Browsing by Author "Vatalaro, Robert J"

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    Advancing Technology to Manufacture Trusses From Hardwood Lumber
    (University of Minnesota Duluth, 2001-09) Brashaw, Brian K; Vatalaro, Robert J; Lackore, Michael; Ross, Robert J; Wang, Xiping; Forsman, John
    Low-grade hardwood lumber is abundant across the Lake States and the Northeast United States. This product has historically been used as pallet lumber, crating material, and firewood with values of $200-$300 per thousand board feet. Further, several low-valued hardwood species have become prevalent in these areas through past forestry practices. In order to actively manage the forests for historical species, new and higher value markets must be established. The purpose of this project was to evaluate the use of sugar maple (Acer saccharum) and red maple (Acer rubrum) as structural lumber in metal plate pitched and parallel chord trusses. Groups of trusses were manufactured with both chords and webs from hardwood lumber, from softwood chords and hardwood webs and from chords and webs from softwood lumber. Testing was completed according to ANSl/fPI 2-1995, Standard for Testing Metal Plate Connected Wood Trusses. Results showed that both pitched and parallel chord trusses manufactured from hardwood lumber had strength and stiffness that was equivalent to or better than softwood trusses manufactured from spruce-pine-fir (SPF) and southern yellow pine (SYP) lumber. Trusses manufactured with SPF chords and hardwood webs had properties that were equivalent to or better than complete SPF trusses. The findings indicate that the potential use of low-grade hardwood lumber as truss lumber would result in large volumes of this material being utilized in a higher value application.
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    Demonstration of Hardwood Trusses in Residential Construction Projects
    (University of Minnesota Duluth, 2002-01) Brashaw, Brian K; Vatalaro, Robert J; Ross, Robert J; Wang, Xiping
    The hardwood lumber industry is a key component of the forest products industry in the Lake States and Northeast regions of the United States. Two of the primary lumber species include sugar maple (Acer saccharum) and red maple (Acer rubrum). High grade lumber from these species has an extremely high value, often exceeding $1,500/thousand board feet (M bdft). Lower grades of maple including pallet lumber usually sell for $200 to $275/M bdft. A cooperative Lake States research team developed the technical and economic background necessary for using low grade maple as structural components in metal-plate trusses and prefabricated wood I-joists. Specific projects that have been completed addressed the following research topics: lumber yield and recovery, lumber properties, acce\erated drying schedules, truss plate fasteners, truss fabrication and testing, I-joist fabrication and testing, and :financial assessments. An important step prior to implementation was the development of several demonstration projects using structurally graded maple lumber. A relationship was established with the Duluth Chapter of Habitat for Humanity International and a demonstration project was developed to use the red maple lumber in trusses for two houses with attached garag~s that were to be built during the summer of 2001. To minimize concerns oflumber length and s_pecies, we chose to use red maple as truss webs with spruce-pine-fir (SPF) chords in the house section and red maple for both the truss chords and webs in the attached garage. Red maple cants were obtained, sawn into 2- by 4-in. dimension lumber and dried using an accelerated kiln schedule. Structural grading was completed using an E-computer with visual overrides for #2 a11d #3 grade lumber. Truss designs were completed and sealed by a professional engineer and the trusses were manufactured by Kylmala Truss in Duluth, Minnesota. Natural Resources Research Institute (NRRI) personnel were involved in the setting of the trusses. There were no specific problems noted from the use of red maple in either the house or garage trusses. A second demonstration project was designed to use sugar maple lumber as web stock in a standard storage truss in a garage built in rural Duluth, Minnesota. Kiln-dried hard maple remaining from earlier projects was graded using a commercial E-computer. The lumber was then provided to Kylmala Truss for use in manufacturing a 6:12 pitch garage truss that spanned 26 ft. The trusses were set by NRRI personnel and covered with oriented strandboard (OSB) sheathing. There were no specific problems or challenges identified from using hard maple in the trusses, although it was difficult to hand nail siding to the hard maple web on the gable end trusses.
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    Evaluation of the Use of Acoustic Technology to Identify Low Value Logs
    (University of Minnesota Duluth, 2007-06) Wang, Xiping; Ross, Robert J; Brashaw, Brian K; Vatalaro, Robert J; Johnson, Scott
    The purpose of this service was to evaluate the feasibility and effectiveness of a resonance based acoustic technique for sorting low grade and low value logs from the chip wood mix stems. This work is conducted under a service agreement between the Natural Resources Research Institute (NRRI) at the University of Minnesota Duluth and the Seneca Sawmill Co. in Eugene, Oregon.
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    Stress Wave Sorting of Red Maple Logs for Structural Quality
    (University of Minnesota Duluth, 2001-11) Brashaw, Brian K; Wang, Xiping; Vatalaro, Robert J
    Existing log grading procedures in the United States make only visual assessments of log quality. These procedures do not incorporate estimates of the modulus of elasticity (MOE) oflogs. It is questionable whether the visual grading procedures currently used for logs adequately assess the potential quality of structural products manufactured from them, especially those in which MOE is of primary concern. The purpose of this study was to investigate the use of stress wave nondestructive evaluation (NDE) techniques to sort red maple logs for the potential quality of lumber obtained from them. Twenty red maple logs were nondestructively evaluated using longitudinal stress wave techniques and sorted into four stress wave grades. The logs were then sawn into lumber. Finally, the lumber specimens were dried and graded a final time using longitudinal stress wave techniques. The results of this study showed that good relationships existed between stress wave times measured in logs and the lumber produced from the logs. It was found that log stress wave grades have a positive relationship with the lumber grades. Logs with high stress wave grades produced high grade lumber. These findings indicate that the longitudinal stress wave technique could be used in sawmills to sort logs/cants for the production of high MOE products.