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 an 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. Hybrid precast connection can be designed to match or exceed the performance of a monolithic connection in terms of energy dissipation, strength, and drift capacity.