The behaviour of exterior beam-column joints

Analytical models for the design of column-beam joints in earthquake resisting multistorey frames, largely developed in New Zealand, are reviewed. These models were based on evidence obtained from the study of interior joints. To verify the applicability of such models also to exterior beam-column joints, where a better anchorage for the beam reinforcement is possible, three units were tested under reversed cyclic simulated seismic loading. Excellent response was exhibited in spite of the use in two units of only about one half of the currently recommended amount of horizontal joint shear reinforcement. After a detailed description of the observed performance of each test unit, an explanation is offered for the surprisingly good response.