Guidelines for Prequalification and Design of Post-Installed and Cast-In Anchors in Australia

Transcription

1 Guidelines for Prequalification and Design of Post-Installed and Cast-In Anchors in Australia David J. Heath 1,2, Emad F. Gad 1,2 and Gary Connah 1 1 Australian Engineered Fasteners and Anchors Council 2 Swinburne University of Technology, Melbourne, Australia Abstract: Guidance for the design of post-installed and cast-in anchors for safety-critical applications in Australian codes of practice is minimal. The current level of guidance has resulted in a lack of consistency for product assessment and limited guidance for design. This paper examines common guidelines for prequalification and design of post-installed and cast-in structural anchors for use in concrete. The current practice in Australia is compared with international practice published in the Guidelines for European Technical Approval (ETAG) and the American Concrete Institute (ACI). Of particular relevance is the guidance offered in AS 3600:2009 Concrete Structures, AS 3850:2003 Tilt-Up Concrete Construction, AS 4100:1998 Steel Structures, and the Australian Technical Infrastructure Committee (ATIC). The comparison of the various guidelines demonstrates a significant disparity between national and international practice. A clear opportunity exists to rationalise and harmonise national guidelines for product prequalification and design methodology, with more rigorous international guidelines which are considered best-practice. This work has been undertaken by the Australian Engineered Fasteners and Anchors Council (AEFAC). AEFAC is an industry initiative formed to develop the framework to improve governance of the Australian anchor industry that is at present largely self-regulated. Key to achieving this is developing minimum standards and consistency in product prequalification and design. This paper outlines the research findings which have formed the basis on which AEFAC has chosen to recommend European practice as the model on which future Australian guidelines for structural anchors should be based. Keywords: Post-installed, cast-in, anchor, prequalification, design 1. Introduction Fasteners used in safety-critical applications involving metal inserts into a concrete or masonry substrate should be designed and detailed by a competent structural engineer. The failure of these fixtures may cause considerable economic loss and risk life safety. Fasteners must be fit for purpose; durable, robust, and possess sufficient integrity for all design actions (1). These types of fasteners form the focus of this paper. In concrete, anchors can be grouped according to their installation method into cast-in-place and postinstalled. Examples of the cast-in-place anchors are headed fasteners, hooked bolts, ferrules and channels. Post-installed anchors can be further classified into two groups being direct installation (power actuated) fasteners and a much larger ensemble being the drill installation fasteners which covers chemical bonded anchors and mechanical anchors (such as expansion and screw anchors). At present, guidelines for specification and installation of anchors in Australia are minimal. The absence of representation in Australian codes of practice has resulted in the anchor industry being largely self-regulated. However, the absence of a regulated framework has numerous shortcomings. The absence of suitable guidelines for the use of anchors in safety-critical applications overseas has contributed to catastrophic failures (2, 3, 4). Such failures have become the catalyst for the tightening of regulatory frameworks, focusing on the critical areas including testing and assessment of products, specification by engineers and training for installers. There is an urgent need for leadership for the advancement of the use of fasteners in the Australian construction industry. This paper summarises current guidance offered in Australia, presents a new initiative to lift quality and safety standards in the Australian construction industry, as well as listing various international guidelines for the specification and installation of anchors and endorses 2. Australian Engineered Fasteners and Anchors Council (AEFAC)

2 In order to lift quality and safety standards for the use of anchors in the Australian construction industry, a new consortium has been formed in 2012, comprising leading national and multinational firms, and an academic institution. This consortium is the Australian Engineered Fasteners and Anchors Council (AEFAC). AEFAC s founding members are Ancon Building Products, Hobson Engineering Co, Hilti (Aust), ITW Construction Systems, Powers Fasteners Australasia, Swinburne University of Technology and Würth Australia ( AEFAC is based at Swinburne University of Technology where it has access to world-class testing facilities for fasteners and anchors. AEFAC was formed to introduce governance to the industry with support and guidance to be provided to engineers (specifiers), manufacturers, installers and field engineers. AEFAC encourages