E. Shehata et al., Fibre reinforced polymer shear reinforcement for concrete members: behaviour and design guidelines, CAN J CIV E, 27(5), 2000, pp. 859-872
This paper describes an experimental program conducted to examine the struc
tural performance of fibre reinforced polymer (FRP) stirrups as shear reinf
orcement for concrete structures. A total of ten large-scale reinforced con
crete beams were tested to investigate the contribution of the FRP stirrups
in a beam mechanism. The ten beams included four beams reinforced with car
bon fibre reinforced polymer (CFRP) stirrups, four beams reinforced with gl
ass fibre reinforced polymer (GFRP) stirrups, one beam reinforced with stee
l stirrups, and one control beam without shear reinforcement. The variables
were the material type of stirrups, the material type of the flexural rein
forcement, and the stirrup spacing. Due to the unidirectional characteristi
cs of FRP, significant reduction in the strength of the stirrup relative to
the tensile strength parallel to the fibres is introduced by bending FRP b
ars into a stirrup configuration and by the kinking action due to inclinati
on of the diagonal shear crack with respect to the direction of the stirrup
s. A total of 52 specially designed panel specimens were tested to investig
ate the bend and kinking effect on the capacity of FRP stirrups, along with
two control specimens reinforced with steel stirrups. The variables consid
ered in the panel specimens are the material type of the stirrups, the bar
diameter, the bend radius, the configuration of the stirrup anchorage, the
tail length beyond the bend portion, and the angle of the stirrups. Based o
n the findings of this investigation, shear design equations for concrete b
eams reinforced with FRP, appropriate for the Canadian Standards Associatio
n (CSA) code, are proposed. The reliability of the proposed equations is ev
aluated using test results of 118 beams tested by others.