Effects of Axial Compression Load and Eccentricity on Seismic Behavior of Nonseismically Detailed Interior Beam-Wide Column Joints

Abstract

Six full-scale nonseismically detailed reinforced concrete interior beam-wide column joints were tested to investigate the seismic behavior of the joints. Axial compression loads varying from zero to high magnitude, as well as quasi-static cyclic loading simulating earthquake actions were applied. The overall performance of each test assembly was examined in terms of lateral load capacity, drift, stiffness, energy dissipation capacity, and joint shear strength. Three levels of axial compressive column load were investigated to determine how this variable might influence the performance of the joint. The tests also explored the effects of centerline eccentricity on the performance of interior beam-wide column joints subjected to earthquake loading. All the specimens failed at the joint panel with gradual strength deterioration, low attainment of structural stiffness, and bond degradation. The low attainment of stiffness and strength was attributed to the bond deterioration of the longitudinal bars through the joint core. It is concluded that special reinforced concrete interior beam-wide column joints with nonseismic design and detailing, could possess the inherent ductility for an adequate response to unexpected moderate earthquakes.