Automated Thermal Spray Technology for Rehabilitation and Maintenance of CivilWorks Infrastructure

摘要

Lead-based paint is no longer used in the field, but repair crews, nearbycommunities, and the environment may be exposed to unacceptable levels of lead as older steel structures are abrasive-blasted before repainting. Onsite dust-containment enclosures used during surface preparation are either inadequate or expensive and cumbersome. Lead exposure problems may be mitigated by the application of long-lasting metal coatings, effectively reducing the frequency of the blast/recoat maintenance cycle. Automated technologies can address containment and metallizing needs while offering higher speed and lower labor costs. They also can protect workers from excessive physical strain, safety hazards, and exposure to toxic materials released during paint removal. This report documents the design, construction, and field testing of a prototype Automated Thermal Spray System (ATSS) for surface preparation and coating of large steel public works structures. Using self-contained vacuum blasting technology, a video inspection system, and a thermal spray system, the remotely operated device was able to remove lead-based paint from part of a steel bridge and recoat the metal with a zinc/aluminum coating. Initial indications are that ATSS base operating cost of $5.20 per square foot, for blasting and recoating combined, would be lower than the cost of blasting alone with environmental containment.