SEISMIC PERFORMANCE OF BEAM-COLUMN JOINTS IN REINFORCED CONCRETE BUILDINGS SUBJECTED TO REVERSIBLE VERTICAL CYCLIC LOADING

Abstract

Three identical half-scale of exterior beam-column joints of RC buildings with different arrangement of connections detailing are designed, constructed and tested under reversible vertical cyclic loading. Each set consists of reinforced concrete beams, column and foundation beam which represents the exterior joints of the ground floor of RC buildings. The objectives of this study are to examine seismic performance, to observe visual damages and to classify different types of damages which occur in beam-column joints. The first set is designed beam-column joint in accordance to BS 8110 where no anchorages of bars are tied between beam and column. Second set comprises of three anchorage bars from column are placed and tied with top of reinforcement bars in the beam. Third set is designed with cross-bracing of reinforcement bars at the intersection of beam-column joint. Results showed that the beam-column connections which designed according to BS 8110 without anchorage bars suffer the most severe damages as compared to connections with anchorage bars and cross-bracing bars. Beam-column joint with cross-bracing bars experienced less damage as compared to two types of joints. Visual structural damages of beam-column joints include cracks prorogation, the spalling of concrete shell, buckling of longitudinal reinforcement bars and fractured of shear reinforcement bars. Therefore, it is an appropriate time to revise and replace the current code of practice to seismic code so that reinforced concrete buildings which are constructed in Malaysia are save under long-distant earthquake excitation and local earthquake.