碳化对水泥固化铅污染土的电阻率特性影响规律  

EFFECT OF CARBONATION ON ELECTRICAL RESISTIVITY OF CEMENT SOLIDIFIED LEAD-CONTAMINATED SOILS

作　　者：章定文[1,2] 曹智国[1,2] 张涛[3] 刘松玉[1,2] 

机构地区：[1]东南大学岩土工程研究所,江苏南京210096 [2]东南大学江苏省城市地下工程与环境安全重点试验室,江苏南京210096 [3]江苏省交通规划设计院股份有限公司,江苏南京210014

出　　处：《岩石力学与工程学报》2014年第12期2563-2572,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：江苏省自然科学基金项目(BK2011618);国家自然科学基金资助项目(51279032);中央高校基本科研业务费专项资金项目(2242014R30020)

摘　　要：为确保重金属污染场地再开发利用的稳定性和安全性，采用室内加速碳化试验研究碳化对水泥固化铅污染土电阻率特性的影响规律。人工配制不同铅含量的污染土，采用水泥固化后进行室内加速碳化试验，分析碳化作用对固化土电阻率和pH值的影响规律，并讨论固化土的电阻率与无侧限抗压强度的相关关系。试验结果表明，碳化作用下水泥固化铅污染土的电阻率随着碳化时间和水泥掺入量的增加而增大，随着铅含量、孔隙率和饱和度的增加而减小。提出一个能够有效反映碳化时间、水泥掺入量和铅含量等因素对固化土电阻率影响的表征参数，采用该参数替代 Archie 电阻率模型中的土体孔隙率即可将Archie电阻率模型扩展应用到水泥固化重金属污染土领域。固化土的pH值随着铅含量增加而有所降低；碳化后固化土的pH值从11～12降低到8～9。固化土的电阻率与强度具较好的对应关系，电阻率法可作为一种有效的水泥固化铅污染土性能评价方法。In order to ensure the safety utilization of heavy metal contaminated ground,it is necessary to investigate the effect of carbonation on the performance of cement solidified heavy metal-contaminated soils. Artificial contaminated soils with three different lead contents were solidified using cement,and the electrical resistivity and pH values of the solidified samples before and after carbonation were tested. The carbonation led to an increase of the electrical resistivity of cement solidified lead-contaminated soils,but the electrical resistivity decreased with the increase of lead content,porosity and degree of saturation. A modified Archie′s electrical resistivity model was proposed by replacing the porosity with a parameter which represented the influence of carbonation time , cement content , and lead content on the electrical resistivity of cement solidified lead-contaminated soils. The Archie′s electrical resistivity model was extended to heavy metal contaminated soils. The results also showed that adding lead reduced slightly pH values of the solidified soils,and the pH values of the samples varied from 11–12 to 8–9 after carbonation. There is a nonlinear relationship between the electrical resistivity and the unconfined compression strength of solidified soils.

关 键 词：土力学 水泥固化铅污染土 碳化 电阻率 电阻率模型 pH值 无侧限抗压强度 

分 类 号：TU41[建筑科学—岩土工程]