Monitoring the Durability Issues of Asphalt Concrete

Abstract

The asphalt cement binder is prone to environmental issues such as ageing and moisture damage. This has a great significance in the performance of asphalt concrete pavement which may be more susceptible to failure throughout its fatigue life. In the present assessment, roller compacted slab samples have been prepared in the laboratory at optimum binder content. Additional samples have been prepared with a binder of  0.5 % below and above the optimum. Asphalt concrete beam specimens were obtained from the slab samples with the aid of a diamond saw. Asphalt concrete beam specimens were practiced to four point’s repeated flexural stresses after practicing moisture damage and long term ageing. The rate of change in the flexural strength was monitored and compared among the various testing conditions at 20 ºC environment and under constant micro-strain level of 750. It was observed that the higher flexural strength could be detected for aged specimens while lower flexural strength was observed for moisture damaged specimens as compared with the control mixtures. The flexural strength of the asphalt concrete specimens declines significantly at higher or lower binder content than that at the optimum.