Evaluation of the effect of SBR polymer on fatigue and rutting behavior of Stone Mastic Asphalt

Stone Mactic Asphalt (SMA) has been considered by road makers due to its many advantages. From the advantages of this asphalt is improving the rutting resistance of asphalt mixtures, reducing the growth of cracks, improving the slip resistance, reducing the noise pollution caused by vehicle traffic. In this study, SBR polymer (Styrene Butadine Rubber) was used to improve the functional properties of stone mastic asphalt mixtures. This polymer was used as solid polymer which was mixed to the bitumen and liquid polymer which was mixed directly to asphalt mixture. For this purpose, the Marshall tests, indirect tensile fatigue, Wheel track and moisture sensitivity tests were performed on SBR-modified SMA specimens. The results indicated that the use of mixed SBR polymer in bitumen had a positive effect on fatigue and rutting resistance of SMA mixtures. However, the polymer did not have any substantial effect on moisture sensitivity of SMA mixtures comparing to the control mixture.