离子土壤固化剂改性膨胀土的试验研究

利用离子土壤固化剂（ionic soil stabilizer，简称ISS）对河南安阳地区膨胀土进行化学改性试验研究，通过不同配比的自由膨胀率试验结果，结合施工成本，得出ISS溶液改良膨胀土的最优配合比为1:350。对ISS溶液最优配合比改性后土体进行收缩试验、膨胀性试验、固结快剪、高压固结及水浸泡试验。试验结果表明，改性土线缩率减小，膨胀性指标降低，抗剪强度增大，土体由亲水性变成憎水性，且能达到较好的水稳定性，即膨胀土经化学改性为非膨胀土。ISS改性膨胀土的机制可解释为，通过ISS溶液与土粒离子进行强烈的交换作用，打开土粒与水分子之间的“电化键”，降低土颗粒表面吸附水膜厚度，包裹在黏粒颗粒表面的疏水基团覆盖膜使土对水的敏感性减弱，从根本上减少了土体吸水性和膨胀性。

Experimental study of ionic soil stabilizer-improves expansive soil

The chemical improving expansive soil of Anyang in Henan province by experiment with ionic soil stabilizer is studied. Through free swelling ratio test results combined with construction cost, the optimal ratio of ISS solution is identified as 1:350. The soil test was carried out after the soil is chemical treated in optimal ratio of ISS solution. The soil tests include the shrinkage test, swelling index tests, consolidated quick shear test, high-pressure consolidation test and water immersion test. The soil test results show that the linear shrinkage ratio and swelling index decrease, shear strength Increase; and the improved soil has been changed from hydrophilicity to hydrophobicity and has good water stability; videlicet, the expansive soil become non-expansive after chemical treatment. It appears that the mechanism of action of ionic soil stabilizer on expansive clay can be explained through cation exchange with the surface and interlayer cations. This reduces the density of the electrical charge around the clay particles which leads to them being attracted closer to each other to form flocs; it is an irreversible process which leads to reduction of expansion and modification of the engineering properties of the expansive soil.