date: November - December Client: Contractor: Specification: Hampshire County Council. Raynesway Construction Southern Ltd (main contractor). Foster Yeoman (cold recycled bitumen bound material). Specification for Highway Works.

44 Summary Cold recycled bitumen bound material with a foamed bitumen binder (Foamix ) has been used extensively in highway and footway works in Hampshire as it enables the use of recycled asphalt from other projects and saves energy compared to conventional hot asphalt. This project was undertaken as part of the term maintenance programme. It was trying to push the boundaries towards a new way of using Foamix in footways. Normally a full surface course would have been placed, but in this case a surface dressing was laid on top of the Foamix instead. The B3047 at Martyrs Worthy was chosen for its rural location as a suitable test area. The existing footway surfacing was removed along with any plant/ root damaged/ contaminated sub-base. The footway was overgrown and significant clearing was required prior to work starting. The total length of the footway which was reconstructed was 711m. The footway was constructed to allow for a 0.08m Foamix layer. Foamix was also used to repair any areas where damaged sub-base had been removed. The total quantity of Foamix used on site was 100m 3 for the base/ binder course and 50m 3 for repairing the sub-base. A surface dressing was laid on top and the use of Foamix in this new application was successful. Technical benefits! The surface dressing was laid straight on top of the Foamix, avoiding having to lay a full surface course.! Foamix was used both for the base/ binder course and for repairing the subbase, avoiding the need to bring different materials to site.! Foamix was easy to handle and available from the nearby depot at Micheldever. Environmental benefits! Reuses asphalt from highway works elsewhere in Hampshire in new asphalt.! Less energy required for cold mix material, saving in CO 2 emissions.! Saving in use of primary aggregates. Benefits to local authorities The use of recycled aggregates in this project had double benefits for Hampshire County Council. It contributed to targets under the Public Service Agreement for diversion of materials from landfill and also led to cost savings compared to conventional methods. It also demonstrated a new application for Foamix, which can now be used elsewhere in the county. Recycling had direct tangible benefits for the local authority as well as broader environmental and technical benefits.

45 Hampshire County Council Partners in Innovation (PII) Demonstration Project 3 Recycled Surface Dressing Sweepings Background This series of leaflets describes a number of projects demonstrating the technical, environmental and cost benefits that arise from the use of recycled and secondary aggregates in highway works in Hampshire. Working in partnership together, Hampshire County Council, Raynesway Construction Southern and Foster Yeoman adopted sustainable policies for highway maintenance works. A Partners in Innovation project, carried out by TRL and funded by the Department of Trade and Industry, enabled these practices to be captured in a number of demonstration projects. The material diverted from landfill as a result of the partnership is assisting Hampshire County Council to meet their Public Service Agreement (PSA) target to divert an additional 40,000 tonnes of material from landfill per annum by Activity: Location: Application: Material: Amount used: Date: Client: Contractor: Specifications: Reuse of surplus surface dressing chippings. Various sites across the county. Routine highway maintenance. Recycled surface dressing chippings. 4,000 tonnes ongoing. Hampshire County Council. Road Maintenance Services Ltd. Specification for Highway Works. British Standard for Chipping Grading BS EN TRL Road Note 39, Design Guide for Road Surface Dressing.

46 Summary In surface dressing operations on highways, there are always some surplus unused materials. After the surface dressing has been laid, further surplus material is generated as sweepings of loose material from the road surface. In Hampshire there are a number of remote sites where unused surface dressing chippings have been stockpiled for some years. These sites are now receiving post surface dressing sweepings as well as the unused material. The surface dressing sweepings would previously have been sent to landfill or used on farmers tracks. In 2003 these stockpiles were estimated to be in excess of 4,000 tonnes. Hampshire County Council and their surface dressing contractor, Road Maintenance Services, developed techniques to enable the surplus chippings to be reused in further surface dressing works. This saved the import of further high quality primary aggregates. The material came in a range of sizes including 6mm, 10mm and 14mm. It was required to be screened before it would be suitable for use. A dry screening process was used to remove the majority of contaminants, and the screened material was then lightly coated with bitumen to remove the high dust content of the resulting material. In the 2004 season (May to August), these recycled coated chippings were used at 33 sites across Hampshire. In all, 1613 tonnes of 10mm material and 1554 tonnes of 6mm material were laid using either a 10/6mm racked in dressing or 10/6mm double dressing specification. To date, all sites treated using the recycled chippings are performing well. Monitoring is continuing every 6 months. Following the overall success of the trials, preparations are underway for a similar programme in Economic benefits! Cost of recycled surface dressing chippings: 66,479! Value of equivalent primary aggregate chippings: 94,530! Savings using recycled surface dressing chippings: 28,051 The cost savings illustrated here largely arose because of the long haulage distance for the equivalent primary material and the surface dressing sweepings having no value. Environmental benefits! The use of the locally sourced recycled surface dressing sweepings saves on the environmental impacts of haulage of equivalent primary aggregates.! The reuse of the surface dressing sweepings prevents their disposal to landfill and avoids the use of primary aggregates. Benefits to local authorities The use of recycled aggregates in this project had double benefits for Hampshire County Council. It contributed to targets under the Public Service Agreement for diversion of materials from landfill and also led to cost savings compared to the use of primary aggregates. Recycling had direct tangible benefits for the local authority as well as broader environmental and technical benefits.

47 Hampshire County Council Partners in Innovation (PII) Demonstration Project 4 Bar End Household Waste Recycling Centre Background This series of leaflets describes a number of projects demonstrating the technical, environmental and cost benefits that arise from the use of recycled and secondary aggregates in highway works in Hampshire. Working in partnership together, Hampshire County Council, Raynesway Construction Southern and Foster Yeoman adopted sustainable policies for highway maintenance works. A Partners in Innovation project, carried out by TRL and funded by the Department of Trade and Industry, enabled these practices to be captured in a number of demonstration projects. The material diverted from landfill as a result of the partnership is assisting Hampshire County Council with their Public Service Agreement (PSA) target to divert an additional 40,000 tonnes of material from landfill per annum by Activity: Location: Applications: Materials: Use of recycled and secondary aggregates in the construction of a new household waste recycling centre and access road. Bar End Industrial Estate, Winchester. General fill, capping, sub-base, structural backfill, cold recycled bitumen bound base & binder course, coarse aggregate for fibre reinforced concrete Recycled asphalt, recycled aggregate, recycled railway ballast, incinerator bottom ash aggregate. Date: June - December Client: Contractor: Designer: Specification: Hampshire County Council. Natta Building Company (main contractor). Foster Yeoman (cold recycled bitumen bound material). Onyx (incinerator bottom ash aggregate). Cemex (concrete). Valetta (surfacing contractor). Hampshire County Council. Specification for Highway Works and TRL Report TRL611.

48 Summary Hampshire County Council wished to build a new household waste recycling centre for Winchester on a previously developed site at Bar End. The use of recycled aggregates was maximised as part of the design philosophy. Hampshire County Council wanted the project to be an example of how the council should work on future developments. As a result, recycled and secondary aggregates were used in a number of applications, including high value applications such as asphalt and concrete. Demolition material from the previous development was reused in the works. Other recycled and secondary aggregates were imported as necessary. Incinerator bottom ash aggregate from a local waste-to-energy plant was used as coarse aggregate in the base and binder layers of the access road. Recycled aggregates were used in the concrete base slab for the centre. The site includes a number of other sustainability features including a sustainable urban drainage system (SUDS). Technical benefits! The maximum use of material already on site minimised the overall import of aggregates to the site.! The recycled and secondary aggregates performed as well as primary aggregates in all applications.! High value use of incinerator bottom ash aggregate in asphalt and recycled aggregate in concrete. Environmental benefits! Minimises use of primary aggregates and disposal of materials to landfill.! Less energy required for cold recycled bitumen bound material compared to conventional hot asphalt, saving in CO 2 emissions.! Demonstrates beneficial use for incinerator bottom ash aggregate. Benefits to local authorities The use of recycled aggregates in this project had double benefits for Hampshire County Council. It contributed to targets under the Public Service Agreement for diversion of materials from landfill and also led to cost savings compared to conventional methods. It also demonstrated that recycled and secondary aggregates can be successfully used in a number of applications, including high value ones. Recycling had direct tangible benefits for the local authority as well as broader environmental and technical benefits.

