洞渣湿喷混凝土的制备与性能研究

Research on Preparation and Performance of Wet Shotcrete with Cave Slag

研究了单方用水量、砂率以及矿物掺合料对洞渣湿喷混凝土(CSWSC)工作性能和力学性能的影响,得出CSWSC的最优配合比,并提出了CSWSC的制备方法;对比研究了掺加与未掺加粉煤灰及微珠的CSWSC的物理和力学性能差异;采用室内和小型湿喷试验对姑两隧道开挖所得的洞渣机制砂的各种性能指标,CSWSC拌合物的工作性能、回弹率和抗压强度进行了研究。结果表明,当粉煤灰掺量为20%,水胶比为0.45,砂率分别为50%、55%和60%时,CSWSC工作性能优异,初凝时间在2 min左右,终凝时间在5~8 min之间,回弹率约为10%,28 d试样抗压强度大于30 MPa。

The effect of unilateral water consumption,sand ratio and the mineral admixture content on the working performance and mechanical properties of wet shotcrete with machine-made sand from cave slag(CSWSC)were studied.The optimum mixture ratio of CSWSC was obtained,and the preparation method of CSWSC was put forward.The difference between the mechanical properties of without fly ash and with fly ash were compared and studied.The performance index of machine-made sand and performance,resilience and compressive strength of CSWSC were studied by indoor and small jet experiments.The results show that the machine-made sand concrete with 20%of fly ash,0.45 of water-binder ratio and 50%,55%,60%of sand rate has excellent performance.Meanwhile the initial setting time of concrete is about 2 min,the final setting time is 5-8 min,the rebound rate is about 10%,and the compressive strength is more than 30 MPa at 28 d.