1. RPF – 17 May 2001 Validation of HMA Design Guidelines Validation of Draft Guidelines for the Design of HMA in SA OBJECTIVES  Feedback  Status of Validation

2. RPF – 17 May 2001 Validation of HMA Design Guidelines Scope of Presentation  Design Procedures & Performance Testing  Study of Rut Resistance Testing  Workshops on HMA Design Guidelines

3. RPF – 17 May 2001 Validation of HMA Design Guidelines Design Procedures Validated  Selection of Mix Type  Rating of Design Objectives  Volumetric Design Bulk RD & COMPACT Software Densely Graded Mixes Stone Mastic Asphalt

4. RPF – 17 May 2001 Validation of HMA Design Guidelines Volumetric Design of Densely Graded Mixes

5. RPF – 17 May 2001 Validation of HMA Design Guidelines Mod Marshall Compaction Voids Criteria Traffic Level Eq. Field Compaction (75 Blows) Allowable Void Content Range after additional compaction to simulate trafficking Min - Max Total No of Blows Void Content MinimumMaximum Light3.5% - 5.5%75 + 153.0%4.5% Medium4.5% - 6.5%75 + 453.0%5.0% Heavy5.5% - 7.0%75 + 754%5.0% Very Heavy 5.5% - 7.0%75 + 754%5.0%

6. RPF – 17 May 2001 Validation of HMA Design Guidelines Volumetric Design of Stone Mastic Asphalt (SMA)  Recommended Trial Binder Content BRD  2.75 : BC = 5.5% & BRD < 2.75 : BC = 6.0%  4 Samples Compacted @ 50 blows  VCA Coarse Aggr.  Dry Rodded Test  VMA  17.0% & VIM  3.0%  VCA mix (with mastic) < VCA drc (without mastic)

7. RPF – 17 May 2001 Validation of HMA Design Guidelines Study of Rut Resistance Testing  8 Field Mixes Mixes paved on various roads, incl national and provincial roads and urban streets Actual designs based on Marshall Method  8 Laboratory Mixes (Experimental) Different Binder Contents Different Binder & Mix Types

8. RPF – 17 May 2001 Validation of HMA Design Guidelines Field Mixes Mix NoRoadLocationAggr.Mix type (Binder) 1N2-25DurbanQuartziteAC Med (60/70) 2P111/1CarletonvilleAndesiteBTB (40/50) 3N2-21HardingDoloriteAC Med (60/70) 4N3-12Gilloolly’sQuartziteS/O BRASO 5N3-7XHarrismithDoloriteAC Crs (60/70) 6N3-7XHarrismithDoloriteSMA (60/70) 7CK1Cape TownHornfelsAC Med (60/70) 8CK2Cape TownHornfelsAC Med (60/70) 9CCPPretoriaNoriteAC Med (60/70)

9. RPF – 17 May 2001 Validation of HMA Design Guidelines Rut Resistance Tests Validated In Study  Modified Marshall Compaction  Gyratory Compaction  Transportek Wheel Track Test (TWTT)  Dynamic Creep Test  Confined Impact Test (CIT)  Axial Loading Slab Test (ALS)

10. RPF – 17 May 2001 Validation of HMA Design Guidelines Modified Marshall Compaction

11. RPF – 17 May 2001 Validation of HMA Design Guidelines Gyratory Compaction

12. RPF – 17 May 2001 Validation of HMA Design Guidelines Comparison of Gyratory and Modified Marshall Compaction

13. RPF – 17 May 2001 Validation of HMA Design Guidelines Transportek Wheel Tracking Test (TWTT)

14. RPF – 17 May 2001 Validation of HMA Design Guidelines TWTT Downward Deformation

15. RPF – 17 May 2001 Validation of HMA Design Guidelines Gyratory Compaction vs TWTT

16. RPF – 17 May 2001 Validation of HMA Design Guidelines Confined Impact Test (CIT)

17. RPF – 17 May 2001 Validation of HMA Design Guidelines CIT – Measurement of Deformation TEST SPECIMEN AFTER TESTING TOP OF SPECIMEN BEFORE TESTING B B A

18. RPF – 17 May 2001 Validation of HMA Design Guidelines CIT – Performance Ratings Rating of Rutting Resistance CIT Deformation after 680 blows with Marshall Hammer Very Good< 3 mm Good3 – 10 mm Medium10 – 14 mm Poor> 14 mm

19. RPF – 17 May 2001 Validation of HMA Design Guidelines CIT – Field Mixes

20. RPF – 17 May 2001 Validation of HMA Design Guidelines Dynamic Creep vs TWTT

21. RPF – 17 May 2001 Validation of HMA Design Guidelines Experimental Laboratory Mixes Mix NoBinder ContentBinder TypeMix type 1Optimum60/70 PenAC Medium 2Opt + 1.0%60/70 PenAC Medium 3Opt – 0.5%60/70 PenAC Medium 4Optimum60/70 PenGap Graded 5Optimum80/100 + SBSAC Medium 6Optimum60/70 PenSMA 7Optimum60/70 + EVAAC Medium 8Optimum60/70 + SBRAC Medium

22. RPF – 17 May 2001 Validation of HMA Design Guidelines Comparison of Rut Resistance of Laboratory Mixes  Modified Marshall Compaction  Gyratory Compaction  Transportek Wheel Track Test (TWTT)  Dynamic Creep Test

23. RPF – 17 May 2001 Validation of HMA Design Guidelines Influence of Binder Content: Modified Marshall Compaction

24. RPF – 17 May 2001 Validation of HMA Design Guidelines Influence of Binder Content: Gyratory Compaction

25. RPF – 17 May 2001 Validation of HMA Design Guidelines Influence of Binder Content: Transportek Wheel Track Test

26. RPF – 17 May 2001 Validation of HMA Design Guidelines Influence of Binder Type: Modified Marshall Compaction

27. RPF – 17 May 2001 Validation of HMA Design Guidelines Influence of Binder Type: Transportek Wheel Track Test

28. RPF – 17 May 2001 Validation of HMA Design Guidelines Conclusions Validity of Rut Resistance Tests  Modified Marshall Compaction Good Indicator of Workability & Stability  Gyratory Compaction Good Correlation of Terminal VIM with Rut Resistance  Transportek Wheel Tracking Test Best Prediction of Rut Resistance

29. RPF – 17 May 2001 Validation of HMA Design Guidelines Conclusions Validity of Rut Resistance Tests  Dynamic Creep Test Not Applicable to Stone-Skeleton & Modified Sand-Skeleton Mixes  Confined Impact Test Validity Questionable

30. RPF – 17 May 2001 Validation of HMA Design Guidelines Conclusions Influence of Mix Composition  Binder Content Higher Binder Contents  Lower Rut Resistance  Binder Type SBS Mod Mix  Highest Rut Resistance SBR Mod Mix  Lower than SBS Mod, but still Very Good EVA Mod Mix  Similar to Non-modified Mix

31. RPF – 17 May 2001 Validation of HMA Design Guidelines Conclusions – Workshops on HMA Design Guidelines  Cape Province Venue:University of Stellenbosch Date:Tuesday, 12 th June 2001  KwaZulu Natal Venue:Roads Dept. Pietermaritzburg Date:Wednesday, 13 th June 2001  Gauteng Venue:University of Pretoria Date:Thursday, 14 th June 2001  Time:08:00  17:00