Implementation of Conductive Concrete Overlay for Bridge Deck Deicing at Roca, Nebraska

Conductive concrete is a relatively new material technology developed to achieve high electrical conductivity and high mechanical strength. In research sponsored by Nebraska Department of Roads, a conductive concrete mix specifically for bridge deck deicing was developed. In this application, a conductive concrete overlay is cast on top of a bridge deck for deicing and anti-icing. This technology has been successfully implemented in a demonstration project at Roca, about 15 mi south of Lincoln, Nebraska. The Roca Spur Bridge has a 36-m (117-ft) long and 8.5-m (28-ft) wide conductive concrete inlay. Temperature sensors and a microprocessor-based controller system were installed to monitor and control the deicing operation of the inlay. The construction was completed and the bridge was opened to traffic in the spring of 2003. Data from the first deicing event showed that an average of 500 W/sq m (46 W/sq ft) was generated by the conductive concrete to raise the slab temperature about 9 deg C (16 deg F) above the ambient temperature. The details of the construction and deicing operation of the conductive concrete inlay are presented.