Steel-reinforced concrete has been the backbone of modern construction, but it's far from perfect. The steel has a tenancy to corrode over time, jeopardizing the overall structural integrity of the material. Recently, Blaine Brownell, AIA, wrote about two alternatives –continuous basalt fiber and bamboo – for Architect magazine, a sister publication to Concrete Construction. Both have significant economic and environmental potential. According to Brownell:
ReforceTech, in Norway, has developed a novel version of CBF. Reinforced with basalt fibers, the company’s 0.5- to 10-millimeter-diameter BFRP MiniBars are composed of fibers wrapped with polymer resin in a helical shape and can span from 20 millimeters to 200 millimeters in length. The bars are mixed directly into the concrete without impairing its workability, the company says, reducing or altogether eliminating the need for steel reinforcing. Moreover, contractors do not need to consider the exact positioning of the rebar and the miniature bars do not protrude from the finished concrete surface.
When used in precast architectural cladding, ReforceTech’s basalt fibers not only eliminates the need for rebar but also significantly reduces panel thickness. “We already have precasters in Europe making insulated wall panels where the exterior wythe is down to 1.5 inches from the older 3-inch thickness,” said Alvin Ericson, a technical consultant at ReforceTech, in an email.
Read more about ReforceTech's CBF and find out what Brownell has to say about bamboo.