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

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