49 Hampshire County Council Partners in Innovation (PII) Demonstration Project 5 A3 Bus Priority Corridor Background This series of leaflets describes a number of projects demonstrating the technical, environmental and cost benefits that arise from the use of recycled and secondary aggregates in highway works in Hampshire. Working in partnership together, Hampshire County Council, Raynesway Construction Southern and Foster Yeoman adopted sustainable policies for highway maintenance works. A Partners in Innovation project, carried out by TRL and funded by the Department of Trade and Industry, enabled these practices to be captured in a number of demonstration projects. The material diverted from landfill as a result of the partnership is assisting Hampshire County Council with their Public Service Agreement (PSA) target to divert an additional 40,000 tonnes of material from landfill per annum by Activity: Location: Application: Material: Amount used: Date: Client: Contractor: Designer: Specification: Construction of A3 bus priority corridor. Portsmouth to Clanfield. General fill, unbound sub-base, capping, lower trench fill. Recycled asphalt (road planings), recycled concrete aggregate (crushed kerbs), subsoil. 3,900 tonnes. April 2002 to May 2005 (project ongoing, expected completion date April 2007). Hampshire County Council. Dyer and Butler. Hampshire County Council Engineering Consultancy; Atkins. Specification for Highway Works.

50 Summary The A3 bus priority corridor project was included in Hampshire County Council s Local Transport Plan The project is managed under a Local Authority and bus company partnership and is designed to provide residents with the choice of a reliable, convenient and safe service as an alternative to using a car. The works affect a 12 km stretch of road from Portsdown Hill to Clanfield and involve road widening and carriageway and footway reconditioning. Some of the existing wide verges were reallocated for the bus lane. At the project inception point, Hampshire County Council adopted a preference towards using recycled materials. The contractor therefore used the road planings generated by the works in the capping layer of the widened road, in the sub base for the footpaths and as trench fill material. The existing kerbs were crushed using a low noise, non-invasive machine and used as a gravel type material to form the sub base of the resurfaced footways. Topsoil and subsoil were also recovered and reused, with any surplus being diverted to other Dyer and Butler works. A long-lived surface dressing was applied to minimise the disruption which would otherwise be caused by resurfacing works in the future. Material Use Sheets were trialled in this project. The information gathered allows linking of surplus materials from one site to another and reduces the need for primary aggregate. The project is over half way through and shown to be embracing the goals of sustainable development. New practices are being developed, which will be used in other HCC projects to promote recycling and best practice. Technical benefits! The reuse of materials generated in-situ minimised the need to import primary aggregates and reduced haulage costs.! The road planings were used successfully in capping and sub base layers and as trench fill material.! Introduction of Material Use Sheets extended the possibilities of recycling at other sites within the county. Environmental benefits! Reduction in use of primary aggregates and waste disposed to landfill.! Reduction in noise by use of low noise crusher for the concrete kerbs.! Use of more durable surfacing reduces future disruption and gives better whole life cost for the project. Benefits to local authorities The use of recycled aggregates benefited Hampshire County Council in two ways. It contributed to targets under the Public Service Agreement for diversion of materials from landfill (3,900 tonnes to date) and also led to cost savings ( 87,000) compared to conventional methods. Whole life costing enabled the use of more durable surfacing and material use sheets enabled surplus materials to be used elsewhere in the county. Recycling had direct tangible benefits for the local authority as well as broader environmental and technical benefits.

51 Hampshire County Council Partners in Innovation (PII) Demonstration Project 6 North Popley Development Background This series of leaflets describes a number of projects demonstrating the technical, environmental and cost benefits that arise from the use of recycled and secondary aggregates in highway works in Hampshire. Working in partnership together, Hampshire County Council, Raynesway Construction Southern and Foster Yeoman adopted sustainable policies for highway maintenance works. A Partners in Innovation project, carried out by TRL and funded by the Department of Trade and Industry, enabled these practices to be captured in a number of demonstration projects. The material diverted from landfill as a result of the partnership is assisting Hampshire County Council with their Public Service Agreement (PSA) target to divert an additional 40,000 tonnes of material from landfill per annum by Activity: Location: Application: Material: Amount used: Access road for new school on greenfield site. North Popley, Basingstoke. Cement bound sub-base, cement bound trench backfill, general fill, cold recycled bitumen bound base. Chalk, recycled asphalt m 3 chalk; 300 m 3 asphalt. Date: May to June Client: Contractor: Designer: Specification: Hampshire County Council Estate Practices. Mildren Construction Ltd (main contractor). Envirosoil Ltd (stabilisation). Bardon Aggregates (surfacing). Foster Yeoman Limited (cold recycled bitumen bound material). Hampshire County Council Engineering Consultancy. Specification for Highway Works and TRL Report TRL611.

52 Summary North Popley is a new, mixed development site near Basingstoke, comprising residential units, a school and sports facilities. The site owners, Hampshire County Council, are carrying out preliminary infrastructure works to provide a spine road and services across the site. Contract 1 of the works entailed constructing 250m of 6.1m wide single carriageway access road and footways for a new secondary school. The site is underlain by chalk, and it was decided to stabilise this by the addition of 2% ordinary cement to form cement bound sub-base. The contractor, Envirosoil, treated a 225 mm thickness of chalk in situ using rotovating plant (picture on previous page). Cement stabilised chalk was also used as sub-base for 200m of footway and as backfill in trenches for the drains, but in these instances the chalk was excavated, treated ex-situ and compacted into place. The chalk above sub-base level was excavated and reused as general fill. In all, over 1,000 m 3 of chalk that would otherwise have been disposed to landfill and replaced with imported aggregates was retained on site. The asphalt pavements for the access roads were constructed using a 250 mm layer of cold recycled bitumen bound material with foamed bitumen (Foamix ) (picture below). As Foamix is laid cold, it results in energy savings compared with conventional hot asphalt. The recycled asphalt came from maintenance works on the A325 at Alice Holt. The Foamix was overlain with a 55mm binder course and a 45 mm hot asphalt surface course. A total of 300 m 3 of Foamix was used in the access road. Technical benefits! The reuse of materials in situ minimised transport and material costs.! The use of Foamix reduced energy costs.! The recycled materials performed as well as primary materials. Environmental benefits! Reduction in use of primary aggregates.! Reduction in waste being disposed to landfill within the county.! Surplus asphalt planings from another site were successfully recycled.! Reduction in lorry movements and energy. Benefits to local authorities The use of recycled aggregates in this project had double benefits for Hampshire County Council. It contributed to targets for diversion of materials from landfill and also led to cost and energy savings compared to conventional methods. The use of in situ stabilisation significantly reduced lorry movements and associated disruption on the narrow local access roads. Having been shown to be successful on this small preliminary contract, stabilisation and Foamix can be used on a much larger scale on the spine road for the whole North Popley Development. Recycling had direct tangible benefits for the local authority as well as broader environmental and technical benefits.

53 Appendix B: Demonstration projects: full case studies Appendix B 1

54 Appendix B 2

55 Demonstration Project 1: Embankment stabilisation on A325 at Alice Holt Construction project: Application: Product: Material: Region: Title: Road building Selected granular fill Class 6F5 Selected granular material (coarse grading) Recycled aggregate South East A325 Major Maintenance Alice Holt Embankment Fill Date: September 2004 to January 2005 Client: Contractor: Designer: Hampshire County Council Raynesway Construction Southern Ltd (RCS) Hampshire County Council Recycled aggregate suppliers: Wessex Construction Ltd Day Aggregates TJ Aggregates Specification: Conditions of contract: Specification for Highway Works, May 2004 amendments ICE 7 th edition Background This project is a major maintenance scheme contracted out from Hampshire County Council (HCC). The project is a three phase operation with RCS being involved at present in phase two, which involves the stabilisation of the A325 near Alice Holt. The project is working on the section of the A325 between the junction of the B3006 at Sleaford and north to the county boundary at Holt Pond, a distance of about 1.8km. There are three sections of road requiring stabilisation of the embankment. The first section is 300m long on one side of the road. The second section is 150m long on both sides of the road and the third section is 400m long on one side of the road. One area requiring stabilisation was restricted in size by the presence of an area of archaeological importance. At this area gabion baskets were used to stabilize the embankment. The gabion baskets were filled with limestone, but to create a steep slope some recycled aggregate was used as backfill to the gabions. The embankment was made up of poor quality clay at a variable slope and had been suffering from instability. The embankment was dug out in benches. The material that has been removed from the site was due to be laid on a local farmer s field. Unfortunately this was not possible because the wet weather made the field too slippery for vehicles to travel easily. Approximately 9,000 tonnes of material was removed during the excavation of the existing embankment and this was disposed of at a local landfill site. The excavated material was replaced with Class 6F5 selected granular fill to the same profile (see Figure 1). The embankment ranges from 0.8m to 5.0m in height and the works required a total of 29,000 tonnes of imported fill. The new embankment was built at a uniform slope of 1:3. The imported fill was supplied by recycled aggregates derived from processing construction and demolition material from Day Aggregates Ltd and TJ Transport from Selborne, thus avoiding the use of primary aggregates. The area has an ancient Roman monument at the southern end of the site so when the area was being excavated procedures were put in place to protect the archaeological site. The resurfacing works were carried out by Hanson PLC in December 2004 and January mm of road surface was planed off and sent to Foster Yeomen s (FY) Micheldever plant for processing into Foamix. The road was then surfaced with hot rolled asphalt. All of the surfacing work took place overnight with the road being shut for 4 weeks. Technical benefits The recycled aggregates are a suitable material to be used as general fill. The specification called for Class 6F5 selected granular fill, which is normally used as a coarse grained capping layer, rather than Class 1A general granular fill. This was to ensure a well graded granular material with a high angle of internal friction was used. The recycled aggregates met this specification and performed as well as primary aggregates. Appendix B 3

