Structural assessment of eccentrically loaded GFRP reinforced circular concrete columns: Experiments and finite element analysis

Although extensive research of glass fiber reinforced polymer (GFRP) reinforced concrete columns has been performed, none of the previous studies investigated the structural performance of polypropylene macro synthetic fiber reinforced concrete (MSFRC) columns having GFRP reinforcement. The present study aims to examine the structural performance of GFRP reinforced circular concrete columns consisting of polypropylene macro synthetic fibers (GMSFRC columns) under concentric and eccentric loading. Identical steel bars reinforced concrete columns (SMSFRC columns) were also fabricated and tested under the same loading conditions. The experimental program consisted of 18 columns (1200 mm high and 300 mm in diameter) to measure the axial load-carrying capacity (LCC), axial deflections, failure modes, and cracking patterns under different eccentric loadings. SMSFRC columns portrayed higher axial LCC (up to 23%) and lower deformation capacity (up to 18%) than GMSFRC columns. Both GMSFRC and SMSFRC columns depicted similar failure behavior. The eccentric loading led to similar reductions in axial LCC for both GMSFRC and SMSFRC columns. Threedimensional finite element analysis (FEA) of GMSFRC columns was done in ABAQUS using an improved plasticity model for MSFRC. The proposed FEA model predicted the structural behavior of GMSFRC columns with only 2.35% and 7.72% deviations for axial LCC and equivalent deflections of specimens, respectively.

Automated summary

This study investigated the structural performance of GFRP reinforced circular concrete columns with polypropylene macro synthetic fibers (GMSFRC columns) and compared them with identical steel bars reinforced concrete columns (SMSFRC columns) under concentric and eccentric loading. The experimental results showed that SMSFRC columns had higher axial load-carrying capacity and lower deformation capacity compared to GMSFRC columns. Both types of columns exhibited similar failure behavior, and the finite element analysis model predicted the structural behavior of GMSFRC columns with good accuracy.