Title Behavior of Reinforced Concrete Beams with Externally Post-Tensioned Steel Rods Under High Temperature
Authors 이수헌(Lee, Swoo-Heon) ; 박정환(Park, Jung-Hwan)
DOI https://doi.org/10.5659/JAIK.2026.42.8.327
Page pp.327-334
ISSN 2733-6247
Keywords Reinforced Concrete Beam; Externally Post-Tensioning; Steel Rod; Fire-Damaged; Strengthening; Cerakwool
Abstract This experimental study investigated the thermal behavior of reinforced concrete beams strengthened with externally post-tensioned steel rods under fire exposure. A total of three specimens were prepared and tested to failure in a horizontal heating furnace. The first specimen served as the control specimen without externally post-tensioned steel rods, while the second and third specimens were reinforced with 22 mm diameter externally post-tensioned steel rods. In the third specimen, the steel rods were insulated with Cerakwool during testing. Cerakwool is a high-temperature insulating material that maintains stable performance under elevated temperatures. It can be easily cut with a knife and applied conveniently to curved surfaces. All three specimens were subjected to a concentrated load at mid-span while the temperature was gradually increased. The experimental results showed that the strengthening method using insulated externally post-tensioned steel rods delayed the rapid increase in beam deflection by approximately 30 minutes. In addition, the method reduced the total deflection by more than 27 percent.