Electrical Resistance Heating of Conductive Concrete Containing Steel Fibers and Shavings

摘要

Conductive concrete is a category of concrete 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. Steel fibers and steel shavings were used for the conductive materials in this study. A conventional concrete slab, 1.2 x 3.6 m (4 x 12 ft), has been constructed with a 9 cm (3.5 in.) conductive concrete overlay for conducting deicing experiments in the natural environment. The conductive concrete mixture was developed at the University of Nebraska-Lincoln specifically for bridge deck deicing. Anti-icing and deicing experiments were conducted in five snowstorms. The average power density of approximately 590 W/m~2 (55 W/ft~2) was delivered to the conductive concrete overlay to prevent snow accumulation and ice formation. The experiment setup, energy consumption, and costs during the winter storms of 1998 are presented. A coupled thermal-electric finite element analysis was conducted to study the joule heating of the conductive concrete overlay. The numerical results showed that the model served as a useful tool for predicting the heating performance of the conductive concrete overlay.