Behavior of connections and floor diaphragms in seismic-resisting precast concrete buildings

This paper describes the results of an experimental study of a half-scale two-story precast concrete structure built with a dual structural system (combination of structural walls and frames). A typical feature in some of the beam-to-column connections in the test structure was that the beam bottom longitudinal bars in the joint region were poorly anchored. The test structure was subjected to simulated seismic loading until the structure reached failure. This paper emphasizes the observed response of the precast structural elements and their connections during testing, including beam-to-column connections, column-to-foundation connections, and diaphragms. An evaluation of the bond between the topping slab and the precast concrete floor is also discussed. Seismic design criteria and code implications for connections and diaphragms in precast concrete buildings resulting from this research are explored, and recommendations for their design are offered.