The Study of Properties of Multigrade Asphalt Concrete by Comparison the Aggregate between Steel Furnace Slag and Limestone

Abstract

                Multigrade asphalt concrete is mixture of hot mix asphalt and aggregates. It uses the same aggregate gradation as general asphalt concrete, but uses multigrade asphalt instead of asphalt cement as a binder. The objective of this research is to compare the properties of multigrade asphalt concrete by using steel furnace slag and limestone as aggregates. The compaction of multigrade asphalt concrete was done by the Marshall method and gyratory compactor with different number of gyration.

                 The results indicated that the steel furnace slag aggregate had higher specific gravity and soundness and lower abrasive resistance than limestone. The design for the steel furnace slag aggregate had higher density, stability, flow and percentage of asphalt cement than limestone in both Marshall and gyratory compactions. When testing the properties of multigrade asphalt concrete, the steel furnace slag aggregate had a higher strength index and resilient modulus and less rutting than limestone. It was concluded that multigrade asphalt concrete using steel furnace slag aggregate are better than limestone in the construction of asphalt concrete pavement.