水玻璃复配改良膨胀土的试验研究

Experimental Study on the Modification of Expansive Soil with Sodium Silicate Compounds

为提高水玻璃改良膨胀土的作用效果,选用氯化钙、氯化铝、阳离子型聚丙烯酰胺和十六烷基三甲基溴化铵4种物质,与硅酸钠以不同配合比复配改良膨胀土,采用改进后的自由膨胀率试验方法测试改良土的自由膨胀率,筛选与硅酸钠复配改良膨胀土效果较好的化学组合,并分析不同组合改性剂的经济性和适用性,测试最佳配比改性土的变形和强度指标。研究结果表明,硅酸钠和4种物质复配改良膨胀土效果均有所提高;硅酸钠和阳离子型聚丙烯酰胺复配最为合适;硅酸钠和阳离子型聚丙烯酰胺掺量分别占干土质量的2.5%和0.5%时,改性效果最佳,改性土能够较好满足工程需要。

In order to improve the modification effect of sodium silicate on expansive soil, different dosages of calcium chloride, aluminium chloride, cationic-type polyaerylamide and hexadecyl trimethyl ammonium bromide are mixed with sodium silicate to modify the expansive soil, and then the free swelling ratios of modified soils are determined with improved test method. The best compounding of modified expansive soil is determined, and then the economy and applicability of modified expansive soil are analyzed and the deformation and strength of expansive soil are tested. The results show that, （a） all of the above four materials can improve the modification effect of sodium silicate; （b） the sodium silicate and cationic-type polyaerylamide are the best combination; and （c） when the content of sodium silicate and cationic-type polyacrylamide are 2.5% and 0.5% to dry soil weight respectively, the modified expansive soil can completely satisfy engineering requirement.