Biocementation of calcareous sand using soluble calcium derived from calcareous sand
Biocementation of calcareous sand using soluble calcium derived from calcareous sand
复制标题
使用源自钙质砂的可溶性钙对钙质砂进行生物胶结
DOI：
10.1007/s10064-017-1106-4
复制
发表时间：
2018-11-01
影响因子：
4.2
通讯作者：
Wang, Yang
中科院分区：
文献类型：
--
作者：
Liu, Lu;Liu, Hanlong;Wang, Yang
微生物诱导碳酸盐沉淀法是近年来发展起来的一种土壤改良方法。在这种方法中，碳酸钙被原位沉淀，作为胶结剂。氯化钙通常用作MICP法的钙源。使用氯化钙会导致两个问题。一是氯化物对混凝土有腐蚀性，二是氯化钙的成本相对较高。对这种方法的一个改进是使用其他替代钙源。本文提出了一种利用富钙钙质砂制取可溶钙，并将其作为MICP法的钙源来改良土壤性质的方法。对比研究了石灰砂中产生的可溶性钙与相同钙浓度的氯化钙对MICP值的处理效果。试验结果表明，随着胶结液加入量的增加，钙质砂的强度和硬度增加，渗透性降低。扫描电子显微镜(SEM)和X-射线衍射仪分析表明，使用可溶性钙时，生成了针状矿物形态的文石晶体，而使用氯化钙时，生成了菱面体矿物形态的方解石晶体。本研究还表明，利用钙质砂中产生的可溶性钙，采用MICP法处理钙质砂是可行的。
A soil improvement method based on a microbially induced carbonate precipitation (MICP) process has been developed in recent years. In this method, calcium carbonate is precipitated in-situ to act as a cementing agency. Calcium chloride is normally used as the calcium source for the MICP process. The use of calcium chloride causes two problems. The first is chloride is corrosive to concrete, and the second is the cost of calcium chloride is relatively high. An improvement to this method is to use other alternative calcium sources. A method to produce soluble calcium using calcium rich calcareous sand and use it as a calcium source for the MICP process to improve the properties of soil has been proposed in this paper. A comparative study between the effect of MICP treatment using soluble calcium produced from calcareous sand and that using calcium chloride with the same concentration of calcium was carried out. The results from both series of tests showed that with increasing amounts of cementation solutions, the strength and stiffness of the treated calcareous sand increased and the permeability decreased. The scanning electron microscopy (SEM) and X-ray diffraction analyses revealed that the aragonite crystals with an acicular mineral morphology were formed when the soluble calcium was used, whereas the calcite crystals with a rhombohedral mineral morphology were formed when calcium chloride was used. This study also shows that it is feasible to treat calcareous sand using a MICP method with soluble calcium produced from calcareous sand.