Influence of Lamination Aspect Ratios and Test Methods on Rolling Shear Strength Evaluation of Cross-Laminated Timber
Publication: Journal of Materials in Civil Engineering
Volume 31, Issue 12
Abstract
Rolling shear (RS) strength may govern load-carrying capacity of cross-laminated timber (CLT) subjected to high out-of-plane loading because high RS stresses may be induced in cross layers and wood typically has low RS strength. This study investigates RS strength properties of non-edge-glued CLT via experimental testing (short-span bending tests and modified planar shear tests) and numerical modeling. CLT specimens with different manufacturing parameters including two timber species (New Zealand–grown Douglas fir and Radiata pine), three lamination thicknesses (20, 35, and 45 mm), and various lamination aspect ratios (4.1–9.8) were studied. The lamination aspect ratio was found to have a substantial impact on RS strength of CLT. Higher aspect ratios led to a significant increase of RS strength, and an approximately linear relationship could be established. With similar lamination aspect ratios, the Radiata pine CLT had higher RS strength than the Douglas fir CLT. The two different test methods, however, yielded comparable RS strength assessments. Numerical models were further developed to study the influence of the test configurations and gaps in the cross layers on stress distributions in the cross layers. It was also found that the compressive stresses perpendicular to the grain in cross layers had negligible influence on the RS strength evaluations.
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Acknowledgments
The authors would like to thank Specialty Wood Products Partnership, New Zealand Douglas fir Association, the National Institute of Food and Agriculture, US Department of Agriculture and McIntire Stennis under accession number 1014025 for partially funding the project. Mr. Neal Wang, Ms. Thea Xu, and Mr. Alan Poynter are also greatly acknowledged for providing assistance in the experimental testing.
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Published In
Journal of Materials in Civil Engineering
Volume 31 • Issue 12 • December 2019
Copyright
©2019 American Society of Civil Engineers.
History
Received: Jan 26, 2019
Accepted: Jun 19, 2019
Published online: Oct 10, 2019
Published in print: Dec 1, 2019
Discussion open until: Mar 10, 2020
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