1. AAPA 2011 Study Tour – Surface Treatments #1 Surface Treatments #1

2. AAPA 2011 Study Tour – Surface Treatments #1 Spray Seals o Preventative maintenance o Seal procurement/selection o Breakdown of seals used o Primerseals o Reseal practice o Fog sprays o Rejuvenation o Sand Seals o Seals unique to South Africa www.aapa.asn.auIntroduction

3. AAPA 2011 Study Tour – Surface Treatments #1 www.aapa.asn.au

4. AAPA 2011 Study Tour – Surface Treatments #1 Road Network www.aapa.asn.au Municipal (Council) Provincial (State) National (Federal) o South African National Roads Agency Ltd o Independent statutory authority owned by the South African Government

5. AAPA 2011 Study Tour – Surface Treatments #1 Road Network www.aapa.asn.au 153 000 km paved 90% Spray Sealed Reseal rate - 7 to 12%

6. AAPA 2011 Study Tour – Surface Treatments #1 SANRAL Network www.aapa.asn.au Description Non TollAgency Toll BOTTotal Dual Carriageway 6105204431 573 4-Lane Undivided 11299240550 2-Lane Single 12 429101360514 047 Total 13 0501 8321 28816 170 % of SANRAL Network 81%11%8%

7. AAPA 2011 Study Tour – Surface Treatments #1 Preventative Maintenance Allocation of funding is optimised using modeling tools such as HDM4 and dTIMS Avoid worst first, preventative maintenance given priority. Roads in a poor state of repair are maintained in a safe condition (signing, lowering speed limits) until rehabilitation funding can be secured www.aapa.asn.au

8. AAPA 2011 Study Tour – Surface Treatments #1 www.aapa.asn.au

9. AAPA 2011 Study Tour – Surface Treatments #1 Preventative Maintenance Extract the greatest value from maintenance funding to maintain the road in a good condition Economy of scale o 80km sections www.aapa.asn.au

10. AAPA 2011 Study Tour – Surface Treatments #1 Selection of Treatments Consultants perform investigation, design, tender documentation and site supervision A number of alternatives put forward from which a treatment is recommended Based on similar reasons to Australia o Cracking, traffic, texture, turning movements… o Reality check Road authority will assess the alternatives based on cost, motivation provided by Consultants, functionality, appropriateness and compare it with surfacings of adjacent sections on the same route www.aapa.asn.au

11. AAPA 2011 Study Tour – Surface Treatments #1 Seal Selection Seal type varies between authorities Western Cape Province www.aapa.asn.au

12. AAPA 2011 Study Tour – Surface Treatments #1 Seal Selection SANRAL Western Region www.aapa.asn.au

13. AAPA 2011 Study Tour – Surface Treatments #1 Sealing New Works Primersealing not practiced o Prime and seal o 50% dry back requirement o PMB emulsion double seals in winter Rehabilitation under traffic; build, prime and seal the road in half widths. Stop/go traffic control on the remaining lane operates 24 hours per day Undertaken on sections up to 4km in length. www.aapa.asn.au

14. AAPA 2011 Study Tour – Surface Treatments #1 www.aapa.asn.au

15. AAPA 2011 Study Tour – Surface Treatments #1 Sealing Practice #1 Sealing embargo, May – August Use of cutters discouraged o Risk of bleeding in summer o Perceived OH&S issues Cutter added at depot/plant Maximum cutter levels o heavy traffic 3% o light traffic 5% o SANRAL does not permit any cutter www.aapa.asn.au

16. AAPA 2011 Study Tour – Surface Treatments #1 Sealing Practice # 2 www.aapa.asn.au

17. AAPA 2011 Study Tour – Surface Treatments #1 Sealing Practice # 3 Measures to minimise stone loss o Spraying when pavement temperatures 25°C & rising o Use of emulsion binders o Aggregate precoating o Perform sealing in lane widths with work closed overnight. Rolling and sweeping the following day when the pavement has warmed. Traffic is only permitted on the seal when the pavement temperature is above 15°C. o Fog sprays www.aapa.asn.au

18. AAPA 2011 Study Tour – Surface Treatments #1 Fog Spray Diluted CRS60 emulsion (50:50) over final layer of aggregate Bind aggregate together, prevent early stone loss Alternative to prespraying, adds binder in lightly trafficked areas www.aapa.asn.au

19. AAPA 2011 Study Tour – Surface Treatments #1 www.aapa.asn.au

20. AAPA 2011 Study Tour – Surface Treatments #1Rejuvenation Common treatment Oxidized binder Fill fine cracks Slow set emulsion Diluted 50:50 No design method o 0.8 – 1.0 l/m 2 o Trial patches 3 years life www.aapa.asn.au

21. AAPA 2011 Study Tour – Surface Treatments #1 www.aapa.asn.au

22. AAPA 2011 Study Tour – Surface Treatments #1 Sand Seals www.aapa.asn.au Graded sand or grit Low volumes roads Initial seal - 3 years Reseal - 15 years

23. AAPA 2011 Study Tour – Surface Treatments #1 Sand Seal www.aapa.asn.au

24. AAPA 2011 Study Tour – Surface Treatments #1 www.aapa.asn.au

25. AAPA 2011 Study Tour – Surface Treatments #1 www.aapa.asn.au

26. AAPA 2011 Study Tour – Surface Treatments #1 www.aapa.asn.au End of Part 1