NUMERICAL ANALYSIS OF THE SHEAR STRENGTH OF REINFORCED CONCRETE BEAMS CONSIDERING THE REPLACEMENT OF STEEL STIRRUPS BY GFRP BARS

Abstract

The use of GFRP bars in concrete beams has been widely studied as a substitute for longitudinal reinforcement, due to its high tensile strength and immunity to corrosion. However, the application of these bars in stirrups (transverse reinforcement) has also gained attention, since corrosion significantly affects these reinforcements, which are more exposed to aggressive environmental agents. Despite its advantages, GFRP presents brittle behavior and low ductility, which contrasts with steel, which has a higher modulus of elasticity and ductility. In addition, the low ductility of GFRP limits its application, despite its high tensile strength. However, there is a lack of national studies on the use of GFRP as stirrups in concrete beams, with few works in Portuguese on the subject. In this context, the study performs a parametric analysis using the finite element method, focusing on the shear strength of reinforced concrete beams reinforced with GFRP stirrups, using the Abaqus/CAE software. The analysis is based on validated numerical simulations comparing beams with steel and GFRP stirrups. Considering the ELS of sensory acceptability, with the limit displacement set as ℓ/250 to ensure visual comfort, the beams in which the steel stirrups were replaced by GFRP stirrups showed, on average, a reduction of 77.74% in load capacity.