Effect of chemical treatment used in MICP on engineering properties of cemented soils
Effect of chemical treatment used in MICP on engineering properties of cemented soils
复制标题
DOI：
10.1680/geot.sip13.p.022
复制
发表时间：
2013-03-01
期刊：
影响因子：
5.8
通讯作者：
Soga, K.
中科院分区：
文献类型：
--
作者：
Al Qabany, A.;Soga, K.
尽管大量的研究涉及微生物诱导的碳酸盐沉淀（MICP）在土壤中，很少注意到的效果的化学浓度在处理中使用的碳酸钙的沉淀模式和它们对MICP水泥土的工程性质的影响。在这项研究中，无侧限抗压强度试验进行了处理，使用0.1，0.25，0.5和1 M尿素氯化钙溶液的砂样。结果发现，尽管测试样品的强度在MICP处理后都有所增加，但这种增加的幅度取决于处理中使用的浓度，并且使用低化学品浓度（即尿素和氯化钙）溶液导致样品更强。渗透性测试结果表明，使用高尿素氯化钙浓度的溶液导致在方解石沉淀的早期阶段的渗透性迅速下降，而使用低化学品浓度的溶液被发现导致在一个更渐进和均匀的渗透性下降。所观察到的化学浓度对MICP水泥土的强度和渗透性的影响可能对现场应用的MICP设计产生影响。
Despite the large number of studies concerned with microbially induced carbonate precipitation (MICP) on soils, little attention has been paid to the effect of the chemical concentration used in the treatment on the precipitation pattern of calcium carbonate and their influence on engineering properties of MICP cemented soils. In this study, unconfined compressive strength tests were conducted on sand samples treated using 0.1, 0.25, 0.5 and 1 M urea-calcium chloride solutions. It was found that, although the strength of tested samples all increased after MICP treatment, the magnitude of this increase depended on the concentration used in the treatment and that the use of a low-chemical-concentration (i.e. urea and calcium chloride) solution resulted in stronger samples. Permeability test results showed that the use of a high-urea-calcium chloride-concentration solution resulted in a rapid drop in permeability at the early stage of calcite precipitation, whereas the use of a low-chemical-concentration solution was found to result in a more gradual and uniform decrease in permeability. This observed effect of chemical concentration on the strength and permeability of MICP cemented soils can have implications for the design of MICP for field applications.