In this paper. cyclic load tests were carried out on 3 concrete beam-interior column frame assemblies, in order to investigate the effects of prestress on ultimate strength of the joint cores. The variables adopted in the test were the type of the beams, ie. PC and RC, and prestress in the beams. From these tests it was found that the prestress and the type of the beams did not affect the ultimate strength of the frame assemblies, although the input horizontal shear into the joint cores increased with the magnitude of the prestress.
