Cracking Analysis of Plain Concrete under Coupled Heat Transfer and Moisture Transport Processes

摘要

A smeared cracking approach is developed in this paper to simulate the crack propagation in plain concrete caused by coupled heat transfer and moisture transport processes. The cracking state of each concrete element is described using an original concept-local relative crack density (LRCD). Furthermore, a numerical relationship between LRCD and the moisture transport property is proposed to consider the accelerating influence of crack propagation on moisture diffusion. Finally, a global relative crack density is suggested to denote the cracking state of the entire concrete structure, which may serve as an appropriate index to evaluate the overall deterioration level of the structure. A finite element-based computational methodology is developed to simulate the coupled thermohydrochemome- chanical deterioration processes, and is expanded further to implement the simulation of crack propagation. The proposed method establishes a reasonable analytical basis for quantitative long-term durability assessment of concrete structures.