水泥固化重金属污染膨胀土物理性质试验研究

重金属污染对生态环境和工程安全均造成严重不利影响,而对重金属污染膨胀土的固化研究还处于初级阶段。采用南阳地区膨胀土,通过室内添加硝酸铅和硝酸镉溶液分别配制3种不同浓度的重金属污染膨胀土,并采用水泥进行固化。在不同的水泥固化剂掺量下,对固化的重金属污染膨胀土进行击实、液塑限和自由膨胀率试验研究。比较分析干密度、自由膨胀率和液塑限随重金属浓度、水泥掺量的变化规律。试验表明,随着重金属Pb、Cd浓度的增加,污染膨胀土的干密度和自由膨胀率增大,而液塑限降低;掺入水泥后,污染膨胀土的干密度和自由膨胀率随着水泥掺量的增加而降低,液塑限提高,并且水泥对铅污染膨胀土的固化效果优于镉污染膨胀土。

Study on the physical properties of solidified heavy metal contaminated expansive soil with the cement

Heavy mental pollution has serious adverse effects on ecological environment and engineering safety, but the study on solidified of the heavy mental contaminated expansive soil is still at the preliminary stage. The expansive soil of the experimental was from Nan yang, and added lead nitrate and cadmium nitrate solution to respectively prepared three kinds of different concentrations of heavy metal pollution soil, added cement to solidified; To do compaction test, liquid plastic limit and free expansion rate experimental after solidification, comparison of dry density, free expansion rate and liquid plastic limit change rule at different heavy metal content and different amount of cement. Experimental results show that dry density and free expansion rate is increased, liquid plastic limit is decrease with the concentration increase of heavy metal Pb, Cd; After mixed with cement, the dry density and free expansion rate is decrease, liquid plastic limit is increase, the effects of cement to solidified Pb is better than the Cd.