Behavior of Repaired Reinforced Normal and High Strength Concrete Beams Failed in Shear

This paper presents investigation on the strength and deformation characteristics of reinforced normal and high strength concrete rectangular beams failed in shear and repaired by epoxy injection.Eight simply supported reinforced concrete beams without shear reinforcement are tested, four of which are made with normal-strength concrete (NSC) and four with high-strength concrete (HSC). The span of the simply supported beams is 1.28 m with 100 mm wide by 200 mm deep cross section. All are tested under two-point loads.Method of epoxy injection is used to repair cracks in the failed-in-shear beams. Careful repair process is adopted and proved successful.Main conclusions are: successful repair method is used to increase or at least restore shear capacity of beams; the increase is observed higher in normal-strength beams; repaired diagonal shear cracks do not reopen (generally) after retesting, instead, new nearby diagonal shear cracks are developed and the repaired beams show a lower stiffness and greater ductility than original beams.