Reliability evaluation of chloride diffusion in fatigue damaged concrete

Chloride diffusion is widely used to evaluate the durability of concrete structures. For civil concrete structures, millions of cycles of repeated loads are expected during their intended life. Those fatigue loads may lead to progressive damage of concrete. The objective of this paper is to study the time-variant reliability of chloride diffusion in fatigue damaged concrete structures through integrating damage mechanics, nonlinear analysis, numerical simulation of diffusion processes, and reliability methods. A phenomenological fatigue damage model of concrete is introduced. The strip method is adopted to simulate the nonlinear response of concrete structures. The chloride diffusion process is analyzed by finite difference methods. Using the important sampling method, the time-variant reliability of chloride diffusion in fatigue damaged concrete structures is assessed.