Seismic strengthening of beam column joint by using cementitious laminates

Abstract

The paper discusses the aspect of retrofitting technique adopted for a reinforced concrete beam column joint specimen under cyclic loading. Specimens designed based on Indian standard specification with non-ductile and ductile detailing were tested under cyclic loading. To extend the life span of beam column joints, strengthening is required and this can be effectively achieved using cementitious laminates like Slurry Infiltrated Mat CONcrete (SIMCON) and Ferrocement. Fiber Reinforced Cementitious Composite like SIMCON have been applied on the joints in different volume fraction and aspect ratios. Ferrocement is a composite material of weld mesh and woven mesh embedded in mortar with various volume fractions. It is bonded to the beam column joint for strengthening. In this study, six full scale reinforced concrete exterior beam column joints, out of which, two control specimens and two specimens strengthened by the SIMCON and two specimens strengthened by Ferrocement were cast and tested under cyclic loading. The displacement is increased monotonically using a hydraulic push and pull jack. The hysteretic curves of the specimen have been plotted. The energy dissipation capacity of retrofitted beam column joints with SIMCON and ferrocement configurations has been compared. In addition, comparisons were made between experimental and analytical results of control specimen and retrofitted specimen. The experimental results indicate that the proposed strengthening method is effective to enhance the ultimate loading capacity, stiffness and energy dissipation.