Effect of single face compaction on stability and flow of asphalt specimen

Abstract

Recent research on the performance of bond strength between pavement layers results in the preparation of double layered specimen becomes inevitable. Double layered specimen may be in field scale or laboratory scale. Marshall mixture design method is normally adopted to prepare double layered specimen in laboratory, incorporating the compaction of binder course at both faces and followed by a single face compaction of wearing course. Due to that, compaction at single face only will raised potential scepticism over the quality of the compacted mixture. This paper focused on the performance of stability and flow for single face compacted wearing course specimen prepared using Marshall procedure at a thickness of 50mm for Asphaltic Concrete mixture of nominal maximum aggregate size 10 mm (AC10) and Stone Mastic Asphalt of nominal maximum aggregate size 14 mm (SMA14). The stability and flow was investigated with the increasing compacting effort. The stability and flow at optimum compacting effort was also checked. From the research, it was noticed that stability increased with compacting effort while flow shows a decreasing trend. A stability and flow value of 12.8 kN and 2.27 mm as well as 10.4 kN and 2.61 mm was recorded for AC10 and SMA14 respectively at optimum compacting effort. Such observation may be accounted to the aggregate gradation in the mixture besides the binder properties of two different binders used. Despite the adoption of single face compaction in specimen preparation, at optimum compacting effort, the stability and flow values was also found to be within the range as specified by local specifications