PUBLISHED PROJECT REPORT PPR829. The performance of EME2 in Scotland. M McHale

Transcription

1 PUBLISHED PROJECT REPORT PPR829 The performance of EME2 in Scotland M McHale

2 Report details Report prepared for: Project/customer reference: Copyright: Transport Scotland Martin McLaughlin Transport Research Laboratory Report date: July 2017 Report status/version: 1.1 Quality approval: M McHale (Project Manager) M Winter (Technical Reviewer) Disclaimer This report has been produced by the Transport Research Laboratory under a contract with Transport Scotland. Any views expressed in this report are not necessarily those of Transport Scotland. The information contained herein is the property of TRL Limited and does not necessarily reflect the views or policies of the customer for whom this report was prepared. Whilst every effort has been made to ensure that the matter presented in this report is relevant, accurate and up-to-date, TRL Limited cannot accept any liability for any error or omission, or reliance on part or all of the content in another context. Contents amendment record This report has been amended and issued as follows: Version Date Description Editor Technical Reviewer 1.1 October 2016 Draft version MM MW 1.2 January 2017 Client review MM June 2017 Final MM HV Document last saved on: 27/07/ :50 Document last saved by: McHale, Michael PPR829

3 Contents Executive Summary iii 1 Introduction 1 2 Methodology Selection of EME2 sites from the Scottish network Scheme information Test Methodology Site investigation Laboratory testing 6 3 Laboratory results Cores Visual condition Layer thicknesses Grading Grading results Binder richness modulus Binder richness results Recovered binder properties Penetration and softening point Voids Stiffness In situ stiffness Construction stiffness Design stiffness Cracking resistance Triaxial cyclic compression Comparison with other UK sites Stiffness Implications of lower stiffness 17 4 Conclusions Recommendations 19 i PPR829

4 5 Acknowledgments 20 6 Bibliography 21 Appendix A: Binder richness modulus 22 Appendix B: Core logs 23 ii PPR829

5 Executive Summary The lower bound layers of a flexible road pavement, known as the binder course and base, are responsible for carrying and spreading heavy vehicle traffic loads without deforming or cracking. Enrobé á Module Elevé (EME2) is the generic title for a high strength, long-life asphalt mixture that was developed in France. It comprises a fine aggregate grading and utilises a high volume of hard grade bitumen compared to traditional materials such as DBM50 and HDM50. This report describes the second part of a study commissioned by Scottish Road Research Board (SRRB) to assess the performance of EME2 mixtures and determine whether they need to be modified for use in Scotland. The first part of the study comprised a laboratory investigation to assess the influence of using softer grade binders with two EME2 designs comprising two different aggregate sources. This report relates to the second phase of the project that assesses the in-service performance of EME2 materials used on three Scottish road network sites. The M876 was selected as it is believed to be one of the oldest EME2 sites in the UK, having been in service for over 10 years. An additional two sites were selected on the A9 at Bankfoot and Crubenmore, which were respectively 6.6 and 4.1 years old. The latter site was selected because it utilised a softer binder (Grade: 30/45) and was considered to provide key information relevant to the first part of the study. Some of the data collected was also compared to information collected on EME2 samples taken from three Highways England (HE) sites. The condition of the EME2 layers from the A9 sites was found to be in good condition. In particular, the appearance of A9 Crubenmore cores was noted to be very uniform and well bonded with no sign of voids. Some of the M876 cores showed signs of debonding between the binder course and base layers, and were described to be dusty or gritty to the touch. The measured mean core depths taken from the core logs corresponded well to the design depths specified in the original contracts. Laboratory testing showed that the gradings of the EME2 mixtures from the M876 and A9 Bankfoot sites were found to contain an excess of fine materials, particularly on the 2mm and 75μm sieve, respectively. The penetration and softening point of the extracted binders were broadly in keeping with the expected fall in penetration and increase in softening point that is expected following construction: i.e. there was no significant indication of ageing or hardening of the binder in service. The minimum richness modulus, an estimation of binder film thickness, was met on the A9 sites, but not on the M876. The M876 voids content at 5.3% was found to be close to the top end of the specified maximum of 6%. The EME2 materials sampled from the A9 sites produced mean voids content of 2.2% and 1.3%, indicating the material had been compacted to a higher standard. The mean indirect tensile stiffness modulus (ITSM) of the binder course and base course materials sampled from the oil lane at the three sites ranged between 4GPa to 5GPa. This compares to a range between 7.7GPa to 9.2GPa for EME2 samples taken from the HE network. A comparison of stiffness for samples taken from the wheelpath and the oil lane showed that there was no significant difference in the stiffness values. This indicates that little or no deterioration of the material has occurred owing to trafficking in the wheelpath. Although the in situ ITSM values are considered to be low, they broadly compare with testing carried out at the time of construction and values determined on materials from Scotland tested as part of Phase I of the study. Using a relationship derived from Phase I of iii PPR829

6 the study, the equivalent design stiffness ranges between 5GPa to 6.7GPa. This is below the long-term stiffness of 8GPa normally adopted for analytical design purposes. Recommendations include investigating why the EME2 materials tested as part of this study produced significantly lower stiffnesses than EME2 materials produced in England. Results from the study highlight the need to develop an analytical design method that incorporates fatigue performance and is not skewed towards materials with high stiffness. The latter would provide a better model for predicting the performance of asphalt and better assess the use of materials with enhanced properties such as EME2. In the absence of a new model, it is recommended that any proposal to use EME2 to decrease construction thickness should be subject to a critical technical review. Finally, it is recommended that the performance of crack, seat and overlay schemes incorporating EME2 should be monitored and reviewed, including the consequence of the EME2 possessing a lower than expected long-term design stiffness. iv PPR829

