Seismic resistance of composite beam-columns in multi-storey structures. Part 1: Experimental studies

The behaviour of partially encased composite beam-columns under the combined effects of earthquake and axial loads is experimentally investigated in a series of cyclic and pseudo-dynamic tests. The beam-column specimens tested in the experimental programme use an improved system of detailing which offers advantages in terms of efficiency and economy of fabrication and achieves an enhanced seismic performance by delaying the onset of flange buckling, while still retaining the traditional benefits offered by composite columns. Two cyclic and five pseudodynamic tests using a range of axial loads and seismic excitations have been performed and the results presented and examined. The experiments demonstrate the excellent performance of the element, and reaffirm the applicability of composite beam-columns to the earthquake-resistant design of multi-storey structures.