Behavior of RC Beams Strengthened with NSM-CFRP Strips Exposure to Fire

Abstract

The behavior of reinforced concrete beams strengthened with Near-Surface-Mounted (NSM) Carbon Fiber Reinforced Polymer (CFRP) strips using epoxy adhesive and insulated protection schemes after being exposed to fire was investigated in this paper. The following four beams will be subjected to an experimental test: As a reference specimen, a reinforced concrete beam flexural strengthened with NSM-CFRP strips using epoxy adhesive will be tested to failure at ambient temperature. Three RC beams were flexural reinforced with NSM-CFRP strips using epoxy adhesive, one of which was left uninsulated, while the other two were insulated with plastering, with the protection schemes including a thinner insulation layer along the bottom face of the beams (25 mm) and a thicker one at the CFRP anchorage areas (25 to 50 mm). These specimens will be exposed to fire in a gas furnace according to the ISO 834 standard fire curve, and adjustments will be observed after the specimens have been heated. In general, they were all heated without any load and then allowed to cool to room temperature. They were then subjected to four-point bending (simply supported and two-point load) until their failed. The fire behavior of NSM-CFRP reinforced RC beams will be investigated, with an emphasis on the NSM strengthening system's effectiveness during a fire. The conduct of the NSM-CFRP strengthening system on RC beams thermally insulated with fire protection schemes, on the other hand, will be evaluated in the event of a fire. Finally, the fire insulation's efficiency will be investigated.