沥青搅拌站碱性回收废粉在沥青混合料中的应用研究

采用沥青搅拌站回收的碱性废粉掺入沥青混合料,代替部分矿粉,研究碱性废粉部分代替矿粉的可行性以及可掺入的最大量。按废粉占矿粉的比例为0%、30%、50%和70%,分别制备不同废粉掺量的沥青混合料,进行车辙试验、浸水稳定度试验、飞散试验、冻融劈裂试验,以检验废粉掺量变化对沥青混合料车辙以及水稳定的影响。试验结果表明:随着碱性废粉掺入量的增加,沥青混合料的动稳定度、浸水残留稳定度减小,飞散损失增加,冻融劈裂抗拉强度比减小。当废粉掺量为50%时,沥青混合料的动稳定度略超过《公路沥青路面施工技术规范》(JTG F40-2004)要求,浸水残留稳定度、冻融劈裂残留稳定度均不满足规范要求。当废粉掺量为30%时,沥青混合料的动稳定度、浸水残留稳定度、冻融残留强度比满足规范要求,得到所研究碱性废粉在沥青混合料中的最大掺入量为30%。

Study on Application of Alkaline Waste Powder Recycled from Asphalt Mixing Plant in Asphalt Mixture

The alkali waste powder recycled from asphalt mixing plant has been mixed in asphalt mixture to replace some mineral powder,the feasibility and maximum amount of alkali waste powder mixed in asphalt mixture have been studied.According to 0%,30%,50%and 70%proportion of waste powder in mineral powder,asphalt mixtures with different waste powder content have been prepared respectively,and rutting test,immersion stability test,flying test and freeze-thaw splitting test have been carried out to test the influence of waste powder content on rutting and water stability of asphalt mixture.The test results have shown that with the increase of alkaline waste powder incorporation,the dynamic stability and immersion residual stability of asphalt mixture decrease,the flying loss increases,and the freeze-thaw splitting tensile strength ratio decreases.When the content of waste powder is 50%,the dynamic stability of asphalt mixture slightly exceeds the requirements of"Technical Specifications for Construction of Highway Asphalt Pavements"JTG F 40-2004,and the residual stability of immersion water and freeze-thaw splitting cannot meet the requirements of the specifications.When the content of waste powder is 30%,the dynamic stability,immersion residual stability,Freeze-thaw splitting strength ratio of asphalt mixture could meet the requirements of the specifications,and the maximum content of waste powder in the asphalt mixture is 30%.