水泥-水玻璃双液注浆材料工程性能及孔隙结构

Engineering properties and pore structure of cement-sodium silicate double solution grouting material

水泥-水玻璃双液注浆材料由于其凝胶时间短、早期强度高、材料经济且来源广泛等诸多优点,而被大量用于工程注浆堵水中.通过黏度试验、凝胶时间试验、线膨胀试验与低温氮气吸附试验,深化了对双液注浆材料基本性能的认识,同时结合试验结果提出最优双液注浆材料配合比.凝胶时间试验表明,在水泥掺量增加、温度升高的过程中,浆液的凝胶时间从148～367s减少到71～211s;黏度试验表明,由20℃升温到50℃时,黏度从10.39～178.57m2/s非线性降低到6.84～83.58m2/s,浆液表现出明显的非牛顿流体的特性;浆液结石体低温氮气吸附条件下,浆液孔径分布在2～10nm,浆液孔隙分布均匀,不易发生渗漏现象;凝固后的浆液结石体线膨胀系数在30℃到60℃有下降趋势,但浆液仍表现为热膨胀性,而在大于70℃时线膨胀系数变为负值,浆液结石体出现收缩性质.

Cement-sodium silicate double solution grouting material has been widely used in engineering grouting because of its short gel time, high early strength, economical and wide range of material resources, etc.. The basic properties of the double solution grouting material were investigated by viscosity test, gel time test, linear expansion test and low temperature nitrogen adsorption test. The optimum mixture ratio of double solution grouting material is proposed. The gel time test shows that the gel time decreases from 148-367 s to 71-211 s in the process of cement dosage increasing and temperature increasing. Through the viscosity test, it is found that when the temperature increases from 20℃ to 50 ℃, the viscosity of double solution grouting material nonlinearly reduces from 10. 39-178. 57 m2/s to 6. 84-83. 58 m2/s, and the slurry shows obvious characteristics of non-Newtonian fluid. Under the condition of low temperature nitrogen adsorption, it can be seen that the slurry pore, size distribution is between 2 nm and 10 nm, and it is not easy to leak because of its size distribution＇s uniform. The linear expansion coefficient of the solided crystal decreases from 30℃ to 60℃, but it still has the thermal expansion property. In the meantime, when the temperature is above 70℃, the linear expansion coefficient is negative, and its crystal shows the characteristics of the shrinkage.