7 1 Introduction The lower bound layers of a flexible road pavement, known as the binder course and base, are responsible for carrying and spreading heavy vehicle traffic loads without deforming or cracking. In addition, it is important that these constructed layers are durable and water resistant. Enrobé á Module Elevé (EME2) is an asphalt mixture, developed in France, that has been available as a material option for binder course and base since 2006 (HD26/06). EME2 comprises a fine aggregate grading and utilises a high volume of hard, paving grade bitumen compared to traditional materials such as DBM50 and HDM50. It needs to be compacted on a substrate or foundation that has a high stiffness modulus. It is laid at a higher temperature and produces a dense material which has lower voids than traditional materials. The current standard (HD26/06) allows for a decreased construction thickness of up to 15% when using EME2 compared to pavements constructed of DBM50 and HDM50. Conversely, a similar thickness of EME2 can be used to increase the predicted pavement design life. Studies of the performance of EME2 are of value to ensure that the best designs are being used and that the layers are constructed to last as long as possible. Premature failure of these lower bound layers must be prevented in order to avoid expensive repairs and long delays to road users. In 2013 the Scottish Road Research Board (SRRB) commissioned TRL to investigate whether the current design of EME2 mixtures could be improved for use in Scotland. It had been considered that the use of softer paving grade bitumens could reduce the risk of thermally induced damage, and also facilitate compaction during construction. The study comprised two phases: Phase I - laboratory investigation; and Phase II in-service performance. The Phase I report (Artemendi & McHale, 2015) describes a laboratory investigation and results, and discusses the findings to assess the influence of using softer grade binders with two EME2 designs comprising two different aggregate sources. The study showed that EME2 mixtures made with the current design (i.e. hardest binder, Grade: 15/25 pen) produced the highest stiffness, deformation resistance and best resistance to fatigue. Fracture toughness and flexural strength at 0 C indicated that there were no significant differences between the mixtures produced with different penetration grade binders. The EME2 mixtures produced with the softer binders (Grades: 30/45, 40/60 pen) were considered to have equivalence in terms of design stiffness to conventional materials such as HDM and DBM50. Importantly, results from the four-point bending fatigue tests suggested that all the EME2 mixtures were more resistant to fatigue cracking when compared to traditional materials. This has potential implications for analytical pavement design where similar fatigue characterisation is currently adopted for all binder and base materials. This report relates to the second phase of the project and assesses the in-service performance of EME2 materials used over the longer term, and validates some of the findings of the laboratory study. 1 PPR829

8 2 Methodology In parallel to this study, Highways England (HE) commissioned TRL to assess the performance of EME2 on the HE network. It was therefore agreed that a similar approach to the selection of sites for destructive sampling and testing should be adopted. The main advantage of this approach was that collected information and test data could be shared and in some instances would be directly comparable. 2.1 Selection of EME2 sites from the Scottish network The HE selection criteria were that individual sites needed to be a minimum of 5 years old, and at least 500m in length. Three sites in Scotland were selected. The M876 was selected as it is believed to be one of the oldest EME2 sites in the UK, having been in service for over 10 years. An additional two sites were selected on the A9 at Bankfoot and Crubenmore, which were respectively 6.6 and 4.1 years old. Although the latter site did not meet the age criteria it was selected because the EME2 utilised a softer binder (Grade: 30/45) and was considered to provide key information relevant to the SRRB study. Table 2.1 lists the sites that were selected and sampled as part of the study. Table 2.1 Investigated sites Road Name Age (yrs) M A9 Bankfoot 6.6 Material Layer CHART Section/link Ch. EME 0/20 Binder 14401/ to EME 0/20 Base 14401/ EME 0/14 Binder 10432/ to EME 0/14 Base 10432/ Length 1.035km 1.714km A9 Crubenmore 4.1 EME 0/14* Binder 10442/53-0 to EME 0/14* Base 10442/ km * Non-standard binder grade 30/45 pen used. Other sites used 15/25 pen. Figure 2.1, Figure 2.2 and Figure 2.3 were obtained from Transport Scotland s pavement management system, IRIS and show the location of the three sites with the extent of the EME2 material shown in red. 2 PPR829

9 Figure 2.1 Location of EME2 on M876. Reproduced by permission of Ordnance Survey, on behalf of HMSO, Crown copyright and database rights, All rights reserved. Ordnance Survey Licence number PPR829

10 Figure 2.2 Location of EME2 on A9, Bankfoot. Reproduced by permission of Ordnance Survey, on behalf of HMSO, Crown copyright and database rights, All rights reserved. Ordnance Survey Licence number PPR829

11 Figure 2.3 Location of EME2 on A9, Crubenmore. Reproduced by permission of Ordnance Survey, on behalf of HMSO, Crown copyright and database rights, All rights reserved. Ordnance Survey Licence number PPR829

