Comparative Performance Evaluation of Effects of Modifier in Asphaltic Concrete Mix

Abstract

This article describes how the gradual increase in traffic volume, poor design and construction practices and lack of attention to maintenance during the last few decades has caused an accelerated and continuous deterioration of the road network in Pakistan. The above factors are among the main causes of pavement failures, especially rutting. Rutting failure occurs when the pavement surface exhibits wheel path depressions caused due to softening of asphalt. In this article, different modifications were used in bitumen to reduce rutting, and compared it with unmodified bitumen. Low Density Polyethylene (LDPE) and crumbed rubber were used as modifiers. The compacted asphalt mixes were tested for resistance to rutting using wheel tracking machine at 25°C and 55°C temperatures. From this research, it is concluded that the crumbed rubber modified bitumen is a better option than LDPE, especially at high temperatures. However, conventional (unmodified) bitumen gives satisfactory performance at low temperatures.