56 Embankment height varies from 0.8m to 5m high Existing soft clay fill removed New 1:3 slope being constructed ROAD Backfill of 6F5 material Existing slope Steps dug out from existing embankment Figure 1 Showing the works carried out at Alice Holt Plate 1 Embankment fill at Alice Holt Cost benefits There were cost savings for this project by using recycled aggregate rather than the primary aggregates. The savings largely arose because of the difference in haulage costs. The primary aggregates would have had to travel from the Mendips whereas the recycled aggregates were supplied from a local source. The cost savings that were made by using the recycled aggregates were passed onto the client to help secure the contract. Environmental benefits The environmental benefit of this project was a reduction in the quantity of primary material used because the embankment was replaced with recycled aggregate. This reduces overall waste within the county by using material that would otherwise be disposed to landfill. There were also savings in transport distances by using a local supply of recycled aggregates. The road planings were taken to FY s plant at Micheldever for recycling into cold recycled bitumen bound material. This diverted a material that would normally be disposed to be made into a useful product. Appendix B 4

57 Supply chain The use of recycled aggregates on this project was promoted by RCS. They wanted to use the recycled aggregates to save costs and transport distances of the material. There were no objections from the contractor about using the recycled materials. Regulatory issues The area at the southern end of the site falls into a site designated as a Scheduled Ancient Monument with important Roman remains present. Consultation with the English Heritage to obtain a Scheduled Monument Consent to allow work off the carriageway to be carried out was required. The design specification showed that 6F2 material was to be used as fill to the embankment. This is a coarse grained capping material. However, in the 2004 amendments to the Specification for Highway Works new categories were introduced for capping materials imported to site. For the material to be classed as 6F2 material it would have to be produced on site. There was no material available on site which could be classed as 6F2 material so it sourced elsewhere. If the material was to be brought onto site then it would have been classed as 6F5 material which is required to meet slightly different specifications. The permitted constituents are slightly different from Class 6F2; in particular, recycled asphalt is not permitted in Class 6F5 but is permitted as up to 50% in Class 6F2. This has caused some confusion between the client s representative, the contractor and the supplier, with additional testing being required to meet the new specification requirements. Details of parties Client Hampshire County Council - Highways Maintenance Contact: Andy Harding The Castle Winchester Hants SO23 8UD Tel: andy.harding@hants.gov.uk Contractor Raynesway Construction Southern Ltd Contact: Lloyd Allan Partnership House Moorside Road Winchester SO23 7RX Tel: Lloyd.allen@raynesway.com Appendix B 5

58 Demonstration Project 2: Recycled asphalt in footway works on B3047 at Martyr Worthy Construction project: Application: Product: Material: Region: Title: Footways Bitumen bound base (roadbase) Cold recycled bitumen bound material Recycled asphalt South East B3047 Martyr Worthy footway works Date: November to December 2004 Client: Contractor: Designer: Hampshire County Council Raynesway Construction Southern Ltd (RCS) Hampshire County Council Cold recycled bitumen bound material supplier: Foster Yeoman Limited (FY) Specification: Specification for Highway Works Background Hampshire County Council (HCC) has a contract for all of the necessary repairs on the roads within the county called the Term Maintenance Contract. This does not include motorways or the trunk road network. Alongside the Term Contract are separate major works carried out within the county, these are awarded on a case by case basis. HCC has formed a partnership with RCS and FY for the Term Maintenance Contract. RCS are also involved with some of the major maintenance works within Hampshire. HCC signed a Public Service Agreement (PSA) with the government in April 2002 which is effective until March The PSA requires HCC to achieve more demanding performance targets than would otherwise be expected. One of the targets was to divert up to 40,000 tonnes per annum of household, commercial and industrial waste from landfill through the Hampshire Natural Resources Initiative by To achieve this target a working group was set up including individuals, community groups, commerce and industry. RCS and FY have been involved in the PSA Working Group and are committed to recycling within Hampshire. The following case studies are based on the work that they have been undertaking over the period June 2004 to March Cold recycled bitumen bound material (Foamix ) One of the ways in which the partnership has been pursuing sustainable construction methods is by the use of cold recycled bitumen bound material with foamed bitumen as the main binder, commonly known as Foamix. RCS and FY have been using Foamix in a number of different applications throughout the county. They expect to have used approximately 12,000 tonnes by the end of the period. They spent time during the summer months experimenting with Foamix and trying different applications. They have used Foamix in footpaths, road maintenance and on private driveways. They have found that the Foamix works well if laid in dry conditions but does not work so well if laid in wet weather. The Foamix remains stable once it has been laid for a couple of days before rain, but it is better if a sealing layer is put on top. They have found the Foamix to perform well and are growing in confidence in using it for a variety of different applications. They have been using the Foamix a lot in haunching applications all over the county. It has been used as an alternative to the sub base, base and binder courses of roads and footways. Figures 1 and 2 show how the Foamix has been used in different road types to replace traditional materials. It is possible to use different quantities of Foamix depending on the volume of traffic using the road. Figure 1 shows the reduced volume of material required in building a classified road when Foamix is used compared with primary materials and Figure 2 compares the materials needed for a B road using Foamix. RCS have been keeping a record of what happens to all of the material they remove from the roads under their Term Maintenance Contract. A summary of the main material flows is shown in Figure 3. Some of the material was reprocessed Appendix B 6

59 Normal Classified road 40mm surface course 60mm binder Classified road using Foamix 40mm surface course 60mm binder 150mm road base 210mm Foamix 200mm sub-base Figure 1 Showing the layers found in a normal classified road and a classified road using Foamix B road using primary aggregrates 100mm surfacing B road using Foamix 40mm surface course 60mm binder 200mm road base 275mm Foamix 150mm sub-base Figure 2 Showing the layers of B roads using primary aggregates and the layers using Foamix RCS Routine Maintenance Road Works Major Maintenance Schemes: Road material removed Maintenance of Farmers' tracks Waste material dug out Recycled Materials Supplier Other users Landfill Foster Yeoman Foamix plant Road maintenance and new construction Others Can be counted in the PSA Inputs of material Not counted under PSA Figure 3 Showing the material flow from RCS works and the savings that can be counted towards the PSA Appendix B 7

60 by Wessex Construction and then re-used by others or by RCS, who estimate that for every lorry load of waste material they take to Wessex for processing they take a lorry load of processed material back. Some of the waste material that was removed during road maintenance went to FY s Foamix plant. Some of the Foamix produced there was then used by RCS when carrying out road maintenance. Other waste material removed during road maintenance went straight to farms and was used on farm tracks, with the remaining material going to landfill. RCS are also involved in a major maintenance scheme at Alice Holt on the A325 near Farnham. This is not part of the Term Maintenance Contract and so the material has been tracked separately. RCS is taking over 18,000 tonnes of recycled material from a variety of sources that has been regularly sampled and approved for construction of new embankments. B3047 footway works at Martyr Worthy This project is being undertaken as part of the Term Maintenance programme. It is trying to push the boundaries towards a new way of using Foamix in footways with a surface dressing laid straight on top of the Foamix. The B3047 has been chosen for its rural location which will not be used as frequently as an urban area and so makes it ideal for using as a test area (shown in Plate 1). Plate 1 The Martyr Worthy footway prior to laying Foamix The project has been used to trial the use of Foamix in the layers up to binder course with surface dressing instead of a full surface course laid on top of it. The existing footway surfacing was removed along with any plant/ root damaged/ contaminated sub-base. The footway was overgrown and significant clearing was required prior to starting work. The total length of the footway constructed was 711m and allowed for a 0.08m Foamix layer. The Foamix was also used to repair any areas where damaged sub-base had been removed. The total quantity of Foamix used on site was 150m 3 broken down to 100m 3 for the surface layer and 50m 3 for repairing the sub-base. The area treated was large enough to monitor whether laying surface dressing straight on top of the Foamix was successful. One of the contractor s concerns was that when the Foamix is laid it generally does not produce a smooth finish, therefore if the surface dressing is laid on top the overall finish may not be as smooth as with a normal surface course. This might also result in problems with ponding. The site was visited a couple of days after the Foamix was laid and the surface appeared satisfactory (see Plates 2 and 3). The scheme proved very successful, with the quality of the finished product being comparable with that of conventional construction. Conclusions RCS estimate that over the period June 2004 to April 2005 they will have used 12,000 tonnes of Foamix in Hampshire. They will also have used approximately one lorry load of recycled aggregate produced at Wessex Construction reprocessing plant for every lorry load of waste material removed during maintenance work and taken to the reprocessing plant. RCS have used Foamix in different applications across the county to determine if it functions effectively and performs well. They have found the Foamix to be a very good product which works well in dry weather. The use of recycled aggregates and Foamix reduces the demands on primary aggregates and reduces the quantity of waste going to landfill. RCS have aided HCC in meeting their public service agreement by using recycled and secondary materials in their construction works. Appendix B 8

