基于MICP技术的自修复混凝土研究进展

混凝土是一种应用广泛的建筑材料,但其在使用过程中,极易出现裂缝,尤其在水利工程中。混凝土裂缝不仅影响建筑的美观,而且会对结构的安全性产生不利影响。利用微生物诱导产生碳酸盐晶体(MICP)的技术可以制成自修复混凝土,这种混凝土能够在其自身出现裂缝时实现自我修复,从而提高混凝土材料的耐久性能,节约维修成本。对国内外文献中自修复混凝土的工作原理、制备方法、材料特性以及影响自修复效果的因素进行了总结分析。从工作原理上主要介绍了矿化微生物的选择和矿化过程;从制备方法上主要汇总了自修复混凝土采用的细菌固载方法;从材料性能上主要分析了自修复混凝土的微观性能和宏观性能;从修复效果上主要总结了修复剂成分、养护条件以及裂缝特征等因素的影响。根据梳理,自修复混凝土目前所能修复的最大裂缝宽度为0.97mm,最大深度为27.2mm,仍有大的发展潜力。基于目前的研究现状,文章提出了自修复混凝土进一步的研究方向,旨在为该项技术的发展起到一定的推动作用。

Research progress of self-healing concrete based on MICP technology

Concrete is a w idely2used building material, but it is pro ne to cracking during its serv ice life, especially in w ater conser2 v ancy pr ojects. The cracks not o nly affect the look of buildings, but also adv ersely affect the securit y of the str ucture. The tech2 nolog y of micro bial induced ca rbonate precipitation ( MICP) can be used to fabricate self2healing co ncr ete. This concrete can self2 heal when it has micro2cr acks, and thus has better durability and saves maintenance costs. T his paper summarizes and analyzes domestic and for eign literatur e o n the w or king mechanism of the self2healing concrete, the prepa ratio n methods, the characteris2 tics o f self2healing co ncr ete, and the affecting factors of self2healing effect. Reg arding the mechanism, it mainly int roduces the select ion of self2r epairing micro org anisms and the mineralization processes. Regar ding the pr epar at ion, it mainly summarizes the bacterial immobilizat ion methods used in self2healing concr ete. Reg arding the perfo rmance, it mainly analyzes the micro sco pic pr operties and macr oscopic propert ies o f self2healing co ncr ete. Reg arding the hea ling effect, it mainly summarizes three influen2 cing facto rs including r epairing agent compositio ns, curing conditio ns, and cracks char act eristics. Acco rding to the literature re2 v iew , the maximum w idt h of cracks that can be healed fo r self2healing concrete is 0. 97mm and the max imum depth is 271 2 mm.The self2healing co ncrete still has g reat dev elo pment po tential. Based on the curr ent research pr og ress, this paper points out the further research directions o f self2healing co ncr ete. It is aimed to push fo rw ard the dev elopment of this techno log y.