聚氨酯改性沥青制备及其混合料路用性能研究

Preparation of Polyurethane Modified Asphalt and Road Performance of Its Mixture

为改善沥青混合料的路用性能,以热塑性聚氨酯弹性体(TPU)为改性剂对基质沥青改性,制备了聚氨酯改性沥青(APU),并对其流变性能、弯曲蠕变劲度进行试验,另外采用AC-13级配,对不同改性剂掺量的沥青混合料进行车辙、低温小梁弯曲及浸水马歇尔试验。结果表明,TPU掺量为12%时,APU耐高温等级达70℃,相比于基质沥青,其蠕变劲度下降了33.1%,蠕变速率提高了22.3%。另外,该掺量的沥青混合料的动稳定度提高了3.93倍,抗弯拉强度和最大弯拉应变分别提高了50%和76%,浸水马歇尔稳定度和残留稳定度分别提高了110%和8.6%。TPU改性剂有利于改善沥青混合料的高低温性能及抗水损害性能,具有良好的研究和推广价值。

To improve the road performance of asphalt mixture, the polyurethane modified asphalt(APU) was prepared with thermoplastic polyurethane elastomer(TPU) as modifier in the base asphalt. The rheological properties and bending creep stiffness were tested. Using AC-13 gradation, the rutting, low trabecular bending and immersion Marshall test were carried out on asphalt mixture with different APU contents. The results showed that, when the content of TPU was 12%, the high temperature resistance of APU reached 70 ℃. Compared with the base asphalt, the creep stiffness of APU decreased 33.1%, the creep rate increased 22.3%. Moreover, the dynamic stability of this APU mixture increased 3.93 times, the flexural tensile strength and maximum flexural tensile strain increased 50% and 76% respectively, the immersion Marshall stability and residual stability increased 110% and 8.6% respectively. The TPU modifier could significantly improve the high and low temperature performance and water damage resistance of asphalt mixture, which had good research and promotion value.