Researchers have discovered a potential replacement for steel rebar that utilizes hemp and thermoplastics.
Despite its widespread use for supporting concrete structures, steel rebar can shorten the lifespan of those structures because of its susceptibility to rust. Replacing this supporting framework with a material that is not prone to rusting could increase the lifespan of these structures.
Researchers at Rensselaer Polytechnic Institute, have designed a hemp rebar that, in preliminary testing, is proving to be as strong as its steel counterpart but without the corrosion issues.
The hemp rebar is created by combining rope made of hemp material and plastic fibres with thermoplastics in a heated die to form a durable bar. This bar can be forged on demand in any shape or size required. The process is considerably more environmentally friendly and cost-effective than glass fibre reinforced polymer (GFPR) rebar, which is usually used in corrosive environments where steel isn’t an option.
Hemp is a remarkably resilient plant able to thrive even in unstable climate conditions and sequesters atmospheric carbon at a very high rate, making its production reliable and environmentally friendly. The fibre from hemp is also highly durable, making it ideal for construction. It will likely become increasingly popular over time in many formats, not just as rebar. We are already seeing it used as a replacement for concrete in the form of hempcrete.
RPI’s hemp rebar research is still in its infancy, with the first official paper scheduled for publication next year, but no doubt a large part of the future.