A multi-scale approach for modeling self-healing concrete by coupling water ingress and crack healing process

在2022财年，建立了水渗透和自愈过程的多尺度模型。渗水过程分为三个过程，分别为渗水过程和裂缝渗水过程，以及从裂缝到基质的吸水过程。初步模拟了裂纹愈合过程与经过时间和初始裂纹宽度的关系。采用多尺度模型进行数值分析，可以定性地模拟干湿循环下裂缝的逐渐愈合过程，导致水阻逐渐增大。利用二维轮廓线对这一过程进行了合理的可视化，并分别采用细菌和聚乙烯醇(PVA)纤维两种不同的技术进行了自愈实验。通过记录裂纹宽度的变化，定期观察裂纹的愈合过程。在自愈前后还进行了吸水试验，显示标本中累积的水分减少。

In FY2022, a multi-scale model coupling water penetration and the self-healing process was established. The water penetration process was integrated with three processes, water penetration in matrix and cracks, respectively, and water absorption from crack to matrix. The crack healing process was tentatively modeled in relation to elapsed time and initial crack width. The numerical analysis using the multi-scale model can qualitatively simulate the gradual crack healing process with drying-wetting cycles, resulting in a gradual increase in water resistance. The process was visualized using two-dimensional contours reasonably.In addition, self-healing experiment was performed using two different technologies: the application of bacteria and polyvinyl alcohol (PVA) fibers, respectively. The crack healing process was observed periodically by recording crack width changes. Water absorption test was also performed before and after self-healing, exhibiting reduced accumulative water in the specimens.