石粉在三级配泵送混凝土中应用研究

结合糯扎渡水电站工程建设，以C25三级配泵送混凝土为研究对象，对比研究了7.0%、10%、15%、20%（质量百分比）4个不同石粉含量下分别选择不同粉煤灰掺量（0、15%、25%）配制的机制砂混凝土的工作性和不同龄期的强度。研究结果表明，25%掺量的粉煤灰与15%含量的石粉产生了良好的叠加效应，使混凝土获得了较佳的工作性和强度。研究结果同时显示，石粉作为掺合料不利于三级配泵送混凝土的配制，对其工作性带来不利影响，水粉比宜控制在0.37左右。

Research on application of stone powder to three-graded pumpcrete

Combined with the construction of Nuozhadu Hydropower Station， the workabilities and the strengths of various ages of the artificial-sand concretes with various fly ash contents （0， 15%， 25%） are respectively selected for the comparative study made on the concrete mixed with stone powder contents of 7.0%， 10%， 15% and 20% （mass fraction） by taking the C25 three-graded pumpcrete as the study object. The study result shows that better superimposed effect is to be obtained from fly ash content of 25% and stone powder content of 15%； by which better workability and strength can be got by the concrete. At the same time， the study shows that it is unfavorable to take stone powder as an admixture for mixing the three-graded pumpcrete， as it is bring an adverse effect. Consequently， the ratio of water-powdery materials （cement， fly ash and stone powder） is suitable to be controlled at about 0.37.