United States Department of Agriculture Undervalued Hardwoods for Engineered Materials and Components Second Edition Forest Forest Products General Technical Report March Service Laboratory FPL–GTR–276 2020 Abstract This report summarizes information on the use of wood from hardwood species in engineered materials, components, and structures. It includes information on use in a wide variety of engineering products and applications. Keywords: Wood; hardwoods; engineered products March 2020 Ross, Robert J.; Erickson, John R., eds. 2020. Undervalued hardwoods for engineered materials and components: second edition. General Technical Report FPL-GTR-276. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 108 p. A limited number of free copies of this publication are available to the public from the Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53726-2398. This publication is also available online at www.fpl.fs.fed.us. 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Submit your completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Washington, D.C. 20250–9410; (2) fax: (202) 690–7442; or (3) email: [email protected]. USDA is an equal opportunity provider, employer, and lender. Undervalued Hardwoods for Engineered Materials and Components Second Edition Edited by Robert J. Ross, Project Leader John R. Erickson, Former Director (deceased) USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin Contents Preface .................................................................................................................................................................. iii Preface to the First Edition .................................................................................................................................. iv Chapter 1—Undervalued Hardwood Utilization from the Forest Manager’s Perspective ....................................1 Chapter 2—Basic Wood Properties of Hardwoods ................................................................................................7 Chapter 3—Sorting Hardwood Logs ...................................................................................................................19 Chapter 4—Grading and Properties of Hardwood Structural Lumber ................................................................27 Chapter 5—Drying and Heat Sterilization of Hardwood Lumber for Structural Uses ........................................39 Chapter 6—Engineered Trusses from Undervalued Hardwoods .........................................................................49 Chapter 7—I-Joists and Headers .........................................................................................................................57 Chapter 8—Ultrasonic Grading of Hardwood Veneer .........................................................................................61 Chapter 9—Properties of Hardwood Laminated Veneer Lumber ........................................................................73 Chapter 10—Red Maple Lumber Resources for Glued-Laminated Timber Beams ............................................77 Chapter 11—Hardwoods for Timber Bridges: A National Program Emphasis by the USDA Forest Service .....89 Chapter 12—Hardwoods for Engineered Specialty Products ..............................................................................95 Chapter 13—Cellulose Nanomaterials and Their Products from Hardwoods ...................................................103 ii Preface This edition of Undervalued Hardwoods for Engineered Materials and Components builds upon the first edition with important new content: • Implications of utilizing these materials for forest managers (Chapter 1) • Fundamental properties of wood from hardwood species (Chapter 2) • Technologies for sorting hardwood logs (Chapter 3) • Ultrasonic grading for hardwood veneer (Chapter 8) • Hardwoods for specialty engineered materials and products (Chapter 12) • Nanocellulosic products (Chapter 13) The objective of this book is the same as that of the first edition—to serve as a primary reference on use of the undervalued resource in engineered components. It is a compilation of results obtained from research and development studies focused on using low-grade hardwood material in engineered applications. I worked with several well-respected technical authorities in preparing this edition, and I thank the technical contributors: Brian K. Brashaw, PhD, Program Manager, Forest Products Marketing Unit, Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA John J. Janowiak, PhD, Professor Emeritus, Penn State University, University Park, Pennsylvania, USA Ronald Sabo, Research Forest Materials Engineer, Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA C. Adam Senalik, PhD, P.E., Research General Engineer, Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA Edward Thomas, Research Computer Scientist, Northern Research Station, USDA Forest Service, Princeton, West Virginia, USA James P. Wacker, P.E., Research General Engineer, Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA Xiping Wang, PhD, Research Forest Products Technologist, Forest Products Laboratory, USDA Forest Service, Madison, Wisconsin, USA Janice K. Wiedenbeck, PhD, Project Leader, Northern Research Station, USDA Forest Service, Princeton, West Virginia, USA Michael Wiemann, PhD, Wood Technologist and Botanist, Forest Products Laboratory, USDA Forest Service, Madison, WI, USA As in the first edition, some sections originally appeared in technical journals, research reports, and various symposium proceedings. This book is dedicated to John R. Erickson (1934–2014), P.E., Director and Research Engineer, Forest Products Laboratory. Undervalued Hardwoods for Engineered Materials and Components, Second Edition is available in digital format from the USDA Forest Service Forest Products Laboratory website. Robert. J. Ross, Editor iii Preface to the First Edition The hardwood lumber industry is a key component of the forest products industry in the Lake States and Northeast regions of the United States. Sugar maple (Acer saccharum) and red maple (Acer rubrum) are two of the primary species of timber growing in these regions. High-grade lumber from these two species is very valuable, with prices exceeding $1,500 per thousand board feet. Conversely, lower grades of lumber from these species sell for only $200 to $275 per thousand board feet. Engineered wood components represent one of the fastest growing segments of the forest products industry. Most engineered components are manufactured from softwoods such as Douglas-fir, the southern pines, or spruce-pine-fir lumber. During the past decade, significant research and development efforts have been devoted toward investigating the use of lower grade hardwood resources in engineered materials and components. Studies aimed at developing appropriate drying technologies, lumber grading procedures, and various engineered materials and components have been conducted. This publication is a compilation of results obtained from research and development studies focused on using low-grade hardwood materials in engineered components. Part One focuses on basic information about this resource: availability, mechanical properties, log grading techniques, and appropriate drying methods. Part Two summarizes studies that examine use of this resource in trusses, laminated veneer lumber, I-joists, and other applications. This publication was designed to