Modelling of concrete beams reinforced with FRP re-bars

A finite element analysis of reinforced concrete beams with fiber-reinforce d plastic re-bars is performed. Corrosion of steel rebars is a common probl em encountered in the civil construction sector, due to the porosity of con crete. The use of fiber-reinforced polymers (FRP) instead of steel re-bars can lead to a better corrosion-resistant reinforced concrete with applicati ons in many construction fields. The need for non-linear geometrical and ma terial models implies the use of numerical methods such as the finite eleme nt method. In this paper the use of a first-order shear-deformation theory in the analysis of concrete shells reinforced with internal composite unidi rectional re-bars is proposed. The theory is implemented in a shell element that allows for a layered discretization of the laminate materials. A perf ect plastic and a strain-hardening plasticity approach are used to model th e compressive behavior of the concrete. A dual criterion for yielding and c rushing in terms of stresses and strains is considered, which is complement ed by a tension cut-off representation. The material law for the unidirecti onal re-bars is linear elastic/brittle, whereas the concrete allows for ela sto-plastic-brittle behavior. A simply-supported concrete beam, reinforced with composite re-bars is analysed. The effects of the reinforcement and th e comparison of composite and steel re-bars on concrete are discussed. Comp arison between numerical and experimental results is made for a RC beam rei nforced with pultrusion rods. (C) 2001 Elsevier Science Ltd. All rights res erved.