Engineering Bioinspired Multifunctional Microbial Polymeric Fiber (BioFiber) for Concrete Self-Healing

这项研究将研究一种富含仿生多功能微生物聚合物纤维的新型自修复混凝土，以提高民用基础设施的耐用性和弹性。混凝土是地球上最常用的人造材料，由于在持续载荷和恶劣的操作环境下形成裂缝，因此存在长期耐久性问题。该项目将利用自然启发的自修复和微生物碳酸钙沉淀 (MCCP) 概念以及断裂力学原理，研究新型仿生纤维增强混凝土复合材料 (BioFRC) 的基于科学的设计策略。 BioFRC 可以智能地、自主地在早期阶段修复裂缝并防止形成重大缺陷，从而提高混凝土结构的耐久性。研究成果将与民用基础设施可持续生物工程解决方案的各种教育和外展活动相结合。 K-12、本科生、研究生和代表性不足的学生将参加有关自修复基础设施和跨学科教学模块的研究研讨会，并在该项目期间开展讲座。该研究的具体目标是发现自主微生物自修复混凝土的过程-结构-性能关系。该研究将研究（1）限制裂纹生长的损伤控制机制，（2）损伤区域附近的自主自激活，用于损伤响应性愈合激活，以及（3）治愈损伤的有效材料。通过耦合聚合物/纤维工程、断裂力学和微生物学的原理，并通过综合实验和数值工作，将实现对两种关键机制及其相互作用的基本理解：协调断裂过程，以及平衡 MCCP 与裂纹体积的产生。研究活动和方法将追求三个具体目标：(i) 了解微生物聚合物纤维的机械、桥接和断裂机制和形态，(ii) 了解微生物聚合物纤维在裂纹发生前的性能和细菌生存能力，以及 BioFRC 中裂纹发生后的 MCCP 活化/动力学，以及 (iii) 测试研究方法的稳健性以及混凝土潜在的耐久性和弹性增强。该奖项反映了 NSF 的法定使命，并被认为值得支持通过使用基金会的智力优点和更广泛的影响审查标准进行评估。

This research will investigate a new self-healing concrete enriched with bioinspired multifunctional microbial polymeric fibers to improve durability and resilience of civil infrastructure. Concrete, the most commonly used manmade material on earth, suffers from long-term durability issues due to formation of cracks under sustained loading and in harsh operating environments. Using nature-inspired concepts of self-healing and microbial calcium carbonate precipitation (MCCP) coupled with principles of fracture mechanics, this project will investigate science-based design strategies for a new bioinspired fiber reinforced concrete composite (BioFRC). BioFRC can intelligently and autonomously heal its cracks at early stages and prevent formation of major defects, thereby increasing durability of concrete structures. The research outcomes will be integrated with diverse educational and outreach activities on sustainable bio-engineered solutions for civil infrastructure. K-12, undergraduate, graduate and underrepresented students will be engaged in research workshops on self-healing infrastructure and interdisciplinary teaching modules, and lectures will be developed during the course of this project.The specific goal of the research is to discover process-structure-property relationships for autonomic microbial self-healing concrete. The research will investigate (1) damage control mechanisms to limit crack growth, (2) autonomic self-activation near damage zones for damage-responsive healing activation, and (3) effective materials to heal the damage. By coupling principles from polymer/fiber engineering, fracture mechanics and microbiology, and through integrated experimental and numerical work, fundamental understanding of two crucial mechanisms and their interactions will be achieved: harmonizing fracture processes, and balancing MCCP with crack volume creation. The research activities and methodologies will pursue three specific objectives: (i) to understand mechanical, bridging, and breaking mechanism and morphology of microbial polymeric fibers, (ii) to understand microbial polymeric fibers’ performance and bacterial survivability before occurrence of cracks, and MCCP activation/kinetics after occurrence of cracks in BioFRC, and (iii) to test the robustness of the research approach and potential durability and resilience enhancements in concrete.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.