On the Finite Element Modelling of Long-Term Behavior of Pre-cracked RC Beams Strengthened with FRP

The principal objective of this paper is to numerically study the time-dependent behavior of reinforced concrete (RC) beam externally bonded with an FRP system considering concrete pre-cracking and FRP stress-lagging. Load-sustaining experiments were performed on seven specimens with different loading paths before strengthening. Based on the authors’ previous study, an advanced finite element (FE) model was presented. The FE model included the time-dependent behaviors of materials and the bond-slip response between concrete and steel bars. From the results of the FE model, the time-dependent deflections and strains were reasonably predicted, as well as the gradual cracking of concrete along with time. The complicated changes of structural stress/strain with time were investigated. Also, the sensitiveness of FRP-concrete interfacial creep on long-term deformation was discussed.