Abstract:
Dense Graded Aggregate Base (DGAB) construction is a major
contributing component in flexible pavement construction in terms of pavement
structural capacity and the project cost. However, the production processes related
to DGAB construction impose more significant financial, environmental, and social
concerns, which stresses the effective compaction in DGAB construction. DGAB
compaction process is controlled by three governing factors: moisture content (MC),
compaction effort, and layer thickness, where compaction effort can be minimized
when field compaction takes place at MC levels closer to the estimated Optimum
Moisture Content (OMC). Hence, the relationship among maximum dry density
(MDD), OMC, and compaction effort should be well established for a given layer
thickness in such a laboratory method that best interprets the field practice. Information
on the current industry compaction practices was gathered by conducting a
questionnaire survey. Simultaneously, laboratory and field tests were carried out to
compare the compaction behavior of DGAB at different MCs and energy levels.
Moisture density plots of different laboratory and field compaction tests were
compared to determine the most suitable laboratory compaction method to simulate
the field compaction of DGAB. The study revealed that the vibratory hammer
test resulted in the highestMDDand the lowestOMC,wheremoisture-density curves
of the field compaction tests were approaching the vibratory hammer test curve with
the increase of compaction effort, emphasizing that the vibratory hammer test best
simulates field compaction, when compared to other laboratory impact compaction
tests.
