固化盐渍土的自生体积稳定性

Autogenous volumetric stability of solidified saline soil

为避免盐渍土在固化过程中可能发生的体积变形危害,研究其自生体积稳定性。制备了290mm长的试件,利用高精度位移测量系统,测试了不同含量的氯盐与硫酸盐在不同固化剂体系下引起的固化土的线性膨胀/收缩率,分析了C a2+、N a+以及含水率对膨胀/收缩率的影响。结果表明:固化氯盐盐渍土不会发生较大的体积变形,而固化硫酸盐盐渍土可能引起巨大的膨胀率;采用矿渣-粉煤灰-水泥复合固化剂,参与化学反应而产生膨胀性产物的C a2+减少,可以降低固化盐渍土的膨胀率。当C a2+不足而N a+充分时,氯盐和硫酸盐不会对化学反应起促进作用。含水率会影响固化土结构的疏密程度以及膨胀性产物的生长位置。

The autogenous volumetric stability of solidified saline soils was investigated to prevent damage to roads caused by volume changes of the road foundations. Specimens with the length of 290 mm were prepared for linear expansion/shrinkage measurements of soils containing various amounts of chlorine and sulfate radicals. The specimens were solidified by three types of soil stabilizers. The studies analyzed the effect of calcium ions, sodium ions, and water content on the expansion and shrinkage. The results show that chlorine causes little volume variation but sulfate radicals can cause significant expansion of the solidified soil. Slag-fly ash-cement stabilizer provides less calcium ions for chemical reactions than cement resulting in less expansion of the solidified saline soil specimens. When there are few calcium ions but many sodium ions, the chlorine and the sulfate radicals do not stimulate chemical reactions in the soil. The water content influences the spacing between soil particles and the expansion.