Using FRP to recover the load-carrying capacity of fire-exposed reinforced concrete slabs

Abstract

This paper presents the experimental results on the ultimate strength of fire-exposed reinforced concrete (RC) slabs with and without Fiber Reinforced Polymer (FRP) strengthening. The experiments were carried out on 9 RC slab specimens. One specimen was not subjected to fire to use as the control specimen. Other 8 specimens were divided into 2 groups which were subjected to fire with durations of 45 and 75 minutes. After exposing to fire, 2 specimens of each group were strengthened by FRP. The results showed that the color of these specimens changed from gray color of normal concrete to light yellow, light pink, black gray after exposing to fire. The strength of fire-exposed specimens reduced less than 10.5 % probably because the steel reinforcement recovered its strength. Strengthening with 1/2 and 1 FRP layer increased the strength of fire-exposed specimens by 46.6 % and 65.4 %, respectively, compared to that of the control specimen.