Simple Model to Predict the Ultimate Response of R/C Beams with Concrete Overlays

摘要

The report describes a study in which a relatively simple computer model was developed to predict the ultimate response of R/C composite beams retrofitted with concrete overlays. The model, which uses idealized bilinear laws for steel and interface shear flow, as well as an elasto-plastic idealized law for concrete, was implemented in a microcomputer program called URCCO. The model was tested against measured data. For specimens in which flexure was the primary mode of failure, the calculated loads were reasonably accurate, but the calculated displacements were, on the average, low. A parametric study was conducted to identify possible beneficial effects of certain parameters associated with the ultimate strength, the interface shear, and the ductility of the composite specimens. Results show that beams with tensile overlays which are moderately reinforced have a relatively low interface shear and, hence, exhibit desirable strength and ductility.