Drones as Damage Detectors? Researchers Consider Remote Aircraft as Bridge Inspection Tool

According to the American Society of Civil Engineers, nearly one quarter of bridges across the country are structurally obsolete and 11 percent are structurally flawed.

Timber bridges in Pennington County, South Dakota.

Timber bridges in Pennington County, South Dakota.

Researchers from the Forest Products Laboratory (FPL) and South Dakota State University are on a mission to identify effective inspection methods, especially where there are accessibility challenges for inspectors, in an attempt to improve this statistic. The team is posing an interesting question as part of their search: Can drones help detect bridge damage? FPL Research General Engineer James Wacker is taking to the skies to find out.

Wacker and his fellow researchers are investigating whether the use of a remotely piloted aircraft, or drone, is a cost effective solution to help inspectors pinpoint areas of structural decay and degradation. Drones can be armed with high-resolution cameras that allow for recording of highly detailed images and videos, along with other tools such as infrared imaging.

Beginning in early spring 2017, the researchers will team up with the South Dakota Department of Transportation to conduct a drone inspection of two timber bridges in South Dakota. High-quality images from the drone will be evaluated and compared with data from conventional inspections.

The final results of the study will be issued in a report that will document the drone inspections and offer recommendations for drone-based inspection procedures.

To learn more about this study, read the full Research in Progress report.

Blog post by Francesca Yracheta

    “Timber Innovation Act” Resurfaces in Congress

    A bill promoting the construction of tall wood buildings has been reintroduced to Congress.

    CLT offers outstanding structural, thermal, and acoustic performance.

    Cross laminated timber makes tall wood buildings possible.

    The bipartisan Timber Innovation Act is an effort to spur economic development with new and innovative uses for wood as a building material. The legislation will accelerate the research and development of wood for use in construction projects, focusing on the construction of buildings more than 85 feet tall.

    Reaching such great heights requires the use of mass timber products, such as cross laminated timber, or CLT. Researchers here at the Forest Products Laboratory (FPL) have been studying CLT from all angles, including engineering properties, fire and moisture performance, and how they hold up during earthquakes. A quick search of this blog turns up a great reading list on CLT if you’d like to learn more.

    U.S. Senator Debbie Stabenow (D-MI), ranking member of the Senate Committee on Agriculture, Nutrition and Forestry, joined Senator Mike Crapo (R-ID) and U.S. Representatives Suzan DelBene (WA-01) and Glenn Thompson (PA-05) to reintroduce the bill.

    “Advancing tall wood building construction through the Timber Innovation Act is a win for working families and our environment,” DelBene said. “Technological advancements in cross-laminated timber have made it easier for us to support healthy forests, wildlife habitats and rural economies dependent on forest products. Encouraging the use of green building materials instead of building materials dependent on fossil fuels reduces greenhouse gases creating a cleaner, healthier environment for future generations.”

      Measuring Sustainability: How Do Wood Pallets Stack Up?

      There are more than 1.8 billion pallets in service in the United States each day, and ninety-three percent of these pallets are made from wood. That staggering statistic begs the question of just how sustainable wooden pallets really are. Luckily, we know who to ask.

      Researchers at the Forest Products Laboratory (FPL) have set out to investigate the life cycle of wooden pallets in an effort to help manufacturers keep up with the demand for environmentally friendly pallets.

      Wooden pallets used for shipping purposes in the United States (NWPCA 2016).

      Wooden pallets used for shipping purposes in the United States (NWPCA 2016).

      Supervisory Research Forest Products Technologist Rick Bergman said the life-cycle assessment (LCA) study has a number of goals and benefits.

      “LCA is a method used to measure the environmental impacts. For example, greenhouse gas emissions that result from the production of a product over its entire life cycle,” Bergman said. “From the extraction of raw materials through production, use, recycling, and ultimately, disposal of the product.”

      Researchers are also using the information to help the National Wooden Pallet and Container Association (NWPCA), with whom FPL has a memorandum of understanding, develop future environmental product declarations that will result in more sustainable pallet use, and pinpoint areas of success and improvement within the production market.

      Bergman and his team will survey a number of pallet manufacturing facilities to collect the assessment data and plan to present the findings at a future conference on LCA or green building.

      To learn more about this project and the life of wooden pallets, read the full Research in Progress report.

      Interestingly, this isn’t FPL’s first foray into the world of pallets. Click here for a historical perspective dating back to the 1930’s and a great video showing just how monumentally “pallets move the world.”

      Blog post by Francesca Yracheta

        Is What You See What You Get? Linking Forest Health to Wood Quality

        They say you can’t judge a book by its cover. But can a piece of wood be judged by the tree it was cut from? Researchers from the Forest Products Laboratory (FPL) and the University of Georgia are working to find out.

        Loblolly pine is widely planted in the southeastern United States. The plantations are highly productive, generating lumber for construction, and they are managed specifically to address increased population growth. This makes loblolly pine one of the most important tree species in the world in terms of wood use.

        These weakened and dead loblolly pine trees show symptoms of southern pine decline.

        These weakened and dead loblolly pine trees show symptoms of southern pine decline.

        Recently, a phenomenon dubbed ‘southern pine decline’ (SPD) has contributed to high levels of tree mortality and decreased forest productivity. SPD is not entirely understood, but appears to be the result of a combination of physical and biological factors.

        The forest industry has suggested that stands with symptoms of SPD have different weight scaling factors than stands not affected, and thus it appears that green moisture content is altered by SPD. Based on this observation, researchers are looking to determine whether trees affected by SPD have different wood density that would negatively affect the overall quality of the wood.

        The project will involve studying trees from 14 stands in Alabama and Georgia, seven with SPD symptoms, and seven without. Trees will be selected from each stand, inspected for insect, disease, and fungal activity, and rated on their overall health. Cores (samples of wood) will also be taken from each tree and examined using various methods to determine moisture content and density. The data will then be analyzed to establish a link between wood quality and forest health.

        For more details on this study, check out this Research in Progress report. The project is scheduled for completion in 2018.

          Blast Testing Shows CLT Can Take the Heat

          Here at the Forest Products Laboratory (FPL), we sometimes get a little destructive. We bend and break wood samples of all sizes, and we even shoot lumber out of a cannon at 100 miles per hour.

          But explosions? That’s a bit out of our wheelhouse. Not that wood can’t handle it. Particularly when it’s used in engineered products like cross-laminated timber (CLT), which FPL researchers have studied from many angles, including fire performance, use in earthquake-prone regions, and the effects of moisture on CLT.

          Recent tests of CLT structures show just how tough this material can be. A series of live blast tests were conducted at Tyndall Air Force Base by WoodWorks in cooperation with the U.S. Forest Service and Softwood Lumber Board.

          The specifics of the tests are outlined in this great Woodworking Network article, but if you’re looking for a spoiler, the results were promising, and they “will be used to further expand the use of wood solutions for Department of Defense applications and other blast-resistant construction.”

          You can view all the tests at http://bit.ly/2hwVE1g and we posted our favorite below. While not a dramatic view of the explosion itself, this high-speed shot shows the wood panels moving with the force of the blast without being destroyed.

          WoodWorks will publish the complete results in 2017.