Behavior of CFRP-strengthened RC beams with web openings in shear zones: Numerical simulation

Abstract

The passing of service ducts and pipes often necessitates web openings in reinforced concrete (RC) beams. The strength and stiffness of the beam are reduced due to such web opening(s). Existing experimental research has shown the possibility of utilizing externally bonded Carbon Fiber-reinforced polymer (CFRP) to compensate for the strength loss of beams. However, there have been few finite element (FE) methodologies for predicting and estimating the performance of such RC beams. This paper uses nine different FE models to simulate a CFRP strengthened web opening using ABAQUS. This paper evaluates RC beam performance with web openings in the shear zone and proposed reinforcement of CFRP. Nine RC beams with openings, numerical tested under 2-loads. The models were constructed using the ABAQUS software by FE to simulate RC beams with a CFRP strengthened by two rectangular web openings. This paper studies the sequential effect of the different fundamental parameters on the strengthened RC beams' overall stiffness and shear strength response, achieving optimum utilization of the strengthened technique in load-bearing capacity and potential deflection. Results have shown no need to strengthen small web openings in the RC beams' shear zone. Beams with large openings in the shear zone need strengthening with CFRP; the beam's efficiency has been significantly improved using 2-layers of CFRP sheets around the web opening and a single-layer CFRP strip in the flexural zone bottom the chord.