再生细骨料取代率对混凝土工作性的影响

摘要

以不同流动性的混凝土再生细骨料取代率为变化因素，对混凝土初始坍落度、1 h 坍落度、快速工作度以及28 d 抗压强度进行了测试。研究表明，不同流动性的再生混凝土再生细骨料总比例在30%~40%左右变化时，对混凝土工作性影响不大，再生混凝土的强度甚至高于基准混凝土；在保持再生混凝土配合比其他掺量不变条件下，再生细骨料对坍落度要求较高的混凝土适应性较好，最高取代率为30%。通过快速工作度测定方法建立了混凝土快速工作度与坍落度之间的关系，为快速推算混凝土坍落度并实时监控混凝土施工状态提供参考。%The initial concrete slump,1 h slump ,fast workability and 28 day compressive strength were tested,re-spectively on the substitution rate of the recycled fine aggregate with the different mobility of concrete.The research showed that the influence on the workability of concrete was little,recycled concrete strength even higher than that of the reference concrete,at the recycled aggregate proportion in the change of 30%~40%.In the condition of the con-stant concrete mixture proportion keeping other content of the recycled concrete,it was more suitable for the fine ag-gregate to the concrete with higher slump,the highest substitution rate of 30%.Through the method of fast workabili-ty determination,the relationship between the concrete fast workability and slump was established .It was provided for the rapid calculation of concrete slump and monitoring the concrete construction in real-time.