海工混凝土自修复双壁微胶囊及其裂纹应答机理研究

混凝土裂纹严重影响海洋基础设施的安全性和耐久性，微胶囊技术对于海工混凝土微裂纹的自修复具有重要的意义。然而，现有微胶囊存在修复剂与固化剂的接触率低，修复材料自身防护性能及与混凝土基体附着性能不佳，微胶囊与混凝土间裂纹应答机理尚未明确等问题。本项目拟通过控制摩尔比、乳化温度、搅拌速度、pH值等因素，应用相反转法、界面封闭法，合成解决上述问题的多尺度双壁微胶囊，并制定合成工艺；研究囊芯界面组装机理及囊壁吸附模型；揭示组分与工艺条件、双壁微胶囊微结构及修复相关性能间的定性、定量关联性；推演双壁微胶囊的多尺度与不同应力状态间的本构关系；建立“微损伤长大—衰减过程”裂纹应答模型；阐明双壁微胶囊尺度及含量对海工混凝土耐久性的影响规律；提出双壁微胶囊的优化设计方案并通过正交试验验证。本项目的开展可为微胶囊在海工混凝土自修复技术中的研发提供实验依据与理论基础，具有重要的科学意义和应用价值。

Concrete cracks seriously influence the safety and durability of the marine infrastructure construction. Microcapsules technology is of great importance for micro-cracks of self-healing marine concrete. However, the presence of microcapsules exist some problems. The contact rate between restorative agent and curing agent was poor. The protective properties of the material itself, and adhesion properties between the microcapsules and concrete matrix are limited. And crack response mechanism between microcapsules and concrete is not yet clear. In this project, to solve the problems above, double-walled microcapsules with multiple spatial-scales will be synthesized by phase inversion or Interface sealing method, controlling the molar ratio, emulsifying temperature, stirring speed, pH, etc., and the synthetic processes for different spatial-scale will be formulated. The mechanism of core interface assembly and shell adsorption model will be researched. The qualitative and quantitative correlations among the components and process conditions, microstructure of double-walled microcapsules, and the relevant healing properties will be revealed. The constitutive relation between multi-scale of double-walled microcapsules and the states with different stress will be deduced. The “micro-damage grow/damping” model of crack response mechanism will be established. The influence of scale and content of the double-walled microcapsules on the durability of marine concrete will be clarified. The optimized design scheme for double-walled microcapsules will be made and certificated by the orthogonal experiment. This project can provide the experimental evidence and theoretical foundation for the research and development of microcapsules to marine concrete self-healing techniques, and it has important scientific significance and practical applications.