12 2.2 Scheme information Available information on the selected schemes, including design thickness, binder used and relevant specifications, is shown in Table 2.2. Table 2.2 Original EME2 requirements Road Name Date laid Aggregate size Design thickness* Binder Additional information M876 Jul-05 0/20mm 260mm** 15/25 pen Reconstruction: fully flexible Draft UK Spec TRL636 A9 Bankfoot Mar-09 0/14mm 145mm 15/25 pen Structural maintenance: Crack, seat and overlay of existing CBM layer TSIA No 44; MCHW Cl 930 A9 Crubenmore Aug-11 0/14mm 150mm 30/45 pen*** Reconstruction: flexible composite HD26/06; MCHW, Cl 930 *Extracted from IRIS database ** In addition to the thickness of 260mm, an improvement layer consisting of 60mm HRA was laid on top of the Type 1 sub-base to assist compaction of the EME. ***Recognised as a departure from the HD26/06 standard 2.3 Test Methodology Site investigation Six pairs of 150mm diameter cores were taken at distance intervals of approximately 50m on each site. One core was taken from the nearside wheelpath and one from the adjacent oil lane. The approach was to compare the properties of cores taken from the oil lane with those taken in the nearside wheelpath. The rationale was that the latter would have been subject to heavy trafficking and the former would be more representative of the original condition at the time of construction Laboratory testing Samples from the upper EME2 binder course and lower base layers were tested at TRL s laboratory in Crowthorne and Aggregate Industries (AI) laboratory in Derby. The SRRB study is a collaborative project with AI acting as the principal partner. Cores from the M876 and A9 Bankfoot were tested by TRL and cores from the A9 Crubenmore were tested courtesy of AI. During preparation the cores were trimmed such that their depth did not exceed 70mm and that the final sample did not include any material from adjacent layers. Laboratory tests were carried out on all the samples to determine: Grading and bitumen content Air voids content Richness modulus Penetration and Softening Point of bitumen 6 PPR829

13 Indirect Tensile Stiffness Modulus (ITSM) at 20 C In addition to the above, fracture toughness and triaxial cyclic compression tests were carried out on samples of EME2 from the Crubenmore site at AI s laboratory in Derby. These specialist tests were carried out on virgin materials as part of Phase I of the study. The tests were carried out to see if similar properties were found with the EME2 that had been in service for 4.1 years. 3 Laboratory results This section describes the testing carried out on the cores, summarises the results and compares them with the specification requirements used at the time of construction. 3.1 Cores Visual condition Images of the cores are shown in Appendix B. The condition of the EME2 layers from the A9 sites were both found to be well-bonded and in good condition. In particular, the cores containing the softer grade of binder (30/45) from Crubenmore looked dense and uniform with no indication of voids. Figure 3.1 shows an image of one of the cores and it can be seen that the lower layers look denser than the surface course (top of image). Figure 3.1 EME2 core from Crubenmore The older cores from the M876 (10.2 years), although dense in appearance, showed signs of debonding between the binder course and base layers, and were described as being dusty or gritty to the touch. 7 PPR829

14 3.1.2 Layer thicknesses Allowing for pavement course tolerances, the measured mean core depths taken from the core logs complied with the original design depths shown in Table 2.2. Average depths for the combined EME2 layers were 250mm, 148mm and 155mm for M876, A9 Bankfoot and A9 Crubenmore, respectively. 3.2 Grading The particle size distributions of the EME2 mixtures were determined in accordance with BS EN : 2002 and are shown in Figure 3.2, Figure 3.3 and Figure Grading results It should be noted that the original job standard mixes were not available for the EME2 mixtures. The grading envelopes shown below are based on the aggregate grading target limits specified in PD6691 (BSI, 2015). Compared to this specification, Figure 3.2 shows that grading analysis conducted on the M876 cores contained more fine aggregate than specified, particularly the percentage passing the 2mm sieve. Similarly, Figure 3.3 shows that the grading of the EME2 mixtures from the A9 Bankfoot site to be on the fine side, particularly on the 75 microns sieve. Samples from the A9 Crubenmore (Figure 3.4) show the EME2 grading to be compliant, although it should be noted that only two cores were used in the analyses. Figure 3.2 M876 grading for EME2 (0/20mm) 8 PPR829

15 Figure 3.3 A9 Bankfoot grading for EME2 (0/14mm) Figure 3.4 A9 Crubenmore grading for EME2 (0/14mm) 9 PPR829

16 3.3 Binder richness modulus Table 3.1 contains the results of the binder richness modulus calculations which are based on binder content tests and aggregate grading. The method used to calculate the richness modulus (Sanders & Nunn, 2005) is reproduced in Appendix A. The richness modulus is an estimation of binder film thickness. Table 3.1 Binder content and binder richness modulus Test Layer Site Age No. of samples Mean* Std Dev Spec.** Minimum target binder Content Binder richness modulus Binder Binder M % A9, Ba % A9, Cr % M A9, Br A9, Cr *Green is for values at or above the specification in use at the time, amber is 0.2 below specification, and red is 0.3 or more below specification. ** Minimum target binder content and binder richness modulus from PD6691 (BSI: 2015) Binder richness results The original EME2 designs would have targeted a minimum binder richness modulus value of 3.6. This was done in order to avoid lengthy fatigue testing which is still required by the French standard on which EME2 was originally based. The results in Table 3.1 show that the binder richness modulus requirements were met at the A9 sites, but not at the M876. The calculated value of 3.3 at the M876 indicates that the aggregate mix is likely to be more thinly coated and is likely to be a direct result of the combination of binder content and fine grading used. The binder content is at the minimum target, but it is considered that the high percentage of fine aggregate found in the mix (Figure 3.2) would have led to an increase in the surface area of aggregate to be coated. 3.4 Recovered binder properties Binder recovery was carried out using the rotary evaporator method to BS EN :2013. The viscosity of the recovered binder was established through testing its penetration (BS EN 1426:2015) and it s Softening Point (BS EN 1427:2015). Table 3.2 shows the results of the binder penetration and soften point tests carried out on the recovered binder from each of the sites. 10 PPR829

