新型酸性水玻璃注浆材料的研究与应用

针对城市地铁穿越砂层时注浆预加固的材料问题,研究磷酸-水玻璃注浆材料的凝胶时间、凝胶形态和砂土固结体强度的影响因素以及工程应用材料配比,设计磷酸-水玻璃注浆材料室内凝胶性能试验和砂土固结体强度试验,并与传统的硫酸-水玻璃注浆材料进行系统性对比,最后根据室内试验选择合适的材料配比进行现场注浆试验。试验结果表明:1)磷酸-水玻璃混合液中,当磷酸的掺量增大时,磷酸与水玻璃的体积比增大,混合液的pH值减小,凝胶时间增大,存在一一对应的关系;2)磷酸-水玻璃混合液的pH值是磷酸-水玻璃浆液凝胶时间和凝胶形态的决定性因素;3)磷酸-水玻璃浆液中磷酸质量分数、水玻璃波美度和混合液体积比分别变化时,加固体抗压强度稍有变化,影响较小。

Study and Application of a New Acid Water Glass Grouting Material

In view of the problem of material pre grouting reinforcement in urban metro crossing sand layer, the gel time, gel form, influencing factors of strength of sand consolidation material of phosphoric acid water glass grouting material and engineering application ratio of materials are studied. Laboratory test on gel properties of phosphoric acid water glass grouting material and test on compressive strength of soil consolidation are designed and compared with those of traditional sulphuric acid water glass grouting material. After that，field tests are carried out. The test results show that: 1) With the increase of the concentration of phosphoric acid, the volume ratio of phosphoric acid and sodium silicate increases, the pH value of mixed liquor decreases and the gel time increases. 2) The pH value of the mixed solution of phosphoric acid water glass is the decisive factor of the gel time and the gel shape. 3) The variations of phosphoric acid concentration, water glass Baume and volume ratio of mixed liquid in phosphoric acid water glass grout have a little effect on the compressive strength of the consolidation body.