Numerical modeling of the interaction between reinforcement and concrete at early age—A comparison between glass fiber reinforced polymer and steel rebars

Abstract

AbstractThis study has been undertaken for the assessment of steel/glass fiber reinforced polymer (GFRP) reinforced concrete mechanical behavior at an early stage. We developed a numerical model to describe the hydration process by using a chemo‐thermo‐mechanical scheme in ABAQUS finite element software. Mechanical properties of early age concrete versus hydration degree were determined using De Shutter's laws. The thermal and the autogenous strains are numerically implanted. Mazars elastic model was used to describe the concrete cracking. In addition, experimental validation of the established numerical model was performed and compared to the available literature. These data are selected for both plain and steel reinforced early age high‐strength concrete (HSC). Moreover, two mechanical boundary conditions were taken into account in accordance with the numerical simulations. Thermal conditions were considered in isothermal (20°C) and semiadiabatic conditions. Steel rebars were substituted by the GFRP under the same reinforcement percentages and configurations. The Interface between the steel and the GFRP reinforcement, and HSC was considered a perfect surface condition. Numerical predictions of the GFRP reinforcement were compared to those of steel reinforcement. Our results prove that the GFRP rebars restrain the concrete strains more than steel rebars. The GFRP rebar postpones concrete cracking compared to steel reinforcements. Furthermore, the concrete stress in the GFRP reinforced element is lower than the concrete stress in the RC steel.