观音岩电站右岸大坝碾压混凝土配合比优化设计

Optimal design of mix proportion of rolling concrete for dam of Guanyinyan Hydropower Station at right bank

云南观音岩水电站碾压混凝土大坝施工前,为了保证混凝土质量,在选定水泥、粉煤灰、外加剂和骨料等材料的基础上,进行了配合比试验。主要试验内容包括:最佳砂率、骨料级配、外加剂掺量、VC值以及混凝土极限拉伸值、抗冻抗渗性能、线膨胀系数、自生体积、比热、导热系数、绝对温升等。根据试验结果,最终选定了大坝碾压混凝土配合比。实际施工效果表明,混凝土砂浆骨料包裹均匀,泛浆良好,抗冻、抗渗、温升等指标均满足设计要求。

Before the construction of rolling concrete dam of Guanyinyan Hydropower Station, to guarantee the concrete quality, the mix proportion test was conducted by selecting the concrete, fly ash, admixture and aggregate etc. The main test contents included the optimal sand rate, aggregate gradation, admixture amount, VC value and the limit tension value, anti - frost and an- ti - seepage capability, linear expansion coefficient, autogenous volume, specific heat capacity, thermal conductivity, and abso- lute temperature rise of the concrete. The final concrete mix proportion was determined according to the test result. The practical construction shows that the aggregate is packaged homogeneously by slurry, the slurry bleeding is appropriate, and the indexes of anti - frost, anti - seepage and temperature rise etc. meet design demand.