participation from other industry stakeholders and is actively courting various organisations for their input and opinion. A comprehensive review was undertaken by AEFAC of international guidelines for the specification and installation of anchors including the two primary considerations, European and U.S. practice. AEFAC has resolved that the specifications and design provisions outlined by the European Organisation for Technical Approvals (EOTA) in the Guidelines for European Technical Approvals (ETAG) are the most appropriate for Australian practice. These guidelines have been subsequently endorsed by AEFAC for use in Australia. This endorsement is consistent with the technical specification set by the Australian Technical Infrastructure Committee (ATIC) for the use of anchors in concrete (5). AEFAC has commenced the adaption of ETAG 001 (Metal Anchors for Use in Concrete) for Australia and will be promoting it in the near future as an industry code of practice. Among other initiatives, AEFAC will also develop a training and certification scheme for installers to enhance the quality and reliability of installation of anchors. 3. Guidelines For Design 3.1 Australian guidelines There are no standards for design, testing or evaluation of anchors in Australia, except for brace fixture inserts for temporary bracing of precast panels that is covered in AS 3850 and under review at the time of writing. Clause 14.3 of Australian Standard 3600 (9) references anchorage to concrete, requiring the design strength to be equal to 0.6 times the ultimate strength of the connection and advises cone-type failure to be investigated in the case of shallow anchorages. The design of the metal bolt component of an anchorage may be performed in accordance with Clause 9.3 of Australian Standard (10). However, this design is strictly limited to the bolt component and does not address other components that may exist in an anchor such as a cone or sleeve. It is therefore apparent that these standards do not suitably assess the interaction of the anchor with the substrate, leaving considerable scope for further guidance. Consequently, engineers typically rely on design data or software tools provided by suppliers which often lack consistency in terminology and design approach. Further, there is a fundamental lack of knowledge of factors affecting the performance of an anchor. In general, coverage of anchoring in undergraduate engineering programs in Australia is a bare minimum and formal local training opportunities have been very limited. 3.2 Concrete Capacity (CC) method A sophisticated theoretical model exists for anchor design that is universally accepted in Europe and the U.S. (11, 12). The underlying theory of the design methods adopted in ETAG 001 is the same as that adopted America. The theory is termed the Concrete Capacity Design (CCD) method and was originally proposed in 1995 [13]. An inverted pyramid related to the localised capacity of concrete utilised by the anchor predicts concrete failure due to applied loading and has been demonstrated to be very accurate and first published in ETAG 001 in The development of this theory is beyond the scope of this article and has been covered extensively elsewhere (1, 13). The CC method permits a reduction in the failure load using modification factors to account for eccentricity of loading in tension, shear, bending, edge and spacing effects, reinforcement, state of the concrete (cracked or non-cracked), concrete member thickness and details of fixture including plate stiffness, plate thickness and hole clearance. The model includes provision for the performance of anchors in cracked concrete and requires the assumption of cracked concrete unless non-cracked may be justified for the design life of the anchor (8). Products such as headed studs, undercut anchors, specially designed expansion anchors or bonded expansion anchors may operate in cracks of limited width, provided they have the appropriate approval. Depending on the reinforcement configuration, the capacity of the anchor may be increased or decreased. An increase will occur when the reinforcement intersects the failure plane. However, a dense shallow layer of reinforcement may

3 have a deleterious effect on anchor performance, reducing anchor capacity through a shell spalling factor. Fixture details also become an important consideration as these influence the design actions and the restraint provided to the fixing. In general, fixings are not considered to transfer compression to the substrate. There are a number of failure modes requiring consideration when designing anchors. Figure 1 (a) illustrates the modes of failure requiring consideration when designing for tension loads while Figure 1 (b) illustrates the modes of failure requiring consideration when designing for shear loads. It may therefore be seen that consideration of the substrate is an integral part of the anchor design process. Figure 1: Failure modes needing to be considered during anchor design (12). 3.3 Guidelines in Europe (AEFAC endorsed) The European Organisation for Technical Approvals is the body overseeing the drafting of Guidelines for European Technical Approvals (ETAGs) as well co-ordinates all activities relating to the issuance of European Technical Approvals (ETAs). The EOTA was established on December 21, 1988 as a legal body under Belgian Law. The goal of the EOTA is to remove technical barriers to trade in the construction products sector. EOTA comprises EU Member States and European Free Trade Association (EFTA) States who have contracted to the European Economic Area Agreement. EOTA formed as a result of the European Union s Construction Products Directive (CPD) which is the legal

