Sources: Rensselaer Polytechnic Institute, Troy, N.Y.; CP staff
One of the first projects at Rensselaer Polytechnic Institute’s (RPI) new Institute for Energy, Built Environment, and Smart Systems centers on innovative, cost-effective hemp processing technologies, leading to development of a conventional concrete rebar alternative. Researchers characterize hemp as yielding some of the plant kingdom’s strongest fiber, matching glass fiber pound for pound.
RPI Assistant Professor of Architecture Alexandros Tsamis and Professor of Mechanical Engineering Dan Walczyk seek to develop a) machines that can separate fibers from the inner, woody hemp plant core without adversely affecting mechanical properties of the former; and, b) sustainable degumming and hemp bio-composite processing methods. Targeted machinery and methods could net a natural fiber-reinforced thermoplastic rebar. Measured against steel rebar, hemp fiber reinforcement would represent a replacement of significantly lower embodied carbon, but one imparting comparable or better service life when factoring corrosion-free performance.
“Rensselaer is pleased to be a partner in an effort to develop and commercialize hemp as an industrial product,” says Acting Vice President for Research Robert Hull. “Rensselaer is home to world-class researchers and platforms focused on driving discovery in advanced manufacturing and the built environment. A major focus of the Institute for Energy, the Built Environment, and Smart Systems will be to create products that drive decarbonization of the construction industry, in this case by helping to incorporate industrial hemp into New York infrastructure.”
RPI officials reviewed the potential for hemp fiber-based concrete reinforcement during an early-2022 workshop on the “Seed to City Hemp Initiative,” aimed at supporting Empire State construction, manufacturing and agriculture interests. The event was an outgrowth of the Industrial Hemp Agricultural Research Pilot Program, launched in 2015 and superseded by the New York State Hemp Plan, which now counts nearly 800 authorized growers and approximately 30,000 acres registered for the crop. Plan participants are bound by strict terms confining crops to industrial grade hemp use and calling for destruction of plants whose tetrahydrocannabinol, or THC, levels test above a certain threshold.