纳米二氧化硅对活性粉末混凝土力学性能影响的试验研究  

Research on the influence of the Reactive Powder Concrete Mechanical Properties by Nano-Silica

作　　者：刘丹[1] 杜应吉[1] 史凯方[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《中国农村水利水电》2011年第12期127-130,134,共5页China Rural Water and Hydropower

基　　金：国家"十一五"科技支撑计划重点项目(2006BAD11-B03)

摘　　要：活性粉末混凝土(RPC)是一种具有超高力学性能的新型水泥基复合材料,根据最大密实度理论配制而成。纳米SiO2比RPC中各成分的粒径都小,不但可以进一步物理填充其微小空隙,而且具有很高的火山灰活性。通过考虑水胶比、硅灰掺量、矿渣掺量三个因素,采用L9(34)正交设计,确定出RPC的基准配合比,再添加不同掺量的纳米SiO2,通过分析7d和28d的强度值,发现当纳米SiO2的掺量为0.5%～1%时,提高了RPC的抗折强度、抗压强度和劈拉强度。同时结合电镜扫描,发现纳米SiO2使水泥基体水化反应更加充分,并且改善了界面结构,降低了浆体的结构缺陷,从微观方面说明了纳米SiO2提高其力学性能的机理。Reactive powder concrete （RPC） is a new type of cement composite material with high mechanical properties, which is designed according to the maximum density theory. Nano-SiO2 is smaller than the diameter of each component in RPC, it not only can fill the tiny gaps physically but also has high pozzolanic activity. The base mix of RPC is selected through orthogonal design of L^9 （3^4 ） by considering the water-cement ratio, silica fume and slag. Then, by adding different contents of nano -SiO2. It is found that the flexural strength, compressive strength and splitting tensile strength is enhanced when the content of nano-SiO2 is between 0.5% and 1% by analyzing the strength values of 7 d and 28 d. If combined with SEM , you can find that the nano-SiO2 makes the cement ma- trix respond more fully and improve the interface structure and reduce the structural defects of cement paste which shows the mechanism nano-SiO2 enhance its mechanical properties from the micro.

关 键 词：活性粉末混凝土 纳米SIO2 正交设计 力学性能 微观分析 

分 类 号：TU528.31[建筑科学—建筑技术科学]