地下结构混凝土微胶囊自修复法及力学模型

Self healing Micromechanical Model of Microcapsule enabled Self healing Concrete in Underground Structures

摘要:

由于受到外环境和内环境的共同作用，地铁隧道结构的劣化现象是不可避免的，且用常规方法难以修复.而微胶囊自修复混凝土为地铁隧道结构的修复提供了新的方法，它能够智能、大范围地修复细微裂缝，且对结构造成的初始损伤较小.为此，提出了基于泰勒弹性损伤模型的受拉荷载下地下结构微胶囊自修复混凝土的二维自修复细观力学模型，建立了损伤修复演化方程，给出了修复后柔度的求解公式.微胶囊自修复水泥的试验与数值对比分析表明，该模型不仅能够模拟地下结构微胶囊自修复混凝土的损伤修复现象，而且具有较好的计算精度.

关键词:地铁隧道; 微胶囊自修复混凝土; 二维; 受拉荷载; 自修复细观力学模型

Abstract:

Subjected to complex internal and external environment, the degradation of concrete lining in urban metro tunnels seems inevitable. It is difficult to repair it by traditional methods. Concretes with microencapsulated healing agents are very appealing due to the advantage of self healing and potentiality of controllable healing on a large scale with little initial damage. Based on Taylor’s model, a 2D self healing micromechanical model of microcapsule enabled self healing concrete in underground structures subjected to tensile load is proposed. The kinetic equations of damage healing evolution and the formulations of compliance after healing are developed. In the end, the comparison between the theoretical and experimental results of microcapsule enabled self healing mortars verifies that with the model, the phenomenon of damage and healing of microcapsule enabled self healing concrete in underground structures can be simulated, and rational results can be obtained.

Key words:metro tunnel; microcapsule enabled self healing concrete; 2D; tensile load; self healing micromechanical model