Accelerated Life Testing of Reinforced Concrete Based on Performance Degradation and Reliability Modeling

Abstract

This paper proposes a design for a testing program for accelerated life testing of reinforced concrete in the sulfite saline soil area. According to the situation of saline soil area, a constant current was used to accelerate the corrosion of steel rebar, and the wet sand with complex salt solution was used as electrolyte. The accelerated life testing was carried out, and a certain amount of accelerated life data was collected using electrochemical technique. By using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and X-ray photoelectron spectroscopy (XPS), the microstructure and composition of corrosion products were analyzed. According to present codes, the critical corrosion current density of reinforced concrete was obtained. The linear model and exponential model were used to fit the average value of data corresponding to each time point respectively. Furthermore, based on the Wiener stochastic process, a reliability model for the degradation of reinforced concrete was established, and the accelerated life of reinforced concrete specimens was predicted. The results showed that the experimental scheme can effectively simulate the natural corrosion state of steel rebar in the sulfite saline soil area of western China. Corrosion current density can be used as the key factor for the durability deterioration of reinforced concrete specimens, and it can be used to judge the corrosion state of the reinforced concrete. Wiener stochastic process can effectively describe the durability degradation process of reinforced concrete specimens. By integrating the life data of the degradation process, the accelerated life reliability function established by this method can directly reflect the accelerated life of the specimen. The method is simple in calculation, and has certain value of popularization and application.