61 Plate 2 Close up of surface at Martyr Worthy Plate 3 Completed footway at Martyr Worthy Appendix B 9

62 Details of parties Client Hampshire County Council - Highways Maintenance Contact: Andy Harding The Castle Winchester Hants SO23 8UD Tel: andy.harding@hants.gov.uk Contractor Raynesway Construction Southern Ltd Contact : Lloyd Allen Partnership House Moorside Road Winnal Winchester SO23 7RX. Tel: Lloyd.allen@raynesway.com Cold recycled bitumen bound material supplier Foster Yeoman Limited Contact: Martin Dudley Marston House Marston Bigot Frome Somerset BA11 5DU. Tel: martin.dudley@foster-yeoman.co.uk Appendix B 10

63 Demonstration Project 3: Recycled surface dressing chippings Construction project: Application: Product: Material: Region: Title: Pavements - roads, car parks, etc. Bitumen bound surface course Aggregates for bituminous materials (surface course) Recycled surface dressing chippings South East Reuse of surplus surface dressing chippings Date: 2004 Client: Contractor: Designer: Hampshire County Council Road Maintenance Services Ltd Hampshire County Council Recycled aggregate supplier: Road Maintenance Services Ltd Specification: Specification for Highway Works British Standard for Chipping Grading BS EN Surface dressing work in accordance with TRL Road Note 39, Design Guide for Road Surface Dressing. Background In surface dressing operations on highways, there are always some surplus unused materials. After the surface dressing has been laid, further surplus material is generated as sweepings of loose material from the road surface. In Hampshire there are a number of remote sites where unused surface dressing chippings have been stockpiled for a number of years. These sites are now receiving post surface dressing sweepings as well as the unused material. The surface dressing sweepings would previously have been sent to landfill or used on farm tracks. In 2003 these stockpiles were estimated to be in excess of 4,000 tonnes. Hampshire County Council and Road Maintenance Service Ltd (RMS) wanted to find a use for the excess surface dressing chippings and sweepings. The material came in a range of sizes including 6mm, 10mm and 14mm. The material required screening before it would be suitable for use. Some investigations had already taken place into cleaning the chippings but at the time it was found that the washing facilities required and transport costs made this option uneconomic. There have since been developments in the screening processes to allow the water to be re-used, and this option will be reconsidered in the future. RMS suggested using a dry screening process to remove the majority of contaminants. The screened material would then be lightly coated with bitumen to bind the high dust content of the resulting material to the aggregate, thus reducing the dust problem. This process was trialled by RMS at their depot in Cheshire. The material was screened, coated with bitumen and laid successfully as a surface dressing. An agreement between Hampshire County Council and RMS was established so that any savings that were made would be put straight back in to undertaking additional works. Stockpiled material was transported, where necessary, to strategic sites around the county and after purchasing the necessary screening equipment RMS started to screen the chippings in the autumn of While this activity was being undertaken RMS developed the plant necessary to coat the chippings. Programme In May to August 2004, these recycled coated chippings were used at 33 sites across Hampshire. In all, 1,613 tonnes of 10mm material and 1,554 tonnes of 6mm material were laid using either a 10/6mm racked in dressing or 10/6mm double dressing specification. The resistance to skidding of aggregates used in surface dressings is measured by the Polished Stone Value (PSV) test. The required value of PSV for any site depends on a number of factors, including the anticipated traffic load and the geometry of the road. The higher the PSV, the greater the skid resistance. Due to the mix of chippings prior to the screening process, the Polished Stone Value (PSV) of the resultant material could only be assumed as 60 PSV for the Appendix B 11

64 Plate 1 The dry screening of the surface dressing chippings 10mm and 55 PSV for the 6mm chippings. As a number of the sites where the material was to be laid required a PSV of 65 the use of the recycled material needed to be carefully managed. In some cases where double dressings were being used, it was possible to coordinate use of the 10mm recycled chippings as the first application, with the primary 6mm layer being a 65 PSV virgin aggregate. The performance of the recycled material during placement was equivalent to that expected of primary material. To date all sites treated using the recycled chippings are performing well. Monitoring is continuing every 6 months, particularly related to the overall skidding resistance on site where a higher PSV primary chipping was used. Due to the overall success of the trials, preparations are underway for a similar programme in Facts and figures By screening and re-screening the stockpiles the resources available were optimised as follows: 1,900 tonnes of 6mm material were recovered 2,300 tonnes of 10mm material were recovered This material was then processed though the coating plant and stored ready for use. Cost benefits Cost of recycled surface dressing chippings: Haulage costs 13,495 Screening costs 32,045 Coating costs 14,896 Administration 6,043 Total costs 66,479 Value of primary aggregate chippings 94,530 Savings using recycled surface dressing chippings 28,051 The cost savings illustrated here of using the recycled materials largely arose because the long haulage distance of the equivalent primary material and the surface dressing sweepings having no initial value. Appendix B 12

65 Environmental benefits The virgin materials would normally be sourced from a quarry in Wales for the higher (65) PSV material. The nearest source of virgin material for PSV requirements of 50 is Somerset. The use of the locally sourced recycled surface dressing sweepings reduces the impact of haulage. Other environmental benefits include the avoidance of the surface dressing sweepings going to landfill and reduction in the use of primary aggregates. Plate 2 The laid recycled surface dressings Conclusions The use of stockpiled excess surface dressing material and sweepings in Hampshire has many advantages. The material is available and would otherwise be used in lower value applications such as farm tracks, or sent to landfill. In Hampshire the primary aggregate that would otherwise be used for this application would require a long haulage distance. This turn has an impact on the cost of the aggregate and is associated with an environmental burden. The material has been used on a large number of sites across Hampshire. The placement behaviour of the recovered material was found to be very similar to equivalent surface dressings using primary aggregate. Testing is being carried out on a 6 monthly bases on the sites where a double dressing has been used. The PSV of these sites is being tested to ensure that it continues to meet safety requirements. It is currently too early to compare the PSV of the recycled material with primary aggregate over any significant time frame. However, due to the success of the trial so far a similar works programme is planned for Contact details Client Hampshire County Council Highway Maintenance Contact: Andy Harding The Castle Winchester Hampshire SO23 8UD. Tel.: andy.harding@hants.gov.uk Contractor Road Maintenance Services Ltd. Appendix B 13

66 Demonstration Project 4: Bar End Household Waste Recycling Centre Recycled and secondary aggregate use in the construction of a Household Waste Recycling Centre and Access Road at Bar End Winchester Construction project: Application: Product: Material: Region: Title: Pavements roads, car parks, etc. General granular fill Capping Selected granular fill: backfill to structures Unbound sub-base Concrete surface slab Bitumen bound binder course Bitumen bound base Class 1A Well graded granular material Class 6F3 Selected granular material Class 6F2 Selected granular material (coarse grading) Class 6P Selected granular material Type 1 Granular sub-base material Type 4 Granular sub-base material Cold recycled bitumen bound binder course material Cold recycled bitumen bound base material BS EN aggregate Grade 0/20 Recycled aggregate Recycled asphalt Incinerator bottom ash Spent railway ballast South East Recycled and secondary aggregate use in the construction of a Household Waste Recycling Centre and Access Road at Bar End Winchester Date: June 2004 to December 2004 Client: Contractor: Designer: Recycled aggregate Supplier: Hampshire County Council, Environment Department, Waste Management Group Natta Building Company Hampshire County Council Engineering Consultancy Onyx/ Foster Yeoman Local suppliers Reused material on site Specification: Conditions of contract: Specification for Highway Works, May 2001 amendments ICE 7 th Edition Conditions of Contract for Civil Engineering, with Foster Yeoman as nominated subcontractor for the supply of cold recycled bitumen bound material. Summary Hampshire County Council (HCC) wished to build a new household waste recycling centre (HWRC) to serve Winchester on a previously developed site at Bar End. The use of recycled aggregates in the construction of the HWRC and access road has been maximised by the client insisting on the use of recycled materials. HCC wanted the project to be an example of how the council should work on future developments. The engineering consultant was involved at an early stage and Appendix B 14

