Grantee Research Project Results
2015 Progress Report: Green Oak as a Sustainable Building Material
EPA Grant Number: SU835729Title: Green Oak as a Sustainable Building Material
Investigators: Shelton, Ted , Stuth, Tricia , Taylor, Adam M , French, Robert C. , Retherford, Jennifer , Bennett, Richard M , Attea, Paul , Barnett, Matthew , Cajka, Kenna , Cid, Lorena , Comer, Bailey , Chang, Irene , Holmes, Bryce , Parsley, Josh , Rasnake, Tyler , Roberts, Blake , Todd, Hunter , Voit, Maik , Whitmore, Stephen , Fuller, Hayley , Ramsey, Scott , Roth, Katie , Zwycewicz, Ryan
Current Investigators: Shelton, Ted , French, Robert C. , Taylor, Adam M , Bennett, Richard M , Collett, Brad , Retherford, Jennifer , Schwartz, John , Stuth, Tricia
Institution: University of Tennessee
EPA Project Officer: Page, Angela
Phase: II
Project Period: October 1, 2014 through August 14, 2016 (Extended to July 31, 2017)
Project Period Covered by this Report: October 1, 2014 through September 30,2015
Project Amount: $90,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet - Phase 2 (2014) Recipients Lists
Research Category: P3 Challenge Area - Sustainable and Healthy Communities , P3 Challenge Area - Air Quality , Sustainable and Healthy Communities
Objective:
Objective: The primary objectives in Phase II are:
- To develop, detail, and construct a full-scale building using green oak pallet cants as structural members.
- To monitor, record, and analyze the demonstration project for structural, acoustic, and thermal performance over a two-year period as the green oak members dry.
- To disseminate our findings widely through multiple digital media platforms, peer reviewed publications, design award programs, and programs recognizing the integration of pedagogy and practice.
Progress Summary:
Through multiple courses and independent studies in the School of Architecture and College of Engineering and with technical assistance from the Department of Forestry, significant progress has been made toward the realization of Phase II objectives. This progress includes:
- Modifying the prototypical design that emerged from Phase I to make it modular and transportable. This modification was made necessary by the remoteness of the project site. The structure is being assembled in Knoxville and will subsequently be disassembled into modules, trucked to the location of our community partner in Kentucky, and reassembled on its final site.
- Reconfirming and modifying he structural engineering of the new, modular design.
- Evaluating the soil capacity at the ultimate project site and designing a foundation system to receive the demonstration structure.
- Developing construction processes for the construction, raising, and bracing of green oak bents.
- Exploration and development of a layered exterior enclosure system that includes thermal and moisture protection and operable openings.
- The preliminary development of an end grain flooring material derived from structural off-cuts during construction. (This material performed well in small samples when the wood had dried thoroughly but was disappointing in larger tests with greener wood. This remains a tertiary area of investigation.)
- Project submitted for consideration in the 2015-16 American Institute of Architects Committee on the Environment Student Top Ten Green Projects Competition
- Preliminary findings of the research were reported in a peer-reviewed paper and presented at a well-regarded international conference.
- The structural portion of one bay of the demonstration project is fully complete. Green oak pallet cants have been procured for the construction of the other bay.
- About one third of the enclosure system for the first bay has been completed. It is now being modified slightly in response to feedback from a group of professional architects at the end of the fall semester.
Future Activities:
Though the monitoring phase which will measure and record the structural, acoustic, and thermal performance of the system is yet to come, we are able to say that in its initial manifestation the green oak structural system is robust and easily able to withstand the gravitational and lateral loading placed on it during the construction process. Though it requires that one surmount a learning curve and that some tools be slightly modified, as we had hoped, moderately skilled labor using common hand tools can execute the bent based construction process. Though some bents weigh approximately 700 lbs in their wet condition, with proper preparation all were raised and braced into place without the benefit of any mechanical assistance.>
The progress has been slower than expected. This is partially due to smaller than anticipated enrollments in the associated courses and partially due to the construction learning curve. Also, at one point progress was halted for several weeks due to lack of raw material when no hardwood mills within several hundred miles were cutting oak pallet cants. However, progress has sped up as students have become comfortable with and refined the bent-based construction process.>
During the construction process we have had an opportunity to observe the pegged green oak joints as they begin to dry and shrink. All have performed well. There is only one joint that has developed some separation and we are monitoring it to see if an additional peg will be needed at that location. (All of the shoulder pieces are oversized to accept up to four pegs, though they anticipate using only two.) Overall, we have been very happy with the structural performance of the system and don't anticipate any problems on that front.>
As the demonstration structure remains in a climate-controlled environment, we have not yet begun to evaluate its thermal performance. However, we have observed the beginning of changes that we know will create thermal problems such as the separation of columns from the dimensionally stable plywood subflooring as the columns shrink.>
Journal Articles:
No journal articles submitted with this report: View all 2 publications for this projectSupplemental Keywords:
built environment, forest products, energy efficiency, embodied energy, housing, green design, environmentally benign substitute, conservation, design for the environment, green building, alternative construction material, architectural design>Relevant Websites:
Progress and Final Reports:
Original AbstractP3 Phase I:
Green Oak as a Sustainable Building Material | Final ReportThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.