In the late 1990s, a group of engineering professors at Oregon State University designed an innovative product – hollow fiber reinforced polymer (FRP) composite reinforcing bar that is lighter and stronger than traditional rebar. The unique rebar caught the eye of Robert Gibson, owner of Composite Rebar Technologies Inc. (CRT), Madison, Wis., so he purchased the exclusive license for the patented technology more than a decade ago.

Gibson raised money through a private placement – a non-public offering of shares – to continue developing and refining the hollow rebar. “We then built a production machine to manufacture the rebar and conducted all of our testing at the University of Miami,” he says. Now that prototypes have been constructed and tested, CRT is deciding how to manufacture the product en masse.

According to Gibson, CRT’s hollow composite rebar is the only product of its kind and is 50 percent stronger and 25 percent lighter than traditional rebar. “CRT is working on expanding the coverage of our patent so that our hollow bar qualifies for not only infrastructure, but building applications for both national and international markets,” he says.

Traditional solid rebar, often made from steel, is commonly used to reinforce concrete for structures such as bridges and roads. CRT’s rebar features a hollow, load-carrying GFRP core over molded with a corrosion-, impact- and UV-resistant carbon fiber reinforced outer shell to add durability. The company uses a modified pultrusion process to manufacture the hollow rebar.

Because the rebar is hollow, it has the potential to act as a conduit in a piece of concrete, says Gibson. For example, fiber optic cables or wires could run through the rebar in commercial buildings to allow electrical and communication outlets to be installed in the middle of large open areas.

Bringing a new product to market can be daunting. “We participate in a lot of conferences that deal with construction, and we have had display and information booths at everything from ACMA to the World of Concrete shows,” says Gibson.

CRT is banking on its experience in the infrastructure industry to help promote hollow rebar. In addition to the rebar, the company developed Long Life Dowels™, which encapsulate steel in a corrosion-resistant, durable resin and fiber sleeve. “Steel dowels have terrific strength and do the job perfectly, except they are in joints in the highway that are exposed to corrosive materials, salted roads during the winter or close to the ocean,” says Gibson. The sleeve of Long Life Dowels prevents contact between the steel and corrosive elements. Departments of Transportation (DOT) in Wisconsin and Minnesota have approved the Long Life Dowels for use in highway construction.

Gibson hopes that DOTs and other potential customers are equally interested in hollow rebar. “It really is tickling the curiosity of a broad range of people,” says Gibson.