Electrically Conductive Polymer Concrete Overlay as Secondary Anode for Cathodic Protection

Book excerpt: This report describes the development of a premixed electrically conductive polymer concrete overlay for use on bridge decks and other concrete members, in conjunction with cathodic protection systems. A field demonstration was performed on a bridge deck (with corroding reinforcing steel) in Pulaski, Virginia, where an active cathodic protection system uses the electrically conductive overlay as the secondary anode to uniformly distribute the current across the bridge deck surface. The performance of the overlay cathodic protection system was monitored for 18 months. The data show that corrosion of the reinforcing steel embedded in the bridge deck was arrested. The overlay is soundly bonded, and there are no indications that the overlay is wearing due to traffic. This report is the conclusion of the research study. Details of the mix design and the installation of the conductive polymer concrete overlay are described in the Interim Report, FHWA-RD-88-145, dated January 1989.