67 tasked with designing recycled aggregates into the project. Specifications were adapted where necessary to enable the use of recycled and secondary aggregates. Demolition material from the previous development and car park remained on site and was reused in the HWRC and access road. Involvement of Foster Yeoman and Onyx through other HCC initiatives led to the use of processed incinerator bottom ash (IBA) as coarse aggregate in the base and binder layers of the access road using Foamix. Foamix is a term commonly used to describe cold lay asphalt with a binder consisting predominantly of foamed bitumen. It can be used for in situ recycling or in ex situ applications; this allows the use of other recycled or secondary materials as the coarse aggregate, such as IBA in this case study. Recycled aggregate and spent railway ballast were imported for use in earthworks and the concrete base slab of the HWRC was constructed using recycled aggregate as 15% of the coarse aggregate. Close liaison was maintained with the Environment Agency to resolve any environmental concerns or regulatory issues over the use of IBA. The project illustrates how the use of recycled and secondary aggregates can be maximised when the client provides a clear brief, the designer actively specifies alternative materials, the contractor presses his suppliers to provide the required materials and the client and contractor s site staff work together to achieve a satisfactory quality of construction. Background HCC is responsible for the disposal of the waste produced by the 1.6 million residents in the county. There are 26 HWRCs within the county, 24 of which are the responsibility of HCC. The majority were built in the 1970 s and were in need of some upgrading. Some required maintenance and others needed to be pulled down and a replacement built elsewhere. In 2000 it was decided that a site would be needed for a new HWRC to serve the Winchester area. This was the fourth new HWRC to be built as part of this programme. The site at Bar End was owned by HCC and was a brownfield site. The businesses on site had plans to move off the site in the near future so the site would be left empty. The site was chosen as a new location for the HWRC. The HWRC site is approximately 1 acre with a 300m long access road (see Figure 1). Upper access road for public to deposit their waste Lower level concrete slab Retaining wall Ditch leading to River Itchen Drainage Pond Road Downward slope Figure 1 Showing site layout (not to scale) The form of the HWRC is a circular concrete slab as the lower level, on which the containers for the recycled materials will be placed, with concrete retaining walls rising to an upper level where vehicles will park and from where materials can be placed in the containers. There will be a one-way road system for vehicles around this upper level. The access road runs for 300m from the end of the public road at the edge of Bar End Industrial Estate to the HWRC. It is on sloping ground and required a sheet pile retaining wall on the downslope side for the first 100m from the public road. A schematic cross section through the access road is shown on Figure 2. As well as maximising the use of recycled aggregates, the site incorporates a number of other sustainability features. These include a sustainable urban drainage system (SUDS) that will take all the runoff from the site and the access road. All the runoff will be allowed to infiltrate into the ground through swales and a balancing pond with storage capacity for the 1 in 100 year storm. The client (the Waste Management Group in the Environment Department of HCC) made it clear to the Engineering consultancy that the project was to be a demonstration project for sustainable construction techniques. This included using recycled and secondary aggregates in the construction where practicable. The designer therefore specified the materials that were permitted and the method of treatment for site won materials to allow them to be used within the permanent works. Appendix B 15

68 Rain Surface course 45mm Kerb and gully Footpath Foamix base and binder course mm Existing road structure 160mm Foamix Sub-base (recycled aggregates) 150mm SUDS Capping ~200mm Water table 0.9m-2.9m below ground level Figure 2 Diagrammatic cross section of access road (not to scale) Within Hampshire three new incinerators are to be built by the end of This will result in approximately 100,000 tonnes of IBA arising within the county which needs to be managed. It was decided to use processed IBA arising in the county as the aggregate in the base and binder layers of the asphalt pavement in the access road to the HWRC. A small scale trial with IBA as aggregate in asphalt had been carried out in Hampshire in 2003, and there are examples of the use of IBA in asphalt and concrete from elsewhere in the UK and overseas. Plate 1 Stockpiled crushed pavement on site ready for use as granular sub-base Appendix B 16

69 Specification, quality assurance and design The specification for the project is the Specification for Highway Works, incorporating the May 2001 amendments. These permit the use of recycled aggregate and asphalt in a wide range of applications including general and selected granular fill and unbound granular sub-base. The engineering consultant wrote a specific design specification for each different recycled material that was to be used on site. The method statement for the use of IBA in Foamix was written in conjunction with FY and was based on the experience of HCC and FY with Foamix in a number of highway maintenance and new works projects, and the small trial with IBA in Foamix is a term commonly used to describe cold lay asphalt with a binder consisting predominantly of foamed bitumen. Foamed bitumen is produced by the injection of 1 to 2% cold water with air into hot penetration grade bitumen. This process produces a high-volume, low viscosity fluid with low surface tension. These properties enable the foamed bitumen to coat a wide range of moist, cold recycled aggregates. Foamed bitumen can be used for in situ and ex situ recycling, which allows the use of other recycled or secondary materials as the coarse aggregate. Hydraulic binders can be added to vary the properties of the asphalt product. Materials bound with foamed bitumen, on its own or with lime and pulverized-fuel ash, are highly workable; they can be stockpiled or reworked if necessary up to 48 hours after production. For an increased rate of curing, foamed bitumen can be combined with Portland cement or other hydraulic binder. The design is based on existing guidance on the use of foamed bitumen in the Specification for Highway Works and recent design guidance for cold recycled bituminous materials produced by TRL as TRL Report TRL611. Technical benefits A number of technical benefits have arisen by using recycled aggregates on site. The demolition waste and asphalt from the existing car parking were already on site so the crushing and grading were carried out in situ using a mobile crushing plant. The use of recycled aggregates and recycled asphalt in the sub-base and earthworks was praised by the contractor, who stated that they were easier to lay than the equivalent primary materials. The cut-and-fill balance was designed so that as much of the sub-base of the existing car park as possible was used as recycled aggregate in the new works. There was a requirement for a net import of materials to the site. This was met by recycled aggregates and spent railway ballast from local sources. As well as capping and unbound sub-base, these materials were used as general granular fill and as structural backfill to the retaining wall along the access road and the concrete retaining walls around the base slab of the HWRC. The materials performed very well; they met all specification and quality requirements and were easy to handle and compact. The use of recycled aggregates in the base slab concrete caused some technical problems in the mix design which were overcome. The concrete was fibre reinforced to prevent shrinkage cracking and incorporated 15% recycled aggregates as the coarse aggregate in the concrete. The concrete had a compressive strength of c25/30 and a maximum aggregate size of 20mm. The technical benefits of using IBA in Foamix were identified by FY as being an easy material to handle which was very consistent in its properties. A programme of testing for the Foamix was prepared to demonstrate that its performance was satisfactory. All of the works have now been completed with the Foamix being laid in early November. The Foamix went down very well and there have been no problems with the strength testing that has been carried out. The project was completed to programme and opened on 15 th December The quantities of recycled materials used on site are shown in Table 1. Table 1 Quantities of recycled materials used on site Application SHW Classification Quantity Chalk imported from adjacent park and ride scheme and rock chalk General fill 978 m 3 imported from other construction sites Planed lean-mix, bituminous planings and track ballast from other Sub-base and fill to structures 2032 m 3 construction sites Recycled aggregates Fibre reinforced concrete 17.1 m 3 Processing on site-won concrete/ bituminous material 478 m 3 Crushed concrete/ planings imported from other sites Class 6F capping layer beneath roads and paved areas 673 m 3 Crushed concrete/ planings imported from other sites General Fill beneath roads and paved areas 672 m 3 Crushed concrete/ planings imported from other sites ARRW-Class 6N/ 6P 163 m 3 Crushed concrete/ planings imported from other sites Sub-base 381 m 3 HWRC RW- HWRC RW- Class 6N/ 6P 361 m 3 IBA Foamix 1200t Parapets reused from another construction site 80m Appendix B 17

