1. Asphaltic Concrete Mix Design
Seksyen Loji Dan Kuari
JKR Woksyop Persekutuan KL

2. Construction Of Road in the 60’s by JKR

3. STILL Little PROBLEMS IN ROAD RESURFACING !
Is this JKR Works After 100 Years
STILL Little PROBLEMS IN ROAD RESURFACING !

4. BRUCE G MARSHALL
YOU NEED
TO HELP

5. Road Structure
Wearing Course
BinderCourse`
Roadbase
Sub-base
Subgrade

6. Cracking

7. Cracking Why cracking in asphalt surfacing undesirable?
It allows surface water to penetrate into the lower pavement layers, causing localised weakening of the pavement structure.
It reduces the dynamic modulus of the surfacing, making it less able to distribute imposed traffic loads.

8. Possible Causes of Cracking
Excess fines in mixture.
Insufficient bitumen.
Insufficient compaction.
Improperly proportioned mixture.
Voids content too high.
Rolling when mixture too cold.
Overheating the bitumen.
Wet mixing time too long.
Improper joint preparation & construction.
Over Rolling - vibratory roller.
Too high amplitude - vibratory roller.

9. Rutting

10. Rutting Why rutting in asphalt surfacing undesirable?
It creates an irregular road profile, thus poor riding quality, dangerous to traffics.
It increases roughness, thus increases vehicle operating costs.
It allows surface water to accumulate, thus increases risk of skidding and aquaplaning, and water infiltration into pavement structure.

11. Possible Causes of Rutting
Excess bitumen.
Excess fines in mixture.
Improperly proportioned mixture.
Excessive tack coat.
Excessive segregation.

12. Skidding

13. Skidding
Does asphaltic concrete road surfacing lack the necessary macrotexture for skidding resistance at high speeds ?

15. Possible Causes of Smooth Surface Texture
1. Excess fines in mixture.
2. Excess bitumen.
3. Over rolling.
4. Rolling when mixture too hot.
5. Excessive segregation.
6. Abrasion of aggregates by traffic.

17. The solution ?
Porous Asphalt

18. Stone Mastic Asphalt

19. Component Of Asphalt
Aggregate
Filler
Bitumen

23. Aggregate - The Major Component Of Premix Production.

24. Basalt
Granite

25. Coarse Aggregate Testing
1 Test Per Stockpile Per 2,500 Tons Of Asphaltic Concrete Produced;
* Aggregate Crushing Value.
* Sodium Sulphate Soundness.
* Flakiness Index.
* Water Absorption.
* Polished Stone Value (Wearing Course Only).

27. Limestones in wearing course?

30. Fine Aggregate Testing
1 test per stockpile per 2,500 tons of asphaltic concrete produced;
* Sodium Sulphate Soundness.
* Water Absorption.

31. Sand or quarry dust?
Fine aggregate: Natural sand, mining sand or quarry fines.

32. Cement or limestone?
Mineral filler: Rock dust, limestone dust, hydrated lime or hydraulic cement.
Anti-stripping agent: Ordinary Portland cement.
Material passing 75 um to bitumen ratio by weight
Mineral Filler / Anti Stripping Agent

33. or ?
Bitumen grade: Penetration grade (MS 124).

34. Bitumen Testing * Penetration. * Softening point.
* Solubility in Trichloroethylene.
* Ductility.
* Flash point.
* Retained penetration after thin film oven.
* Loss on heating.
Test frequency: Not stated in JKR Guidelines or JKR/SPJ. Recommends one set of test per every bitumen delivery to the plant.

35. BITUMEN QUALITY PENETRATION TEST 5 seconds penetration value in 0.1 mm
100 gramme
needle
5 seconds
bitumen at 25
degrees
Celsius
penetration
value
in 0.1 mm

36. Mix Design

39. Mix Design Requirements
Grading of combined aggregates + filler - Table 4.8 JKR/SPJ.
Bitumen content - Table 4.9 JKR/SPJ.
Marshall method of mix design - Clause JKR/SPJ.
Test parameters of Marshall specimens - Table 4.10 JKR/SPJ.
Establish design aggregate grading and bitumen content with tolerances in Table 4.11 JKR/SPJ.

40. Mix Design Requirements
Grading of combined aggregates + filler - Table 4.8 JKR/SPJ.
Bitumen content - Table 4.9 JKR/SPJ.
Marshall method of mix design - Clause JKR/SPJ.
Test parameters of Marshall specimens - Table 4.10 JKR/SPJ.
Establish design aggregate grading and bitumen content with tolerances in Table 4.11 JKR/SPJ.

41. Table 4.8 - Gradation Limits For Asphaltic Concrete
B.S. Sieve Size, mm % Passing By Weight

42. Mix Design Requirements
Grading of combined aggregates + filler - Table 4.8 JKR/SPJ.
Bitumen content - Table 4.9 JKR/SPJ.
Marshall method of mix design - Clause JKR/SPJ.
Test parameters of Marshall specimens - Table 4.10 JKR/SPJ.
Establish design aggregate grading and bitumen content with tolerances in Table 4.11 JKR/SPJ.

