Uplift Capacity of Polyurea-Coated Light-Frame Rafter to Top Plate Connections
Publication: Journal of Materials in Civil Engineering
Volume 24, Issue 9
Abstract
This paper demonstrates the potential for using field-applied structural coatings to reinforce traditional framing members and standard building ties, thereby providing an improved and continuous foundation to roof load pathway. Tension tests were performed on light-frame rafter to top plate connections, some of which were reinforced with a hurricane tie, to establish how much of a difference a polyurea coating made as the joints between the stud and top plate, and top plate and rafter, were loaded to failure. The tests indicate that polyurea provides universal strengthening compared with hurricane ties with the added advantage that members and joints can be protected from a multitude of threats, including corrosion attributable to moisture, damage attributable to flood; and, with self-extinguishing properties fire. The addition of the coatings allowed both unreinforced and reinforced configurations to withstand higher loads (200–400% more). In general, the polyurea delayed the onset of failure and significantly strengthened every configuration by increasing the amount of work/energy required to pull it apart; in some cases, by almost 800%.
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Acknowledgements
The authors would like to thank the U.S. Dept. of Commerce for supporting this research under NOAA SBIR Phase I and Phase II contract No. WC133R-09-CN-0108. They would also like to thank Mr. Rajesh Vuddandam for his help with running the pull tests and acquiring data at the Univ. of Alabama in Huntsville and Mr. John Becker, president of Creative Material Technologies, for helping to select the polyureas used in this study. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the authors and do not necessarily reflect the views of the Dept. of Commerce.
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Information
Published In
Journal of Materials in Civil Engineering
Volume 24 • Issue 9 • September 2012
Pages: 1201 - 1210
Copyright
© 2012 American Society of Civil Engineers.
History
Received: Aug 29, 2011
Accepted: Jan 26, 2012
Published online: Jan 28, 2012
Published in print: Sep 1, 2012
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