Strengthening of t-cross sectioned reinforced concrete beams against shear and flexure

Bonding of steel plates on the bottom face of a beam is widely used for strengthening reinforced concrete beams against flexure. But over the years it has been observed that only bonding steel plate wasn?t enough to strengthen reinforced concrete beams, therefore additional precautions were taken. However, it has been faced with some important ductility problems in the recent studies. In the first part of this study steel plates bonded on the bottom face of the beam is supported with side edge plates and bolts to provide sufficient ductility as well as flexural strength. It is usually necessity to strengthen the reinforced concrete beams against both flexure and shear. In the second part of this study steel plate strengthened reinforced concrete beams for flexure with insufficient stirrups were strengthen against shear. In the experimental work, fourteen reinforced concrete beams were tested under monotonic loads. Half of them were for bending and the other half them were for shear and bending. Two of them were simple reinforced concrete beams for comparison purposes. The parameters for bending test were the type of the steel plates (perforated and plain), the type of the bond (with or without epoxy) and the existence of compression plate. The strengthening variables in flexure specimen repeated in flexure-shear specimen with using same shear precaution technique. The experimental results are compared in terms of strength, ductility, rigidity and energy consumption. Strength increased nearly three times and ductility increased successfully with used strengthening method. Also beams with insufficient stirrups prevent from shear failure.