4 basis to develop criteria assessing products for use in all member states and serves to remove technical barriers in the products sector. The purpose of an ETAG is to provide a specific set of test and evaluation requirements for a product or family of products. An ETA is the certificate issued on the basis of a favourable technical assessment of a product for a given ETAG test option number. The ETA is certification that the product is considered fit for its intended use. If an ETAG does not exist for a given product area, an alternative path for obtaining an ETA is possible via a Common Understanding of Assessment Procedure (CUAP) that has been adopted by the Approval Bodies acting jointly in EOTA. The Approval Bodies are nominated by EU member states to issue ETAs. For example, the Approval Body in Germany is the German Institute for Building Technology (DIBt). The application for an ETA is the responsibility of the manufacturer. The European design guideline for fasteners and fastening groups is CEN/TS 1992 Part (14-18) which covers: Part 4-1: General Part 4-2: Headed Fasteners Part 4-3: Anchor channels Part 4-4: Mechanical systems Part 4-5: Chemical systems Inserts embedded in precast concrete elements for transient lifting and handling purposes are covered by CEN/TR 15728:2008 Design and Use of Inserts for Lifting and Handling Precast Concrete Elements (19). The design method for cast-in anchor channels based on CEN/TS 1992 Part 4-3 is also summarised in the Verein zur Förderung und Entwicklung der Befestigungs-, Bewehrungs- und Fassadentechnik e.v. (VBBF) publication Design of Anchor Channels (20). Other guidelines are published by EOTA such as Technical Report 029 Design of Bonded Anchors (21) which summarises the design of bonded anchors. Guidelines also exist to assist with the selection and specification of anchors such as the British Standard 8539 Code of practice for the selection and installation of post-installed anchors in concrete and masonry (22). A similar set of guidelines was developed by the Health and Safety Authority in Dublin, Ireland and published as the Code of Practice for the Design and Installation of Anchors (23) Selecting Approved Anchors One of the most important design considerations when selecting an anchor is the state of the concrete. Concrete may crack due to a variety of reasons. Where no guidance is available to indicate the state of the concrete, the designer should demonstrate via analysis of stresses, that cracking will not be experienced during the service life of the anchor, if the anchor is to be designed for noncracked concrete. For all other applications, cracked concrete should be assumed. Anchors designed for cracked concrete automatically qualify for use in non-cracked concrete. The selection of an anchor is dependent on the nature of the ETA classification as per the Option number, discussed in greater detail in Section Design methodology The design of an anchor is complex and time consuming which may be overcome through software made available by product manufacturers. However, design of an anchor should only be performed by a suitably qualified engineer. ETAG 001 Annex C offers different tiered design methods for postinstalled anchors, with method A being the most stringent, accounting for all failure modes, while methods B and C have reduced test requirements. The design method correlates with the ETA Option number (refer to Table 1) and considers tension, shear and combined tension and shear loading. Factors to be assessed during the design of anchors include the following (14): 1. Installation conditions in concrete on site 2. Drilling method and drill bit diameter in case of post-installed fasteners 3. Bore hole cleaning 4. Installation tools 5. Sustained (long term) and variable loads on the fastener 6. Variable loads on the concrete structure (crack cycling) 7. Crack width in the concrete structure

