多孔玄武岩细集料含水状态对沥青混合料水稳定性能影响研究

Effect of Water Content State of Porous Basalt Fine Aggregate on Water Stability of Asphalt Mixture

多孔玄武岩可以替代优质天然集料作为石材,在确保路面性能的基础上,实现节约资源的目的。但由于其表面的多孔特性,在用于路面时,需重视其水稳定性能。本文设计了AC-20沥青混合料,通过马歇尔试验得到混合料的最佳沥青含量,并制备出对应级配的沥青混合料,以浸水马歇尔试验得出的残留稳定度和冻融劈裂试验得出的冻融劈裂试验强度比评定沥青混合料的水稳定性能研究。研究发现,集料粒径越小,对水的敏感程度越高,越容易吸水;水分会影响沥青与集料之间的黏附情况,从而对混合料的稳定性产生不利影响。SBS改性沥青混合料水稳定性能优于70号石油沥青混合料。

Porous basalt can replace other high-quality natural aggregate as stone,saving resources while ensuring the pavement performance.However,due to its porous surface,attention should be paid to its water stability performance when it is applied to pavement.In this paper,an AC-20 asphalt mixture was designed.The optimal asphalt content of the mixture was obtained by Marshall test,and the corresponding graded asphalt mixture was prepared.The water stability performance of the mixture was evaluated based on the residual stability obtained by the immersion Marshall test and the splitting strength ratio by the freeze-thaw splitting experiment.It was found that the smaller the aggregate particle size,the more sensitive it is to water,and the more likely it is to absorb water.Besides,the moisture affects the adhesion of asphalt to the aggregate,and adversely affects the stability of the mixture.The water stability of SBS modified asphalt mixture is better than that of No.70 petroleum asphalt mixture.