70 Plate 2 Base slab containing recycled aggregate concrete Cost benefits The cost benefits of this project arose because the recycled aggregates were from the demolition of the buildings and the existing access road on the site. There were no landfill tax or aggregates levy charges to be paid because all of the material available on site was reused and all the imported materials were recycled or secondary aggregates, and hence not subject to the Aggregates Levy. This also reduced the transport cost associated with bringing primary aggregates onto site. Another saving identified was that the crushing machine only had to be brought onto site once. The use of the recycled materials saved money in the sub-base and capping layers. The concrete incorporating the recycled materials cost more than if equivalent primary materials had been used instead. There were some marginal additional costs in producing the concrete due to design trials and the additional material handling required for blending the RCA with the other coarse aggregates. Environmental benefits The major environmental benefit of this project was the reduced requirement for primary aggregates. In specifying that no primary material could be used as Type 1 material on site, a large saving of primary aggregates was made. This also resulted in the use of the demolition material on site so that less waste was generated by this development. This in turn required fewer lorry movements than if all of the demolition material had to be removed and new primary aggregates brought onto the site. In Hampshire three, new energy from waste plants will be operational by the end of This will generate 100,000 tonnes per year of IBA which requires utilisation or disposal. This project was acting as a demonstration of how IBA can be a useful resource in construction. If this demonstration project is successful it will provide Hampshire with an alternative to landfill for IBA. Supply chain HCC Waste Management Group is the client for the building of the HWRC and access road. They secured the Bar End site about 4 years ago (2000) and drew up an outline for the scheme. They involved HCC Engineering Consultancy in 2002 to design the HWRC and access road. HCC saw this project as an opportunity to demonstrate as many aspects of sustainable construction as possible. The council wanted to lead by example in using recycled materials for a HWRC, showing that it can be done and that these perform as well as primary materials. They are hoping that by demonstrating the use of recycled aggregates in this project it will encourage the use of recycled and secondary aggregates in similar applications. If this project is successful they will use more recycled materials in future council projects and it will affect the way contracts are produced. See Figure 3 for an illustration of the supply chain. Appendix B 18

71 Client HCC Waste Management Group Design Foster Yeoman HCC (Technical Advice Group) PSA Working Group and IBA Working Group Designer HCC Engineering Consultant Main Contractor Natta Building Company Nominated Sub-contractors Foster Yeoman and Onyx Track Ballast purchasd through Whitchurch Hot Rolled Asphalt supplier Foster Yeoman Concrete suppliers RMC Figure 3 Contractual arrangements The Engineering Consultancy was tasked with incorporating the use of secondary and recycled aggregates into the design specification to ensure an acceptable performance. For each of the activities using recycled aggregates a material specific specification was included if the use of the material was not already covered by the existing specification. One of the major parts to the project was that no primary material was to be used for Type 1 sub-base. In April 2002 HCC signed a Public Service Agreement (PSA) with the government for the period up to March The PSA required HCC to achieve more demanding performance targets than would otherwise be expected. One of the targets was to recycle 40,000 tonnes of household, commercial and industrial waste through the Hampshire Natural Resources Initiative. To achieve this target a working group was set up including individuals, community groups, commerce and industry. The working group included HCC s term maintenance contractor for highway works, Raynesway Construction Southern Ltd (RCS), and the materials supplier Foster Yeoman Ltd (FY). FY has a new mobile Foamix plant which they were prepared to move into Hampshire so that it could be used on road maintenance schemes. It was recognised that a large quantity of IBA would be arising within the county. HCC set up an IBA Working Group, involving HCC, RCS, FY and the operator of the energy-from-waste plants, Onyx Environmental Group plc. It was decided that if a demonstration project using IBA as the aggregate in Foamix could be undertaken it would provide a useful solution for a new waste stream arising within the county. The HWRC development was on a brownfield site and it was thought that this would be an ideal place for a demonstration project. FY helped the HCC Engineering Consultancy to develop the method statement for IBA, which was issued with the tender document. Within the design specification it was identified that the Foamix used on site had to be supplied by FY and would contain the IBA from the Chineham energy-from-waste plant near Basingstoke. There were some concerns over the commercial implications of this so the price of the Foamix was fixed before the specification was sent out for tender. The contract was put out for tender in February 2004 and was awarded to Natta Building Ltd in May 2004; work commenced in June The site was cleared prior to work starting. Natta Building Ltd were committed to using recycled materials and proceeded to use the materials available on site. There were not enough recycled aggregates available on site to carry out all of the Type 1 sub base work so additional materials were brought in by a number of different suppliers. Recycled aggregates were brought on site from local suppliers. Natta had a contract with RMC to supply them with the concrete containing recycled aggregates for the base of the HWRC. Appendix B 19

72 Onyx stockpiled 1,200 tonnes of IBA at the Rainham Marshes landfill site in Essex. The IBA was weathered for at least three months and testing was undertaken to ensure the quality of the ash. Onyx processed the IBA to remove impurities, screened and graded the material to ensure the correct size and quality for use in the Foamix. The processed IBA was delivered to the FY depot at Micheldever and mixed with the other ingredients to form the Foamix used in the base and binder course of the access road. The project has proceeded very successfully to date and the HWRC opened on 15 December The project illustrates the benefits of a collaborative approach, whereby various departments within HCC and other parties in the PSA and IBA Working Groups interacted positively to suggest possibilities and overcome potential obstacles. The strong lead given by HCC on sustainability and working in partnership set the tone for the whole project. Plate 3 Foamix being laid at the HWRC Regulatory issues The major regulatory issue for this project was gaining planning permission for the development on the site initially; no known problems or issues have been raised. This was agreed before the project became a demonstration project. The use of Foamix containing IBA was an issue of concern to the Environment Agency (EA), because a ditch at the edge of the site leads to the River Itchen which is a candidate Special Area of Conservation under the Habitats Regulation and therefore has a high level of protection. The EA required further investigation to be carried out to identify the risks, if any, of using the IBA within the Foamix. Viridis carried out a qualitative risk analysis to identify any risks that the use of IBA at the site might cause. It was found that the risk of the IBA causing harm to human health or the environment was very low. A programme of leaching tests and environmental monitoring was agreed by all parties to ensure that the use of IBA in Foamix did not pose any risk to the environment. The extensive testing of the IBA prior to use, preconditioning and the mixing into the Foamix meant that the IBA was no longer classed as a controlled waste. The Bar End site was not therefore considered to require a Waste Management Licence or exemption to receive the Foamix. Conclusions This case study has shown how a number of different recycled and secondary aggregates can be used in a construction project with the same efficiency as if primary aggregates had been used. This case study has shown that construction projects can be influenced by the client and that specifying the use of recycled and secondary aggregates at the beginning of the project can have a beneficial effect. The importance of having all stakeholders in the project involved in using the recycled aggregates has been illustrated by the success of this project. If one party is not committed to using the recycled and secondary aggregates it can influence the cost and quality of material that is supplied. Appendix B 20

73 The specification for the Foamix used on site had to be supplied by HCC and FY to ensure that it included the use of IBA from Chineham energy-from-waste plant. This was an unusual specification but has allowed the case study to show the application of a large quantity of IBA in Foamix. The Foamix was laid at the beginning of November 2004 with many interested parties visiting the site to see the operation. The project has already been a success in raising the awareness of using recycled aggregates in construction, which was demonstrated by the number of visitors who made the trip to the site to see the Foamix being laid. It will hopefully encourage other contractors to use IBA in Foamix with confidence. Details of parties Hampshire County Council Environment Division - Waste Management David Ward The Castle Winchester Hampshire SO23 8UD Tel: Hampshire County Council Engineering Consultancy Simon Fryer The Castle Winchester Hampshire SO23 8UD Tel: Environment Agency Peter Kelly Colvedene Court, Wessex Way Colden Common SO21 1WP Tel: Onyx SELCHP Ltd Peter Lewis Landman Way, Off Surrey Canal Road London SE14 5RS Tel: Foster Yeoman Ltd Martin Dudley Marston House, Marston Bigot Frome Somerset BA11 5DU Tel: Appendix B 21

