废旧PP/SBR复合改性沥青流变及疲劳特性分析

Analysis on Rheological and Fatigue Properties of Waste PP/SBR Composite Modified Bitumen

为提高道路沥青的路用性能,研究利用废旧聚丙烯(Polypropylene,PP)和丁苯橡胶(Styrene Butadiene Rubber,SBR)对基质沥青进行复合改性,通过布氏黏度、高低温流变和疲劳性能试验对复合改性沥青的性能变化规律进行系统分析并评价。结果表明:PP的掺加可显著改善SBR改性沥青的高温弹性变形及恢复性能,提高其临界温度2~9℃,但会引起抗疲劳性能和低温应力松弛性能一定程度衰减;然而,只要将PP掺量控制在6%以内,其不利影响相对较小。综合分析高低温性能和疲劳性能表现,废旧PP/SBR复合改性沥青的推荐最佳掺量为:6%PP+4%SBR。

In order to enhance the road performance of matrix bitumen,waste polypropylene(PP)and styrene butadiene rubber(SBR)were utilized to modify matrix bitumen.The performance variation law of the composite modified bitumen was compared and analyzed through rotational viscosity test,high-and low-temperature rheological test and fatigue test.The results demonstrated that the addition of PP could significantly enhance the high-temperature elastic deformation and recovery performance,and increase the corresponding critical temperature by 2~9 ℃,while it might degrade the fatigue resistance and low-temperature stress relaxation performance to a certain extent with regrading to SBR modified bitumen;however,the adverse effect was relatively small as long as the PP content could be controlled within 6%.Based on the comprehensive analysis of high and low temperature performance and fatigue characteristics,the recommended proportion of waste PP/SBR composite modified bitumen is 6%PP+4%SBR.