细粒式SMA薄层罩面的击实影响因素

参考规范中SMA的级配范围进行不同的细粒式SMA的级配设计,分别进行马歇尔试验.通过对比相应的体积参数,分析了级配、温度和温拌剂对SMA击实的影响.试验结果表明,关键筛孔通过率对矿料间隙率VMA的影响较大,形成SMA骨架的粗集料的级配对VMA的影响较小;当VCAmix＜VCADRC时,SMA有可能没有形成良好的骨架结构,规范中通过VCAmix＜VC DRc判定SMA形成骨架结构存在不足;SMA的击实受温度的影响较大,所使用的温拌剂能够改善沥青的针入度指数,可以降低沥青混合料的击实温度20℃左右.

Influencing factors of compaction about the fine-grained SMA of thin overlay

Different gradation design refer to the gradation range of SMA in norms,and each gradation＇s Marshall experiment was carried out respectively.The influence of gradation,temperature and warm mix agent to the volume parameters is analyzed by comparing the corresponding volume parameters.The results show that key sieve passing rate has a greater impact on the VMA than the gradation of coarse aggregate forming the skeleton of SMA.When VCAmix＜VCADRc,SMA might not form a good skeleton structure.There are deficiencies to determine SMA forming the skeleton structure by VCAmix＜VCADRc in the norms.The compaction of SMA is largely influenced by temperature.Warm mix agent used in the test can improve the asphalt penetration index and can reduce the compaction temperatures of asphalt mixture about 20℃.