直投式聚乙烯改性沥青混合料的路用性能

Pavement Performance of Directly-injected PE Modified Asphalt Mixture

通过直投式聚乙烯改性沥青混合料配合比设计,研究了其路用性能,主要包括高温稳定性、低温抗裂性、水稳定性。结果表明:对比直投式聚乙烯改性沥青混合料和SBS改性沥青混合料,直投式聚乙烯改性沥青混合料油石比相对于SBS改性沥青混合料少,约低0.1%~0.2%;直投式聚乙烯改性沥青混合料的稳定度和动稳定度相对于SBS改性沥青混合料高,动稳定度约为SBS改性沥青混合料的1.3~1.5倍,说明采用直投式改性对于高温稳定改善效果显著;直投式聚乙烯改性沥青混合料低温抗裂性和水稳定性均较好,低温弯曲破坏应变高于规范要求的2500με,但弯拉强度和弯拉应变均低于SBS改性沥青混合料,对于低温影响性能改善不如SBS改性明显;工程验证的结果与室内试验的结果相当,表明直投式聚乙烯改性沥青混合料具有良好的路用性能;从造价方面来说,采用直投式聚乙烯改性相对于SBS改性造价低,具有良好的经济价值;直投式沥青改性剂可直接混入矿料和基质沥青之中,并通过混合搅拌等方式产出改性沥青混合料,这样可有效减少改性剂加工、储存等诸多繁琐的环节,有效实现资源和能源成本的节约,从而为直投式聚乙烯改性沥青的应用提供技术基础。

Through the mix design of directly-injected PE asphalt mixture,the road performance,mainly including high temperature stability,low temperature crack resistance and water stability,is studied.The result shows that(1)comparing directly-injected PE modified asphalt mixture with SBS modified asphalt mixture,directly-injected PE modified asphalt mixture has lower asphalt-aggregate ratio,which is about 0.1%-0.2%lower than that of SBS modified asphalt mixture;(2)the stability and dynamic stability of directly-injected PE modified asphalt mixture are higher than those of the SBS modified asphalt mixture,and the dynamic stability is about 1.3-1.5 times that of the SBS modified asphalt mixture,indicating that the directly-injected modification has significant effect on improving the high-temperature stability;(3)the low temperature cracking resistance and water stability of directly-injected PE modified asphalt mixture are better,the bending failure strain at low temperature is higher than 2500μεrequired by the specification,while the flexural tensile strength and flexural strain are lower than those of SBS modified asphalt mixture,and the improvement of low temperature performance is not as obvious as SBS modified asphalt mixture;(4)the result of engineering verification are consistent with the result of laboratory test,indicating that the directly-injected PE modified asphalt mixture has good pavement performance;(5)in terms of cost,the cost of directly-injected PE modification is lower than that of SBS modification,which has good economic value;(6)the directly-injected asphalt modifier can be directly mixed into the mineral aggregate and the matrix asphalt,and the modified asphalt mixture can be produced by mixing and stirring,which can effectively reduce many complicated links such as the processing and storage of the modifier,effectively realize the saving of resource and energy cost,and thus provide a technical basis for the application of the directly-injected PE modified asphalt.