SMC再生SBS沥青的流变性能和微观特性研究

Study on rheological properties and microscopic characteristics of SMCreclaimed SBS asphalt

【目的】探究新型温拌再生剂甲基苯乙烯共聚物(styreneic methyl copolymer,SMC)对老化苯乙烯系热塑性弹性体(styrene butadiene styrene,SBS)改性沥青的再生效果和再生机理。【方法】首先,在室内制备不同老化程度的沥青。然后,采用SMC再生剂对不同老化程度的SBS改性沥青进行再生。接着,对再生后的SBS改性沥青进行动态剪切流变和低温弯曲蠕变试验,以评价其流变性能。最后,开展红外光谱试验以揭示其作用机理,进行电镜扫描试验以验证SMC再生剂的再生效果。【结果】SMC再生剂会降低老化SBS改性沥青的车辙因子,降低老化SBS改性沥青的恢复率,同时会使老化SBS改性沥青的低温性能得到极大提升。SMC再生剂未与SBS改性沥青发生化学反应,两者仅为物理共混。同时,SMC再生剂能够弥补沥青因老化产生的裂缝。【结论】SMC再生剂对老化SBS改性沥青具有较好的修复效果,能够为沥青的再生提供一种新的途径。

[Purposes]This paper aims to explore the new type of warm mixing recycling agent of styreneic methyl copolymer(SMC)recycling effect and mechanism of aging styrene butadiene styrene(SBS)modified asphalt.[Methods]Firstly,the old asphalt with different aging degrees was prepared indoors.Secondly,a SMC recycling agent was used to regenerate the styrene butadiene styrene(SBS)modified asphalt with different aging degrees.Then,dynamic shear and flexural creep tests were carried out on SMC regenerated asphalt to evaluate its rheological properties.Finally,the mechanism was revealed by the Fourier transform infrared reflection test,and the SMC recycling effect was evaluated by the scanning electron microscope test.[Findings]The results show that the SMC recycling agent reduces the rutting index and the recovery rate of aging asphalt,furthermore,it significantly improves the low-temperature performance of aging asphalt.The SMC recycling agent and aging asphalt are physically blended without chemical reaction.Besides,SMC recycling agent can compensate the cracks caused by asphalt aging.[Conclusions]The SMC recycling agent has a better repair effect on aging asphalt,which can provide a new way for asphalt regeneration.