Shear capacity of continuous concrete slabs with CFRP reinforcement
Jan Bielak, Jonah Schöneberg, Martin Claßen, Josef Hegger
Abstract
This paper provides new experimental results of shear tests on reinforced single span concrete slabs with cantilever simulating continuous elements. As longitudinal and shear reinforcement, carbon-fiber reinforced polymers (CFRP) in form of grids were utilized that are perfectly suited for thin, planar elements. In comparison with single span tests, an increase in shear capacity of continuous systems has been shown, both for members with and without shear reinforcement. A discussion of the definition of shear slenderness in continuous systems enables the incorporation of this effect into shear models for FRP-reinforced specimens. A key finding of the test series is that a variation of support conditions and load introduction in continuous members, even if producing identical distributions of internal forces, may lead to disparities in deformation behavior and fracture kinematics. Eventually, these effects also influence the shear strength of the members. This effect is not covered by most of the currently promoted shear strength models.