3种速凝剂对水工喷射混凝土性能影响研究

Influence of Accelerator on Performance of Hydraulic Shotcrete

为得到3种速凝剂掺入量对水工喷射混凝土性能的影响,从市场购买3种普通速凝剂,分别测试其单项指标,并借助混凝土喷湿机等试验工具,通过现场试验的方法测定3种速凝剂对水工喷射混凝土性能影响。试验结果表明:①本次所取3种速凝剂的单项判定均达标,可以开展掺速凝剂水工喷射混凝土性能试验。②3种速凝剂掺入量对水工喷射混凝土性能影响相差较小。③喷射现场速凝剂掺入量控制为水泥用量的3%~5%左右为宜,不同工程的掺入量需以试验调整后确定为准。④掺入量过多会大大降低混凝土强度,失去其速凝的价值;掺入量较少,则易造成已喷射成型的水工混凝土大面积脱落,以及回弹量较大,难以达到理想效果。

In order to obtain the effect of three kinds of accelerators on the performance of hydraulic shotcrete,three kinds of common accelerators were purchased from the market,and their individual indexes were tested respectively,and with the help of concrete humidifier and other test tools,the effects of three kinds of accelerators on the performance of hydraulic shotcrete were determined by field test.The test results show that①the individual judgments of the three accelerators are up to the standard,and the performance test of hydraulic concrete mixed with accelerator can be carried out.②there is little difference in the effect of three kinds of rapid setting agent on the performance of hydraulic shotcrete.③it is appropriate to control the amount of rapid setting agent in the injection site to about 3%or 5%of the amount of cement,and the amount of rapid setting agent in different projects should be determined after the adjustment of the test.④too much addition will greatly reduce the strength of concrete and lose its rapid setting value;with less addition,it is easy to cause large area shedding of sprayed hydraulic concrete and large amount of rebound,so it is difficult to achieve ideal effect.