Hemp has been at the center of innovation since the 2018 Farm Bill first passed, allowing for the continued exploration of the plant as it relates to creating alternative, and often more sustainable, materials.
The plant material is increasingly being used as a textile, with rising products like hemp shoes and hemp denim making waves in the fashion industry. Though, we’re also collectively witnessing just how versatile hemp can be, as we see hemp used as a steel rebar alternative, a material used to create homes and even working to power batteries.
And these inventive discoveries don’t appear to be letting up, as University of Nebraska-Lincoln (UNL) researchers have newly developed a hemp-based concrete block, Straight Arrow News reports. The invention could potentially help to usher in a new era of eco-friendly construction, as the team notes the sustainable qualities of this unique material.
“This product is basically tailored for someone who wants a lower carbon footprint,” said Marc Maguire, an assistant professor at UNL’s Durham School of Architectural Engineering and Construction and leader of the research team. “We’re very comfortable saying it’s carbon negative. Though one can debate how negative, we compare very favorably to the status quo.”
According to the team, these blocks are just as sturdy as traditional cement and 25% lighter. These hemp-based cement blocks are made with a combination of hemp’s fibrous core and a binding agent.
The team believe this manufacturing process could be crucial to reducing atmospheric carbon dioxide. Specifically, carbon sequestration and carbonation are the natural processes at play here, which store and remove atmospheric carbon. Sequestration happens long term through plants, soils and ocean, and these hemp-based blocks are also able to absorb CO2 over time.
While standard cement blocks also absorb carbon dioxide, the cement production industry creates CO2 emissions, which cancels out the positive effects to some degree. The hemp-based cement blocks may work to fix this gap, and they also meet the American Society for Testing and Materials’ load-bearing structural standards.
“Our goal from the beginning was to meet all these minimum requirements that an engineer would normally need to abide by,” Maguire said. “So now, the decision is very easy for them. We haven’t really had any challenges in that respect. It took us maybe three months of trial and error in the lab, but ultimately we met those requirements.”
Like most other hemp alternatives out there, actually implementing these new products in the marketplace is a tedious process that generally involves more than meets the eye. In this case, research shows that it would take 260,000 acres of hemp to replace a billion pounds of concrete.
Compared to the only 28,000 acres of hemp harvested in the U.S. in 2022, there is clearly a major gap to bridge.
Maguire is realistic and voiced that he doesn’t expect his hemp blocks to fully replace concrete. Rather, he says that the invention is augmenting the market. And the team has already seen a number of parties interested in utilizing the material.
“I personally get calls every week about this,” Maguire said. “It’s exciting. As we ramp up production, hopefully, we can start fulfilling some of this.”
This material, often dubbed “hempcrete,” isn’t brand new, however. The material has steadily gained prominence in recent years as a lightweight, insulating, fire-resistant, eco-friendly building material.
As humans have used hemp for a variety of purposes throughout history, it’s perhaps unsurprising that humans in 6th century France appeared to use the material for civil construction. Romans also used hemp fiber to reinforce the mortar in their buildings, alongside a number of other early humans who similarly used hemp in construction.
While it’s not yet widely used, hempcrete has been utilized to build homes and other buildings around the globe. Who knows? Soon enough, hemp-based concrete could very well be the new norm, with researchers like Maguire and his team helping to push the conversation forward.
