珍珠岩粉火山灰活性研究

Investigation on pozzolanic activity of perlite powder

为促进珍珠岩作为水泥基辅助胶凝材料应用,分别采用化学分析活性组分的活性率法、XRD法、砂浆强度比的活性指数法定量分析评判珍珠岩粉火山灰活性大小,并讨论其影响因素.珍珠岩粉化学分析活性组分硅和铝量占全部硅和铝量百分率即活性率32.95%,与沸石粉的相当但低于硅灰的;通过珍珠岩粉XRD{2132}峰半高宽法测定非晶态SiO2含量而计算得其火山灰活性55.23%;以砂浆强度比表述的活性指数研究显示两种细度珍珠岩粉达到国家标准中沸石粉的要求,掺30%珍珠岩粉的活性指数均大于火山灰活性界值0.62.尽管各种方法测试的珍珠岩粉火山灰活性表征参数及其结果有差异,但都可得出珍珠岩粉有较高火山灰活性的结论,其火山灰活性还受SiO2和Al2O3含量、结构非晶态的比率、粉末细度、水化环境等因素影响.

In order to develop perlite used as pozzolano in cement-based material, pozzolanic activity of perlite powder is investigated in the paper. Pozzolanic activity of perlite powder was respectively determined in three ways ： analysis of chemical constituents, XRD and ratio of mortar strength with admixture to without it. Then the effect factors on pozzolanic activity of perlite powder were discussed. The results from analysis of chemical constituents indicated that the proportion of active SiO2 and active Al2O3 in total SiO2 and total Al2O3 for perlite powder is 32.95%, and it is similar with zeolite powder, hut smaller for condensed silica fume. Pozzolanic activity of perlite powder can be calculated to 55.23% with abundance of non-crystal SiO2 to be measured by XRD {2132} data. With pozzolanic activity index （PAI） that is ratio of mortar strength with admixture to without, research showed that PAl values of perlite powder in different fineness are larger than zeolite＇s according to the national standard. Meanwhile PAI values of mortars with 30% perlite powder are all above critical value 0.62 for pozzolanic activity. In spite of some difference of parameters due to the express of pozzolanic activity and their data from various test ways, it was concluded that perlite powder has high pozzolanic activity and pozzolanic activity of perlite powder is affected by following factors： content of SiO2 and Al2O3 in chemical constituent, proportion of vitrescence in texture, powder fineness and hydration environment in cement-based material.