Evaluation the effect of using polymers on the performance of wearing asphalt mixture

Abstract

In Iraq , the increasing in number of vehicles and trucks with their heavy traffic loading and under high temperature , a variety of pavement distresses continues to develop affecting the performance and economy of pavement construction. Polymer modified asphalt mixtures have been used to resist the distresses that produced and developed from the applied stresses. Several distresses effect on the performance of HMA. The primary forms of distress are fatigue cracking , rutting , moisture damage and thermal cracking. These distresses reduce the services life of HMA and increase the maintenance costs.The main objective of this research is to find the effect of polymers on the performance of asphalt mixtureby using one asphalt cement grade (40-50) from Al-Daurah refinery with two types of locally available polymers (Low-Density Polyethylene LDPE and Styrene Butadiene Styrene SBS) with three percentages for each type. These percent are (1, 3 and 6) % for (LDPE & SBS) by weight of asphalt cement. Each type of these polymers is blended with asphalt cement by using the wet process. The experimental work showed that all polymer-modified mixtures have stability and indirect tensile strength higher than the control mixtures. It can be concluded that the addition of (1% LDPE) and (3% SBS) to asphalt mixtures showed better improvement on the performance properties of pavement modified with these polymers , in which the referred percent represent the optimum percent of concentration for blending polymers