Efficiency of GFRP Reinforcement in Concrete Columns having Hybrid Fibers: Experiments and Finite Element Analysis

Abstract

This investigation explores the structural performance of glass fiber reinforced polymer (GFRP) reinforced concrete columns incorporating hybrid fibers (GHFRC columns) under different loading conditions. The hybrid fiber reinforced concrete (HFRC) consisted of two kinds of fibers (steel, SF and polypropylene, PF). A total of nine GHFRC specimens with a diameter of 250 mm and a height of 1150 mm were fabricated and tested to failure. A 3D finite element model (FEM) was developed for the GHFRC specimens using ABAQUS 6.14. The definition of HFRC was performed using an improved concrete damaged plasticity model and the definition of GFRP material was performed by using a linear elastic model. The test results revealed that the ductility of GHFRC columns was improved with the reduction in the ligature spacing. The columns eccentricity showed higher ductility indices than concentric columns. The loading eccentricity resulted in a substantial decrease in the axial strength (AS) of GHFRC columns. The close correlation between tests and FEM results validate the applicability of FEM. A mathematical model was suggested for predicting the AS of GHFRC specimens by taking into account the axial influence of GFRP bars and the confining influence of GFRP ties.