Experimental study on seismic performance of prefabricated column-column connection with prestressed steel strands

In order to achieve totally assembled connection for steel tube columns in construction site, a prefabricated column-column connection with prestressed steel strands was proposed in this paper. In order to investigate a suitable mode of strand arrangement and the seismic performance of this connection, low-cycle reciprocating quasi-static tests were carried out for a connection with full-length steel strands and a connection with segmented steel strands. The results showed that the deformations and damage modes of the two connections were similar, and the hysteretic curves of the two connections have the same trend. Compared with the connection using full-length strands, the ultimate bearing capacity of the connection using segmented strands was increased by 11.65% in the positive direction and 4.93% in the negative direction. Therefore, the method to connect the segmented steel strands by using connectors, which is more suitable in construction site, is superior to full-length method. In addition, the steel strands of the two connections have good redundancy with the maximum axial force of 0.78 Ty (Ty is the yield axial force of the steel strands), and the connections can guarantee the desired seismic resistance. Moreover, a two-stage design method of elastic design and ultimate bearing capacity design of this column-column connection was also established in this paper. By using the ABAQUS software, the seismic properties of connections with different pretensions were simulated. The results indicated that the increase of pretension can improve the bearing capacity, initial stiffness and the equivalent stiffness degradation coefficient of this column-column connection.