Effect of SBS modified bituminous binder on pavement performances

SBS modified bituminous binder consisting of 4, 4.5, 5, 5.5 and 6 weight % of bitumen was prepared in high speed sheer mixer. Their performance in relation to temperature susceptibility, low temperature cracking, fatigue, rutting in hot condition and workability was tested by penetration, softening point, viscosity and ductility test as per their standard specifications. It is found that with increasing amount of SBS in bituminous binder, the penetration value decreases and softening point increases, which shows improved high temperature performance of modified bituminous binder. The increased value of ductility confirms an improvement in low temperature performance of SBS modified bituminous binder. However, a linearly decreased in penetration index was observed after the blending of SBS with bitumen more than 4% by weight showing the temperature sensitivity. Therefore, the 4% dosages of SBS is the optimized amount to achieve improved performances of SBS modified bituminous binder.