ABSTRACT
This paper presents a brief account of the results from a series of tests on a new configuration of partially-encased composite steel/concrete beam-columns. The models were designed to provide improved performance for earthquake resistance, incorporating two novel features. The first is variable pitch confining stirrups, with reduced spacing in the potential plastic hinge zone. The second is the provision of additional transverse bars to delay local buckling at large strain levels, and to increase the interaction between the two materials. A number of tests were conducted under constant axial loads and variable amplitude lateral cyclic loading. This was followed by verification tests under realistic earthquake loading, using the pseudo-dynamic testing technique. In addition, the experimental programme included several tests on specimens typical of European practice to quantify the difference in behaviour. In comparison with the conventional models, the new form exhibits significant improvement in ductility and energy absorption capacity.
