Structural repair of shear-deficient reinforced concrete beams using SIFCON

Abstract

This article reports on the structural behaviour of shear-deficient reinforced concrete beams repaired with Slurry Infiltrated Fibre Concrete (SIFCON), and proposes a simple analytical procedure for predicting the shear capacity of the repaired beams. SIFCON is made by pre-placing short, discontinuous steel fibres into the form, followed by infiltrating the fibres with cement-based slurry. A series of 14 shear-deficient reinforced concrete rectangular beams was tested under third-point loading to study the effectiveness of using externally applied SIFCON jackets as a method of increasing the beams' shear capacity. The parameters investigated included the shear span-to-effective depth ratio (a/d), amount of longitudinal reinforcement (ρ) and the thickness of the jacket (t). For the range of variables tested, the results indicate that all the beams failed in shear tests and those repaired with SIFCON displayed an excellent shear capacity. The use of SIFCON jackets as external shear reinforcement eliminated the brittle shear failure and increased the ultimate shear strength of the repaired beams from 25–55%. This indicates that SIFCON may be considered as a promising material for design–maintain–rehabilitate programme of concrete structures.