摘要: |
According to the National Bridge Inventory, of the more than 200,000 steel bridges listed, between 80 and 90 percent were painted with lead-based paint. Of the approximately 7,000 bridges in Virginia with steel superstructures, well over half were painted with systems that contain lead-based formulations. Removing the failed and failing lead-containing paint from highway bridges without jeopardizing environmental quality and worker health has become an increasingly vexing problem. The expense and liability involved in disposing of the debris add to the problem. The cost of maintaining such structures is an increasing burden because of the requirements for dealing with lead in the environment and workplace, especially when traditional methods are used. In the Virginia Department of Transportation alone, there has been an 86 percent reduction in the number of structures painted between 1990 and 1996 because of the cost and uncertainty in dealing with lead. This report documents a field trial of a unique procedure named ElectroStrip (trademark) that uses an electrochemical treatment to cause paint to debond from structural steel. Proven in the laboratory, this is the first use of this technology at a production level. As part of a bridge painting contract, ElectroStrip was used to remove 74 workdays, the ElectroStrip was used to remove 74 sq mi of lead-based paint from the beam of a bridge in service on the Virginia interstate system. Over the course of 7 workdays, the ElectroStrip method removed the original paint system and generated 63 percent less solid debris than full abrasive blasting would have done. |