WoodWorks Leads Blast Testing Project For Cross-Laminated Timber

by | Dec 19, 2016 | News

Videos are now available showing a series of live blast tests on three cross-laminated timber (CLT) structures at Tyndall Air Force Base, conducted by WoodWorks in cooperation with the US Forest Service and Softwood Lumber Board. Post-test observations were exciting. All structures remained intact and matched modeling predictions with acceptable levels of damage under significant explosive loading. The results of this testing will be used to further expand the use of wood solutions for Department of Defense applications and other blast-resistant construction. Watch the videos here: https://bit.ly/2hwVE1g

The CLT structures—each two-story, single-bay structure with anchorage to an existing concrete slab—were constructed in full by Lendlease over a period of eight days. Each structure was constructed using a different grade of CLT (i.e., grade designations V1, E1 and V4 per ANSI/APA PRG-320 provided by DR Johnson, Nordic and SmartLam, respectively) and included window and door openings (with doors provided by American Direct) consistent with an actual building. Self-drilling screws provided by MyTiCon and adhesive anchors provided by Hilti were utilized in concert with angle steel to connect the constituent panels of each structure.

Three shots were performed to demonstrate the effectiveness of CLT over a spectrum of blast loads. The first two shots were designed to stress the CLT structures to within their respective elastic limits. The third shot was designed to push the structures beyond their elastic limits such that post-peak response could be observed. Reflected pressure and peak deflections were recorded and will be used to thoroughly document the response of the structure in time, and support a design methodology for predicting elastic response of CLT under dynamic loads.

Initial observations deriving from these tests are positive. For the first two tests, peak recorded deflections were consistent with pre-test predictions, indicating the efficacy of the design assumptions and supporting design methodologies. Results from the third test indicated a controlled response in which localized panel rupture was observed but connection integrity and load carrying ability were not compromised for any of the three structures. Over the next couple months, WoodWorks will be working with Karagozian & Case, Inc. and the University of Maine to thoroughly post-process and analyze the results of these tests.

From Business Wire: https://www.businesswire.com/news/home/20161215005337/en/WoodWorks-Leads-Blast-Testing-Project-Cross-Laminated-Timber

“Plywood On Steroids” Changing Maine Lumber Industry

by | Feb 17, 2016 | News

A new kind of engineered lumber is being tested at the University of Maine. This new “plywood on steroids” could compete with other construction materials like concrete and steel, and this new industry may help add value back into Maine’s forests.

“It would be a new market, it would be a new factory, sort of like making furniture, except it’s really big pieces,” said Steve Shaler, director of the School of Forest Resources at UMaine.

The new market would be for cross laminated timber, an engineered plywood created and tested at the University of Maine. CLT is made with different types of wood from Maine’s forests.  It’s then pressed into a strong construction material, ready to use at construction sites.

“They come out as large panels, solid panels with windows and door openings pre-cut, maybe utility locations pre-cut, and they’re swung into place and connected together and they go up very very quickly with very little cutting on site, very little waste on site,” said Bill Davids, professor and chair of the Department of Civil and Environmental Engineering.

“This is for taller structures, four stories, 10, there are buildings now that are made out of wood that are 10 stories tall,” said Shaler. The blocks of spruce, pine and fir were stress tested and broken under 10,000 pounds of force, which is stronger than normal lumber, but lighter than other building materials like steel and concrete.

From WCSH 6 News: https://www.wcsh6.com/news/plywood-on-steroids-changes-lumber-industry/41656511