Reinforced Concrete Beams with Plates Glued to their Soffits

Abstract

Reinforced concrete beams can be strengthened and stiffened by gluing steel plates to the tension face of the beam. However, experimental tests show that shear and flexural forces can cause these externally bonded plates to peel away before the design load is reached. In this paper, peeling due to shear forces and the interaction between shear peeling and flexural peeling is studied, and the results are used to formulate a design procedure to prevent debonding due to peeling for reinforced concrete beams that have been strengthened or stiffened by gluing steel plates to their soffits. It is shown that this system is better suited for the strengthening of reinforced concrete slabs than reinforced concrete beams, although it enhances the serviceability requirements of both types of structures.