预处理硅灰对水泥净浆和砂浆的性能影响

为充分利用硅灰的优良性能，对商品硅灰进行了不同pH值下机械化学分散预处理，用马尔文纳米激光粒度仪测试硅灰分散液的颗粒粒径和Zeta电位，并将预处理硅灰液掺入水泥中，成型水泥净浆和水泥砂浆试样，测试净浆试样室温和砂浆试样室温、冻融循环及高温下的性能。结果表明，提高分散水pH值、加入聚羧酸减水剂有利于硅灰分散细化，降低其沉降速度；掺预处理硅灰可以提高水泥净浆和水泥砂浆的力学性能，以及水泥砂浆耐高温和抗冻性性能。

Effect of Pretreatment of Silica Fume on Cement Paste and Mortar Performance

In order to fully take advantage of the excellent performance of silica fume, commercial silica fume was mechanical and chemical pretreatment dispersed at different pH values in this paper. Malvern zetasizer nano tests particle size and zeta potential of the dispersion of silica fume. Molded cement paste and cement mortar specimens by mixing with pretreatment dispersed silica fume and cement, then test properties of paste specimens at room temperature and properties of mortar specimens at room temperature, freeze-thaw cycles and high temperature. The results showed that high dispersion of water pH value and polycarboxylate were conducive to disperse and refine silica, and reduce the settling velocity. Doped pretreatment silica fume can improve the mechanical properties cement paste and cement mortar. It can improve the resistance to high temperature and frost resistance properties of cement mortar.