Creep deformation of FRP-plated R/C tensile elements using solidification theory

Anumerical study on R/C tensile elements reinforced by external FRP plates and subject to longterm loading is presented. Relative slips between concrete, steel bars and FRP plates are considered, governed by interface shear stress – slip laws. Solidification theory and exponential algorithm are used to obtain incremental constitutive equations for concrete as well as for steel-concrete and FRP-concrete interface laws. Cohesive normal stresses across transverse cracks in concrete are considered. The incremental differential system is transformed into a non linear algebraic system by a finite difference discretization with respect to axial coordinate. Two different problems are studied: a) for short term loadings, the increase of tension stiffening effect due to plating; b) for long term loadings, the influence of plating on creep deformation.