5 8. Environmental conditions such as air pollution, alkalinity, aggressive environment, humidity, concrete installation temperature, service temperature, etc. 9. Location of fasteners in the concrete component 10. Minimum dimensions of the structural component. 3.4 Guidelines in the U.S. Design models in the U.S. are closely aligned with those in Europe. In terms of safety concept, Europe uses partial safety factors denoted by gamma (γ), whereas the U.S. uses strength reduction factors denoted by phi (Ø). Relatively small differences exist in the design methodology, with one example being the U.S. adopting a more conservative approach to overhead bonded anchor installation following the ceiling collapse in Interstate 90 Connector Tunnel in Boston (3). The design of cast-in and post-installed anchors in the U.S. is covered in ACI 318 Appendix D (12) which is referenced in the International Building Code 2012 (24). The design of post-installed anchors is very similar to that adopted in ETAG 001 with only minor differences. ACI 318 recognises code-compliant post-installed anchors as those having approvals through ACI (25) covering expansion and undercut anchors and ACI (26) covering bonded anchors (refer to Section 4.2). However, ACI (12) does not include requirements to establish the structural capacity of proprietary connections such as cast-in channel. 4. Guidelines for Prequalification Prequalification is the path to safeguarding quality by promoting uniformity and consistency in testing and assessment criteria for anchor products. The prequalification, based on harmonised assessment and design procedures, provides the highest level of certainty that a product is fit for its intended use. AEFAC recognises prequalification as promoting best-practice, using products independently assessed to state-of-the-art standards. Many anchor products available in Australia have prequalification either from Europe or the U.S. The issuing of an approval is a document stating the information and data needed to design and install an anchor (27). The testing and evaluation procedures are intricate due to the complexity of the potential failure modes and behaviour under different installation and environmental conditions. The intent of prequalification is discussed further below. 4.1 Guidelines in Europe (AEFAC endorsed) In order for a product to be accepted in the European market it must first comply with a harmonised European Code or have been awarded a European Technical Approval (ETA). Assessment and design provisions for concrete anchors were in existence through national provisions in the early 1970 s, although development of qualification criteria for the European Union s Construction Products Directive (CPD) did not begin until the 1980 s (28). Working groups for anchors in the early 1990 s with the first submission for an ETAG being made in 1997 which was followed by the awarding of the first ETA in 1998 by DIBt. On the 1 st July, 2013, European Technical Assessments will be superseded by European Technical Approvals for a favourable assessment of a product. ETAs issued prior to this date will be honoured for the duration of their validity, usually five years Benefits of European Technical Approvals Anchor products having prequalification most likely require a modest upfront investment. However, this is cheap insurance against a product that is not fit for purpose that may require costly remedial action or cause failure, at some time in the future. There are clear advantages to selecting anchor products with ETAs, which include: Confidence for designers and installers knowing the product has qualified under a harmonised assessment and design procedure reflecting it is fit for its intended use. ETAs reflect the required level of performance according to current state-of-the-art assessment techniques that have been independently verified. Minimum quality and safety standards are achieved. A safety margin exists for reasonable variations from the manufacturer s installation instructions.

6 Traceability of the product from fabrication to packaging to on-site. Installation instructions supplied by the manufacturer with all required information for installation Scope of guidelines The scope of the document outlines important details of the prequalification, including factors such as type of anchor, type of concrete, materials, key dimensions, type of actions, and restrictions to ensure quality of the design and installation. The European prequalification for post-installed anchors used in construction is ETAG 001 Metal Anchors for Use in Concrete (8) and is compatible with European Standards. ETAG 001 comprises Parts 1 6 (8, 29-33) and Annex A C (11, 34, 35) as follows: Part 1: Anchors in General Part 2: Torque-Controlled Expansion Anchors Part 3: Undercut Anchors Part 4: Deformation-Controlled Expansion Anchors Part 5: Bonded Anchors Part 6: Anchors for multiple use for non-structural applications Annex A: Details of tests Annex B: Tests for admissible service conditions detailed information Annex C: Design methods for anchorages Part 1 of ETAG 001 contains the essential requirements and assessment methods, while Parts 2 5 contain specific requirements, required tests and assessment methods for specific types of metal anchors. Part 6 of ETAG 001 relates to metal anchors used in non-structural applications, while Annex A and B relate to test requirements. The design of post-installed anchorages has been incorporated into Annex C. The four main types of anchors covered in ETAG 001 include torque-controlled