This project developed a novel material approach to solving the reinforcement corrosion problem was developed. This approach created a stainless-steel coating method to produce a highly cost-effective and corrosion resistant metallic multilayer composite steel bar. This concept can enable transportation infrastructure to last for 100 years or longer in corrosive environments. Several different manufacturing approaches were explored at the laboratory scale, and corrosion and mechanical testing was performed. Eventually a method was developed that yielded a material with proper mechanical behavior in terms of strength and ductility/bendability as well as corrosion performance indicating a 13-fold decrease in corrosion rate in comparison to conventional carbon steel rebar. This method applies stainless steel to a carbon steel billet (7-inch square, 25-40 feet long) through hot-wire laser cladding. The billet is then heated to approximately 1200oC before hot rolling into the final deformed reinforcing bar. This approach was demonstrated at a modern steel mill facility. At the end of the project, a 1500-pound batch of stainless coated reinforcement was produced, indicating that this process has meaningful scalability to be used in transportation infrastructure projects. If successfully commercialized, this IDEA product has the potential to provide the transportation industry with a cost-effective solution to the rebar corrosion problem that would allow roads, bridges, tunnels, and other structures to have significantly longer lifetimes, while also being safer and more sustainable, and affordable to maintain.
The Final Report is available.