Seismic Performance of Precast Columns Connected with Two Different Connection Modes

The precast reinforced concrete building is made of precast components, which are connected at the joints via reliable connection approaches. Therefore, the study on the stability and reliability of the connections should be conducted to improve the safety and integrity of the precast structure. In this paper, experiments on two connection modes, i.e. corrugated pipe confined with spiral stirrup connection and steel sleeve connection, were carried out. The experimental tests consisted of six specimens, including one cast-in-situ specimen, three precast specimens using steel sleeve connection and two precast specimens using corrugated pipe confined with the spiral stirrup. The influence of artificially unbonded length at the connection joint is also studied. All specimens were tested under low-frequency cyclic repeated loading to analyse their seismic performance under different connection modes. The experimental results showed that the precast columns using the two proposed connections have a similar or even better seismic performance compared with the cast-in-situ column. The installation of proper unbonded treatment on the longitudinal reinforcement in the connection is beneficial in improving the seismic performance of precast columns and the length of 5 times of the longitudinal reinforcement’s diameter is recommended.