Parameters Influencing Performance of Fiber-Reinforced Polymer Systems in Concrete

Abstract

Fiber-reinforced polymers (FRPs) have been increasingly used in concrete repair and retrofitting works. The systems involve the use of FRP composites and adequate adhesives to secure load transfer. While many studies have been conducted on the mechanical properties, durability, and economic aspects of FRP, little information is available on the effect of parameters, such as the thickness of epoxy adhesive, concrete compressive strength, concrete surface roughness, and concrete temperature on the overall performance of the system. An attempt was made to address the influence of these parameters on the FRP systems through studying the flexural failure loads, deflection, and modes of failure for carbon fiber–reinforced polymers (CFRP) applied to concrete beams. Specimens were tested with three surface roughness conditions and three epoxy adhesive thicknesses. Concrete compressive strength and the effect of exposure to 100°C for 2 h were also studied. Results of this work reveal that the surface roughness condition and adhesive thickness have a significant impact on the performance of CFRP systems. Less impact was encountered for the variation in concrete strength and increasing ambient temperature to 100°C. CFRP reinforcement enhanced the toughness of moderate-strength concrete more than for high-strength concrete. Recommendations are provided for applicators as well as for future research.