Concrete cover separation failure of overlay-strengthened reinforced concrete beams

This paper presents an analytical approach based on the concrete tooth model for overlay-strengthened beams failed with concrete cover separation at the cut-off point of overlay end. The length of concrete cover separation required for the peak load of overlay-strengthened beam to be reached is derived from the proposed analytical procedure which is based on experimental observations. The reliability and accuracy of the proposed analytical procedure has been verified by comparing the analytical and experimental crack spacing as well as peak load of the overlay-strengthened beams. Finally, the concept of maximum efficient capacity of overlay strengthening method is presented.

► We developed an analytical approach for strengthened beams failed with concrete cover separation.
► We developed a check-flowchart for identifying the inherent failure mode of strengthened beams.
► The concept of maximum efficient capacity of overlay strengthening is presented and verified.