Flexural Performance of Fire-Damaged Reinforced Concrete Beams Repaired by Bolted Side-Plating

摘要

To study the flexural performance of fire-damaged reinforced concrete (RC) beams repaired by bolted side-plating (BSP), six RC beams were fabricated and exposed to fire in accordance with the ISO 834 temperature curve. Then five of the damaged beams were retrofitted by the BSP technique and all the beams were tested under four-point bending. The effects of bolt spacing, stiffeners, plate depth, and plate thickness on the flexural capacity, stiffness, and ductility of the strengthened beams were investigated. The displacement and strain data were measured using the digital image correlation (DIC) technique. The results indicate that the strength and stiffness of the damaged RC beams significantly, increased after strengthening, but the enhancement in ductility was highly dependent on the retrofitting parameters. The strengthening effect increased with the increase of plate thickness and the decrease of bolt spacing. The degree of partial interaction between the bolted steel plates and the RC beams could be improved by restricting the relative slips on the steel-concrete interface and the buckling of the steel plates. The reliability of the DIC technique in measuring displacement was verified, and it can be employed to analyze the failure modes of BSP beams.