Flexural repairing of heat damaged reinforced concrete beams using NSM-BFRP bars and NSM-CFRP ropes

Abstract

The introduction of Basalt Fiber Reinforced Polymer (BFRP) bars marks a significant milestone in the construction industry's pursuit of advanced and sustainable materials. The application of near-surface mounted (NSM) BFRP bars presents a promising, emerging approach for restoring heat-affected reinforced concrete (RC) elements. This study investigated experimentally and theoretically the flexural performance of rectangular RC beams subjected to a temperature of (650 °C) for 3 h, followed by repairing using NSM-BFRP bars and NSM carbon fiber-reinforced polymer (CFRP) ropes. Among the twelve designed RC beams, seven were repaired with NSM-BFRP bars and three with NSM-CFRP ropes to address flexural deficiencies. The primary focus areas included failure modes, ultimate capacity, and the recovery percentage of original flexural capacity. Results showed that recovering percentages ranging from 88.2 % to 127 %, beams repaired using NSM-BFRP bars gave almost the same behavior as those repaired using NSM-CFRP ropes. Theoretical outcomes agreed well with experimental findings, in alignment with the ACI 440.2R-08 guidelines.