Resistance of Fine Graded Asphalt Concrete Wearing Course to Rutting at Varying Temperatures and Densities

Abstract

One of the road pavement distresses is rutting. Rutting occurs as the effect of the vehicle tires that roll continuously on the same wheel-path of the road pavement. Rutting occurs due to repetitive wheel loadings which cause the road to be fatigue. This research attempts to measure the capability of Asphalt Concrete Wearing Course (ACWC) layer to support rutting at varying temperatures and densities. This research is carried out using Wheel Tracking Machine that is able to measure predicted rut depth on an asphalt mixture specimen due to repetitive wheel loadings. The wheel of Wheel Tracking Machine has a width of 5 centimeters and a  pressure of 6.5 kg/cm². The wheel of Wheel Tracking Machine moves at speed of 42 passing per minute. The test is carried out for 1 hour and the rutting is observed at the 42^nd, 210^th, 420^th, 630^th, 1260^th, 1890^th, and 2520^th passing. The ability of asphalt concrete layer to support rutting is defined as Dynamic Stability (DS) expressing the number of wheel passing required to create 1 mm depth rutting. The specimens are in a plate form of 30 cm in length and width and 5 cm in thick, and are of 3 density: 2.293  gr/cm³;  2.200 gr/cm³; and 2.084 gr/cm³_. The specimens are then tested using Wheel Tracking Machine at temperatures of  30^oC, 45 ^oC, and 60^o C. The research results show that more dense ACWC has better ability to support rutting. The higher temperature in ACWC mixture results a decrease in the ability to support rutting. At higher temperature, the density does not give a significant influence in supporting rutting.

Keywords: asphalt concrete, rutting, density, temperature