盐溶液浸泡养护固化土的耐久性分析

基于改善固化土养护环境的思路,提出了用硅酸钠、硫酸钠和氢氧化钠的混合溶液以及饱和石灰水养护固化土,以期达到提高固化土的耐久性,延长固化土使用寿命的目的。通过无侧限抗压强度试验、干湿循环试验、冻融循环试验以及扫描电子显微镜试验对两种盐溶液养护进行了对比研究。试验结果表明,硅酸钠、硫酸钠和氢氧化钠的混合溶液养护与饱和石灰水养护均可提高固化土的强度、抗干湿循环以及抗冻融循环的耐久性;硅酸钠、硫酸钠和氢氧化钠的混合溶液养护对强度和耐久性的提高优于饱和石灰水养护;微观结构分析表明,两种溶液养护固化土生成了较多致密的凝胶物质,增加了黏聚力,降低了孔隙率,减少了大孔隙。

Durability of Stabilized Soil Cured with Saline Solution

In order to improve the durability and prolong the service life of the stabilized soil, the methods of curing stabilized soil in the mixture solution of sodium silicate, sodium sulfate and sodium hydroxide and in the saturated limewater were proposed based on the idea of improving the curing environment of stabilized soil. The unconfined compression strength test, dry-wet cycle test, freezing-thawing cycle test and scanning electron microscope(SEM) test were conducted to compare the two kinds of saline solution curing methods. The results showed that curing stabilized soil in the mixture solution of sodium silicate, sodium sulfate and sodium hydroxide or in the saturated limewater could improve the strength, the resistance of dry-wet circulation and freezing-thawing circulation; Considering the effect on improvement of strength and durability, curing in the mixture solution of sodium silicate, sodium sulfate and sodium hydroxide was better than curing in the saturated limewater; Microscopic structures showed that the two kinds of curing methods generated more dense gel material, increased the cohesion, reduced the porosity, and decreased the macropore of the stabilized soil.