Steel fiber confined graphite concrete for pavement deicing

Abstract

Electric heating concrete is a specialized concrete containing electrically conductive components to attain stable conduction of electricity. Due to its electrical resistance, a thin electric heating concrete overlay can generate heat to prevent ice formation on a concrete roadway when connected to a power source.This electric heating concrete (EHC) deicing technology has been implemented in China at a large scale for the first time. Steel fibers and graphites had been used at conductive fillers in fabricating EHC. A 3.5-in. (9 cm) thick electric heating concrete layer was cast on the top of two existing parking ramps in Harbin. The East Ramp is 135 feet (41 m) long and 18.5 feet (5.6 m) wide and the North Ramp is 135 feet (41 m) long and 25 feet (7.6 m) wide, both having a steep slope of 15%. The overlay on each parking ramp was divided into 20 blocks.The electric heating concrete overlays were cast in place. Transformers converting 220 V AC to 48 V AC were used for the power source. Steel angle structural shapes were embedded in the electric heating concrete for electrodes. Some electric wires were pulled off from the electrodes during the construction. As a result, the power to a few blocks on each ramp was cut. A hand-held magnetic field meter was used to troubleshoot the disconnection locations. Based on measurements of the magnetic field strengths, all the disconnected wires in the hardened concrete were detected and reattached to the electrodes. The drilled holes were patched with carbon cement paste. Subsequent testing showed that good heating performance was successfully restored.