Title: Evaluation of Electrically Conductive Concrete Containing Carbon Products for Deicing

Author(s): Christopher Y. Tuan and Sherif Yehia

Publication: Materials Journal

Volume: 101

Issue: 4

Appears on pages(s): 287-293

Keywords: ridge deck; concrete; deicer; fiber; test

DOI: 10.14359/13362

Date: 7/1/2004

Abstract:
Using electrically conductive concrete for deicing is an emerging material technology. Due to its electrical resistance, a thin layer of conductive concrete can generate enough heat to prevent ice formation on concrete pavement when energized by a power source. Under research sponsored by the Nebraska Department of Roads, a concrete mixture containing steel fibers and steel shavings was developed specifically for concrete bridge deck deicing. The mixture has a compressive strength of 31 MPa (4500 psi) and provides average thermal power density of 590 W/m2 (55 W/ft2) with a heating rate of 0.14 °C/min (0.25 °F/min) in a winter environment. The average energy cost was about $0.8/m2 ($0.074/ft2) per snowstorm. During development of the conductive concrete, several drawbacks about using steel shavings in the mixture were noticed. As a follow-up effort, carbon and graphite products were used to replace steel shavings in the conductive concrete design. The electrical conductivity and the associated heating rate were improved with the carbon products. A conductive concrete deck has been implemented for deicing on a highway bridge at Roca, located approximately 24 km (15 mi) south of Lincoln, Nebr. The Roca Spur Bridge has a 36 m (117 ft) long and 8.5 m (28 ft) wide conductive concrete inlay, which has been instrumented with temperature and current sensors for heating performance monitoring during winter storms. Experimental data and operating costs are presented in this paper