冻融循环对聚合物改性沥青混合料的抗裂性能影响

Influence of Freeze-thaw Cycles on the Crack-resistance Performance of Polymer Modified Asphalt Mixture

为了研究冻融破坏对寒冷地区常用路面材料抗裂性能影响,通过半圆弯拉试验,并利用断裂韧度指标分析冻融循环次数和盐浓度对SBSMM、CRMM和CCRMM抗裂性的影响。结果表明:SBSMM、CRMM和CCRMM三种聚合物改性沥青混合料抗裂性能随着冻融循环次数和盐浓度的增加而减小,并且在冻融循环达到20次时趋于稳定;对比冻融循环次数和盐浓度变化对混合料抗裂性能影响发现,冻融循环次数对混合料抗裂性能影响更加显著;对比三种聚合物改性沥青混合料在不同冻融循环次数和盐浓度下的断裂韧度变化可以得出,CCRMM的抗裂性能最好,CRMM次之,SBSMM最差。

To study the influence of freeze-thaw damage on the crack resistance of common pavement materials in cold area,the semi-circular bending tensile test was carried out,and the influence of freeze-thaw cycles and salt concentration on the crack resistance of SBSMM,CRMM and CCRMM was analyzed by fracture toughness index.The results show that the anti-cracking performance of SBSMM,CRMM and CCRMM polymer modified asphalt mixture decreases with the increase of freeze-thaw cycles and salt concentration,and tends to be stable when the freeze-thaw cycles reach 20;By comparing the influence of freeze-thaw cycles and salt concentration on the crack resistance of the mixture,it is found that the effect of freeze-thaw cycles on the crack resistance of the mixture is more significant.Comparing the change of fracture toughness of three kinds of polymer modified asphalt mixture under different freeze-thaw cycles and salt concentration,it can be concluded that the crack resistance of CCRMM is the best,CRMM is the second,SBSMM is the worst.