This paper describes both full-scale testing and detailed finite-element modeling of a precast concrete moment-frame assembly extracted from the perimeter moment frame of a 10-story prototype building. The assembly comprises two beam spans and three columns, and the center column is subjected to monotonically increasing downward displacement to simulate a column loss scenario. Failure of the assembly was due to non-ductile fracture of the bottom anchorage bars near the welded connection to the center column. Component-level testing of the welded connection detail revealed reductions in ductility of the anchorage bar in the heat-affected zone where the bar was welded to a connecting angle, leading to premature fracture. Finite element analyses revealed that large bending moments, due to eccentricities in the welded connection details, also contributed to the premature fracture of the anchorage bars in the moment-frame assembly. Finite element analyses and comparisons with experimental measurements also provide insight into the load-carrying mechanisms of the precast concrete assembly, including initial flexural action followed by arching action.
Proceedings Title: Proceedings of the 2014 Structures Congress
Conference Dates: April 3-5, 2014
Conference Location: Boston, MA
Pub Type: Conferences
Buildings, Concrete structures, Finite-element method, Full-scale tests, Nonlinear analysis, Precast concrete, Progressive collapse, Seismic design