SMA-5钢渣沥青混合料的组成设计与性能评价

Composition Design and Performance Evaluation of SMA-5 Steel Slag Asphalt Mixture

为更好地促进小粒径钢渣在薄层沥青混合料中的应用,采用V-S(volumetric mix)法设计SMA-5沥青混合料的集料掺配比例;等体积替换掺加1.18~2.36 mm、2.36~4.75 mm两种粒径钢渣于SMA-5沥青混合料中,分析其对沥青混合料试件的粗集料间隙率VCAmix、最佳沥青用量的影响;借助车辙试验、小梁弯曲试验、冻融劈裂试验与浸水马歇尔试验对钢渣沥青混合料的高温稳定性、低温抗裂性与水稳定性进行评价。结果表明:掺入钢渣降低了集料间的骨架结构效应,提高了混合料沥青用量;复掺钢渣降低了沥青混合料的高温稳定性,但随着钢渣掺量增加,各掺配方案下沥青混合料的低温性能均降低,水稳定性、高温稳定性均提升;推荐SMA-5钢渣沥青混合料中2.36~4.75 mm粒径钢渣掺量75%为最优配比。

In order to promote the application of small-size steel slag in thin-layer asphalt mixtures,the aggregate mix ratio of SMA-5 asphalt mixtures was designed using the V-S(volumetric mix)method.Adding 1.18~2.36 mm and 2.36~4.75 mm steel slag aggregates(equal volume replacement of limestone aggregates)into SMA-5 asphalt mixtures,and its effect on the percent voids in coarse mineral aggregate VCAmix in asphalt mixtures and the optimum asphalt content of asphalt mixtures was analyzed.The high temperature stability,low temperature cracking resistance and moisture stability of steel slag asphalt mixtures were evaluated using rutting test,beam bending test,freeze-thaw splitting test and water-immersion Marshall test.The results show that the inclusion of steel slag reduces the effect of skeleton structure between aggregates and increases the amount of asphalt used in asphalt mixture.The high temperature stability of asphalt mixture is reduced by adding steel slag.However,with the increase of steel slag content,the low temperature performance of asphalt mixture decreases,and the moisture stability and high temperature stability increase.It is recommended that 75%of steel slag of 2.36~4.75 mm in SMA-5 steel slag asphalt mixture is the optimal ratio.