聚氨酯/纳米ZnO复合改性沥青及其混合料性能研究

Research on polyurethane/nano-ZnO composite modified asphalt and its mixture properties

为提升沥青路面的路用性能,选用聚氨酯、纳米ZnO和基质沥青制备聚氨酯/纳米ZnO复合改性沥青。以针入度、软化点、延度和135℃运动黏度为评价指标,研究改性剂对沥青性能的影响,采用软化点差值评价储存稳定性,并制备3种复合改性沥青AC-13C混合料进行车辙试验、小梁弯曲试验和浸水马歇尔试验,研究改性沥青混合料的性能。结果表明,聚氨酯和纳米ZnO的掺入能显著改善基质沥青的高低温性能,且储存稳定性符合规范要求。复合改性沥青混合料能够满足沥青路面的路用性能,5%聚氨酯复配3%纳米ZnO掺量的改性沥青混合料改善高温性能和水稳性能效果最好,与基质沥青混合料相比其动稳定度提高了2.32倍,残留稳定度上升了9.0%,最大弯拉应变(-10℃)提升了8.3%。综合考虑路用性能改善效果,推荐选用5%聚氨酯复配3%纳米ZnO为复合改性沥青及其混合料的最佳掺量。

In order to improve the road performance of asphalt pavement,polyurethane/nano-ZnO composite modified asphalt was prepared by polyurethane,nano-ZnO and matrix asphalt.Taking penetration,softening point,ductility and 135℃viscosity as evaluation indexes,the influence of modifier on asphalt performance was studied,and the storage stability was evaluated by softening point difference.Three kinds of composite modified asphalt AC-13C mixture were prepared for rutting test,trabecular bending test and immersion Marshall test to study the performance of modified asphalt mixture.The results show that the incorporation of polyurethane and nano-ZnO can significantly improve the high and low temperature performance of the matrix asphalt,and the storage stability meets the requirements of the specification.The composite modified asphalt mixture can meet the road performance of asphalt pavement.The modified asphalt mixture with 5%polyurethane and 3%nano-ZnO content has the best effect on improving high temperature performance and water stability.Compared with the matrix asphalt mixture,the dynamic stability is increased by 2.32 times,the residual stability is increased by 9.0%,and the maximum flexural tensile strain(-10℃)is increased by 8.3%.Considering the improvement effect of road performance,it is recommended to use 5%polyurethane compound 3%nano-ZnO as the best content of composite modified asphalt and its mixture.