再生白云石/水泥乳化沥青胶结料性能评估

Performance characterization of recycled dolomite-cement emulsified asphalt binders

以采石场废弃的白云石粉部分代替乳化沥青胶结料中的水泥,在改善胶结料性能、降低生产成本的同时为尾矿的污染问题提供新的解决途经.本研究选取中裂和慢裂两类阳离子乳化剂进行乳化沥青的制备和性能测定.而后采用废弃白云石粉部分替代乳化沥青胶结料中水泥,通过黏聚力试验和抗压抗折试验对胶结料的宏观力学性能进行分析,确定白云石粉在胶结料体系中的最佳掺量.通过微观表征对白云石粉的增强机制进行了分析.实验结果表明:白云石粉末可以有效提升乳化沥青胶结料的抗压和抗折强度;添加白云石的水泥乳化沥青胶结料内部会发生去白云石化反应;添加适量的白云石粉有利于促进硅酸钙的水化,改善浆体孔结构,从而有效提升胶结料的宏观强度.

Partial replacement of cement in emulsified asphalt binder with waste dolomite powder from quarries can improve the performance of the binder and reduce production costs while providing a new solution to the tailings problem in China.In this study,two types of cationic emulsifiers,medium cracking and slow cracking,were selected to prepare emulsified asphalt and test its properties.Then waste dolomite powder was used to partially replace cement in emulsified asphalt cement,and the macroscopic mechanical properties of the cementitious material were analyzed through the cohesion test and the compressive and flexural test to determine the optimum dosage of dolomite powder in the cementitious material system.The strengthening mechanism of dolomite powder was analyzed by microstructure characterization.The experimental results show that the dolomite powder can effectively improve the compressive and flexural strength of emulsified asphalt binder.The dolomite-added cement emulsified asphalt binder will undergo a dedolomitization reaction.Adding an appropriate amount of dolomite powder to the system is conducive to promoting the hydration of calcium silicate and improving the pore structure of the slurry,thereby effectively improving the macroscopic strength of the cementitious material.