高盐度环境下固化渣土强度特性研究

Engineering Characteristics of Solidified Metal Contaminated Soil under High Salinity Environment in the Guangdong Province

本项研究目的在于揭示高盐度环境下,渣土在水泥固化后的强度特性。选取深圳市某受纳场的建筑渣土作为研究对象,水泥掺量10%和20%(相对土壤质量),用0 mol/L和1 mol/L氯化钠模拟盐溶液环境,选择0‰、1.5‰、3‰、6‰(相对土壤质量)锌和铜离子作为金属污染离子,养护龄期分别为7 d、14 d、28 d和90 d。实验数据显示,在水泥掺量不变前提下,固化金属渣土的无侧限抗压强度随着铜离子浓度的上升而下降。在铜离子浓度不变的情况下,固化金属渣土的无侧限抗压强度随着水泥的掺入量增加而提高。金属离子浓度较高的固化渣土在前期的养护中抗压强度随养护时间的增加有明显提升。在铜离子的影响下,固化金属渣土的无侧限抗压强度随着盐浓度的上升而提升。在锌离子的环境下,固化金属渣土的无侧限抗压强度随着盐浓度的上升而下降。通过电子显微镜技术分析固化金属渣土的微观形貌特证,低浓度金属渣土中发现大量水化硅酸钙。

The aim of this study is to study the mechanical behavior of cemented soils in the saline environment.The kaolin soils from a Shenzhen receiving field was selected,the cement content was 10%and 20%(by weight),NaCl solution at 0M and 1M was selected to simulate the saline environment.Zn and Cu ions at 0‰、1.5‰、3‰、6‰(by weight)was selected.The curing day was 7,14,28 and 90 days.The results show that at the constant cement content,the strength of cemented soil decreased as the Cu ion concentration increased.At the constant Cu ion content,the strength of cemented soil will increase as the cement content increases.The ion content has great effect on the curing day,as the strength increases significantly.At the influence of Cu ion,the strength increases as the salinity increases.However,the strength decrease as the Zn ion content increases.SEM picture shows there are much of calcium silicate formed in the Cu ion condition.