TheApplication of RecycledAggregates of Construction Debris inAsphalt ConcreteMix Design

Document Type : Original Research Paper



The purpose of this research was to evaluate the application of recycled aggregates of construction
debris such as concrete, cement block and rubbles from Pars-Kangan site in asphalt concrete mix design. To
evaluate the performance of aggregates different mix designs with recycled aggregate percentages of 0, 10,
30, 50 and bitumen percentages of 4, 4.5, 5, 5.5, 6, and 6.5 were provided and two Marshall specimens (Totally
48 specimens) prepared for each mix design. Marshall test was conducted on the specimens to evaluate their
physical and mechanical properties. The test results indicated that the increase of recycled aggregates
percentage in asphalt concrete mix design leads to lower strength in Marshall specimens. Hence, in the next
round of research the same asphalt concrete mix designs with bitumen-sulfur proportion of 60-40 were
provided in order to increase the strength of aggregates. The Marshall physical and mechanical test results
specified that sulfur has a significant role in increasing the strength of specimens. But increasing the
recycled aggregates resulted in decrease of strength. By comparing the test results, it was inferable that sulfur
doesn’t have a significant role in increasing the technical specifications of aggregates, and it only increases the
strength of specimens.