For the first time in modern history, hemp is being used to repair deteriorating bridges.
Researchers at the University of Kentucky College of Engineering have produced a hemp wrap, identified as CatStrong BHW 2500. The wrap was used in the repair of a deteriorated wood pier-pile on a bridge located over Blaine Creek in Lawrence County, Kentucky.
Typically, these repairs or replacements are made with carbon fiber wraps. In 2012, UK developed the CatStrong Wrap system in cooperation with the Kentucky Transportation Cabinet (KYTC) and the Federal Highway Administration (FHWA) using carbon fiber fabrics in an effort to minimize extensive bridge closers, costs, and repair time. It was first deployed on a bridge near Paducah.
Issam Harik, Raymond-Blythe Professor of Civil Engineering and Program Manager at the Kentucky Transportation Center (KTC) at UK, and Dr. Abheetha Peiris, Research Engineer at KTC, have been leading a team of researchers working on an Innovative Bridge Research and Deployment in cooperation with FHWA, KYTC, and UK. All proceeds from all CatStrong products go to UK to support students and product development.
“More than 35 bridges have been repaired in Kentucky using the CatStrong products to strengthen bridge beams, columns, and piles. They have included carbon fabrics with capacities reaching 120,000 pounds per foot (1750 kN/m), and rod panels with capacities reaching 195,000 pounds per foot (2550 kN/m)," Harik said.
Hemp was added to the CatStrong family of products since it is a growing industry in Kentucky. Hemp has many advantages. As a natural fiber, it's a renewable resource, biodegradable, and has a much smaller carbon footprint when compared to synthetic fibers such as carbon, glass, and aramid fibers. The limitations are low strength, incompatibility with existing resins (e.g., epoxy, polyester), manufacturing processes, and it is seasonable. Some of the limitations can be overcome with ongoing and future research.
Click here for the original article from JEC Group.