AN ABSTRACT OF THE THESIS OF Byrne Tadaaki Miyamoto for the degree of Master of Science in Wood Science presented on May 8, 2017. Title: Establishing Design Values for Potential Utilization of Western Juniper as a Building Material. Abstract approved: _____________________________________________________________________ Arijit Sinha Western juniper (Juniperus occidentalis) is a conifer that is native to Oregon, California, Washington, Nevada, and Idaho. Juniper is known to have highly decay resistant heartwood and is a popular choice for finished furniture. With recent forest management practices over the past 100 years have resulted in an immense population increase in western juniper stands, transforming the grasslands/sagebrush into juniper forests. Landowners have been encouraged to cutback western juniper to restore grassland habitat, but there is no major market associated with juniper. This study assessed the strength and durability properties of western juniper in order to develop design values in collaboration with the West Coast Lumber Inspection Bureau (WCLIB). The data will be presented to American Lumber Standard Committee (ALSC) for inclusion in the National Design Specification. Design values assigned to western juniper will allow contractors to use this species in structural and non-structural applications, especially for State funded projects. Samples were harvested from three locations in eastern Oregon, one location in northeast California, and one location in southwest Idaho. Tests were performed according to procedures described in ASTM Standard D143 small-clear specimens for compression, bending, and shear. Average strength values were calculated and compared to similar wood species. Most properties were similar to those of other species, but modulus of elasticity was significantly lower. The differences between species might be attributed to cell wall structure and distribution of lignin in the cells. Design values for western juniper were calculated using the strength values following the ASTM Standard D245 procedure for establishing structural grades and related allowable properties for visually graded lumber. Durability of western juniper was assessed using laboratory decay tests, marine tests, and ground contact exposure. The long term marine durability and ground contact tests are still on going. The laboratory decay test indicated that western juniper heartwood was highly resistant to attack by brown and white rot fungi. ©Copyright by Byrne Tadaaki Miyamoto May 8, 2017 All Rights Reserved Establishing Design Values for Potential Utilization of Western Juniper as a Building Material by Byrne Tadaaki Miyamoto A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Presented May 8, 2017 Commencement June 2017 Master of Science thesis of Byrne Tadaaki Miyamoto presented on May 8, 2017. APPROVED: _____________________________________________________________________ Major Professor, representing Wood Science _____________________________________________________________________ Head of the Department of Wood Science and Engineering _____________________________________________________________________ Dean of the Graduate School I understand that my thesis will become part of the permanent collection of Oregon State University libraries. My signature below authorizes release of my thesis to any reader upon request. _____________________________________________________________________ Byrne Tadaaki Miyamoto, Author ACKNOWLEDGEMENTS I would like to thank Sustainable Northwest, United States Department of Agriculture, Oregon Department of Transpiration, and Business Oregon for providing funding to make this project possible. I would also like to thank Don Devisser, from West Coast Lumber Inspection Bureau, for helping with the organization of testing as well as the development of design values. I would like to thank the faculty and staff in the wood science department, especially my professors Dr. Arijit Sinha and Dr. Jeff Morrell, for allowing me to work with them and their lab groups. They both have helped and encouraged me through each step of my education. I would like to thank Matthew Konkler, Jed Cappellazzi, and Milo Clauson for always willing to help me with the various aspects of my project. I also would like to thank the front desk staff, Jessica King, Michelle Maller, and Angela Haney. I would like to thank all the student workers that help me with my project, especially Thomas Hutton and Quinton Anderson for spending long days cutting juniper samples, as well as Kayla Naas and Raquel Albee for helping test samples. Lastly, I would like to thank my parents for supporting me throughout school and encouraging me to pursue a higher education. Also thank you to all my friends and colleagues. TABLE OF CONTENTS Page Chapter 1: Introduction ........................................................................................................1 1.1 Research Objectives ...............................................................................................5 Chapter 2: Literature Review ...............................................................................................6 2.1 Western Juniper .....................................................................................................6 2.2 Range and Climate .................................................................................................6 2.3 Expansion ...............................................................................................................7 2.4 Market Research ..................................................................................................10 2.5 Physical and Mechanical Properties ....................................................................11 2.6 Design Values ......................................................................................................15 Chapter 3: Material And Methods .....................................................................................19 3.1 Mechanical Test Materials ...................................................................................19 3.1.1 Dry/Green Ratio Samples .........................................................................21 3.2 Mechanical Test Methods ....................................................................................21 3.2.1 Bending .....................................................................................................21 3.2.2 Compression Parallel ................................................................................23 3.2.3 Compression perpendicular .......................................................................24 3.2.4 Shear ..........................................................................................................25 3.2.5 Moisture Content and density ...................................................................26 3.2.6 Dry/Green Ratio ........................................................................................26 3.2.7 Design Value Calculations ........................................................................27 3.2.8 Statistical Analysis of Mechanical Tests ..................................................30 TABLE OF CONTENTS (Continued) Page 3.3 Durability Materials and Methods .......................................................................31 3.3.1 Marine Durability Samples .......................................................................31 3.3.2 Laboratory Decay Test ..............................................................................32 3.3.3 Ground Contact Test .................................................................................34 Chapter 4: Results and Disscusion .....................................................................................36 4.1 Compression Parallel-to -Grain (||) Test ..............................................................37 4.2 Compression Perpendicular-to-Grain (⊥) Test ....................................................40 4.3 Shear Block Test ..................................................................................................44 4.4 Three-Point Bending Test ....................................................................................47 4.4.1 Modulus of Elasticity (MOE) ...................................................................47 4.4.2 Modulus of Rupture (MOR) .....................................................................50 4.5 Green/Dry Ratio of Compression Perpendicular-to-Grain and Shear .................52 4.6 Strength Values ....................................................................................................53 4.7 Design Values ......................................................................................................53 4.8 Laboratory Decay Test .........................................................................................55 Chapter 5: Summary ..........................................................................................................60 5.1 Summary ..............................................................................................................60 5.2 Conclusion ...........................................................................................................61 5.3 Limitation and Future Work Recommendations ..................................................62 Bibliography ......................................................................................................................64