RC Beams Strengthened with GFRP Plates. I: Experimental Study

TLDR

The study experimentally investigates the static strength of reinforced concrete beams strengthened with GFRP plates glued to their tension flanges. Five rectangular beams and one T‑beam were tested to failure under four‑point bending, with load‑strain and load‑deflection data recorded and compared to predictions. GFRP plates glued to the tension face significantly increase flexural strength and improve cracking behavior by delaying visible cracks and reducing crack widths at higher loads.

Abstract

The static strength of reinforced concrete beams strengthened by gluing glass‐fiber‐reinforced‐plastic (GFRP) plates to their tension flanges is experimentally investigated. Five rectangular beams and one T‐beam were tested to failure under four‐point bending. The measured load versus strain in GFRP plate, steel rebar, extreme compression fiber of concrete, and the load versus deflection for the section at midspan of the beams are plotted and compared to the predicted values. The results indicate that the flexural strength of RC beams can be significantly increased by gluing GFRP plates to the tension face. In addition, the epoxy bonded plates improved the cracking behavior of the beams by delaying the formation of visible cracks and reducing crack widths at higher load levels.