Performance of hybrid moment-resisting precast beam-column concrete connections subjected to cyclic loading

Test results of 10 hybrid precast concrete beam-to-column connections are presented. These tests constitute Phase IV of an experimental program on one-third-scale model precast moment-resisting connections conducted at the National Institute of Standards and Technology (NIST). The objective of the test program is to develop guidelines for the design of moment-resisting precast connections in regions of high seismicity. The hybrid connections consist of mild steel used to dissipate energy and post-tensioning (PT) steel used to provide the required shear resistance. Variables examined were the amount and type of mild steel (ASTM A 615). The amount of post-tensioning steel was varied to control the relative moment capacity contributed by the PT and mild steel. The specimens were subjected to reversed cyclic loading in accordance with a prescribed displacement history. Connection performances were compared to previous NIST tests based on energy dissipation capacity, connection strength, and drift capacity.