Wednesday, January 4, 2012

Beetle-killed spruce: finally good for something?

Make that a definite maybe.

Alaska is an abundant source of fish, wildlife, mountains, minerals and wide-open spaces. Something we don’t necessarily toss into that “abundant” category is beetle-and fire-wasted spruce. But we’ve got acres by the millions of it.

If civil engineering professor Scott Hamel has anything to do with it, these damaged trees might someday become the source for manufacturing wood-plastic composite building materials right here in Alaska. Think jobs, and lower construction costs.

Alaska-made planks for your dream deck?
If you’ve added a deck in the last 10 years, you likely used planks formed from wood-plastic composite (WPCs). It’s been a hot commodity for about a decade. WPCs are considered sustainable because they use recycled plastic and wood by-products. They also don’t require the same chemical treatments that wooden planks do. However, because of their plastic component, they are sensitive to temperature, and little or no testing in cold has been performed. That’s Hamel’s aim.

Hamel, who arrived in August of 2011 at UAA, will set up his first lab here with the newly-awarded  INNOVATE dollars. He’ll test the properties of WPCs at cold temperatures in three different conditions, including one called “relaxation response,” but it’s not the “relaxation response” we usually think of.

Those testing situations are: 
  • Ramp, “applying an increasing extension to a specimen at a constant strain rate until failure.” This will provide findings on stress-strain, strength and rupture.
  • Creep, “applying and maintaining a constant load on the specimen and measuring time-dependent strain response.”  Or, how much does the plank sag over time.
  • Relaxation, “applying and maintaining a constant displacement to the specimen and measuring the time-dependent stress response.”  Or, how much softer or more flexible does the plank become?
Off-the-shelf equipment will be used for most of the testing, except for relaxation. In that case, Hamel will be designing and creating it.

He hopes to add one or two undergraduate research assistants. His timetable for results is a year, and includes publication in peer-review journals. His results may influence an ASTM building standard for structural grade plastics currently under discussion. (ASTM stands for the American Society for Testing and Materials). Hamel is a member of the subcommittee that governs this standard.
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Originally from New Hampshire, Scott Hamel completed a B.S. in Civil Engineering at Worcester Polytechnic Institute in Massachusetts.  After inspecting and designing bridges in Boston for three years, he moved to Boulder, CO to complete a master’s in Civil Engineering with an emphasis in structures. He worked for a structural engineering firm in Denver for three years, designing commercial buildings and earning his license as a Professional Engineer. He completed his Ph.D. at the University of Wisconsin-Madison in structural engineering with a dissertation on computer modeling the behavior of Wood-plastic Composites. He joined the engineering faculty at UAA in 2011 where he teaches courses in structural engineering, such as steel and concrete design.

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