基于显微镜观测的不同钙源下微生物固化砂强度提升机理的宏细观研究  

Macro-micro Study on the Strengthening Mechanism of MICP-treated Sand with Different Calcium Sources Basedon Microscope Observation

作　　者：刘超凡 杜强 曲立强[1] 刘旭梅 LIU Chaofan;DU Qiang;QU Liqiang;LIU Xumei(School of Civil Engineering,Inner Mongolia University of Technology,Hohhot 010051,China;Key Lab of University of Geological Hazards and Geotechnical Engineering Defense in Sandy and Drought Regions,Hohhot 010051,China;Inner Mongolia Engineering Research Center of Geological Technology and Geotechnical Engineering,Inner Mongolia University of Technology,Hohhot 010051,China)

机构地区：[1]内蒙古工业大学土木工程学院,呼和浩特010051 [2]沙旱区地质灾害与岩土工程防御自治区高等学校重点实验室,呼和浩特010051 [3]内蒙古工业大学地质技术与岩土工程内蒙古自治区工程研究中心,呼和浩特010051

出　　处：《内蒙古农业大学学报(自然科学版)》2025年第2期63-71,共9页Journal of Inner Mongolia Agricultural University(Natural Science Edition)

基　　金：内蒙古自治区自然科学基金项目(2022LHMS05010);内蒙古自治区直属高校基本科研业务费项目(JY20220096,ZTY2023056,ZTY2023058)。

摘　　要：微生物诱导碳酸钙沉积(MICP)技术是一种新兴的土体加固技术,而添加不同钙源后固化效果截然不同。选取氯化钙、乙酸钙和乳酸钙作为胶结液钙源,基于数码显微镜观测,结合测定破坏后试件不同部位的碳酸钙含量,总结不同钙源下浸泡法固化试件中碳酸钙的分布规律,从细观角度分析不同钙源产生不同晶型碳酸钙的分布差异,综合分析由不同钙源诱导生成的不同晶型碳酸钙在试件中的宏细观分布对试件强度的影响。试验结果表明:不同钙源下生成的碳酸钙的细观沉积存在差异,氯化钙和乳酸钙为钙源时,主要在颗粒孔隙间沉积,而乙酸钙为钙源时,则主要在颗粒表面沉积;乙酸钙在颗粒表面生成的无效沉积碳酸钙并非完全无效,而是为颗粒提供摩擦力,碳酸钙含量较高时试件同样具有较高强度。Microbial induced calcium carbonate precipitation(MICP)is a burgeoning soil strengthening technique,but dfferent cal-cium sources may result in varying strength effects.This study selected calcium chloride,calcium acetate and calcium lactate as the calcium sources of cementation.By measuring the contents of CaCO,in different parts of samples,the macroscopic distributions of CaCO,in samples with different calcium sources were determined.The differences in the intergranular distribution of different CaCO,crystal types from a microscopic view were also analyzed.Comprehensive analysis revealed how the macroscopic and intergranular distributions of different crystallographic CaCO,influenced the strength of the samples.It was showed that when calcium chloride and calcium acetate were used as calcium sources,CacO,primarily precipitated in the lower part of the sample.In contrast,when calcium lactate was used,CaCO,predominantly precipitated around the periphery of the sample.There are differences in the intergranular precipitation of CaCO,with different calcium sources,CaCO,mainly precipitated in the intergranular pores when calcium chloride and calcium lactate were used as the calcium sources,CacCO,mainly precipitated on the surface of particles while calcium acetate as the calcium source.The ineffective precipitation of CaCO,generated by the calcium acetate on the surface of the particles was not completely‘ineffective',but it provided friction between the particles,and the sample also had higher strength when the content of calcium carbonate was higher.

关 键 词：钙源 MICP 无侧限抗压强度 晶型 无效沉积 

分 类 号：TU41[建筑科学—岩土工程]