expansion anchors, undercut (including screw anchors), deformation-controlled expansion anchors, and bonded anchors. Although an ETAG does not currently exist for cast-in anchors, a CUAP has been developed to evaluate loads acting perpendicular to the longitudinal axis of an anchor channel (36) Options for prequalification The Option number determines the scope of the application for which the anchor has independently verified performance. There are 12 different combinations possible in ETAG 001 (refer to Table 1). The conditions covered in the Option include the state of the concrete (cracked and non-cracked, or non-cracked only), concrete strength (C20/25 to C50/60), direction of loading (single value covering all directions, or separate for tension and shear), effect of reduced edge and spacing distances, and design method. Options 1 (cracked and non-cracked concrete) and 7 (non-cracked concrete) are the most demanding test regimens, while Options 6 and 12 have the least demanding test regimens. The selection of a product therefore necessitates that the Option adequately covers the required criteria Methods of test The following three main types of tests are covered in ETAG 001 (8): Reference tests base level performance of an anchor in ideal conditions is established and used as a comparison for tests for suitability and admissible service condition tests to quantify variation deterioration in performance Suitability tests used to assess the performance of an anchor against deviations from manufacturer s installation specifications that may occur during construction. Gross errors are not covered and should be avoided through suitable training of the installers and supervision on site. Suitability tests cover installation safety, concrete strength, cracked and non-cracked concrete, repeated loads, sustained loads, torque tests, freeze/thaw conditions, and direction of installation. Admissible service condition tests design data relating to the performance of the anchor is collected. These tests reflect conditions that are expected to occur on site under normal conditions including installation performed in accordance with manufacturer s installation instructions. The

7 objective is to determine if the anchor conforms to current experience and if not, a complete test programme must be undertaken. Tests for durability ensure the product performs as expected throughout its design life without suffering a loss in performance due to ambient physico-chemical effects such as corrosion and degradation due to environmental conditions such as moisture, pollution and alkalinity. Supplementary tests are covered in Technical Reports such as TR 020 Evaluation of anchorages in concrete concerning resistance to fire (38) which is used as a basis to determine a fire resistance class in an ETA, and TR 023 Assessment of post-installed rebar connections (39). The existing EOTA testing and assessment procedures for metal anchors are under review and will be amended in the future to cover dynamic and seismic loading. Table 1: ETAG 001 Options for prequalification of metal anchors for use in concrete (8). Option No. Concrete Requirements for Specification Reduced Single edge & spacing Cracked & noncracked Noncracked only C20/25 C20/25 to C50/60 value (all directions) Tension & shear values Design Method as per Annex C 1 X X X X A 2 X X X X A 3 X X X X B 4 X X X X B 5 X X X C 6 X X X C 7 X X X X A 8 X X X X A 9 X X X X B 10 X X X X B 11 X X X C 12 X X X C 4.2 Guidelines in the U.S. A similar system exists in the U.S. relative to that adopted in Europe for the testing and assessment of anchor products, including reference tests, reliability tests and service-condition tests. Both systems adopt an identical statistical procedure based on a 5%-fractile of the ultimate loads and assuming a normal distribution with unknown standard deviation and a confidence level equal to 90%. Two systems exist in parallel for the assessment of anchor products: i) American Concrete Institute, and ii) ICC Evaluation Service (ICC-ES), a subsidiary of the International Code Council (ICC) which issues Evaluation Service Reports (ESRs). There is substantial agreement between the two systems (27). Post-installed mechanical anchors are assessed under ACI (or AC193 (40) under the ICC-ES system), while post-installed bonded anchors are assessed under ACI (or AC308 (41) under ICC-ES system). While an ACI standard does not currently exist for cast-in channel, ICC-ES have published AC232 Acceptance criteria for anchor channels in concrete elements (36) which is very similar to CUAP 06.01/01 (37). 5. Training for Installers The performance of anchors can be particularly sensitive to installation, such as sensitivity to cleaning in the case of bonded anchors. While the construction industry in Australia relies on appropriately

