Wood Stronger Than Steel: A New High-Tech Material

While nothing can be quite as beautiful as a simple, natural piece of solid lumber, recent innovations in the area of high tech wood products celebrate just how much potential and versatility there is within a working forest. Scientists have developed a new process that can transform any species of wood into a material stronger than steel – and even some high-tech titanium alloys. According to Scientific American, this new “super material” could be used to make everything from ultra-tall wooden buildings to bullet-resistant armor plates.

Abundant, renewable and low-cost, wood is already an invaluable resource, especially in its ability to store carbon, which could help mitigate climate change. But its many uses have just expanded dramatically thanks to a strengthening treatment developed by Liangbing Hu, a materials scientist at the University of Maryland, College Park. Hu and his colleagues learned that a two-step process beginning with boiling wood in a solution of sodium hydroxide (NaOH) and sodium sulfite (Na2SO3) to partially remove lignin and hemicellulose, compressing the treated wood until its cell walls collapse and then maintaining its compression as it’s gently heated encourages the formation of chemical bonds between large numbers of hydrogen atoms and in adjacent cellulose nanofibers.

The results are impressive. The team’s compressed wood is three times as dense as the untreated substance, Hu says, adding that its resistance to being ripped apart is increased more than 10-fold. It also can become about 50 times more resistant to compression and almost 20 times as stiff. The densified wood is also substantially harder, more scratch-resistant and more impact-resistant. It can be molded into almost any shape. Perhaps most importantly, the densified wood is also moisture-resistant: In lab tests, compressed samples exposed to extreme humidity for more than five days swelled less than 10 percent—and in subsequent tests, Hu says, a simple coat of paint eliminated that swelling entirely.

A five-layer, plywood-like sandwich of densified wood stopped simulated bullets fired into the material—a result Hu and his colleagues suggest could lead to low-cost armor. The material does not protect quite as well as a Kevlar sheet of the same thickness—but it only costs about 5 percent as much, he notes.

This densified wood could offer an alternative to expensive steel, aluminum alloys and carbon-fiber alternatives, even for applications like vehicles. It remains to be seen whether the scientists can scale up and accelerate the process in order to launch it into widespread use, but if they manage to do it, the possibilities for its use are virtually endless. Imagine a future in which we’re all driving wooden cars around!

Game Changer: Engineered Wood Opens Doors in the Construction Market


Is engineered wood ‘the new concrete?’ As demand grows, some industry sources say mass timber is set to open new doors in construction for the lumber industry, offering lucrative opportunities at the intersection of timber and tech. Advances in the processes used to make cross-laminated timber and other engineered wood products have set up a boom for tall wooden buildings with similar if not better structural integrity than those made with steel and concrete, making the construction industry as a whole more environmentally friendly.

Made from industrially dried quick-growing wood – including pine – CLT is up to four times lighter than reinforced concrete. A building made with CLT instead of traditional concrete uses up to 70 percent less material and can cut construction times by a third, sending project profitability through the roof. Developers are definitely taking note.

In a recent issue of the property insurer GenRe’s ‘Property Matters’ publication, Property/Casualty Senior Consulting Underwriter Leo Ronken examines “what’s so good about wood,” going down a long list of the attributes that have made engineered wood increasingly popular with architects, legislators and construction pros.

“In the global trend toward the construction of buildings that meet ecological needs, wood has some clear advantages over traditional construction materials such as steel and concrete. With advances in engineered wood materials and components come possibilities to construct increasingly larger buildings – a trend being witnessed around the world.”

Real estate services firm JLL has also noted the trend and what it could mean moving forward, calling it a ‘game changer.’

“The emergence of successful mass timber projects across all sectors is a trend which looks set to continue and develop as the industry demands more innovation. As Lucas Epp, Head of Engineering at StructureCraft in North America, says mass timber projects require fewer construction workers on site, less waste and higher quality of work. ‘Mass timber office buildings are also now competing with steel and concrete on cost,’ he adds.”

The forest products industry has long depended on single family homes, but mass timber opens the possibility of entrance into new markets where wooden framing was previously seen as inappropriate. Buildings made with mass timber are able to meet strict building codes, including those measuring fire resistance.

Another benefit of increased demand for CLT is the fact that it can be made with smaller, second-growth timber, reducing the need for so many big, solid logs from older trees and fueling greater efficiency at mills.

Image via Woodworks.org