微生物自修复材料掺量对砂浆裂缝修复效果的影响

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关键词：砂浆;微生物诱导碳酸钙沉淀（MICP）；微生物矿化；裂缝；自修复；力学性能;微观结构

中图分类号：TU578 文献标志码：A doi：10.12415/j.issn.1671-7872.25097

Abstract： By preparing 40mm×40mm×160mm cement mortar specimens， the flow table tests，mechanical strength tests，and pre-crack repair performanceon preset cracks were conducted to investigate the influence of microbial self-healing agent content （ （0%-50%） ）on the workability，mechanical properties，and repair efficacy of cracks with widths of 0.2-0.4mm and 0.4-0.6mm . The matching relationship between dosage and crack width was analyzed to optimize the repair eficiency.The micro-morphology of the deposited products within the crack Zones was observed by scanning electron microscopy （SEM） to reveal the repair mechanism.The results indicate that the fluidity ofmortar is significantly improved by the incorporation of the microbial self-healing agent. A dosage of 50% （204号 leads to a flow spread of 238.8mm ，representing a 64% increase compared to the reference group. However， the mechanical properties decline as the dosage rises， showing reductions of 36.2% in compressive strength and 62.0% in flexural strength observed at the 50% dosage level. The deposition products within the cracks are identified as calcium carbonate induced by microbial metabolism.Their crystal morphology transforms from initial vaterite into stable calcite a，forming dense accumulations that enable eficient crack repair.To balance repair effectiveness and mechanical performance， it is recommended that the dosage of the self-healing agent be limited to within 20% considering both repair efficiency and strength retention. For cracks with widths of 0.2-0.4mm ，a dosage of 5%-15% is suggested， which can achieve a healing ratio exceeding 90% within 8-16d. For cracks of 0.4-0.6mm ，a dosage of 10%-20% is recommended to attain a similar repair level within 16d .This study provides appropriate dosageranges of the microbial self-healing agent for diffrent crack widths，ofering reliabledatasupport its engineering applications.

Keywords： mortar;microbially induced calcium carbonate precipitation （MICP）;microbial mineralization; cracks; self repairing; mechanical properties; microstructure

混凝土作为现代基础设施的核心材料，在长期服役中容易产生裂缝，这不仅影响建筑物的美观与使用性能，还可能诱发结构性安全隐患，对其整体性能产生不利影响[1-2]。（剩余11771字）