17 Softening Pt. Penetration Table 3.2 Penetration and Soften Point of recovered binder Test Layer Site Age (years) No of Samples Mean Range M dmm* 8-12dmm Binder A9, Ba dmm 10-12dmm A9, Cr dmm 31-32dmm M C C Binder A9, Br C C * Decimillimetre (1dmm = 0.1mm); ** Test not undertaken. A9, Cr** Penetration and softening point Table 3.2 shows that results of the penetration and softening point for all the sites are broadly in keeping with the expected fall in penetration and increase in softening point that may be expected since construction. Mean values of 10dmm, 11dmm and 32dmm correspond well to the original Grades of 15/25 pen and 30/45 pen respectively. 3.5 Voids Samples taken from the oil lane were used to determine the percentage of voids in the mix (V m ) using the following equation from BS EN : 2003: Max Density Bulk Density ( ) 100 = V Max Density m % Table 3.3 shows the results of the percentage of voids in the mix calculation for the samples. Table 3.3 Percentage of Voids in the mix Layer Site No. of samples Mean (%)* Std Dev Spec. Binder *Green is for values at or below specification M % A9, Bankfoot % A9, Crubenmore % The M876 voids are towards the top end of specified maximum, when compared with the EME2 materials sampled from the A9 sites. In particular, the A9 Crubenmore results suggest the material has been very well compacted. It should be noted that the EME2 materials on the A9 sites were placed and compacted on top of a lean mix base. In contrast, the EME2 material at the M876 was compacted on a 60mm HRA layer overlying a granular sub-base. The latter improvement layer may not have provided the same level of support during compaction. 11 PPR829

18 3.6 Stiffness In situ stiffness As stated earlier, samples were taken from both the oil lane and the nearside wheelpath so that a comparison between largely un-trafficked and heavily trafficked areas could be made. The ITSM test was used to determine the stiffness modulus for each sample at 20 C and a loading frequency of 2.5Hz. Table 3.4 contains a summary of the mean ITSM results and Figure 3.5 shows the all ITSM results from samples taken from the trafficked areas compared to those from un-trafficked areas. Layer Site Age(yrs) Binder Table 3.4 Summary of mean ITSM results No. of Samples Wheelpath (trafficked) Mean* (MPa) Std Dev. Spec.** No. of Samples Oil lane (un-trafficked) Mean (MPa) Std Dev. Spec.** M A9 Ba Binder A9 Cr. Base *Green is for values at or above 5500MPa, amber is 5500 to 4500MPa, and red is below 4500MPa.Figure **Mean stiffness modulus shall conform to S min5500 (PD6691:2015); A9 Crubenmore was a non-standard mix. Figure 3.5 Comparison of ITSM results from Wheelpath and Oil lane 12 PPR829

19 Based on the mean ITSM results from Table 3.4, the wheelpath stiffness values appear to be slightly lower than the oil lane, with the exception of the base layer from the M876. However, when all the data for both the wheelpath and oil lane are compared in Figure 3.4, it can be seen that there is not a significant difference between the data sets: i.e. the data points are spread across the line of equivalence. The student t-test confirmed that the stiffness of the samples from the nearside wheelpath were not significantly lower than the samples from the oil lane. Importantly, none of the test samples tested exhibit a stiffness that conforms to the requirements of the specification Construction stiffness Samples were taken for ITSM testing at the time of construction for both the A9 sites. The results are compared to those samples taken from the oil lane 4.1 and 6.6 years later in Table 3.5. Table 3.5 Comparison of ITSM results for A9 sites Site Position Age(yrs) No. of samples Mean (MPa) Std Dev. (MPa) A9 Bankfoot A9 Crubenmore Oil lane Various At construction Oil lane Various At construction The mean construction stiffness from Bankfoot site is around 17% higher than the aged samples. As the scheme is 1.7km long it is possible that cored samples are not truly representative of the whole site. The mean construction stiffness from Crubenmore agree well with the cored samples indicating the stiffness of the material has not changed after being in service for 4.1 years Design stiffness As part of the Phase I EME2 study (Artemendi & McHale, 2015), four-point bending (4PB) stiffness was carried out on a range of EME2 materials from Scotland with different binder penetrations. This test is considered to simulate the conditions used in analytical pavement design, i.e. a test temperature of 20 C and a loading frequency of 5Hz. At the same time, the stiffness modulus at 20 C and 2.5Hz using the ITSM test was also determined on material samples. The ITSM is used for contractual compliance testing to ensure that the material possesses a minimum stiffness. Figure 3.6 shows the relationship between 4PB stiffness and ITSM stiffness on virgin (non-aged) samples and this has been used to convert the ITSM results on cores taken from the sites in Scotland to calculate an equivalent design value. The characteristic ITSM stiffness has been used which is defined as the stiffness value below which only 10% of all the samples tested are likely to fall, equating to 1.28 standard deviations below the mean value. 13 PPR829

