脲解型微生物的矿化过程及其在水泥基材料早期裂缝修复中的应用  

Mineralization Process of Urealytic Microorganism and Its Application in Early Age Crack Repair of Cement-based Materials

作　　者：杨春景[1] 白宏洁[1] 张彬[2] 赵峰 YANG Chunjing;BAI Hongjie;ZHANG Bin;ZHAO Feng(Yellow River Water Conservancy Vocational and Technical College,Kaifeng 475004,China;Department of road and Bridge Engineering,Inner Mongolia Vocational&Technical College of Communications,Chifeng 024005,China;School of Mining Engineering,North China University of Science and Technology,Tangshan 063210,China)

机构地区：[1]黄河水利职业技术学院,河南开封475004 [2]内蒙古交通职业技术学院道路桥梁工程系,内蒙古赤峰024005 [3]华北理工大学矿业工程学院,河北唐山063210

出　　处：《材料科学与工程学报》2023年第5期840-849,共10页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(51374088)。

摘　　要：裂缝的产生会对水泥基材料的耐久性产生不利影响,并降低其使用寿命。针对水泥基材料裂缝的修复问题,利用微生物诱导碳酸钙沉淀(MICP)来修复裂缝是一种绿色环保的技术。本研究选用一种脲解型微生物,首先研究了温度、初始pH值和Ca^(2+)浓度对其细菌生长的影响;随后,通过Ca^(2+)浓度变化和钙化速率揭示了CaCO_(3)沉淀的矿化过程;同时,详细探讨了脲解型微生物MICP的矿化机理;然后,制得微生物自修复砂浆试件,并通过折断法制作宽度在0.30~0.45 mm的裂缝,以面积修复率和抗水渗透修复率表征裂缝的自修复效果。实验结果表明,该微生物的最佳温度,初始pH值和Ca^(2+)浓度分别为25℃,7.0~10.0和0~90 mM。加入微生物自修复剂后,经过28 d修复,砂浆试件裂缝的面积修复率和抗水渗透修复率分别为99.2%和95%。与其他裂缝修复方法相比,微生物矿化修复方法具有及时、高效和环保的优点。The generation of cracks will have an adverse impact on the durability of cement-based materials and reduce the service life.Using the microbial induced calcium carbonate precipitation(MICP)to repair cracks of cement-based materials is a green and environmentally friendly technology.Aiming at the problem of repairing cracks in cement-based materials,a kind of urealytic microorganism was selected to study the effects of temperature,initial pH and Ca^(2+)concentration on the growth of bacteria.The Ca^(2+)concentration and the calcification rate were used to reveal the mineralization process of CaCO_(3)precipitation.The mineralization mechanism of MICP was discussed in detail.Then,the microbial self-healing mortar specimens were prepared,and the crack with a width of 0.30-0.45 mm were made by the breaking method.The self-healing efficiency of the crack was characterized by the area repair ratio and anti-penetration repair ratio.The experimental results showed that the optimal temperature,initial pH and Ca^(2+)concentration of the microorganism were 25℃,7.0-10.0 and 0-90 mM,respectively.After adding the microbial self-healing agent,the area repair ratio and anti-penetration repair ratio of the mortar specimens were 99.2%and 95%after 28 d healing time,respectively.Compared with other methods,the microbial mineralization self-healing method has the advantages of timeliness,high efficiency and environmental protection.

关 键 词：裂缝 微生物诱导碳酸钙沉淀 水泥基材料 钙化速率 自修复效果 

分 类 号：TU526[建筑科学—建筑技术科学]