1. OLD CONCRETE MAKES WAY FOR NEW ASPHALT A Laatz, N Cocks, N Burger

2. 1 INTRODUCTION CAPE TOWN CONGESTION ALMOST WORST IN SOUTH AFRICA
NATIONAL ROUTE 2, CAPE TOWN INTERNATIONAL AIRPORT, BORCHERDS QUARRY INTERCHANGE – TRANSPORT HUB
PROJECT – FIRST STAGE OF CONGESTION ALLEVIATION

3. First Impression for Visitors to Cape Town
Project Area
First Impression for Visitors to Cape Town

4. INTRODUCTION cont
RE-CYCLING - DOWN-CYCLING OF CONCRETE AND ASPHALT MATERIALS
CONSTRUCTION OF NEW ASPHALT BASED PAVEMENT
LESSONS LEARNED

5. 2 PROJECT BACKGROUND
CONCRETE PAVEMENT 1970’s – AGGREGATE SULPHATE REACTION ASR/AAR
MAINTENANCE WITH JOINT REPAIRS AND ASPHALT SEALING LAYERS

6. Background
Old Jointed Concrete Pavement from mid 70’s exhibited distress related to ASR/AAR - Repaired Joints and Re-Sealed

7. Background
Concrete Paving Train

8. Concrete Slip-Form Paver
Background
Concrete Slip-Form Paver

9. Handwork Edge Finishing
Background
Handwork Edge Finishing

10. Application of Curing Compound
Background
Application of Curing Compound

11. Revealing the Past
Repaired Joints and Sealed with SAMI and bitumen rubber asphalt overlay

12. 2 PROJECT BACKGROUND cont
IMPROVE AND UPGRADE TRANSPORT HUB FOR PRESENT CONGESTION AND FUTURE
DESIGN – ECONOMICS – RISK MITIGATION
DESIGN - STAYING GREEN – RE-CYCLING - DOWN- CYCLING

13. 3 PROJECT DESIGN TRANSPORT PLANNING – MEDIAN LANE
PAVEMENT DESIGN - ALTERNATIVES
MATERIALS DESIGN – CONCRETE / RAP BLEND AND ASPHALT LAYERS
STRUCTURES DESIGN – PRESENT AND FUTURE

14. Median Lane Design Layer TRH14 Thickness Description UTFC 24 mm
Friction Course 14mm stone - A-E2 AC
40 mm
Dense Asphalt Surfacing – A-E2 BC
90 mm
Dense Asphalt base – A-P1
Subbase
250 mm
Subbase, 2 Layers of 125mm commercial stone stabilised with 3% cement.
SSG
150 mm
Selected Layer Commercial stone
Subgrade
Road Bed in-situ sandy material

15. Existing Reconstruction
Layer TRH14
Thickness
Description
UTFC
24 mm
Friction Course with 14mm stone – A-E2 AC
40 mm
Dense Asphalt Surfacing – A-E2 BC
120/90 mm
Dense Asphalt Base – A-P1 (2/1 lifts)
Subbase
400/300 mm
Subbase, layer 1 – 200/150 in-situ, layer /150mm reclaimed concrete and RAP blend, all stabilised with 3% cement.
SSG 
(Local Pioneering)
200 mm   
300 mm
Middle lane unstabilised in-situ, slow lane 3% cement stabilised acting as mole barrier.
200mm diameter dump rock and geotextile

16. CONSTRUCTION
CONSTRUCTION PHASING
GROUND WATER
LOCAL EMPLOYMENT

17. Construction Phasing

18. Dealing with Water

19. Pioneering

20. Layerworks

21. Local Employment

22. 4 CONSTRUCTION cont RECLAIMING ASPHALT RECLAIMING CONCRETE
OFF-SITE CRUSHING AND BLENDING
ON-SITE PROCESSING

23. Reclaiming Asphalt

24. Reclaiming Concrete

25. Lifted and Loosened

26. Pulverizing for Transport

27. Off-Site Crushing

28. Processing Green Blend

29. Compacting Green Blend

30. CONSTRUCTION cont
BRIDGE WIDENING
PLANNING FOR FUTURE INTERCHANGE

31. Precast Beams (BQ Bridge)

32. Piling for Future Interchange

33. Pile Caps & Dewatering

34. 4 CONSTRUCTION cont LARGE STONE ASPHALT BASE - A-P1
ASPHALT WEARING COURSE - A-E2
ULTRA THIN FRICTION COURSE - A-E2

35. Asphalt Base Trial Section

36. Asphalt Surfacing

37. Asphalt Friction Course

38. 5 LESSONS LEARNED ECONOMIC BENEFITS – BROADER ENVIRONMENT
GRADING MODULUS AND WORKABILITY
GRADING COMPLIANCE
GOING GREEN USING SPOIL AND MAINTAINING STANDARDS

39. Aircraft View

40. Birds Eye View

41. Road User View