20 Design stiffness (MPa) y = 1.22x Characteristic stiffness (MPa) Figure 3.6 Characteristic stiffness (ITSM) v design stiffness (4PB) Table 3.6 shows the equivalent design stiffness using the relationship derived from Figure 3.6. It can be seen that the equivalent design stiffness values are well below the stiffness of 8000MPa normally adopted for the long term stiffness of EME2. Based on the stiffness data collected as part of this study it is unlikely that these values will increase with age, particularly if the material is well compacted. Layer Binder Site Age (yrs) Mean (MPa) Table 3.6 Equivalent design stiffness Std Dev. Wheelpath Char. (MPa) Design* (MPa) Mean (MPa) Std Dev. Oil lane Char. (MPa) Design* (MPa) M A9 Ba Binder A9 Cr. Base *The long-term design stiffness adopted for EME2 in HD26/06 is 8000 MPa. 3.7 Cracking resistance Figure 3.7 shows a comparison of results from semi-circular bending tests to BS EN The test is used to evaluate the cracking resistance of asphalt samples. The mean result of four tests from the A9 Crubenmore site are compared alongside laboratory prepared specimens containing different grades of binder which were tested as part of the Phase I study (Artamendi & McHale, 2015). 14 PPR829

21 fc (microstrain/cycle) K Ic (N/mm 3/2 ) Source Phase 1a Source Phase 1b Crubenmore 5 0 Grade 15/25 Grade 30/45 Grade 40/60 EME2 Binder grade Figure 3.7 Fracture toughness values from SCB test (0 C) The mean fracture toughness of the EME2 Crubenmore samples is in good agreement with those found for laboratory prepared mixtures (Phase 1 study) containing a similar grade of binder. 3.8 Triaxial cyclic compression Similarly, Figure 3.8 shows a comparison of results from triaxial cyclic compression tests to EN , Method B. The test is used to evaluate the resistance to permanent deformation. Again the results for site samples taken from Crubenmore appear to be in good agreement with those for the laboratory prepared specimens Source Phase 1a Source Phase 1b Crubenmore 2 0 Grade 15/25 Grade 30/45 Grade 40/60 EME2 binder grade Figure 3.8 Creep rate values (mean) 15 PPR829

22 Mean ITSM stiffness (Mpa) 3.9 Comparison with other UK sites As part of a separate project for Highways England, EME2 binder course and base materials were sampled from the A34, M1 and M4. These three sites were sampled in a similar manner with cores taken in both the wheelpath and the adjacent oil lane Stiffness The stiffnesses of the materials sampled at the three sites in England are given in Table 3.7. Table 3.7 Summary of ITSM results Wheelpath Oil lane Site Age (years) No. of Samples Mean (MPa) Std Dev. (MPa) No. of Samples Mean (MPa) Std Dev. (MPa) A Binder M Base M A M *Green is for values at or above 5500MPa Figure 3.9 compares the mean ITSM results for EME2 samples taken from the oil lanes at the sites in Scotland and England England Scotland EME2 site Figure 3.9 Comparison of ITSM stiffness for sites in Scotland and England EME2 16 PPR829

23 It can be seen from Figure 3.9 that there is a significant difference in the ITSM stiffness for EME2 samples taken from sites in Scotland and England. A review of aggregate gradings, voids and binder content cannot explain the 60% to 70% increase in ITSM stiffness measured on the EME2s from England compared to the materials from Scotland. The EME2 from the A9 Crubenmore site utilised a softer binder, but all the other materials were made with a 15/25pen bitumen and possessed very similar recovered binder properties: i.e. 9dmm to 11dmm. It is not clear what has caused the difference in measured stiffness. One possible reason could be due to the mineralogy of the aggregate used. Geological data for the materials from England was not available but they are likely to contain aggregates such as limestone. The materials from Scotland comprise acidic aggregates: e.g. granite and basalt. Some studies (Qudais & Al-Shweily, 2007) have shown that aggregate chemistry affects the bitumen-aggregate bond: i.e. the presence of silica usually causes a reduction in bond strength. A more recent study looking at granite aggregates (Horgnies et al, 2011) showed that the mineralogy of the aggregates has a significant impact on their adhesion to bitumen Implications of lower stiffness In Scotland EME2 has not been used to reduce construction thicknesses. Typically its use has been selected or approved to extend pavement life on heavily trafficked parts of the network, or in conjunction with the crack, seat and overlay (CSO) technique. EME2 has been used in the latter owing to its high binder content and low voids: i.e. it is perceived to be more waterproof and crack resistant than traditional asphalt. The laboratory study (Phase I) and in-service results have indicated that the use of softer grade bitumen (Grade: 30/45) reduces the EME2 stiffness, and that the stiffness of EME2 produced in Scotland is significantly lower than EME2 mixtures produced in England. The stiffness of the EME2 produced in Scotland is comparable to or higher than non-aged standard materials such as HDM (4,700MPa) or DBM50 (2,800MPa). For CSO schemes, it is believed that the high volume of binder and low air voids found in EME2 will deliver a longer service life than traditional materials such as HDM and DBM50. Some evidence of this can be found in the first phase of the study (Artamendi & McHale, 2015) where a high resistance to fatigue loading was found in the four-point bending test Current analytical design methods are strongly influenced by material layer stiffness in predicting pavement life or loads to failure. The weakness in the current method is that it assumes that all asphaltic materials possess similar fatigue characteristics. Phase 1 of this study demonstrated that EME2, including material with a softer binder, performs better in the fatigue test than conventional materials. There is a strong need to develop a design method that incorporates fatigue performance and is not, as at present, skewed towards materials that solely possess high stiffness. 17 PPR829

