Moisture Effect on the Strength Properties of Patani-Clay Modified Asphalt Concrete

Abstract

Traditional asphalt concrete is an important road surfacing material and tends to fail when submerged in water for a period under traffic load. The study is aimed at investigating the effect of clay, sourced from Patani, as modifier of asphalt concrete on Marshall mechanical properties and its resistance to moisture damage under soaking duration of 2, 4 and 7 days. Clay was used to partially replace the mineral filler at dosage rates ranging from 0% - 14% by weight of the mineral filler component in the total mix. The Marshall Mix Design Method was adopted to determine the optimum bitumen content of 5% and also used to prepare clay-modified asphalt concrete samples. Atterberg Limit Test was conducted on the soil sample for identification. The results show that the clay used is classified as inorganic, high plasticity clay in the AASHTO system's A-6 group. The control mix with no clay content addition had the lowest Marshall stability value of 8.4 kN and increased to 18.73 kN when clay sourced from Patani was incorporated at 4%, representing an increase of 123% over the control mix. Marshall stability values were substantially retained under soaking duration up to 7 days and maximizing antistripping properties of asphalt concrete mix.