Documenting the Carbon Impact of Laminated Veneer Lumber Production

 

Laminated veneer lumber

Research Forest Products Technologist Richard D. Bergman continues his good work for the environment with a recent publication, Life-Cycle Inventory Analysis of Laminated Veneer Lumber Production in the United States.

Bergman’s study found that documenting the actual environmental performance of building products is becoming widespread and important because of concerns that some organization’s green-marketing claims are actually misleading. This is known as “greenwashing” in the business and borrows from the term whitewashing.

Developing environmental product declarations (EPDs) for building products is one way to provide scientific documentation that counters efforts to greenwash. Life-cycle inventory (LCI) data are the underlying data for subsequent development of life-cycle assessments (LCAs) and EPDs. EPDs are similar to nutritional labels for food.

This report follows data and reporting requirements as outlined in the Product Category Rules (PCR) for North American Structural and Architectural Wood Products and contains the LCI components for producing a North American EPD. At present, many EPDs for structural wood products made in North America exist. LCI compiles all raw material and energy inputs and outputs associated with the manufacture of a product on a per-unit basis within defined system boundaries. These boundaries can be limited to only one stage within the product life-cycle.

Multiple sequential LCI stages are usually combined to produce an LCA. LCAs describe the total environmental impact for a particular product. Many engineered structural wood products have been developed in the last several decades; for example, laminated veneer lumber (LVL ), which is comprised of many thin layers of dry wood veneers glued together with resins to form lumber-like products. LVL is designed to be used in the same manner as solid wood  products such as sawn lumber. Structural wood products such as LVL used in building construction can store carbon for long periods, which is typically greater or far greater than the carbon dioxide emissions released during manufacturing.

Environmental product declarations based on LCA data are an important means of documenting the environmental performance of building products. The International Organization for Standardization (ISO) requires that underlying LCI data be recent; this study updates the LCI data for LVL needed to develop an updated EPD. The amount of carbon stored in LVL exceeds total CO2 emissions during manufacturing by about 350 percent.

Cooperators include the USDA Forest Service Forest Products Laboratory, Madison, Wisconsin, and the Consortium for Research on Renewable Industrial Materials, Seattle, Washington.

Ultrasonic Based Nondestructive Evaluation Methods for Wood: A Primer and Historical Review

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With the recent compilation of 50 years of the NDT International Nondestructive Testing and Evaluation of Wood Symposium Series, the recently published Ultrasonic Based Nondestructive Evaluation Methods for Wood: A Primer and Historical Review examines how the nondestructive testing of wood in all of its forms has changed over the last half century. Authors C. Adam Senalik, Greg Schueneman, and Robert Ross provide a basic primer to nondestructive testing using ultrasonic inspection and provide a comprehensive literature review of the use of ultrasonic techniques in the inspection, characterization, classification, and evaluation of wood and wood products as presented in 50 years of the NDT Wood Symposium series.

Ultrasonic inspection of wood has evolved over a half a century of research and development. In addition to the literature review on ultrasound in wood inspection, this report describes basic ultrasonic inspection techniques and analyses. It contains a list of over one hundred species of wood that have been inspected using ultrasound.

Strength grading, determination of elastic constants, and evaluation of moisture content effects are a few of the fields to which ultrasonic inspection have been successfully applied. The most widespread application of ultrasonic inspection with wood is arguably defect detection. There is an ongoing need to detect and assess defects within standing trees, poles, lumber, structures, and engineered wood products. Increased sensitivity and more accurate approximations of remaining wood strength aid inspectors in evaluating the utility and safety of wood structures. Wood is already the most common building material in the world, but with the increased reliability that comes with advanced ultrasonic inspection techniques, its use can only grow.

Wood and Timber Condition Assessment Manual: A New FPL Report

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Deterioration of an in-service wood member may result from a variety of causes during the life of a structure. Periodic inspec­tion of wood used in structures is important for determining the extent of deterioration so that degraded members may be replaced or repaired to avoid structural failure.

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A resistance microdrill used for inspection of a historic Civilian Conservation Corps log cabin.

