Shear performance of FRP reinforced concrete beams: Fid-Bau Portal

Shear performance of FRP reinforced concrete beams

Guadagnini, M. / Pilakoutas, K. / Waldron, P.

The experimental programme reported in this paper focuses on comparing the development of shear carrying mechanisms in concrete beams reinforced with either steel of fiber reinforced polymer reinforcement. The development of strain along the longitudinal and transverse reinforcement was monitored extensively during testing as were the vertical displacements along the beams. Shear reinforcement was provided in the form of external links using glass or carbon fibre. The links were designed so that the theoretical shear capacity of the unreinforced concrete beams could be enhanced up to a value close to their maximum flexural capacity, while attempting to ensure that the predominant mode of failure was due to shear. The following conclusions can be drawn from the reported study:The strain in both the flexural and shear components of FRP reinforcement can reach values much higher than those assumed by the first generation of design codes for FRP reinforced concrete. Shear resisting mechanisms are mobilised in a similar way in both GFRP and steel reinforced concrete beams and failure modes are characterised by similar behavior. For concrete shear resistance, the principle of strain control is accepted, but a new limit of 0.45 % is proposed for determining the amount of flexural reinforcement to be used in concrete shear design. For design of the shear links, the new proposed limit of 0.45 % also seems to lead to more appropriate and cost effectve solutions.