74 Demonstration Project 5: A3 Bus Priority Corridor, Portsmouth to Clanfield Construction project: Application: Product: Material: Region: Title: Pavements roads, car parks, footways etc. General fill General granular fill Unbound sub-base Capping Lower trench fill Re-grading landscape areas Shrub and tree planting Bus lane surface course Class 1A well graded granular material Class 1B uniformly graded granular fill Type 1 unbound sub-base mixture Class 2C/2D general fill Class 5A/5B Topsoil Class 6F3 selected granular material Class 8 miscellaneous fill Recycled Asphalt (road planings) Recycled concrete aggregate (crushed kerbs) Class 2C/2D/5A/5B recycled as general fill South East A3 Bus Priority Corridor Date: Client: Contractor: Designer: Hampshire County Council, Implementation Dyer and Butler Hampshire County Council, Engineering Consultancy and Atkins Consultant providing design resource support Recycled aggregate supplier: n/a Specification: Contract: Specification for Highway Works ICE 5 th edition Conditions of Contract Background By 2020 it is predicted that there will be a 40% increase in road traffic, so alternative transport solutions are needed to ensure that busy urban areas do not become gridlocked. Councils throughout the country are being given tough targets by the Government to increase public transport use, reduce congestion and increase housing. In meeting housing targets, a transport infrastructure must be provided that can accommodate growing numbers of residents. Designed with the future in mind, the A3 Bus Priority Corridor Project is included in Hampshire County Council s (HCC) Local Transport Plan It is managed under a partnership between HCC, Portsmouth City Council (PCC), Havant Borough Council (HBC), East Hampshire District Council (EHDC) and the bus operator First. The A3 Bus Priority Corridor will provide high quality, reliable public transport by offering passengers a priority bus service along the A3 corridor from Gunwharf Quays, Portsmouth to Clanfield, a village north of Horndean. Reliable, safe, clean and timely, the service will represent a realistic alternative to the car, helping to reduce the thousands of car journeys made into and out of Portsmouth every day. The new service has been branded ZIP, and a fleet of distinctive, new-look buses in the white, purple and green ZIP livery are already in use along the route. Appendix B 22

75 Plate 1 Zip bus livery South of Portsdown Hill, PCC are gradually completing bus priority improvements to the corridor. North of Portsdown Hill, the team lead by HCC is building the route in five sections: Section 1 - Portsdown Hill to Purbrook. Section 2 - Purbrook to Waterlooville. Section 3 - Waterlooville Town Centre. Section 4 - Waterlooville to Cowplain. Section 5 - Cowplain to Clanfield. The works affect a 12km long stretch of road and involve road widening, carriageway and footway reconditioning, diversion of statutory undertakers utilities, drainage, replacement street lighting and new/upgraded pedestrian crossings (puffins and toucans). Priority is given to buses over other traffic at junctions and where bus lanes end. For bus passengers the project includes the provision of high quality bus shelters designed for accessibility needs, real-time travel information and help points linked to a new network of CCTV cameras. The scheme includes accommodation works affecting local shops, churches and some residential properties adjacent to the scheme, so that the project is a benefit for the local community. Where appropriate it includes improvements beyond the highway boundary to help mitigate the impact of any road works and to integrate them with other local features and facilities. With the agreement of the landowner, the works can involve things such as resurfacing of driveways or footways, installing new fences, providing off-street parking, rear service roads for deliveries, paving, soft landscaping and other general environmental enhancements. Programme Due to the length of the works the project has been split into 5 main sections as illustrated in Table 1 and some of the sections have been split further into sub-sections. The work was originally programmed to take place over a 5 year period but due to funding constraints it will now take 6 to 7 years. Design, specification and quality submission To ensure the project is delivered in a sustainable way a best practice checklist with supporting tools is under development. Currently only being used in-house on a few trial schemes, the checklist and tools are intended to be cascaded to other sections in the Environment Department at HCC. The checklist is based upon HCC s 12 themes of sustainable development. It is a project based audit form recording progress and development of best practice to ensure the project is sustainable for the full life of the scheme. The supporting tools include Material Use sheets which are to be completed at key project stages with.! Preliminary design quantities.! Detailed design quantities.! Tender quantities.! Start quantities.! Completion quantities. The record sheets split materials on a project into three categories:! Materials on site for reuse.! Materials on site for disposal.! New materials required for site. Appendix B 23

76 Table 1 Programme of works Sections Area covered Status Date of construction Section 1 Portsdown Hill to Purbrook Complete April 2002 to February 2003 Section 2A Purbrook Village Maintenance period February 2004 to April 2005 Section 2B Purbrook Village to Waterlooville Maintenance period October 2004 to March 2005 Section 3A Waterlooville Forrest End Road Maintenance period October 2004 to May 2005 Section 3B Forest End/ Maurepas Way roundabout and Construction May 2005 to December 2005 up Rockville Drive Section 3C Waterlooville main town centre Construction June 2005 to June 2006 Section 3D St Georges Walk to Maurepas Way Maintenance period October 2004 to March 2005 Section 4A Hulbert Road to Queens Inclosure Advanced works Street lighting & CCTV January 2005 to December 2006 Main works Detailed design Section 4B Queens Inclosure Advanced works Street lighting & CCTV January 2005 to December 2008 Main works Detailed design Section 4C Cowplain Advanced works Street lighting & CCTV January 2005 to December 2008 Main works Detailed design Section 5A Catherington Lane to Clanfield Main works Detailed design January 2006 to December 2008 Section 5B Love Dean Lane to Catherington Lane Advanced works Street lighting & CCTV January 2005 to December 2006 Main works Detailed design Section 5C Cowplain to Love Dean Lane Advanced works Street lighting & CCTV January 2005 to April 2007 Main works Detailed design The benefits of recording this information derive from the ability to:! Link surplus materials from one site to another.! Reduce new material requirement.! Promote increased lifecycle. In addition to normal design considerations the design team paid particular attention to whole life costing. An example is the surfacing material specified for the bus lanes. Traditionally surface dressing is specified as it is quick and inexpensive to apply, but this wears out and has to be replaced every few years, causing disruption. For this project, a material with a design life of 20 years was specified. In whole life costing over a 20 year period the application of a higher quality surfacing material instead of repeated surface dressing visits was found to be more cost effective. Hardicrete by Miles Macadam, or an equivalent BBA approved material, was specified for the project. The product is a heavy duty surfacing material 40mm thick, with red coloured 14mm sized aggregate (min PSV 55 Max AAV 12), grouted with bulk mixed, quality-assured, red coloured, modified resin cementitious grout. HCC suggested in the contract documents a preference towards using recycled materials and to recycle rather than dispose of materials normally sent to landfill. Dyer and Butler (D&B) purchased a road planing machine especially for the project. They have used the road planings in the capping layer of the road widening, in the sub base for the footpaths and as trench fill material. The kerb crusher reduced the kerbs to a sandy gravel type material to form the sub-base of the resurfaced footways. For section 2B, earthworks generated material suitable for landscaping and bulk fill operations. The project has generated thousands of tonnes of road planings and occasionally there have been enough road planings and surplus earthworks materials to be reused on other D&B projects. Appendix B 24

77 Plate 2 Laying Hardicrete Plate 3 Section of the bus lane Facts and figures Between April 2002 and March 2005 HCC made an undertaking to Government under the Public Service Agreement (PSA) to achieve demanding performance targets. One of the targets was to recycle 40,000 tonnes per annum of household, commercial and industrial waste though the Hampshire Natural Resources Initiative. In 2004 the A3 Bus Priority project contributed 3,946 tonnes to this target, as detailed in Table 2. Other materials comprise lighting columns, bus shelters, general metalwork, illuminated and non-illuminated signs. Table 2 Cost savings for recycled/reused materials Materials on site for reuse on site or to be recycled Total Material Disposal Processing scheme 2004/2005 saving saving cost cost/saving Section Material tonnage Section 2a Concrete kerbs 92-2, ,780 Planings ,702-8,493-31,195 Other materials Section 2b Concrete kerbs 176-5,452-1,796-7,247 Topsoil and subsoil 1,699-15,274-19,741 38,717 3,702 Planings ,261-6,832-25,093 Other materials ,185 2,047 Section 3 Concrete kerbs 49-4,622-1,523-6,145 Topsoil and subsoil Planings ,379-5,380-19,759 3,946-83,843-45,250 41,850-87,243 Cost benefits Cost savings have been made on the project by using the road planings instead of the primary materials. Although the primary aggregates would not incur a large transport cost as they would have been sourced from Portsmouth, a cost saving was still made. The kerb crusher was used on Sections 1 and 2 of the project because they are long straight sections of road. Section 3 of the work was split into smaller sections through the town centre so as to minimise disruption. This meant that the use of the kerb crusher was not economically viable with the limited length able to be crushed at any one time. D&B calculated that the kerb crusher cost 1,200 per day and that to make it economically viable they would have to crush 1000m of kerb per day. When the works progress to Sections 4 and 5 of the project it is intended to use the kerb crusher again on the long straight stretches where it will be economically viable. Environmental benefits The environmental benefits of using the road planer and the planings generated on site are the reduction in lorry miles, savings in the use of primary materials and reduction in waste produced. Appendix B 25

