[Image above] Bamboo has been used in a variety of construction applications to varying degrees of success, but a new bamboo fiber composite may be the perfect sustainable replacement for steel reinforcements in concrete. Credit: Michael; Flickr CC BY-NC-SA 2.0
Steel has long played an important role in growing and vibrant world economies.
I know this not because global economic statistics tell me so, but because I hail from Pennsylvania, just a few hours north of Pittsburgh, where steel was once more than just an industry—it was a way of life.
At the turn of the 20th century, 37 percent of the world’s steel was produced in the U.S.—with Pittsburgh’s steel mills accounting for 60 percent of what was produced nationally by 1910.
But by the end of the century, steel production in the States, particularly in Pittsburgh, had slowed. Three-quarters of the city’s steel operations had closed up shop in the late 1980s, forcing the Steel City to reinvent itself, which it has, to great success. (Need proof? See it for yourself at MS&T14, October 12–16.)
In 2013, America ranked fifth in overall steel production, generating some 87 million metric tons—far below the 779 million metric tons produced by world leader China.
The production and consumption of steel has been critical in shoring up the economies of China and other developing countries—Brazil, India, and South Korea among them—but these countries are not always capable of producing a supply that can meet an increasingly growing demand.
Enter scientists at Singapore’s Future Cities Laboratory (ETH Zürich’s research lab), who offer bamboo, a natural—and unnaturally strong—wood, as a replacement in places where steel isn’t so plentiful.
Bamboo is Mother Nature’s magic material—sustainable, resilient, and oh-so-abundant in many developing countries.
More than a snack for our furry friends, it has been used in a variety of applications in construction—everything from suspension bridges and scaffolding to small (and not-so-small) homes. Bamboo is strong, almost as strong as steel. It’s also pretty effective at curbing carbon emissions, which makes it an even better and sustainable building material.
What makes it not so ideal is that bamboo, if left untreated, can swell with water and rot. As a result, it hasn’t been used to reinforce concrete with much success—at least, not until now.
Led by Dirk Hebel, the research team at Future Cities has developed a bamboo fiber composite that has, thus far, showed great promise as a replacement for steel reinforcements.
According to a Civil Engineering Magazine (CE) article, the composite—80 percent bamboo, 20 percent adhesive, and 300 percent more dense than raw bamboo—is “water resistant, does not swell, and is durable.”
Further, researchers say that testing of its pliancy and tensile strength show that the composite would be a viable replacement for a steel reinforcement.
“To reintroduce production into cities as part of a complex social and cultural lifestyle, it requires that this production—and the products themselves—do not harm our health or environment,” Hebel says in the CE article. “Renewable and ‘green’ materials like the one we are researching, which do not require a ‘smoke industry,’ but rather a low-tech approach, could be the game-changers whereby small and middle-sized companies can operate as part of an urban system. Wherever bamboo is growing, this process could work out.”
The team will continue to test the bamboo fiber and how it interacts with other materials. They hope to begin pilot testing within the next two years.
For additional developments in the world of bamboo construction (and there are more than one), click here.