Effect of Macrosynthetic and Hybrid Fibers on the Behavior of Square Concrete Columns Reinforced with GFRP Rebars under Axial Compression

Acknowledgments

Notation

A_c

area of concrete (mm²);

A_frp

area of longitudinal GFRP rebars (1,356 mm²);

D

depth of the concrete prism (mm);

d_b

diameter of the stirrup bar (mm);

E_frp

modulus of elasticity of GFRP rebars (GPa);

f_frp

stress in longitudinal GFRP rebars when axial strain (MPa);

f_c

stress in concrete corresponding to strain ɛ_c from cylinder test results (MPa);

$f_c^{\mathrm{\prime }}$

compressive strength of concrete (MPa);

P_A,FRP

load contribution from GFRP rebars from analysis;

P_anal

peak load from the analytical calculation (kN);

P_expt.

average peak experimental load (average of two specimens in kN);

P_peak

peak load of column (kN);

r_b

bent radius of the GFRP stirrup (mm);

V_f

volume of fibers in percentage;

Δ

analytical axial deformation (mm);

δ_peak

axial deformation at the peak from SLVDT (mm);

δ_ult

ultimate axial deformation at 30% drop from the peak (mm);

ɛ_c

strain in concrete;

ɛ_c,peak

peak strain in concrete measured using SLVDT in the full-scale test;

ɛ_c1

strain in concrete measured at extended linear peak of load as shown in Fig. 8;

ɛ_c70

strain in the concrete when the load dropped to 70% of the peak load in the postpeak region of load–deformation plots;

ɛ_cyl,peak

peak strain in concrete measured from stress–strain behavior of cylinder test;

ɛ_frp

strain in GFRP rebars;

ɛ_SG,peak

strain in GFRP rebar at peak load from strain gauge reading (μɛ);

ɛ_SG,ult

strain in GFRP rebar at ultimate load from strain gauge reading (μɛ);

μ

psuedoductility as defined in the present study; and

φ

diameter of rebar (mm).

References