Properties of single face compacted porous asphalt

Abstract

Preparation of double layered specimen at laboratory scale is important in evaluating the performance of bond strength between pavement layers since it is normally less costly. It however involved single face compaction at wearing course layer during the specimen preparation which raised potential skepticism over the quality of the layer compacted at single face only. This paper presents the properties of single face compacted porous asphalt (SFCPA) specimen compared to conventional double face compacted porous asphalt (DFCPA) specimen. These specimens were of Grading A in accordance with the specification from Malaysia Public Works Department (PWD). The permeability and abrasive loss were investigated for specimens fabricated at 3 thicknesses of 35mm, 50mm and 65mm at an allowable limit of ±1mm. 50 blows compaction at each face according to PWD specification is adopted for DFCPA specimen, which resulted in compacting effort of 100 blows compaction for SFCPA specimen was applied for every thickness. For both tests, SFCPA possessed lower permeability and abrasive losses compared to DFCPA. This observation is the consequences of potential aggregate crushing in SFCPA which then partly filled up the voids within the specimen and reducing the permeability. Increased in density as a result of permeability reduction had increased the interlocking between coated aggregate particles, hence the abrasive loss in SFCPA is lessened.