Thermo-mechanical behavior of Glulam beam-to-girder assemblies with steel doweled connections before, during and after fire
Journal of Structural Fire Engineering
ISSN: 2040-2317
Article publication date: 20 January 2022
Issue publication date: 9 August 2022
Abstract
Purpose
The purpose of this paper is to investigate the thermo-mechanical behavior of intermediate-size glued-laminated beam-to-girder assemblies connected with T-shaped slotted-in steel doweled connections at ambient temperature (AT), after and during non-standard fire exposure.
Design/methodology/approach
AT tests were performed using a universal testing machine (UTM) to evaluate the load-carrying capacity and failure modes of the assembly at room temperature. Post-fire-performance (PFP) tests were conducted to study the impact of 30-min and 60-min partial exposure to a non-standard fire on the residual strength of the assemblies. The assemblies were subject to fire in a custom-designed frame, then cooled and loaded to failure in the UTM. A fire-performance test was conducted to investigate the fire-resistance during non-standard fire exposure by simultaneously applying fire and mechanical load with the custom frame.
Findings
At AT, embedment failure of the dowels followed by brittle splitting failure were found to be the dominant failure modes in the beams. In the PFP tests, embedment failure and plastic bending of the dowels were the only observed failure modes. The residual strength of the assembly was reduced by 23.7% after 30-min and 47.8% after 60-min of fire exposure. Ductile embedment failure of the timber in contact with the dowels was the only failure mode observed during the fire-performance test, with the maximum rate of displacement at 57 min into the fire.
Keywords
Acknowledgements
The authors would like to extend their thanks and acknowledge SteelFab, Simpson Strong-tie, David Barber from Arup, and Lee Ennis from Rowan-Cabarrus Community College for their assistance with this project. Any opinions, findings, and conclusions expressed in this paper are those of the authors and do not necessarily reflect the views of those acknowledged. The research team would also like to extend their gratitude and appreciation to several UNCC Student who assisted with sample preparation and fixture construction: Rafi Marandi, Matthew Benfield, and Austin Parker.
Citation
Shabanian, M. and Braxtan, N.L. (2022), "Thermo-mechanical behavior of Glulam beam-to-girder assemblies with steel doweled connections before, during and after fire", Journal of Structural Fire Engineering, Vol. 13 No. 3, pp. 370-390. https://doi.org/10.1108/JSFE-04-2021-0018
Publisher
:Emerald Publishing Limited
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