Abstract
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A numerical integration approach was developed to investigate
the moment-curvature behavior of glass fiber-reinforced polymer
(GFRP) bar-reinforced circular normal-strength concrete (NSC)
and high-strength concrete (HSC) columns. The results obtained
from the developed integration approach were validated with
the experimental results of eight GFRP bar-reinforced circular
concrete column specimens. Out of these eight specimens, four
specimens were cast with NSC having a compressive strength of
37 MPa and four specimens were cast with HSC having a compressive
strength of 85 MPa. A parametric study was carried out
to investigate the effect of concrete compressive strength and
GFRP longitudinal and transverse reinforcement ratios on the
moment-curvature behavior of the GFRP bar-reinforced NSC and
HSC circular columns under combined axial and flexural loads.
The results of the parametric study indicate that increasing the
concrete compressive strength or GFRP longitudinal reinforcement
ratio leads to an increase in the bending moment capacity
and a decrease in the ductility of GFRP bar-reinforced concrete
columns. The confinement provided by the GFRP helixes (transverse
reinforcement) improves both the bending moment capacity
and the ductility of the GFRP bar-reinforced circular concrete
columns. The improvement in the performance (bending moment
and ductility) due to increasing the GFRP transverse reinforcement
ratio was greater in the GFRP bar-reinforced NSC columns than in
the GFRP bar-reinforced HSC columns.