EFFECT OF MODIFIED ASPHALT WITH SBS POLYMER ON MECHANICAL PROPERTIES OF RECYCLED PAVEMENT MIXTURE

Abstract

Due to the increase need for reclaimed asphalt pavement (RAP) and development of recycling technologies, RAP has been used as a substitute for the virgin asphalt binder and aggregates in hot-mix asphalt (HMA) pavements. The research investigates the influence of adding SBS polymer on asphalt mixture containing reclaimed asphalt pavement. In this study, one percentage of RAP (30% by weight of mixture) was used. The SBS polymer percentages used were 3, 4 and 5% by weight of asphalt were three different test methods are used to evaluate the asphalt mixtures: Marshall stability and flow test, indirect tensile strength test and double punch shear test. It can be noticed clearly that the loss in ITS for mixtures containing SBS is lower than mixtures without SBS, also Marshall stability and punching strength increase with the increases of SBS percentages and the flow decrease with the increase of SBS polymer. It was concluded that adding SBS polymer improve the performance of mixtures and it was found that 5% of SBS modified mixture gave the best results due to improve mechanical properties of the mixture compared with the control mixture. It was noted that ITSR, Marshall stability and punching strength increased by 5%, 26.4% and74.8%, respectively, while Marshall flow decreased by 10.5% when adding 5% of SBS polymer to asphalt mixture.