8 trained and qualified welders in structural steel, it is not the case for anchors. In other parts of the world installer training and certification has been recognised as a critical element of quality assurance. While the testing and assessment of an anchor includes provision for a reasonable variation from ideal installation practice, gross errors are beyond the scope of the prequalification. The installer should ensure proper training has been received and adequate supervision of anchor installation is undertaken for the anchor to be considered fit for its intended use. The installation procedure issued in the approval document such as an ETA should always be adhered to. The requirements on installation are the most significant difference between the European and U.S. anchor guidelines. While the responsibility is biased towards the installer in Europe, the culture in the U.S. is to shift the responsibility towards jobsite inspection with the jobsite inspector playing a major role. In Europe, specific anchor installation may only be carried out by appropriate qualified person under the supervision of the person responsible for technical matters on site. The installation must be in accordance with ETA as well as other manufacturer s instructions. Certification of installers is at the discretion of the individual Member State. However, there is a move towards placing the responsibility on the installation company to ensure suitably qualified personnel are on site to meet the requirements of an ETA (27). In the U.S. a special inspector must be present on site as often as required in accordance with the IBC requirements. A new qualification exists for bonded anchor installation, the ACI/CRSI Adhesive Anchor Installer certification program (42). Bonded anchor installation occurring in a direction from horizontal to vertically up, must be certified in accordance with this program. 6. Future Work Future work to be undertaken by AEFAC will focus on lifting quality and safety standards for anchor technology to a similar level currently available in Europe and the U.S. AEFAC has endorsed European guidelines for design, testing and evaluation of anchors and will be working to migrate and adapt these guidelines as necessary to suit the Australian construction industry. The work will include technical documents for use by engineers, guidelines for manufacturers, and comprehensive training for installers to enhance the quality of installation through a certification system. The construction industry in Australia has not had a culture requiring conformity assessment of products which has hampered the correct specification of products. This often leads to either unnecessary testing or products incorrectly accepted or dismissed. The future work of AEFAC will focus on tightening regulation of the industry by providing a framework to promote conformance. Education is of paramount importance for AEFAC to achieve its goals. The AEFAC library will be progressively populated as additional technical guidance notes are developed and education events in the form of workshops, seminars and training demonstrations will be developed for all parties associated with the anchor industry. 7. Conclusions This paper has demonstrated that the cast-in and post-installed anchor industry in Australia has been largely self-regulated with most guidance offered by manufacturers rather than nationally accepted codes. Prior to the formation of AEFAC, the industry was fragmented and lacking in consistency and uniformity for design, installation, testing and assessment of anchors. AEFAC is an industry initiative bringing about change to safeguard the ability to deliver appropriate fastening solutions with the required degree of confidence. Rigorous guidelines for the design and prequalification of post-installed and cast-in anchor products in Europe and the U.S. have been presented. Both systems are underpinned by the state-of-the-art Concrete Capacity method of determining anchor performance and test procedures to guarantee a product will remain fit for purpose throughout its design life. The European system has been endorsed by AEFAC and will be migrated for use by the Australian construction industry. The formation of AEFAC is an important step in creating a local body of knowledge in the anchoring industry with appropriate research and testing capabilities. This initiative will facilitate future enhancements in specification, design and installation standards and encourage local innovation. 8. Acknowledgements The authors wish to acknowledge the technical input from the following members of the AEFAC Technical Committee: James Murray-Parkes (Co-Founder of AEFAC), Joe Rametta (Hilti Aust.),

