Experimental Investigation of the Seismic Performance of Rectangular Reinforced Concrete Columns Subjected to Combined Flexure-torsion Cyclic Loading

This paper investigates the seismic behavior of the rectangular-reinforced concrete columns subjected to pure flexure, pure torsion, and combined flexural-torsional loadings using 4 quarter-scaled experimental specimens. During flexural-torsional loading, the axial rotation to the relative displacement ratios were considered to be 2 and 4. The ultimate displacement capacity and the flexural moment capacities of the specimens under combined flexural-torsional loadings were found to be decreased compared to the pure-flexural case for different rotation over drift ratios. An equation expressing the interaction curve between the flexural and torsional moment strength capacity of rectangular-reinforced concrete sections is proposed.