Reliability Assessment of Concrete under Chloride Penetration and Fatigue Loading Based on Copula Function

Abstract

The reliability of concrete in complex environments is the basis for improving the reliability of concrete structures. A concrete reliability assessment based on multiple degradation factor is proposed. First, chloride penetration and fatigue damage are selected as two degradation parameters for concrete, and series tests are developed to investigate the surface chloride concentration, diffusion coefficient, and degradation of residual strength under coupled effect of chloride penetration and fatigue. Then, two marginal distribution functions of the durability reliability of the concrete are deduced based on two failure modes. Subsequently, fatigue loading the parameters of different typical copula functions are obtained by using the maximum likelihood method (MLM), and copula function selection is carried out according to the Akaike information criterion (AIC) criterion. The joint distribution function is then derived by fusing the two marginal distribution functions using the selected copula function, and a remaining durability reliability model is obtained. Finally, the proposed model is verified by experimental data. This method should be considered as a reference for the evaluation and reliability calculation of concrete structures.