24 4 Conclusions The condition of the EME2 layers from the A9 sites were found to be bonded and in good condition. In particular, the appearance of A9 Crubenmore cores were noted to be very uniform and well bonded with no sign of voids. It is likely that the use of a softer binder (Grade: 30/45) at Crubenmore contributed to a higher level of compaction being achieved during construction. Some of the M876 cores showed signs of de-bonding between the binder course and base layers, and were described to be dusty or gritty to the touch. The M876 binder contents were at the minimum target, and grading analyses showed a high percentage of fine aggregate. It is considered that these factors led to a drier mix with higher air voids. The measured mean core depths taken from the core logs corresponded well to the design depths specified in the original contracts. The gradings of the EME2 mixtures from the M876 and the A9 Bankfoot were found to contain an excess of fine materials, particularly on the 2mm and 75 microns sieve, respectively. The recovered penetration and softening point of the binders were broadly in keeping with the expected fall in penetration and increase in softening point that may be expected following construction: i.e. there was no significant indication of ageing or hardening of the binder. The minimum binder richness modulus (an estimation of binder film thickness) was met at the A9 sites, but not at the M876. The M876 voids content was found to be towards the top end of the specified maximum at 5.3%. The EME2 materials sampled from the A9 Bankfoot and A9 Crubenmore had mean voids content of 2.2% and 1.3%, indicating that the material had been well compacted. The mean ITSM stiffness of the binder course and base course materials sampled from the oil lane at the three sites ranged between 4,036MPa to 4,977MPa. This compares to a specified minimum stiffness of 5,500MPa. A comparison of stiffness for samples taken from the wheelpath and oil lane showed that there was no significant difference. This indicates that no deterioration of the material had occurred owing to trafficking in the wheelpath. EME2 samples taken from Highways England sites produced a stiffness range between 7,714MPa to 9,160MPa, significantly higher than EME2 samples taken from the sites in Scotland. Using a relationship derived from Phase I of this study (Artamendi & McHale, 2015), the equivalent design stiffness ranged between 5,026MPa to 6,697MPa. These values are below the stiffness of 8,000MPa normally adopted for analytical design purposes. The in-service ITSM results indicate that the EME2 mixtures do not cure or stiffen when compared to standard materials (Nunn et al., 1997). The M876 results indicate that it is important to maintain quality control at the asphalt plant as changes in grading can affect the constructed properties of the EME2 mixtures. 18 PPR829

25 4.1 Recommendations The study showed that EME2 mixtures produced in Scotland possess a lower stiffness than mixtures produced in England. It is recommended that this inconsistency be investigated further. Samples made with aggregates from England could be compared directly with typical aggregates used in Scotland. Results from the study, including Phase I, highlight the need to develop an analytical design method that incorporates fatigue performance and is not skewed towards materials with high stiffness. The latter would provide a better model for predicting the performance of asphalt in service and better assess the use of materials with enhanced properties such as EME2. The current standard (HD26/06) allows for a decreased construction thickness of up to 15% when using EME2. This assumes that the long-term design stiffness of EME2 is 8000 MPa. Based on in-service stiffness measurements collected as part of this study, it appears unlikely that EME2 materials produced in Scotland will achieve this value in service. It is therefore recommended that any proposal to use EME2 to decrease construction thickness should be subject to a critical technical review. Finally, it is recommended that the performance of CSO schemes incorporating EME2 should be monitored and reviewed, including the consequence of the EME2 possessing a lower than expected long-term design stiffness. 19 PPR829

26 5 Acknowledgments The work described in this report was carried out in the Infrastructure Division of the Transport Research Laboratory. The cooperation and assistance of both Alan Ferguson and Dougie Millar of Transport Scotland during the site investigation is gratefully acknowledged. The assistance of Ignacio Artamendi (Aggregate Industries), Fiona Coyle and Colin Jones during laboratory testing, and Mike Winter who carried out the Technical Review of this report, is gratefully acknowledged. 20 PPR829

