Experimental studies on precast post-tensioned concrete connections with composite beams and multi-storey columns

Abstract

In this paper, a precast post-tensioned (PT) concrete beam–column connection, composed of PT composite beams with partially bonded tendons, precast multi-storey columns and cast-in-place (CIP) core region, was developed as an emulative connection. Four full-scale beam–column connections, including an interior and an exterior precast connection and the corresponding CIP control specimens, were tested under low reversed cyclic loading to investigate their seismic behaviour. The results revealed that all the connections failed due to flexural failure of the beam ends near the column face. The hysteresis loops of all the connections were pinched but relatively plump, showing good energy dissipation capacity. In comparison to the CIP control specimens, the loading capacity of the precast connections was about 10% higher and 15% lower in the positive and negative loading directions for the interior connections, and about 2% higher and 10% lower for the exterior connections, respectively. The average ductility of the precast interior and exterior connections was 2·99 and 2·70, which was about 3 and 18% higher than that of the CIP control specimens, respectively. The stiffness degradation and residual deformation of the precast connections were found to be similar to those of the CIP control specimens. A degenerated four-linear restoring force model was also developed.