By Ian Randall
A fire-retardant structural material can be made by chemically softening and compressing wood to remove the spaces between cell walls. When burnt, the resulting material forms a protective char layer on its outside which helps preserve its internal strength.
The use of wood in structural applications is limited by both its inherent flammability and susceptibility to rapid collapse on burning. Wood can be made more fire-proof by chemical treatments – such as through injections of halogenated flame retardants, or coatings of inorganic nanoparticles – but these approaches are typically either prohibitively expensive, fail environmental and health standards, or result in insufficient structural strength.
Liangbing Hu and colleagues of the University of Maryland in the US show that their process to create bullet-proof wood through densification also confers fire-resistant properties without recourse to potentially toxic or environmentally-unfriendly materials.
The densified material – which Hu dubs ‘super wood’ – is created by first chemically treating timber with sodium hydroxide and sodium sulfite to partially remove its lignin, the organic polymer which makes cell walls rigid. Subsequent hot pressing creates a dense, laminated material free of lumina – the tiny channels that create a porous structure, supplying oxygen and increasing flammability.
AN has mapped the schools, organizations, and manufacturers across the U.S. and Canada that are powering the domestic timber boom.
The timber industry has long thrived on its small-scale, local nature due to the sourcing of its materials as well as the limits on project size set by the building code. With this has come a good deal of fragmentation and disorganization, so we decided to map out the different schools, organizations, and manufacturers that are leading the way in the research and development of mass timber across the United States and Canada.
Is wood pellet-based electricity less carbon-intensive than coal-based electricity? It depends on perspectives, baselines, feedstocks, and forest management practices
P Dwivedi, M Khanna, and Madisen Fuller
Some studies suggest that the carbon intensity of electricity generated in the United Kingdom by using imported wood pellets from the southern United States is higher than that of coal-based electricity, whereas other studies suggest that the use of wood pellet-based electricity reduces carbon emissions significantly, relative to coal-based electricity. We developed the Forest Bioenergy Carbon Accounting Model (ForBioCAM 1.0) to analyze factors that influence the carbon intensity of wood pellet-based electricity, using a common set of assumptions and the same system boundary. We show that widely differing assessments of the carbon intensity of wood pellet-based electricity depend on the choice of forest management perspectives (landscape or stand), baselines (no harvest, or harvesting for the manufacture of traditional finished wood products), feedstocks (whole trees, pulpwood, or logging residues), forest management practices (change in rotation age), and the duration of the analysis itself. Unlike with a stand perspective, we demonstrate conditions under which a landscape perspective results in carbon savings net of avoided emissions from coal-based electricity. Our results also suggest that the two perspectives of forest management converge in their assessment of the positive carbon effects of various feedstock types used to manufacture wood pellets relative to a no-harvest baseline, and that the use of whole trees for wood pellets results in net carbon savings after a break-even period of about three years relative to a no-harvest scenario. The results of this study can guide future policy deliberations on the use of wood pellets as a renewable energy source worldwide.
By Andrew Moore
The tiny rod-like structures have been shown to improve the strength and durability of concrete structures and reduce the carbon footprint of manufacturing cement.
If you were to walk through downtown Greenville, you would likely notice several landmarks, including the Liberty Bridge and the old county courthouse.
While these iconic structures are unique in their own right, they share one commonality: They’re made of concrete. The coarse, gray material is the very foundation of modern infrastructure. It’s been used in the construction of everything from buildings and bridges to roads and sidewalks.
But despite all its benefits of strength and durability, there’s a major downside to using concrete.
The production of cement, which when mixed with water forms the binding agent in concrete, accounts for 5 to 10 percent of all human-caused carbon dioxide emissions, according to the International Energy Agency. These emissions have been on the rise since the industrial revolution and remain the leading cause of global warming.
Over the past decade, though, researchers from across the country have been working together to create a cleaner version of the versatile building material. And now they plan to test the capabilities of their environmentally friendly alternative in Greenville.
The U.S. Endowment for Forestry and Communities, a Greenville-based environmental nonprofit, has partnered with the U.S. Forest Service, Oregon State University, and Purdue University to study a concrete mixture infused with cellulosic nanomaterials.
Cellulosic nanomaterials are produced by breaking down wood to its smallest, strongest components through mechanical and chemical processes similar to making paper. These tiny rodlike structures have diameters 20,000 times smaller than the width of a human hair and can be seen only using an electron microscope, yet they are as strong as steel with only one-fifth the weight.
“Researchers are testing these cellulosic nanomaterials in a wide range of applications from substrate for computer chips, they don’t warp under heat like plastics do, to car and airplane bodies, lighter and stronger than steel,” said Dr. Alan Rudie, a chemist with the U.S. Forest Service’s Forest Products Laboratory in Wisconsin, in a news release. “Our team expects that concrete will be among the first commercial applications.”
By Pranjal Mehar
A key finding of the study is that positive climate change mitigation effects can be gained only if efforts are made to use more wood for long-lived wood products.
A new study by the University of Eastern Finland has suggested that the way we use wood mitigate climate change. It also supports the economy.
Forests assume a vital job in the worldwide carbon cycle and add to climate change mitigation. Forests ingest carbon from the environment through photosynthesis and store the carbon in living biomass, dead wood, litter and soil.
When wood is collected, a lot of carbon is expelled from the Forest and would then be able to be put away for a considerable length of time in enduring wood items, for example, wooden houses and furniture. Up until this point, numerous examinations have concentrated on carbon put away in Forest, yet fewer investigations have concentrated on the job of wood items.
