硅粉对水工混凝土基本特性影响的研究

Research on the influence of silica fume on the basic characteristics of hydraulic concrete

为研究硅粉对水工混凝土基本性能的影响规律,利用硅粉替代不同质量的水泥和3种不同的细骨料制备了混凝土,并对混凝土的工作性能、密度、强度和蠕变特性进了试验,结果证明:随着硅粉替代比的增加,混凝土的密度、坍落度、密实度和抗压强度均先增后减;而吸水率和泌水量随着硅粉替代比的增加先减后增。随着龄期的增加,混凝土试样的抗压强度逐渐增加;随着加载时间的增加,混凝土试样的蠕变变形也逐渐增加,且在15 d内的蠕变速率最快。硅粉替代比相同时,河砂骨料混凝土的坍落度和密度也最高;玄武岩细骨料混凝土的抗压强度最高;而石灰岩细骨料混凝土的工作性能和强度最低;由此可得河砂和玄武岩砂混凝土的强度和蠕变性能均优于石灰岩砂混凝土的蠕变性能;硅粉的最佳掺量为10%。

In order to study the influence of silica fume on the basic properties of hydraulic concrete,concrete was prepared by using silica fume instead of cement of different quality and three different fine aggregates,and then the work performance,density,strength and creep characteristics of concrete were tested,and the results proved that with the increase of the replacement ratio of silica fume,the density,slump,compactness and compressive strength of concrete increased first and then decreased;While the water absorption and bleeding volume decrease first and then increase with the increase of the replacement ratio of silicon powder.As the curing age increases,the compressive strength of the concrete sample gradually increases;With the increase of the loading time,the creep deformation of the concrete sample gradually increases,and the creep rate is the fastest within 15 days.When the replacement ratio of silica fume is the same,the slump and density of river sand aggregate concrete are the highest;And the compressive strength of basalt fine aggregate concrete is the highest;While the work performance and strength of limestone fine aggregate concrete is the lowest;The strength and creep properties of sand and basalt sand concrete are better than those of limestone sand concrete;the optimum content of silica fume is 10%.