多种注浆材料耐久性能对比试验研究

Experimental study on durability of various grouting materials

从材料的微观结构出发,运用抗水溶蚀、抗渗性能及体积稳定性试验,对比研究了高水注浆材料与纯水泥浆液、水泥-水玻璃和胶砂等常用注浆材料的耐久性能.通过模拟地下动水对材料的侵蚀作用,研究其抗压强度的降低和由于剥离引起的质量变化,并测量该过程中溶蚀液电导率和溶解固形物总量的变化.采用规范规定的标准试验方法测定抗渗性能,体积稳定性则用干缩性能和早期开裂性能进行表征.结果表明：高水注浆材料和纯水泥浆在动水养护条件下强度损失和质量损失率均较小于其他类型的材料,具有较强的抗水溶蚀能力;渗透系数随着水灰比的增加而变大,随龄期的增加而减小,水灰比1.0,1.5和2.0范围内的高水注浆材料结石体28 d渗透系数均能达到1×10^-10 m/s级;基于材料本身的充分反应和石膏等物质的掺入,高水注浆材料体积稳定性能也较为优异,伴随着水灰比的增加,其裂缝宽度逐渐减小,即早期抗开裂性能逐渐提高.

Based on the microstructure,the water resistance,impermeability and volume stability of high water grouting materials,pure cement slurries,cement-water glass and mortar materials were analyzed by durability tests.The decline of compressive strength and the mass loss due to peeling were studied by simulating the erosion effect on the material under the conditions of flowing groundwater,and the changes of the conductivity and total dissolved mass in the process were measured. Impermeability was determined by standard test methods, and volume stability was characterized by dry shrinkage and early cracking performance.Results show that the strength loss and mass loss rate of the high water grouting material and pure cement slurries are less than other types of materials under the conditions of flowing water curing with stronger water resistance.The permeability coefficient increases with the increase of water cement ratio and decreases with the development of age.The permeability coefficient of 28 d of the high water grouting material stones with water-cement ratio of 1.0,1.5 and 2.0 can reach a level of 1×10-10 m/s.Based on the full reaction of the material itself and the incorporation of gypsum and other substances,the high water grouting material has excellent volume stability.With the increase of water-cement ratio,the crack width of the high water grouting material gradually decreases,which means the early cracking resistance gradually increases.