USU Engineering Professor Aims to Strengthen Concrete with Hemp

A professor of civil and environmental engineering is leading the charge to find a solution for the utilization of waste hemp fibers to biomanufacture fire-resistant, high-strength concrete.

Srishti Banerji, along with Bruce Bugbee from Utah State University and Zach Haber from the University of South Florida received $300k from the National Institute of Food and Agriculture, U.S. Department of Agriculture. The team hopes to gather comprehensive experimental data on the physical properties of hemp fibers of different genetics, characteristics of various hemp fiber-concrete mixtures, and room and high-temperature material properties of hemp fiber-concrete.

“High-strength concrete has significant structural benefits over standard concrete, but its dense microstructure makes it prone to fire-induced spalling,” Banerji said. “Spalling or explosion of concrete occurs when moisture in the concrete cannot escape, leading to extremely high vapor pressure and explosion. Our preliminary experiments indicated that the addition of hemp fibers minimized spalling because they melted at a low temperature, 200 degrees Celsius, and created pathways to release the vapor pressure.”

Stalks are a byproduct of medicinal hemp, and this proposed use avoids discarding the stalks by incineration or in landfills. However, the processing of natural fibers for inclusion in concrete is not streamlined. Moreover, before adding hemp fibers to concrete, it is critical to treat the fiber chemically and remove impurities from the fiber to enhance fiber-concrete bonding. Hemp fibers can also increase concrete strength and resistance to cracking through fiber bridging. The goal is to biomanufacture high-strength concrete by adding waste hemp fibers, which will increase its stability at high temperatures.

###

Writer: Sydney Dahle, sydney.dahle@usu.edu, 435-797-7512

Contact: Srishti Banerji, srishti.banerji@usu.edu, 435-797-0990