Huang Peifeng, Yang Xinhua, Dai Yue
School of Civil Engineering and Transportation, Foshan University, 33 Guangyun Road, Foshan, 528200, Guangdong Province, China.
School of Aerospace Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, Hubei Province, China.
AMB Express. 2025 Apr 28;15(1):66. doi: 10.1186/s13568-025-01881-x.
The technique of microbially induced calcium carbonate precipitation (MICP) has a bright prospect in the repair of concrete structures with diseases, so the evaluation of the repair effect and its influencing factors are very important issues for civil engineers. In this paper, multi-phase mixed precipitate models are established by using the random particle generation and packing algorithm. Combined with the cohesive zone model, the deformation and failure behavior of notched cement-mortar microbeams before and after repair under three-point bending loading are numerically simulated. The recovery rate is proposed to characterize the repair effect of microbeam. The repair effect and the influences of the proportion of crystalline phases in the precipitate, particle size and notch location on it are evaluated. It is found that the recovery rate of peak load of microbeam decreases from 22.16 to 20.60% as the proportion of calcite increases from 0 to 1 for the combination case of calcite and vaterite in the particles of the precipitate. However, for the combination case of calcite and aragonite, as the proportion of calcite increases from 0 to 1, the recovery rate of peak load decreases from 35.01 to 20.77%. For only calcite grains as the particles of the precipitate, the recovery rate of peak load increases from 12.73 to 36.85% when the particle size increases from 2 to 3.4 μm. When the distance between the notch center and the microbeam midspan increases from 0 to 40 μm, the recovery rate of peak load increases from 20.44 to 77.26%. The effects of the proportion of crystalline phases, particle size and notch location on the repairing effect of microbeams can be explained from the population of matrix-particle interface and stress concentration degree in precipitate. Considering that the precipitate compositions can be regulated by the control of environmental and process parameters, the research in this paper is of great significance for the engineering application of MICP technique.
微生物诱导碳酸钙沉淀（MICP）技术在病害混凝土结构修复方面具有广阔前景，因此对修复效果及其影响因素的评估是土木工程师面临的非常重要的问题。本文利用随机颗粒生成与堆积算法建立了多相混合沉淀模型。结合内聚区模型，对缺口水泥砂浆微梁在三点弯曲加载下修复前后的变形和破坏行为进行了数值模拟。提出了恢复率来表征微梁的修复效果。评估了沉淀中晶相比例、粒径和缺口位置对修复效果的影响。研究发现，对于沉淀颗粒中方解石和球霰石的组合情况，随着方解石比例从0增加到1，微梁峰值荷载的恢复率从22.16%降至20.60%。然而，对于方解石和文石的组合情况，随着方解石比例从0增加到1，峰值荷载的恢复率从35.01%降至20.77%。对于仅以方解石颗粒作为沉淀颗粒的情况，当粒径从2μm增加到3.4μm时，峰值荷载的恢复率从12.73%增加到36.85%。当缺口中心与微梁跨中之间的距离从0增加到40μm时，峰值荷载的恢复率从20.44%增加到77.26%。沉淀中晶相比例、粒径和缺口位置对微梁修复效果的影响可以从基体-颗粒界面数量和沉淀中的应力集中程度来解释。考虑到沉淀成分可通过环境和工艺参数的控制进行调节，本文的研究对MICP技术的工程应用具有重要意义。
