PARAMETRIC STUDIES OF RC BEAMS STRENGTHENED IN FLEXURE WITH EXTERNALLY BONDED FRP

摘要

Demands on infrastructures, post-strengthening and retrofitting are unavoidable when existing structures age or are necessary to meet changes. A recent methodology to enhance the flexural strength of RC beams uses FRP strips or sheets glued to the tension side of the beam. A number of researchers have shown that the failure mode of an FRP-strengthened RC beam can switch from the ductile mode of an under-reinforced beam to the brittle one. This paper investigates the influences of this strengthening methodology on the response and failure modes of a reference RC beam. A nonlinear fiber frame element with bond-interface between the concrete and the FRP plate serves as the numerical tool to investigate the effects of the plate length and plate width on the responses of simply supported strengthened RC beams. In this paper, the geometry of the beam is kept constant. The parametric studies agree with the experimentally observed results according to which the most commonly encountered failure modes due to loss of composite actions are affected by the plate geometric properties.