基于微生物矿化的砂体胶结强度及耐久性试验研究  

Experimental Study on Cementation Strength and Durability of Sand Body Based on Microbial Mineralization

作　　者：马锋玲[1,2] 韩栋 王利娜 徐耀 鲍志强[2,4] 李蓉 MA Fengling;HAN Dong;WANG Lina;XU Yao;BAO Zhiqiang;LI Rong(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Key Laboratory of Engineering Materials of Ministry of Water Resources,Beijing 100038,China;Center of Engineering and Construction Service,MARA,Beijing 100081,China;Beijing IWHR-KHL Co.,Ltd.,Beijing 100038,China)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [2]水利部水工程材料重点实验室(筹),北京100038 [3]农业农村部工程建设服务中心,北京100081 [4]北京中水科海利工程技术有限公司,北京100038

出　　处：《水力发电》2023年第6期115-121,共7页Water Power

基　　金：流域水循环模拟与调控国家重点实验室自主研究课题(SKL2022TS06);中国水科院基本科研业务费项目(SM0145B022021)。

摘　　要：微生物诱导碳酸钙沉淀技术(MICP)是岩土工程领域中新兴的新型绿色环保地基加固技术之一。基于砂土固化的力学性能和微观测试,研究了MICP技术的固化效果。研究结果表明,微生物水泥胶结砂柱最高强度可达37.9 MPa,抗渗性能可从胶结前的1.72×10-2 cm/s提高至7.66×10-7 cm/s;经100次冻融循环后,试件外观完整,无明显缺陷和掉砂;冻融50次时强度损失率为17.0%,胶结砂体具有良好的抗冻耐久性能。40 mm×40 mm×160 mm棱柱体标准试件抗压强度为13.5 MPa,抗折强度为4.5 MPa;70 mm×70 mm×70 mm立方体标准试件抗压强度为8.6 MPa。微观结构检测可知,石英砂表面与颗粒之间沉积着不同数量的方解石,随着胶结强度的增加,方解石沉积量逐渐提高至趋于稳定,生成量为10%~25%,砂柱孔隙率由34.8%逐渐降至12.1%,且微观孔结构逐渐细化、密实。Microbial-induced calcium carbonate precipitation(MICP)is a new environmental protection foundation treatment technology emerging in the field of geotechnical engineering in recent years.The solidification effect of MICP technology is studied based on the mechanical properties and microcosmic test of sand body solidification.The results show that the maximum strength of microbial cement cemented sand column can reach 37.9 MPa,and the impervious property can be increased from 1.72×10-2 cm/s to 7.66×10-7 cm/s;after 100 freeze-thaw cycles,the specimen has a complete appearance without obvious defects and sand removal;the strength loss rate is 17.0%after 50 freeze-thaw cycles,indicating the cemented sand body has good frost resistance and durability.The compressive strength and flexural strength of standard specimens of 40 mm×40 mm×160 mm cylindrical body are 13.5 MPa and 4.5 MPa respectively.The compressive strength of standard 70 mm×70 mm×70 mm cube specimen is 8.6 MPa.According to the micro structure examination,different amounts of calcite are deposited between the quartz sand surface and particles.With the increase of cementation strength,the calcite deposition gradually increases to a stable amount of 10%-25%,the porosity of sand column gradually decreases from 34.8%to 12.1%,and the microscopic pore structure gradually becomes refined and dense.

关 键 词：微生物水泥 石英砂胶结 碳酸钙沉淀 巴氏芽孢八叠球菌 脲酶活性 抗压强度 耐久性 

分 类 号：TU525[建筑科学—建筑技术科学] TV431.9[水利工程—水工结构工程] TQ172.1[化学工程—水泥工业]