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Conductive concrete overlay for bridge deck deicing
Abstract
Concrete bridge decks are prone to ice accumulation. The deck freezes before the approaches do, making wintry travel on highways hazardous. The use of road salts and chemicals for deicing is an effective method for ice removal but causes damage to concrete and corrosion of reinforcing steel in concrete bridge decks. This problem is a major concern to transportation and public works officials due to rapid degradation of existing concrete pavements and bridge decks. The use of insulation materials for ice control and electric or thermal heating for deicing has been attempted and met limited success. Conductive concrete is a cementitious admixture containing electrically conductive components to attain stable and high electrical conductivity. Due to its electrical resistance and impedance, a thin conductive concrete overlay can generate enough heat to prevent ice formation on a bridge deck when connected to a power source. In 1998, Yehia and Tuan at the University of Nebraska-Lincoln developed a conductive concrete mix specifically for bridge deck deicing. In this application, a conductive concrete overlay is cast on top of a bridge deck for deicing and anti-icing. The mechanical and physical properties of the conductive concrete mix were evaluated in accordance with the ASTM and AASHTO specifications. Two concrete slabs, 2m by 2m and 1.2m by 3.6m (7 ft x 7 ft and 4 ft x 12 ft), have been constructed with a 9 cm (3.5 in.) conductive concrete overlay for conducting deicing experiments in the natural environment. Deicing experiments were conducted in five snowstorms during the winter of 1998 under two scenarios: deicing and anti-icing. Average power of about 591 W/m2 (55 W/ft2) was generated by the conductive concrete to prevent snow accumulation and ice formation. This power level is consistent with the successful deicing applications using electrical heating cited in the literature. The results showed that a conductive concrete overlay has the potential to become the most cost-effective bridge deck deicing and anti-icing method.
Subject Area
Civil engineering
Recommended Citation
Yehia, Sherif Abdel-Aziz, "Conductive concrete overlay for bridge deck deicing" (1999). ETD collection for University of Nebraska-Lincoln. AAI9947127.
https://digitalcommons.unl.edu/dissertations/AAI9947127