43. Mix Design Requirements
Grading of combined aggregates + filler - Table 4.8 JKR/SPJ.
Bitumen content - Table 4.9 JKR/SPJ.
Marshall method of mix design - Clause JKR/SPJ.
Test parameters of Marshall specimens - Table 4.10 JKR/SPJ.
Establish design aggregate grading and bitumen content with tolerances in Table 4.11 JKR/SPJ.

44. Table 4.9 - Design Bitumen Contents
Class of Mix Normal Range of Design Bitumen Content by Weight of Mix
ACW 20 - WC %
ACB 20 - BC %
ACB 28 - BC %

45. Clause 4.2.4.3 Asphaltic Concrete Mix Design
Prepare specimens for standard stability and flow tests as per AASHTO T 245 using 75 blows/face.
Determine bulk specific gravity of specimens as per AASHTO T 166.
Determine stability and flow values as per AASHTO T 245.
Voids analysis; VMA, VFB, VIM.

46. Mix Design Method
MS 535
Specification for asphaltic concrete for road pavement and airfield runway by the Marshall test method.
Asphalt Institute MS-2
Mix design methods for asphalt concrete.

47. Mix Design Requirements
Grading of combined aggregates + filler - Table 4.8 JKR/SPJ.
Bitumen content - Table 4.9 JKR/SPJ.
Marshall method of mix design - Clause JKR/SPJ.
Test parameters of Marshall specimens - Table 4.10 JKR/SPJ.
Establish design aggregate grading and bitumen content with tolerances in Table 4.11 JKR/SPJ.

48. Table 4.10 - Test Parameters For Asphaltic Concrete
Parameter WC BC
Stability S > 500 kg > 450 kg
Flow F > 2.0 mm > 2.0 mm
Stiffness S/F >250 kg/mm >225 kg/mm
Air voids in mix % %
VFB % %

49. Mix Design Requirements
Grading of combined aggregates + filler - Table 4.8 JKR/SPJ.
Bitumen content - Table 4.9 JKR/SPJ.
Marshall method of mix design - Clause JKR/SPJ.
Test parameters of Marshall specimens - Table 4.10 JKR/SPJ.
Establish design aggregate grading and bitumen content with tolerances in Table 4.11 JKR/SPJ.

50. Table 4.11 - Tolerances For Asphaltic Concrete Mixes
Parameter Permissible Variation
% by weight of total mix
Bitumen content. +/- 0.2 %
Fractions of combined
aggregate passing 5.0
mm and larger sieves. +/- 5.0 %
aggregate passing 3.35
mm and 1.18 mm sieves. +/- 4.0 %
aggregate passing 425
µm and 150 µm sieves. +/- 3.0 %
Fraction of combined
aggregate passing 75
µm sieve. +/- 2.0 %

51. Trial Lay
A minimum of 10 tons of each mix shall be placed in trial areas to demonstrate to the satisfaction of S.O. that the mixing, laying and compacting equipment conforms to the requirements of the specification, and that the proposed mixes are satisfactory.
1. Rollers.
2. Paver.
3. Trial site.
4. Tests on premix sample :
Binder content & aggregate grading.
Theoretical maximum specific gravity.
Prepare Marshall specimens.
Specific gravity, volumetric properties, Marshall stability and flow of Marshall specimens.

52. Trial Lay - Continue
5. Record temperatures of premix on lorry, at plant and site.
6. Record laying temperatures.
7. Record laying thickness.
8. Check texture of paved surface.
9. Record rolling temperatures.
10. Record rolling pattern.
11. Check texture and condition of compacted surface.
12. Record compacted thickness and density from core samples.
13. Check consistency in production.
14. Check at least one longitudinal joint.

53. Temperature Of Bitumen < 177 C (350 F)

54. Each aggregate shall be stored in a separate stockpile
Each aggregate shall be stored in a separate stockpile. Stockpiles of sand and other fine aggregates shall be kept dry using waterproof covers or other means.
Aggregate Stockpile

55. Aggregate Grading Test
Batch plant - 1 test per hot bin per day of production.
Drum mix plant - 1 test per cold bin per day of production.

58. Temperature < 163 C (325 F)

59. Sampling of premix

60. Sampling of Premix Sample quantity:
> 20 mm (eg. ACB28) - minimum 24 kg.
< 20 mm (eg. ACW20) - minimum 16 kg.
Sampling from lorry:
> 20 mm - take 4 increments.
< 20 mm - take 3 increments.
One increment approx. 7 kg (use size 2 square-mouth shovel).
Scoop 100 mm below surface.

61. Testing of Premix 1 test per 200 tons of asphaltic concrete produced;
* Bitumen content & grading.
* Maximum specific gravity.
* Preparation of Marshall specimens.
* Bulk specific gravity of Marshall specimens.
* Volumetric properties (VMA, VFB, VIM).
* Marshall stability & flow.

67. Density and Thickness Requirement
1. Required compacted density;
Wearing Course : % Marshall density
Binder Course : % Marshall density
The average thickness over any 100 metre length shall be not less than the required thickness. The minimum thickness at any point shall be not less than the required thickness minus 5 mm.

69. Happy Client !

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