复掺粉煤灰+硅灰+石灰石粉大坝碾压混凝土力学特性研究

Study on Mechanical Properties of Roller Compacted Concrete for Dam Mixed with Fly Ash,Silica Fume and Limestone Powder

随着粉煤灰掺和料成本的日益高昂,有必要寻找低价易得、品质优异的粉煤灰替代碾压混凝土掺和料。文章基于多元掺和料的复合效应,用硅灰、石灰石粉替代部分粉煤灰,设计了三组不同配比的掺和料,开展7天、28天、90天龄期抗压强度、抗拉强度与弹性模量试验,对比分析其力学特性差异。研究结果表明:硅灰和石灰石粉的掺加对碾压混凝土的早期强度无不利影响,且单掺硅灰或复掺硅灰与石灰石粉能有效改善其强度特性。研究结果对解决粉煤灰匮乏难题具有重要意义。

It is necessary to find an alternative RCC admixture with low cost,easy availability and good quality with the increasing cost of fly ash admixture.The paper is based on the compound effect of multiple admixtures.Silica fume and limestone powder are used to replace a part of fly ash.Three groups of admixtures with different proportion are designed.The compressive strength,tensile strength and elastic modulus tests are carried out at the 7th,28th and 90th day.The differences in mechanical properties are compared and analyzed.The results show that the addition of silica fume and limestone powder has no adverse effect on the early strength of RCC,and the strength characteristics of RCC can be effectively improved by mix silica fume alone or mix silica fume and limestone powder both.The research results are of great significance to solve the problem of fly ash shortage.