SBS/PU复合改性沥青混合料性能试验研究

Experimental study on performance of SBS/PU composite modified asphalt mixture

【目的】研究苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrene-butadiene-styrene block copolymer,SBS)与聚氨酯(polyurethane,PU)复合改性沥青混合料的路用性能。【方法】采用2.0%SBS与不同掺量(4.0%、6.0%、8.0%)的PU制备复合改性沥青,并使用这种改性沥青制备密级配沥青混合料AC-13,通过开展马歇尔试验、车辙试验、低温弯曲蠕变试验评价沥青混合料的高温抗车辙、低温抗裂、水稳定性,同时制备4.0%SBS改性沥青混合料和6.0%PU改性沥青混合料作为对照组。【结果】SBS/PU复合改性沥青混合料能够满足沥青路面的路用性能要求。其中,2.0%SBS+6.0%PU复合改性沥青混合料的动稳定度较基质沥青混合料、4.0%SBS改性沥青混合料、6.0%PU改性沥青混合料的分别提升144%、19%、52%,SBS/PU复合改性沥青混合料的高温稳定性较对照组有所提升,水稳定性与对照组相当,低温性能的改善效果不明显。【结论】综合考虑改性效果和经济性,SBS/PU复合改性沥青混合料的最佳掺量为2.0%SBS+6.0%PU。

[Purposes]This study aims to investigate the performance of styrene-butadiene-styrene block copolymer(SBS)and polyurethane(PU)composite modified asphalt mixture.[Methods]The composite modified asphalt was prepared by 2.0%SBS and PU with different dosages(4.0%,6.0%and 8.0%),and modified asphalt was used to produce the dense-graded asphalt mixture AC-13.The high-temperature rutting resistance,low-temperature crack resistance and water stability of the asphalt mixture were evaluated by Marshall test,rutting test and low-temperature bending creep test were performed,and the modified asphalt mixture with 4.0%SBS and 6.0%PU was set as the control group.[Findings]SBS/PU composite modified asphalt mixture can meet the road performance requirements for asphalt pavement.Among them,the dynamic stability of 2.0%SBS+6.0%PU composite modified asphalt mixture was 144%,19%and 52%higher than that of matrix asphalt mixture,4.0%SBS modified asphalt mixture and 6.0%PU modified asphalt mixture,respectively.The high temperature stability of SBS/PU composite modified asphalt mixture was improved compared with that of the control group,and the water stability was comparable to that of the control group,and the improvement effect on low temperature performance was not obvious.[Conclusions]Considering the modification efficiency and economical efficiency,the optimal content of SBS/PU composite modified asphalt mixture is 2.0%SBS+6.0%PU.