A new study intends to fill this gap in knowledge. The study analyzed and applied various methods and models in order to estimate the effects of wood use effects on climate change mitigation and to reveal the environmental, economic and even social effects of wood use.
The examination followed the streams of wood in Lithuania and the Czech Republic beginning from the forest through the wood handling industry until the point when the end products, with an accentuation on carbon conventional and atmosphere moderation impacts.
The outcomes demonstrate that traditional carbon bookkeeping strategies for reap wood items may prompt a huge underestimation of the carbon put away in wood items. The examination discovered that in a few nations, the yearly carbon spending plan in wood items is 40% higher when ascertained with a more definite technique.
By George Plaven
Timm Locke relishes a chance to drive around Portland and showcase the latest commercial buildings made with mass timber, a construction material that uses wood beams and panels instead of concrete and steel.
First stop: Albina Yard, a four-story office building that opened in 2016 featuring cross-laminated timber panels from D.R. Johnson, a lumber company south of Roseburg.
Every piece of cross-laminated timber — or CLT for short — is prefabricated, designed for a specific part of the building, said Locke, director of forest products at the Oregon Forest Resources Institute. That means buildings go up faster, with fewer workers.
Wood is also environmentally superior to steel and concrete, Locke said, because it sequesters carbon and takes less energy to produce.
“There are so many benefits, it doesn’t matter which one you choose to start with,” Locke said.
First developed in Europe, mass timber is now catching on in the U.S., and Oregon is working to position itself as the industry hub, kick-starting rural economies that have traditionally relied on forest products. On Aug. 1, Oregon became the first state to approve language in its building codes allowing for wood-framed buildings up to 18 stories tall.
BY ADELE PETERS
Spinnova has found a way to spin any cellulose–wood, potato peels, even old T-shirts–into new, strong fiber.
In a new pilot factory in Jyväskylä, Finland–a city surrounded by forests and known in part for its lumber and paper industries–a startup will soon begin to turn wood pulp into something new: a type of fabric that could eventually compete with cotton.
Making wood into fabric isn’t new, but older wood-based fabrics like rayon use harsh chemicals that can pollute water and poison workers. The new fabric, made by a startup called Spinnova, uses a mechanical process instead of chemicals; the only byproduct is evaporated water, which is reused in production. Unlike cotton, which uses massive amounts of water in areas often prone to droughts, it needs little water, no pesticides, and no farmland.
The new process uses FSC-certified wood pulp that’s ground into a gel-like material called microfibrillated cellulose, which is made of tiny fibers. The material flows through the startup’s patented machinery to create a network of fibers that are spun and dried into a fluffy, firm wool that can be knit or woven into fabric and then made into clothing, shoes, or other textiles.
By Emily Pollock
M-Fire’s fire-inhibiting wood looks increasingly important in an industry turning back to wood buildings.
The phrase “wood buildings” conjures up images of flammable, unsafe architecture, but M-Fire Suppression Inc. is looking to change that picture. And it wants its fire-resistant wood to be the new face of ecologically friendly building.
One of the most common tests of a material’s fire resistance is a spread test, where inspectors measure how long it takes fire to spread across the material as compared to control materials. Class A is the most fire-resistant class, and M-Fire is currently the only company making Class A fire-protected cross-laminated timber. To do that, the company infuses wood with surfactants that allow fire inhibitors to migrate into the pockets of oxygen in the wood. The result is a product much eco-friendlier than most traditional fire inhibition. M-Fire is currently the only Class A fire inhibitor with UL Greenguard Gold certification, which means that it’s safe around children and schools.
“We don’t even like the name fire retardant near our brand. We’re a fire inhibitor,” said Steve Conboy, the company’s chairman and general manager. “What happens is, we inhibit fire because we break the chemical reaction in the fire.” The inhibitor breaks the chain of free radicals (H+, OH- and O-) released during combustion, giving the fire nothing to feed on.
The fire protection results in what Conboy calls “defended carbon”: carbon that is stored in the wood and will never be released into the atmosphere. A carbon-absorbing building material gives M-Fire’s wood a distinct advantage over carbon-producing alternatives like structural steel.
by Jack McManus
Space Popular’s design gathers service functions into a central prefabricated core (resembling a Nordic hearth) that DIY-ers can build their own house around.
Solutions from the past can often provide practical answers for the problems of the future; as the London-based design and research firm, Space Popular demonstrate with their “Timber Hearth” concept. It is a building system that uses prefabrication to help DIY home-builders construct their own dwellings without needing to rely on professional or specialized labor. Presented as part of the ongoing 2018 Venice Biennale exhibition “Plots Prints Projections,” the concept takes inspiration from the ancient “hearth” tradition to explain how a system designed around a factory-built core can create new opportunities for the future of home construction.
Realized in the form of a brightly-painted model in the exhibition space at Serra dei Giardini, the Timber Hearth system gathers all the service functions, appliances, and fittings that require professional installation in typical residential buildings and contains them within a prefabricated hearth-like structure.
Fabricated in a factory and sized for shipping in one piece, the core is then installed on site and connected to service grids. After that, the remaining construction (including building the floor platforms, partition walls, facade, and roof) can be completed by the homeowners, either by traditional or contemporary timber-frame methods. According to the designers, this affords reasonably-equipped makers the flexibility, freedom, and affordability to build their own perfect home.
A consortium of timber and CLT companies have teamed up with the U.S. Army and Lendlease to test the blast capacity of timber structures in the real world, setting the stage for more mass timber buildings.