Experimental Investigation into the Impact of Compaction Energy Level on Thickness of Flexible Pavement

As a means of gaining a better understanding of the impact of compaction energy levels on the thickness of flexible pavements, this study investigated samples that were 50% thicker than the standard Marshall specimen sizes. The gradations for those longer (thicker) specimens were based on the binder course gradations as specified by the Republic of Turkey’s General Directorate of Highways. To obtain reliable assessments of the thicker specimens, we compared our test results with those of a control group consisting of standard Marshall Briquettes prepared using the same materials. All specimens were compacted with 10 different compaction energy levels that were increased by fives, starting from 50 blows and ending at 95 blows. After determining their lengths, volumes and specific gravities, a special marble cutter was used to split the thick specimens into two equal parts. Those two identical specimens were identified as the "thin specimens". Subsequently, the Marshall stability test and the indirect tensile test were applied both to the standard Marshall specimen group and the thick and the thin specimen groups. The test results showed that asphalt specimens of 47 and 95 mm in height were optimally compacted after being subjected to 65 and 70 blows.