地下水环境下混凝土裂缝自溶型矿物自修复系统设计及愈合机制

Exploring new smart self-healing methods for concrete cracks is one of important ways to improve safety and durability of concrete structures, which is also one of international forefront hot issues in concrete research. In this project, based on groundwater environment features and biologic autolysis theory, a new autolytic mineral self-healing method for autonomic rehabilitation of concrete cracks is proposed, and a new autolytic mineral self-healing system for concrete cracks in the groundwater environment is designed. Based on reaction thermodynamics and dynamics, the control equations and key parameters of autolysis and crystal healing processes of autolytic mineral are studied and determined. Preparation technologies of autolytic minerals with different healing demands and their effect on mineral autolysis and diffusion are studied. The dissolution of mineral protective film and the diffusion, migration and reaction processes of mineral irons in concrete cracks are tailed using TEM method. Growth process, microstructure and interface features of sediment in crack interface region in groundwater condition are monitored using microscopic testing methods such as AE and CT. Effective evaluation methods of self-healing effectiveness of autolytic mineral are studied and determined. Autolysis mechanism and healing process of autolytic minerals for concrete cracks were interpreted at different scales from microscopic, mesoscopic to macroscopic directions. In general, the two key scientific problems of mineral autolysis and healing strength enhancement mechanism of this new method are revealed.

探索混凝土裂缝智能自修复新方法是提高混凝土结构安全性和耐久性的重要途径之一，也是近些年混凝土领域研究的前沿热点之一。本项目基于地下水环境特点与生物自溶仿生原理提出混凝土裂缝主动修复的自溶型矿物自修复新方法，设计出适用于地下水环境的混凝土裂缝自溶型矿物自修复系统；应用反应热力学与动力学理论研究并确定自溶型矿物自溶蚀和结晶愈合的反应控制方程和关键参数；研究基于不同修复需求的自溶型矿物制备工艺及其对矿物溶蚀与扩散的影响规律；采用透射电镜法跟踪矿物覆盖膜的自溶蚀过程及矿物离子在混凝土裂缝中扩散、迁移与反应过程，采用声发射、CT扫描技术等微观测试手段监测水环境下裂缝界面区沉积物生长过程、微观结构及其界面特征；研究并提出自溶型矿物自修复效果的有效评价方法与修复效果；从微观、细观和宏观三个层次阐明自溶型矿物修复混凝土裂缝的自溶蚀机理与愈合过程，从而揭示其自溶与愈合增强机制这两个关键科学问题。