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New Connections for Enhancing Robustness of Precast Concrete Frame Structures



Travis Thonstad, Jonathan Weigand, Joseph Main, Hai Lew


The National Institute of Standards and Technology is continuing its research on the mitigation of disproportionate collapse in structural systems typical of U.S. building construction. As part of this research, two ten-story precast concrete moment frame buildings were designed and beam-column assemblies, representing portions of these buildings, were tested at full scale under an interior column removal scenario. The failure of the tested assemblies initiated prior to achieving the nominal flexural capacity of the beam sections and revealed potential vulnerabilities in the beam-to-column connections caused by eccentricities in the tensile force transfer path and reduced ductility of the reinforcement caused by welding. Motivated by the performance of these assemblies, several alternative connection concepts were developed in coordination with an industry review committee of PCI members. Five of these connection concepts were selected for experimental study and will be tested at five-eighths scale under flexural loads. While the beams and columns in the prototype structure would be subjected to a combination of axial, flexural, and torsional forces during a column removal scenario, developing connection details that possesses better flexural performance will represent a major step toward more robust precast concrete building systems. This paper describes the five proposed connection concepts and summarizes the ongoing connection testing program.
Conference Dates
May 18-22, 2021
Conference Location
New Orleans, LA, US
Conference Title
2021 PCI Convention


Disproportionate collapse, Structural integrity, Structural robustness, Moment resisting connections, Column removal


Thonstad, T. , Weigand, J. , Main, J. and Lew, H. (2021), New Connections for Enhancing Robustness of Precast Concrete Frame Structures, 2021 PCI Convention, New Orleans, LA, US, [online], (Accessed July 12, 2024)


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Created May 18, 2021, Updated July 9, 2024