高扬程泵送机制砂混凝土试验研究与应用

以C40高扬程泵送机制砂混凝土为对象,通过配合比优化设计与试验,研究了水胶比、砂率、粉煤灰掺量等对混凝土的工作性及力学性能的影响,并对混凝土的施工性能进行验证性分析。结果表明:水胶比为0.37、粉煤灰掺量为25%、砂率为42%时,配制的机制砂混凝土具有最优的工作性,28 d抗压强度达到52.8 MPa,电通量为964 C,符合设计要求。对现场浇筑的混凝土进行取样测试,工作性满足施工要求,泵送前的倒置坍落度筒排空时间在5 s以内,泵送后的倒置坍落度筒排空时间在5～10 s,具有良好的施工性能。

Experimental research and application of high lift pumping manufactured sand concrete

The article is based on the C40 high lift pumping manufactured sand concrete. The water-binder ratio,sand ratio and the content of fly ash on the workability and mechanical property of concrete was studied. The construction performance of concrete was also verified. The results show that the workability of manufactured sand concrete mixture is optimal when the water-binder ratio is 0.37,the sand ratio is 42% and the content of fly ash is 25%. The compounding strength of concrete is 52.8 MPa and the electric flux is 964 C. The test results in site show that the slump and expansion of concrete mixture can meet the requirements of construction. The inverted slump cylinder emptying time of concrete mixture is less than 5 seconds before pumping and the time is between 5~10 seconds after pumping. In general,the manufactured sand concrete has good construction performance.