Impact of aggregrate gradation on the performance of porous asphalt mixture

Abstract

Porous Asphalt Mixture (PAM) is preferred in Singapore due to its water-permeable property and many studies are being conducted to improve its capability. Performance of PAM on pathways under the influence of aggregate gradation was studied in this research, especially in terms of permeability, strength and moisture susceptibility. Three gradations were prepared and each gradation was trialled thrice. PG-76 asphalt binder was used for the study and the properties were tested using Permeability Testing Machine and Marshall Apparatus following the ASTM standards. Subsequently, results from the three gradations were compared to come up with a gradation that gave the optimum properties. It is shown from the results that the gradation with the smallest amount of fines and higher percentage of coarse aggregate with size 2.36-4.75 mm and 9.5-13.2 mm gave the optimum performance for pathways in Singapore. The performance of this gradation may also be further investigated by using different types of asphalt binder.