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3. Laboratory Test Methods and
Results
3.2 Compaction
strength test
When a vehicle is driving on the road, the road is
subject to a vertical loading force. The road pavement is then subject to the
compaction and tensile movements due to the repetitive loading. Harold L. Von
Quintus and Thomas W. Kennedy claimed that the main element for the permanent
deterioration of the pavements is the compaction due to the traffic loading, and
figure 6 depicts the effect of the compaction on the pavement deterioration. The
strength of the compaction is related to the flow characteristics of hot mix
asphalt, especially for the low compaction strength, and interior friction angle
of the structural material.
This study employed CBR2.5 test, applying ASTM D
1074, to investigate the resistibility change in hot asphalt mixture. At the
moment of insertion of CBR2.5, the loading force was indicated as the stiffness
of hot asphalt mixture. The experimental temperature was set at 60℃ to simulate
hot summer temperature based on the Marshall standard KS F 2349. The loading
speed was set at 50.8mm/minute, and the loading capacity of the testing
instrument was 5 ton. Figure 6 is influence of pavement destruction by strength
of compaction. Figures 7 and 8 exhibit compaction tester and the experimental
procedure. The compaction test results are shown in table 8 and figure 9. The
change in compaction strength according to the amount of DAMA is shown in figure
10.
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