9 Johannes Krohse and Kamiran Abdouka (Wϋrth), Neil Hollingshead (ITW Construction Systems), Ramil Crisolo (Hobson Engineering Co.) and Tarun Joshi (Powers Fasteners Australasia). The authors would also like to acknowledge the ongoing financial support of the AEFAC Founding Members: Ancon Building Products, Hilti (Aust.), Hobson Engineering Co., ITW Construction Systems, Powers Fasteners Australasia and Wϋrth. 9. References 1. Eligehausen, R., Mallée, R. and Silva, J. F., 2006, Anchorage in Concrete Construction, Ernst & Sohn, Berlin 2. Salmon, M., Fixing Failures Case Study 2: Collapse of a pre-cast concrete section Ireland, 2002, Construction Fixings Association, 3. Ceiling Collapse in the Interstate 90 Connector Tunnel, Boston, Massachusetts, July 10, 2006, Accident Report NTSB/HAR-07/02, National Transportation Safety Board 4. Salmon, M., Fixing Failures Case Study 3: School ceiling collapse West Midlands 2007, Construction Fixings Association, 5. ATIC, 2009, Section SP38: Metal Anchors for Use in Concrete, Australian Technical Infrastructure Committee, 6. AS , Tilt-up concrete construction, Standards Australia 7. DR AS , 2013, Prefabricated concrete elements, Part 1: General requirements, Committee BD-006, Standards Australia 8. ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Part one: Anchors in General European Organisation for Technical Approvals, 9. AS , Concrete Structures, Standards Australia 10. AS , Steel Structures, Standards Australia 11. ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Annex C: Design Methods for Anchorages European Organisation for Technical Approvals, ACI Building Code Requirements for Structural Concrete and Commentary, Report by ACI Committee, American Concrete Institute, Fuchs, W., R. Eligehausen, and J. E. Breen, 1995, Concrete Capacity Design (CCD) Approach for Fastening to Concrete, ACI Structural Journal, 92(1), pp CEN/TS :2009 Design of fastenings for use in concrete, Part 4-1: General 15. CEN/TS :2009 Design of fastenings for use in concrete, Part 4-2: Headed fasteners 16. CEN/TS :2009 Design of fastenings for use in concrete, Part 4-3: Anchor channels 17. CEN/TS :2009 Design of fastenings for use in concrete, Part 4-4: Mechanical systems 18. CEN/TS :2009 Design of fastenings for use in concrete, Part 4-5: Chemical systems 19. CEN/TR 15728:2008 Design and Use of inserts for Lifting and Handling of Precast Concrete Elements 20. VBBF, 2010, Design of Anchor Channels, Verein zur Förderung und Entwicklung der Befestigungs, TR 029, 2010, Design of Bonded Anchors, European Organisation for Technical Approvals, BS , Code of practice for the selection and installation of post-installed anchors in concrete and masonry, British Standards Institution 23. Code of Practice for the Design and installation of Anchors, Health and Safety Authority, 2010, ICC, 2012, International Building Code 2012, International Code Council 25. ACI , Qualification of Post-Installed Mechanical Anchors in Concrete and Commentary, Report by ACI Committee 355, American Concrete Institute, ACI Qualification of Post-Installed Adhesive Anchors in Concrete and Commentary, Report by ACI Committee 355, American Concrete Institute, Hörmann-Gast, A. and Olsen, J., 2012, Adhesive anchors across borders: A current look at the similarities and differences between testing, qualification, and design of adhesive anchors in the U.S. and Europe, SP-283, American Concrete Institute 28. Laternser, K., Silva, J. and Hoermann-Gast, A., European Provisions for the Testing, Assessment and Design of Anchors in Concrete and Masonry, European Organisation for Technical Approvals, ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Part two: Torque-controlled Expansion Anchors European Organisation for Technical Approvals,

10 30. ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Part three: Undercut Anchors European Organisation for Technical Approvals, ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Part four: Deformation-controlled Expansion Anchors European Organisation for Technical Approvals, ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Part five: Bonded Anchors European Organisation for Technical Approvals, ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Part six: Anchors for Multiple Use for Non-structural Applications European Organisation for Technical Approvals, ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Annex A: Details of test European Organisation for Technical Approvals, ETAG 001, Guideline for European Technical Approval of Metal Anchors for Use in Concrete, Annex B: Tests for Admissible Service Conditions Detailed Information European Organisation for Technical Approvals, AC232, 2011, Acceptance Criteria for Anchor Channels in Concrete Elements, International Code Council Evaluation Service 37. CUAP 06.01/01, 2010, Common Understanding of Assessment Procedure for European Technical Approval according to Article 9.2 of the Construction Products Directive: Anchor channels, European Organisation for Technical Approvals 38. TR 020, 2004, Evaluation of Anchorages in Concrete concerning Resistance to Fire, European Organisation for Technical Approvals, TR 023, 2006, Assessment of post-installed rebar connections, European Organisation for Technical Approvals, AC 193, 2012, Acceptance criteria for mechanical anchors in concrete elements, International Code Council Evaluation Service 41. AC308, 2011, Acceptance criteria for post-installed adhesive anchors in concrete elements, International Code Council Evaluation Service 42. ACI-CRSI Certification Program for Adhesive Anchor Installer, Publication CP-80 (12), American Concrete Institute,