| dc.description.abstract | This study aims to continue the research conducted in previous studies [17-19] by performing high-cycle fatigue tests on New RC beams. The main objective is to establish an empirical S-N curve suitable for high-strength steel bar and subsequently discuss the design fatigue limit strength (f_(r,limit)) of high-strength steel bars. The results obtained from this study will provide valuable insights for fatigue design of New RC bridge structures.
The current fatigue test results of SD690 New RC beams reveal a significant diameter effect on the S-N curve for larger-sized rebars (>D25). It is observed that as the diameter increases, the fatigue life decreases, leading to a lower design fatigue limit strength. Therefore, we propose an empirical S-N curve suitable for New RC beams.
This study also investigates the differences in fatigue behavior between New RC beams and conventional RC beams. The comparisons include factors such as steel grade (f_y), rebar geometry (r⁄h), rebar diameter effect, and fatigue crack area. Additionally, the study observes the variation of the EcIe value and crack development in New RC beams. Finally, it explores the appropriate design fatigue limit strength, aiming to assess the suitability of current fatigue design specifications, such as the 2002 edition of the AASHTO LRFD Bridge Design Specifications [1-2], and the 2020 edition of the AASHTO LRFD Bridge Design Specifications [3], for fatigue design of New RC beams. | en_US |