78 The kerb crusher has lessened the disruption of removing the kerbs by providing a non invasive technique. Normally crushing of kerbs is very noisy, but the machine used for this work operated at significantly reduced noise levels. As part of its commitment to continually reviewing and improving its services, the First bus company increased the frequency of Portsmouth Overground 40 and Zip 41 from Sunday 6 February 2005 to every 12 minutes on its Monday to Friday daytime services. This improvement is as a result of a steadily increasing number of passengers using these services, currently 7.4%. Marc Reddy, Deputy Managing Director for First bus operations in Hampshire & Dorset explained, The reasons for this continued and sustained increase in usage are threefold: year-on-year growth in students at South Downs College, investment by Portsmouth City Council and Hampshire County Council to improve road infrastructure as part of working quality partnerships with First, and finally a commitment by First to operate the highest quality fleet on these routes. Conclusions The project is over half way through with the first two sections of work completed and the third section underway. The case study has shown that the A3 Bus Priority Project is embracing the goals of sustainable development and as the project proceeds it is continuing to develop good practices for use by its partners and for use on other Hampshire County Council projects. The project has successfully used road planings generated from the works instead of primary aggregates with consequent cost savings and environmental benefits. The use of the kerb crusher in Sections 1, 2, 4 and 5 provides savings in waste and is a low noise non-invasive method of removing the kerbs. Details of parties Hampshire County Council Implementation Geoff Topps The Castle Winchester Hampshire SO23 8UD Tel: First Hampshire Ltd Mike Smith London Road Hillsea Portsmouth PO2 9RP Tel: Hampshire County Council Engineering Consultancy Chris Murray The Castle Winchester Hampshire SO23 8UD Tel: Dyer & Butler Steve Jayne Mead House Station Road Nursling Southampton SO16 0AH Tel: DYER & BUTLER Appendix B 26

79 Demonstration Project 6: North Popley Development, Basingstoke Construction project: Application: Material: Region Pavements roads, car parks, etc. General fill Cement bound sub-base Cement bound trench backfill Cold recycled bitumen bound base Chalk Recycled asphalt South East Title: North Popley Development Contract 1 Date: May to June 2005 Client: Designer: Main contractor: Stabilisation contracter: Surfacing contractor: Hampshire County Council Estate Practices Hampshire County Council Engineering Consultancy Mildren Construction Limited Envirosoil (Remediation) Limited Bardon Aggregates Cold recycled bitumen bound material supplier: Foster Yeoman Limited Specification: Conditions of Contract: Specification for Highway Works with contract specific amendments based on TRL Report TRL611 Institution of Civil Engineers, 7 th edition Background North Popley is a major new mixed use development on a green field site on the north side of Basingstoke. The site will include about 950 residential units, a neighbourhood centre and a new secondary school with community sports facilities. In total, about 20 ha will be developed. The site is owned by Hampshire County Council (HCC), who will run the school as the Local Education Authority. They are carrying out preliminary infrastructure works to provide a spine road and services across the site. Plots will then be sold to private developers. Contract 1 of the project comprises improvements to the existing roads around the site, which are narrow rural roads, and installation of an access road and services to the site of the new school. The total length of new road is about 250m of 6.1 m width single carriageway. In subsequent phases the spine road will be built across the site, a distance of about 1.5 km. The Contract 1 works have to be completed by August 2005 to enable construction of the new school to start on schedule. In accordance with HCC s corporate policies on sustainability, opportunities are being sought to maximise recycling and the use of recycled and secondary aggregates in the construction. Any methods that are shown to work successfully in the Phase 1A works can be extended to the much larger spine road and associated works. Cement stabilisation of chalk The site is underlain by chalk. It was decided at the design stage to stabilise the chalk in situ with cement to form a cement stabilised sub-base as an alternative to excavating the chalk and replacing it with Type 1 unbound sub-base. The site investigation for the works had shown that the chalk above sub-base level was weak and the original design was to dispose of this material to landfill. However, when the topsoil was stripped for the Phase 1A works the chalk was found to be in better condition that expected. The excavated chalk was therefore retained on site and used as general fill for the footways, saving the import of 400 m 3 of primary aggregates as general granular fill. The excavated chalk was classed as Class 3 general fill and compacted in accordance with the requirements of the Specification for Highway Works. Appendix B 27

80 The amount of cement required to stabilise the chalk for use as cement bound sub-base was determined by laboratory trials. Samples were taken for testing and gave the following results: Material CBR Untreated chalk 13% Chalk + 2% cement 50% Chalk + 4% cement > 100% A California Bearing Ratio (CBR) of 30% is the normal requirement for unbound sub-base. The tests showed that this could be achieved with only a small addition of cement. The use of cement stabilised sub-base was therefore approved, with a requirement that the stabilised material achieved a minimum CBR of 30% by 7 days after stabilisation. A contract specific additional clause for the Specification for Highway Works was produced by HCC to cover the stabilisation of the chalk with cement for the sub-base. The stabilisation works were carried out by specialist contractor Envirosoil (Remediation) Limited in May A 225 mm thickness of chalk was treated in situ with 2% ordinary cement (CEM 1) using specialist rotovating plant to mix the cement into the soil. The layer was then compacted with a vibrating roller and treated with a bituminous tack coat to prevent moisture getting into the stabilised material. The material was tested by HCC using Clegg hammer tests to estimate the in situ CBR of the stabilised material. The tests gave CBR values in the range 50% to 80%, well in excess of the design requirement of 30%. Appendix B 28 Plate 1 Cement stabilised chalk sub-base with bituminous coating to protect it from the weather As well as the 250m of 6.1 m wide access road, cement stabilised chalk was used as sub-base for about 200m of footway. This was not treated in situ, but was excavated chalk from the site. It was mixed with 2% cement, placed and compacted satisfactorily. Excavated chalk mixed with 2% cement was also used to backfill trenches for the drains. Untreated chalk was not suitable for this application, as it might have softened and settled on exposure to moisture. The approximate quantities of materials used are as follows: Material Application Quantity (m 3 ) Untreated chalk Class 3 general fill for footways 400 Chalk + 2% cement Class 8 trench backfill 200 Chalk + 2% cement In situ stabilised sub-base for access road 350 Chalk + 2% cement Ex situ stabilised sub-base for footways 50 Total 1,000

81 Plate 2 Close up of cement-stabilised chalk As a result of these measures, 1,000m 3 of chalk that would have had to be disposed of to landfill and replaced with imported aggregates were retained on site and used in the permanent works. This equates to approximately 200 lorry movements that were saved, plus the savings in landfill space and in primary or recycled aggregate use. This more than offsets any environmental disbenefits from the manufacture of the small amounts of cement used to stabilise the material. If savings on this scale could be repeated across the whole of the North Popley Development, it would very considerably reduce the environmental impact of the construction. Cold recycled bitumen bound material in road pavement As a further sustainability measure, the asphalt pavement for the access roads was constructed using 250 mm of cold recycled bitumen bound material with foamed bitumen (Foamix ) placed in two layers. The material was placed as the base followed by a 55mm binder course of DBM 50 and a 45mm conventional hot asphalt surface course. After laying the Foamix, the individual layers (150mm maximum layer thickness) were tested for stiffness using the German dynamic plate method after one hour and at 24 hours to ensure the correct stiffness had developed. The air void space was also measured by nuclear density gauge to ensure the minimum 93% had been achieved. Actual values averaged around 97%, which were ideal. The top of the Foamix course was sprayed with K170 bitumen emulsion to help seal the layer. The works were carried out in June The contractor for the pavement layers was Bardon Aggregates, and the Foamix was supplied by Foster Yeoman from their depot at Micheldever. Some 300 m 3 of Foamix were laid during construction of the access roads. Foamix is a cold recycled bitumen bound material with foamed bitumen as the main binder. It results in considerable energy savings compared to conventional hot asphalt. It is commonly used with recycled materials, such as recycled asphalt planings, as the coarse aggregate, thus giving double benefits in sustainability terms. The use of Foamix has been highlighted in other case studies in this series, including footway works on the B3047 at Martyr Worthy and the access road to Bar End Household Waste Recycling Centre. The recycled asphalt for North Popley came from arisings from maintenance works on the A325 at Alice Holt, where the use of recycled aggregates to repair a weak clay embankment was highlighted in another case study in this series. A contract specific new clause for the Specification for Highway Works was produced by HCC to cover the production and use of Foamix. This is based on the latest research and standards relating to cold recycled pavement materials, in particular TRL Report TRL611: A guide to the use and specification of cold recycled materials for the maintenance of road pavements. HCC had been a partner in the research project that led to the production of TRL611, and were keen to implement the findings as soon as possible. TRL611 extends the range and application of cold recycled materials in road pavements beyond what was previously allowed and includes a design guide and specification. These will be incorporated into the Specification for Highway Works in due course, but HCC was anxious to utilise them immediately and produced a contract specific clause for this project. Appendix B 29

82 Plate 3 Second layer of Foamix being laid on top of first layer Plate 4 Close up of Foamix Appendix B 30