EAGER- Exploratory Study on Biomineralization in Cementitious Materials for Self-healing of Cracks

这个探索性研究（EAGER）项目的早期概念赠款旨在对水泥材料中生物矿化的潜力进行初步评估，以实现裂缝的自我修复。主要目的是研究所选微生物在混凝土中的生存和有效性，并评估碳酸盐沉积对裂缝修复的影响。微生物引起的碳酸盐沉积将在简单的试管实验和砂浆标本中进行研究。扫描电子显微镜和X射线衍射将用于沉积物的详细表征，并调查是否可以实现足够的碳酸盐沉积来填充裂缝。将进行断裂研究以评估碳酸盐沉积物是否可以促进断裂韧性的恢复。混凝土的准脆性性质及其开裂倾向使得混凝土结构的维护成为一个昂贵且劳动密集的过程。因此，世界各地都在研究开发一种可以修复裂缝的智能基础设施材料。然而，满足这一需求的完美材料还有待开发。近年来，很少有研究者报道，生物矿化技术是有前途的，基于其抗压强度的影响。然而，抗压强度的增加并不足以证明新开发的碳酸盐和破裂材料之间的结合足以恢复由于破裂而损失的部分强度。EAGER的建议仔细制定了一个实验计划，以评估生物矿化的潜力。如果这项初步研究显示出希望，它可以为未来的生物矿化工作铺平道路，以建立自我修复建筑材料的变革概念。

This Early-Concept Grant for Exploratory Research (EAGER) project intends to carry out a preliminary evaluation of the potential of biomineralization in cementitious materials for self-healing of cracks. The main objectives are to examine the survival and effectiveness of the chosen microorganisms in concrete, and to evaluate the effects of carbonate deposition on crack remediation. Microorganisms induced carbonate deposition will be studied in simple test tube experiments and in mortar specimens. Scanning electron microscopy and X-ray diffraction will be used for detailed characterization of the deposits and to investigate if enough carbonate deposition can be achieved to fill up cracks. Fracture study will be performed to evaluate if carbonate deposits can promote regain of fracture toughness.Quasi-brittle nature of concrete and its tendency to crack makes maintenance of concrete structures a costly and labor intensive process. Thus research has been undertaken worldwide to develop a smart infrastructure material which can heal cracks. However, the perfect material that satisfies this need is yet to be developed. In recent years it has been reported by few researchers that bio-mineralization technique is promising based on its effect on compressive strength. However, increase in compressive strength is not a sufficient proof that the bond between newly developed carbonate and cracked material is sufficient to regain part of the strength lost due to cracking. This EAGER proposal carefully develops an experimental plan to evaluate potential of bio-mineralization. If this preliminary study shows promise it could pave the way for future work on biomineralization to establish a transformative concept of self-healing construction materials.