Inspection professionals use a wide variety of techniques to as­sess the condition of wood in service. Visual, mechanical prob­ing, and stress wave or ultrasound-based techniques are all used either individually or in combination by inspectors. Although these techniques are based on solid technical information and supporting research, prior to publication of the Wood and Tim­ber Condition Assessment Manual in 2004, no practical, com­prehensive manual provided information on inspection of wood in service.

According to editor and Supervisory Research General Engineer Robert J. RossThe Wood and Condition Assessment Manual was prepared to address this need. The manual was prepared from numerous re­search studies, inspections, and lectures dealing with assessing the condition of in-service wood and timber. It was intended for inspection professionals. A concerted effort was made to provide clear and concise explanations of various aspects of inspecting in-service wood and timber. To this end, a number of photographs and drawings obtained from actual inspections were included.”

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Rehabilitation efforts for Esterhazy Castle Sopron, Hungary, have begun. The traditional mortise and tenon timber framing system was found to be in excellent condition.

Ross goes on to say, “In preparing this second edition of the Wood and Timber Condi­tion Assessment Manual, I had three objectives: (1) to update the existing chapters to reflect advancements in inspection methods; (2) to develop new material that focuses on a wide range of new techniques and technologies that have been in­vestigated for use in assessing the condition of wood structures and provide estimates of the properties of in-service wood; and (3) to make the manual available in digital format.”

The newly published and comprehensive Wood and Condition Assessment Manual summarizes information on condition assess­ment of in-service wood, including visual inspection of wood and timbers, use of ultrasound and probing/boring techniques for inspection, and assessment of wood and timbers that have been exposed to fire. The report also includes information on assigning allowable design values for in-service wood.

The Wood and Timber Condition Assessment Manual—Second Edition is available in digital format from the  Forest Products Laboratory website.

FPL Helps Recyclable Solar Cells Take Root

The same building blocks nature uses to produce trees are now being used to enhance high-efficiency products such as photovoltaic solar cells.

By producing pilot-scale quantities of cellulosic nanomaterials, the U.S. Forest Service Forest Products Laboratory (FPL) is collaborating with researchers at the Georgia Institute of Technology and Purdue University to demonstrate the potential of cellulosic nanomaterials as a high performance, environmentally preferable material for the 21st century.

“Using cellulosic nanomaterials as a substrate for photovoltaic cells is just one example of the ability of these materials to provide renewable applications for such high-efficiency products,” said Ted Wegner, Assistant Director of the Forest Products Laboratory.

To date, most solar cells have been built on glass or plastic foundations. Neither is easily recyclable and petroleum-based substrates are not very eco-friendly. Cellulose nanomaterials, on the other hand, are renewable and can be sustainably produced. Use of these wood-based materials also creates a potential use for biomaterials harvested through forest restoration projects aimed at reducing catastrophic wildfires.

“These materials offer a profound opportunity to accelerate forest restoration across America, to protect lives and property from wildfire,” said Michael T. Rains, FPL acting director. “It is estimated that a well-established program in wood-based nanotechnology that creates high-value markets from undervalued woody biomass can help restore 7-12 million forested-acres annually,” said Rains. “This could significantly reduce future fire suppression costs.”

Cellulosic nanomaterials are naturally occurring and possess many outstanding qualities. They have strength properties greater than Kevlar®; piezoelectric properties equivalent to quartz; can be manipulated to produce photonic structures; possess self-assembly properties; and are remarkably uniform in size and shape. Because they are naturally abundant, renewable, and cost-effective, reproduction of cellulosic nanomaterials is expected to reach quantities of millions of tons. This exceeds production projections for many other nanomaterials.

A recent study by Georgia Tech College of Engineering, led by Professor Bernard Kippelen, opens the door for a truly recyclable, sustainable, and renewable solar cell technology.

“The development and performance of organic substrates in solar technology continues to improve, providing engineers with a good indication of future applications,” said Kippelen, director of Georgia Tech’s Center for Organic Photonics and Electronics (COPE). “But organic solar cells must be renewable. Otherwise we are simply solving one problem, less dependence on fossil fuels, while creating another: a technology to produce energy from renewable sources that is not disposable at the end of its lifecycle.”