Use of slurry infiltrated fiber concrete (SIFCON) in improving the seismic behaviour of reinforced concrete structures

In this study, behavior of existing beam-column joints under cyclic loading conditions similar to those under earthquake action is investigated and a novel seismic retrofitting technique is proposed. This technique uses prefabricated slurry infiltrated fiber concrete blocks (SIFCON) anchored on the joints with anchorage rods.In compliance with the objective of the retrofitting technique, L-shaped various composite block specimens with different steel fiber density and different thicknesses were produced and tested under cyclic loadings. With these component tests, hysteretic performance of the blocks were investigated and the most ideal choice was decided based on the factors such as lateral stiffness and energy dissipation capacity etc.Sub-standard beam-column connections were prepared and tested under quasi-static cyclic loading with a specified constant axial load. In these specimens, brittle failure mechanism with very little energy dissipation capacity under earthquake-like cyclic loads was observed which is attributed to the pinching phenomenon. The designed specimens showed consistent behavior with similar specimens tested and documented in the literature. These sub-standard specimens were retrofitted with proposed novel technique with different anchorage conditions and tested under cyclic loading conditions. It is shown that in the retrofitted specimens, shear failure was postponed and plastic hinge formation moved away from column surfaces allowing specimens to fail in flexure without any indication of brittle failure, and lateral strength, stiffness, energy dissipation and ductility of the specimens are greatly improved.