27 6 Bibliography Abo-Qudais, S. & Al-Shweily, H. (2007) Effect of aggregate properties on asphalt mixtures stripping and creep behavior. Construction and Building Materials, 21(9), pp Artamendi, I. & McHale, M. (2015). Evaluation of EME2 type mixtures incorporating softer grade binders - Phase I progress report. Published Project Report PPR 750. Crowthorne: TRL Limited (PPR750). British Standards Institution (2015). Guidance on the use of BS EN Bituminous mixtures Material specifications. PD 6691:2015. London: British Standards Institution. Comité Européen de Normalisation (2002). Bituminous mixtures. Test method for hot mix asphalt. Determination of particle size distribution. BS EN :2002. London: British Standards Institution. Comité Européen de Normalisation (2003). Bituminous mixtures. Test method for hot mix asphalt. Bitumen recovery: Rotary evaporator. BS EN :2003. London: British Standards Institution. Comité Européen de Normalisation (2003). Bituminous mixtures. Test methods for hot mix asphalt. Determination of void characteristics of bituminous specimens. BS EN :2003. London: British Standards Institution. Comité Européen de Normalisation (2005). Bituminous mixtures. Test methods for hot mix asphalt. Part 25: Cyclic compression test. BS EN : London: British Standards Institution. Comité Européen de Normalisation (2010). Bituminous mixtures. Test methods for hot mix asphalt. Part 44: Crack propagation by semi-circular bending test. BS EN : London: British Standards Institution. Comité Européen de Normalisation (2015). Bitumen and bituminous binders. Determination of needle penetration. BS EN 1426:2015. London: British Standards Institution. Comité Européen de Normalisation (2015). Bitumen and bituminous binders. Determination of the softening point. Ring and Ball method. BS EN 1427:2015. London: British Standards Institution. Horgnies, M., Darque-Ceretti, E., Fezai, H. & Felder, E. (2011). Influence of the interfacial composition on the adhesion between aggregates and bitumen: investigations by EDX, XPS and peel tests. International Journal of Adhesion and Adhesives, 31(4), pp MCHW. (2008). Volume 1 Specification for Highway Works Series Highway England: Manual of Contract Documents for Highway Works. Nunn, M. E., Brown A., Weston D. and Nicholls, J. C. (1997). Design of long-life pavements for heavy traffic. TRL Report 250. Crowthorne: TRL Limited. Sanders, P. J. & Nunn, M. (2005). The application of Enrobé á Module Élevé in flexible pavements. TRL Report TRL636. Crowthorne: TRL Limited. 21 PPR829

28 Appendix A Binder richness modulus K = ((100B m)/(100 B m )) 5 a Σ K is the binder richness modulus. B m is the binder content (as measured during testing). a = 2.65 / r. r is the density of aggregate r = 100 B m 100. B m ρ G ρ B ρ G is the max density of the sample (as measure during testing). ρ B is the density of Bitumen and was taken to be Σ is the specific surface area of the aggregate, Σ = 0.25G + 2.3S + 12s + 135f. Where G is the proportion by mass of aggregate over 6.3mm, S between 6.3mm and 0.315mm, s between 0.315mm and 0.080mm and f is smaller than 0.080mm. The binder richness modulus should be greater than 3.4 (Sanders & Nunn, 2005). 22

29 Appendix B Core logs B.1 M876 CORE LOG 1 Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 14 HS Sound Debonded Yes -VE EME2 14 HS Sound Intact Yes -VE HRA 20 HS Sound - No -VE Cored at: N/K Subbase type: N/K Remarks: Intact, Debonded after coring Top of core Time of coring: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Core Dia 150 Core Ref: TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MPN/K Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 1 Site Pictures 23

30 CORE LOG 1A Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 20 HS Sound Intact Yes -VE EME2 20 HS Sound Intact Yes -VE HRA 20 HS Sound - Yes -VE Cored at: N/K Subbase type: N/K Remarks: Intact, Top of core Time of coring: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Core Dia 150 Core Ref: 1A TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MPN/K Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 1A Site Pictures 24

31 CORE LOG 2 Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 20 HS Sound Intact Yes -VE EME2 20 HS Sound Intact Yes -VE HRA 20 HS Sound - No -VE Cored at: N/K Subbase type: N/K Remarks: Intact, Top of core Time of coring: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Core Dia 150 Core Ref: TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MPN/K Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 2 Site Pictures 25

32 CORE LOG 2A Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 20 HS Sound Debonded Yes -VE EME2 20 HS Sound Intact No -VE HRA 20 HS Sound - No -VE Top of core Cored at: N/K Time of coring: N/K Subbase type: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Remarks: Intact, Debonded during transportation Core Dia 150 Core Ref: 2A TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MPN/K Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 2A Site Pictures 26

33 CORE LOG 3 Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size SMA 10 HS Type Condition Bond Heavily voided Voids (Yes/No) +VE / -VE Intact Yes -VE EME2 20 HS Sound Debonded Yes -VE EME2 20 HS Voided at Intact Yes -VE HRA 14 HS interface - Yes -VE Top of core Cored at: N/K Time of coring: N/K Subbase type: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Remarks: Intact, Debonded during transportation Core Dia 150 Core Ref: TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MPN/K Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 3 Site Pictures 27

34 CORE LOG 3A Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 14 HS Sound Debonded Yes -VE EME2 20 HS Sound Intact No -VE HRA 14 HS Sound - No -VE Cored at: N/K Subbase type: N/K Remarks: Intact, Top of core Time of coring: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Core Dia 150 Core Ref: 3A TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MPN/K Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 3A Site Pictures 28

35 CORE LOG 4 Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 20 HS Sound Debonded Yes -VE EME2 20 HS Sound Intact Yes -VE HRA 20 HS Sound - No -VE Cored at: N/K Subbase type: N/K Remarks: Intact, Debonded after coring Top of core Time of coring: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Core Dia 150 Core Ref: TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MPN/K Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 4 Site Pictures 29

36 CORE LOG 4A Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 14 HS Heavily Intact Yes -VE voided at EME2 14 HS interface Intact Yes -VE HRA 14 HS Sound - No -VE Top of core Cored at: N/K Time of coring: N/K Subbase type: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Remarks: Intact, Debonded during transportation Core Dia 150 Core Ref: 4A TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MPN/K Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 4A Site Pictures 30

