How does OBC use Marshall method of mix design?
The Marshall mix design method consists of 6 basic steps:
- Aggregate selection.
- Asphalt binder selection.
- Sample preparation (including compaction)
- Stability determination using the Hveem Stabilometer.
- Density and voids calculations.
- Optimum asphalt binder content selection.
Why Marshall test is done?
Marshal stability test is the performance prediction measure conducted on the bituminous nix. The procedure consists of determination of properties of mix, Marshal stability and flow analysis and finally determination of optimum bitumen content. The concept of phase diagram is used for the calculations.
How is Marshall mix design calculated?
Gmm = maximum specific gravity of paving mixture (no air voids) Pmm = total loose mixture = 100% Ps = aggregate, percent by total weight of mixture (P1 + P2 + P3 + Pn) Pb = asphalt, percent by total weight of mixture. Gse = effective specific gravity of aggregate.
Why Marshall stability test is done?
Marshall stability measures the maximum load sustained by the bituminous material at a loading rate of 50.8 mm/minute. The test load is increased until it reaches a maximum. Marshall stability is related to the resistance of bituminous materials to distortion, displacement, rutting and shearing stresses.
What is the scope of a Marshall mix?
1. SCOPE 1.1 This method is used to design Asphaltic Concrete mixes using 4-inch diameter Marshall apparatus. 1.2 This test method involves hazardous material, operations, and equipment. This test method does not purport to address all of the safety concerns associated with its use.
When do you use the Marshall test method?
The Marshall method of asphalt mix design is widely practiced in construction materials laboratories to select and proportion aggregate and asphalt materials for pavement construction.
How is a Marshall mix used for asphaltic concrete?
1.1 This method is used to design Asphaltic Concrete mixes using 4-inch diameter Marshall apparatus. 1.2 This test method involves hazardous material, operations, and equipment. This test method does not purport to address all of the safety concerns associated with its use.
How to reassemble a Marshall mix mold?
Remove the collar and smooth the surface of the mix with a trowel to a slightly rounded shape. Replace the collar, place the mold assembly on the compaction pedestal in the mold holder, and apply 75 blows with the compaction hammer with a free fall in 18 in. Remove the base plate and collar, and reverse and reassemble the mold.