Structural performance of fire-damaged concrete beams retrofitted using bamboo fiber laminates

Fire-induced damage is a serious threat to the structural integrity of reinforced concrete (RC) beams, necessitating an effective retrofitting strategy to restore and improve their performance. This study investigates the structural performance of fire-damaged RC beams retrofitted with bamboo fiber laminates. A comprehensive analysis was performed, incorporating degradation rules to quantify the effect of temperature on both the load-carrying capacity and ultimate deflection of the RC beams. Eight conventionally designed and reinforced RC beams were tested, with two serving as controls. The remaining six beams were tested in pairs at three different temperatures (400 °C, 600 °C, and 800 °C) for 2-h exposure, with one beam featuring the bamboo fiber laminates in each pair. The bamboo fiber laminates enhanced the load-carrying capacity and deflection of the fire-damaged beams when subjected to incremental loading until failure. The deflection was improved by 48.78% at 400 °C, restoring the load-carrying capacity to control levels. The load-carrying capacity was increased by 29.5% at 600 °C, while the deflection was restored by 39.37%. The load-carrying capacity was enhanced by 37% at 800 °C, while the deflection was improved by 4.83%. According to the findings, bamboo fiber laminate is a viable alternative to synthetic fibers for retrofitting fire-damaged beams.