Performance of Fire-deteriorated Concrete Beams Strengthened with NSM Laminates

Exposure of RC beams to fire may lead to a decrease in their load capacity and stiffness of the beams, both during heating and after the beam has cooled following the fire. The degree of damage is related to the fire's intensity in terms of temperature and duration. This investigation is concerned with the effectiveness and suitability of the CFRP near-surface mounted (NSM) laminate system in terms of repairing RC beams after exposure to elevated temperatures. In the experimental work, the ISO-834 standard fire curve was adopted to test the beams. Two beams were tested at normal temperature exposure, while the other beams were heated to the target temperature using a large horizontal furnace. The experimental parameters involved in this study were the type of heat exposure, the level of heat exposure, and the insulation effect. Although a reduction did occur in the stiffness and ultimate load of affected beams, repairs with NSM laminates were found to offer an effective technique for increasing the overall stiffness and load carrying capacity of the beams. (paper)