Time-dependent reliability analysis of steel fiber-reinforced concrete beams under sustained loads

This study was aimed at examining the time-variable flexural capacity of Steel Fiber Reinforced Concrete (SFRC) sections subjected to long-term loading. Based on tests results of two series of steel fiber reinforced concrete beams subjected to sustained loading over a period of ten years, the time variable reliability indices for flexural strength were obtained considering the time-dependent resistance of SFRC beams under applied loads. Results show that under a specified sustained load, the reliability index is significantly higher in SFRC beams than in beams without steel fibers. With the same steel fiber content, the larger the applied load, the smaller is the reliability index. For a service life of 100 years, the reliability index of SFRC beams was found to first increase and then decrease; with the reliability index reaches the maximum value when t = 2a and steel bars begin to rust, and the reliability index significantly decreased when t = 37.8a