不同处治方法下酸性闪长岩沥青混合料长期水稳性能室内试验

为研究不同处治方法下酸性闪长岩沥青混合料的长期水稳定性,针对广西浦北至北流高速公路沿线酸性闪长岩集料,用水泥替代矿粉、消石灰水浸泡集料和抗剥落剂改性沥青等处治方法改善酸性闪长岩与沥青的粘附性.获得3种处治方法的最佳掺量和最佳油石比后,通过冻融劈裂试验和反复冻融烘劈裂试验,评价酸性闪长岩沥青混合料的短期和长期水稳定性.结果表明:3种处治方法的酸性闪长岩沥青混合料短期水稳定性良好;消石灰水浸泡集料和水泥替代矿粉处治方法的10次冻融烘劈裂强度比分别为91%,89%,长期水稳定性较好;抗剥落剂改性沥青处治方法受湿热老化的影响,10次冻融烘劈裂强度比仅为80%,长期水稳定性较差.

Laboratory Test of Long-Term Water Stability of Acid Diorite Asphalt Mixture Under Different Treatment Methods

In order to study the long-term water stability of acid diorite asphalt mixture under different treatment methods, taking the acid diorite aggregate along the highway from Pubei to Beiliu in Guangxi as an example, 3 treatment methods were used to improve the adhesiveness between acid diorite and asphalt, such as cement instead of mineral powder, hydrated lime water immersion aggregate and anti-stripping agent modified asphalt. The optimal dosage and optimal asphalt-aggregate ratio of 3 treatment methods were obtained, the short-term and long-term water stability of acid diorite asphalt mixture were evaluated through freeze-thaw split test and repeated freeze-thaw-bake split test. The results show that the short-term water stability of acid diorite asphalt mixture of 3 treatment methods is good. The 10 times freeze-thaw-bake split strength ratios of hydrated lime water immersion aggregate and cement instead of mineral powder treatment methods are 91%, 89% respectively, and the long-term water stability is good. The anti-stripping agent modified asphalt treatment method is affected by wet and hot aging, the 10 times freeze-thaw-bake split strength ratio is only 80%, and the long-term water stability is bad.