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• 1. [Article] Establishing Design Values for Potential Utilization of Western Juniper as a Building Material

  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 ...

  Citation × Citation Citation Abstract Copy Title: Establishing Design Values for Potential Utilization of Western Juniper as a Building Material Author: Miyamoto, Byrne 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. Title: Establishing Design Values for Potential Utilization of Western Juniper as a Building Material Author: Miyamoto, Byrne 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. Close