Title Shear Strengthening by Externally Post-tensioning Steel Rod in Fire-Damaged Reinforced Concrete (RC) Beam
Authors 이수헌(Lee, Swoo-Heon)
DOI https://doi.org/10.5659/JAIK.2023.39.1.253
Page pp.257-265
ISSN 2733-6247
Keywords Fire-damaged; Reinforced Concrete (RC); Externally Post-tensioning; Steel Rod; Strengthening
Abstract The purpose of this study is to discuss the applicability, strengthening effect and improvements when an externally post-tensioned steel rod system is applied to a fire-damaged reinforced concrete (RC) beam. A total of twelve specimens were prepared in three groups and tested to fail. Group one was not heated, and group two and group three were heated to 700℃ and 1,000℃, respectively. In each group, one beam without externally post-tensioned steel rods was designated as a control beam and three beams had the externally post-tensioned steel rods of 18 mm, 22 mm or 28 mm in diameter. The initial effective tension of about 2,000? was applied to the steel rods. Test results indicated that this can be applied to fire-damaged RC because externally post-tensioning increased the load-carrying capacity by more than 67%. However, additional reinforcement is required in the part where the deviator and anchorage are installed since the concrete surface is weakened by moisture evaporation at high temperatures.