37 CORE LOG 5 Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 14 HS Heavily Debonded Yes -VE voided at EME2 20 HS interface Intact Yes -VE HRA 20 HS Sound - No -VE Top of core Cored at: N/K Time of coring: N/K Subbase type: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Remarks: Intact, Debonded during transportation Core Dia 150 Core Ref: TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MP28/8 Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 5 Site Pictures 31

38 CORE LOG 5A Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 14 HS Sound Debonded Yes -VE EME2 20 HS Sound Intact Yes -VE HRA 20 HS Sound - No -VE Cored at: N/K Subbase type: N/K Remarks: Intact, Debonded after coring Top of core Time of coring: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Core Dia 150 Core Ref: 5A TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MP28/8 Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 5A Site Pictures 32

39 CORE LOG 6 Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size Type Condition Bond Voids (Yes/No) +VE / -VE SMA 10 HS Sound Intact Yes -VE EME2 14 HS Sound Intact Yes -VE EME2 20 HS Sound Intact No -VE HRA 20 HS Sound - No -VE Cored at: N/K Subbase type: N/K Remarks: Intact, Top of core Time of coring: N/K Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Client: Internal TRL LMS Ref: Core Dia 150 Core Ref: TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Project: In service performance of EME2 Project Code: Location: MP28/8 +50m Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Lane: N/K Offset: N/Km 0 Logged by: JW Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: 0 Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 6 Site Pictures 33

40 CORE LOG 6A Layers Aggregate General Remarks PAK test No. Top Btm Thickness Material type Max size EME2 14 HS Type Condition Bond Top half broken Voids (Yes/No) +VE / -VE Debonded Yes -VE EME2 14 HS Sound Intact Yes -VE HRA 14 HS Sound - Yes -VE Cored at: N/K Subbase type: N/K Remarks: Layer 1/Layer 2 debonded, TRL Limited, Crowthorne House Nine Mile Ride Wokingham. RG40 3GA Top of core SURFACING MISSING Time of coring: N/K Client: Internal TRL LMS Ref: Project: In service performance of EME2 Project Code: Lane: N/K Offset: N/Km 0 Logged by: Section Chainage: m Grid Ref X: N/K Grid Ref Y: N/K Checked by: Location: MP28/8 +50m Direction: N/K FWD ch: Coring Date: 30/09/2015 Section: Hole depth: N/Kmm Abbreviations: TS=Thin Surfacing; HRA=Hot Rolled Asphalt; DBM =Dense Bituminous Macadam; HBM=Hydraulically Bound Material; GS=Gritstone; HS=Hardstone; GNT=Granite; LST=Limestone; GVL=Gravel; PQC=Pavement Quality Concrete, GSB=Granular Sub-base Core Dia 150 Core Ref: 6A JW Sampling and logging methods: BSEN :2001 Clause 4.1, BS EN :2003 Clause 4.1, in-house procedure LP20 This certificate refers only to the items tested and may not be reproduced except in full without written approval from TRL Laboratory M anager. Opinions and interpretations expressed herein are outside of the scope of UKAS accreditation. CORE LOG 6A Site Pictures 34

41 B.2 A9, Crubenmore Core ref no C1 layer From To Thickness Layer Agg size Type Appearance Surface course 10 Voids Binder course 14 compact Binder course 14 Granite voids at base Cement bound N/A N/A N/A 35

42 Core ref no C2 layer From To Thickness Layer Agg size Type Appearance Surface course 10 Voids Binder course 14 compact Binder course 14 Granite some voids Cement bound N/A N/A N/A 36

43 Core ref no C3 layer From To Thickness Layer Agg size Type Appearance Surface course 10 Voids Binder course 14 compact Binder course 14 some voids Cement bound N/A N/A N/A 37

44 Core ref no C4 layer From To Thickness Layer Agg size Type Appearance Surface course 10 Voids Binder course 14 compact Binder course 14 compact 38

45 Core ref no C5 layer From To Thickness Layer Agg size Type Appearance Surface course 10 Voids Binder course 14 compact Binder course 14 compact 39

46 Core ref no C6 layer From To Thickness Layer Agg size Type Appearance Surface course 10 Voids Binder course 14 compact Binder course 14 compact 40

47 Core ref no C7 layer From To Thickness Layer Agg size Type Appearance Surface course 10 some voids Binder course 14 compact Binder course 14 Granite some voids 41

48 Core ref no C8 layer From To Thickness Layer Agg size Type Appearance Surface course 10 Voids Binder course 14 compact Binder course 14 Granite compact Cement bound N/A N/A N/A 42

49 Core ref no C9 layer From To Thickness Layer Agg size Type Appearance Surface course 10 voids Binder course 14 compact Binder course 14 granite compact 43

50 Core ref no C10 layer From To Thickness Layer Agg size Type Appearance Surface course 10 voids Binder course 14 compact Binder course 14 granite compact 44

51 Core ref no C11 layer From To Thickness Layer Agg size Type Appearance Surface course 10 some voids Binder course 14 compact Binder course 14 compact 45

52 Core ref no C12 layer From To Thickness Layer Agg size Type Appearance Surface course 10 voids Binder course 14 compact Binder course 14 compact 46

53 B.3 A9, Bankfoot 47

54 48

55 49

56 50

57 51

58 52

59 53

60 54

61 55

62 56

63 57

64 58