苯乙烯-丁二烯-苯乙烯嵌段共聚物-改性胶粉复合改性沥青路用性能流变学分析

Rheological Study of Paving Performance of Styrene-Butadiene-Styrene Block Copolymer-modified Rubber Powder Composite Modified Asphalt

为研究改性剂掺量对苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrene-butadiene-styrene block copolymer,SBS)-改性胶粉(modified rubber powder,MCR)复合改性沥青路用性能的影响,通过常规流变学试验方法,定性对比研究了SBS和MCR改性剂掺量对SBS-MCR复合改性沥青黏弹性的影响,量化分析了沥青胶结料路用性能的变化规律;通过多重应力蠕变试验,对比研究了不同改性剂掺量下沥青胶结料高温抗车辙性能的提升效果和差异;基于低温弯曲蠕变试验对8种沥青胶结料的蠕变劲度模量和蠕变速率进行对比研究,分析比较了材料在低温柔性和应力松弛性方面的差异。结果表明:不同改性剂掺量的SBS-MCR复合改性沥青虽然高温PG分级相同,但其抵抗高温变形的能力却可能存在差异;SBS和MCR改性剂对沥青胶结料劲度模量的提升效果相近;8种SBS-MCR复合改性沥青胶结料低温等级为-24℃,低温路用性能良好;最终推荐改性剂的合理掺量为4%SBS+11%MCR。

In order to study the effect of the amount of modifier on the paving performance of styrene-butadiene-styrene block copolymer(SBS)-modified rubber powder(MCR)composite modified asphalt,the effects of SBS and MCR modifiers on the viscoelasticity of SBS-MCR composite modified asphalt were qualitatively and comparatively analyzed.At the same time,the change law of paving performance of asphalt binder was quantitatively analyzed by conventional rheological test methods.Through multiple stress creep test,the improvement effect and difference of high temperature anti-rutting performance of asphalt binder with different content of modifier were compared.Based on the low temperature bending creep test,the creep stiffness modulus and creep rate of eight kinds of asphalt binders were compared,and the differences in low temperature flexibility and stress relaxation of the materials were analyzed and compared.Results show that although the SBS-MCR composite modified asphalts with different modifiers have the same high-temperature performance grade classification,their ability to resist high-temperature deformation may be different;the effect of SBS and MCR modifiers on the stiffness modulus of asphalt binder is similar;the low temperature grade of 8 kinds of SBS-MCR composite modified asphalt binders is-24℃,and the low-temperature road performance is good;the reasonable recommended final modifier content is 4%SBS+11%MCR.