Residual Strength and Deformation Recovery of RC Beams Strengthened with FRPs Plates under the Sustained Load

Abstract

In this paper, in order to estimate efficacy, creep recovery, and residual strength of Fiber Reinforced Polymers (FRPs) strengthened Reinforced Concrete (RC) beams, long-term flexural experiments and static flexural experiments were carried out. For the long-term experiments, the beams were strengthened with a Carbon Fiber Reinforced Polymer (CFRP) plate and a Glass Fiber Reinforced Polymer (GFRP) plate respectively. The beams were placed under sustained loads for about 550 days. After the 550 days, all of the beams were unloaded for the measurement of deformation recovery. The deflection and strains of rebars and FRPs reinforcements were measures for about 60 days. As the result of long-terms experiment, the beams strengthened with CFRP plate showed a better performance in terms of deflection and strains of rebars. And the strengthened RC beams were very effective in terms of deflection control. Furthermore, the strengthened beams have shown immediate deformation recovery. Through the static flexural experiments, it was shown that the CFRP strengthened beam had high residual strength. It seems that the sustained loads did not affect bond and residual strength of the beams.

Ultimate Bearing Capacity Analysis of CFRP-Strengthened Shield Segments Using Bonding Slip Behavior Experiments

“…Furthermore, the relationship between the ultimate slope and the length is almost proportional. With an increase in the number of CFRP layers, the stress-slope relation is gradually nonlinear after the load value reaches 80%, and the stress-slope curve is more nonlinear with increasing temperature or humidity than the curve shape with an increase in number and length of layers [32,33]. However, increasing the temperature is more effective than increasing the humidity because of the nonlinearity of the stress-slope curve.…”