Conductive concrete overlay for bridge deck deicing: Mixture proportioning, optimization, and properties

Bridge pavement surfaces are prone to ice accumulation, making winter travel hazardous. Current practice is to use road salt and deicing chemicals that cause damage to concrete and corrosion of reinforcing,rr steel. A thin conductive concrete overlay can generate enough heat to Prevent ice formation on a bridge deck. Conductive concrete is a cementitious admixture containing electrically conductive components that attain stable and high electrical conductivity. Due to the electrical resistance and impedance in conductive concrete, heat Is generated when connected to a power source, and can be used for deicing or anti-icing Conductive concrete is a relatively new material technology developed to achieve high electrical conductivity and high mechanical strength. A conductive concrete mixture was developed specifically for bridge deck deicing. Steel fibers and shaving were added to the concrete as conductive materials. Over too trial batches of conductive concrete were prepared and their properties evaluated. In this paper optimization of the conductive concrete mixture proportioning for bridge deck overlay is discussed in detail. The mechanical and physical properties of the optimized mixture are presented. The mechanical and physical properties of the the conductive concrete mixture after 28 days met the ASTM and - I, AASHTO Specifications for bridge deck overlay. Slab heating experiments using,AC and DC pou,er showed that the conductive concrete overlay has the potential to become the most cost-effective bridge deck deicing method.