This paper presents an experimental and analytical study on the shear behavior of concrete beams reinforced
with lab produced glass fiber reinforced polymers (GFRP) bars and stirrups. The bars and stirrups
are manufactured by double parts die mold using local resources raw materials at lab. A total of ten
beams measuring 120 mm wide, 300 mm deep and 1550 mm long were casted and tested up to failure
under four-point load. The main parameters were concrete compressive strength and the vertical GFRP
web reinforcement ratio in the form of the number of GFRP stirrups (without stirrups and with 8 @
215, 8 @ 150 and 8 @ 100 stirrups). The mid-span deflection, inclined crack load and GFRP reinforcement
bars and stirrups strains of the tested beams were recorded and compared. The test results revealed that
the shear capacity increasing by 41% and 82% of the shear carrying capacity of beam without stirrups by
using web GFRP reinforcement of 8 @ 215 and 8 @ 100 respectively. The shear capacity increased by 49%
and 104% as the concrete compressive strength increased from 25 MPa to 45 MPa and 70 MPa respectively.
The maximum value of measured strain in GFRP stirrups reached 0.0095. New approach to calculate
FRP stirrups shear strength was proposed and verified throughout an assessment of experimental
results of current study and previous works. The shear capacities of the tested specimens were calculated
using the strut and tie models (STM) and non-linear finite element analysis (NLFEA). The average ratio of
experimental shear capacity to calculated (Vexp/Vpred) using NLFEA and STM were 1.2 and 0.9 respectively. |
