Electrically conductive concrete composition and system design for resistive heating of pavements with low volume fractions of carbon microfiber

Abstract

The present application relates to a concrete pre-mix composition comprising a cementitious material and a plurality of conductive carbon microfibers mixed with said cementitious material, where said conductive carbon microfibers are present in the concrete pre-mix composition in an amount such that, when said concrete pre-mix composition is hydrated to form concrete and cured, the conductive carbon microfibers are dispersed in the cured concrete in an amount of 0.75% to 2.00% of total mass of the concrete. The present application further relates to a concrete composition, a method of producing an electrically conductive concrete composition, an electrically conductive cured concrete form, and a system for heating pavement.

1 .- 40 . (canceled) 
     
     
         41 . A system for heating pavement comprising:
 an upper layer comprising an electrically conductive concrete form, wherein the electrically conductive concrete form comprises:
 a cured concrete matrix and 
 a plurality of conductive carbon microfibers, wherein said conductive carbon microfibers are dispersed in the cured concrete matrix in an amount of 0.75% to 2.00% of the total mass of the electrically conductive cured concrete form and are positioned to effect resistance heating of the cured concrete form upon application of an electrical current; 
   a plurality of electrodes positioned relative to said upper layer so that electrical current can flow between the electrodes and through the concrete form in said upper layer;   a lower layer comprising a concrete composition positioned below and in contact with said upper layer; and   a power supply connected to the plurality of electrodes.   
     
     
         42 . The system of  claim 41  further comprising:
 a base layer below and in contact with said lower layer. 
 
     
     
         43 . The system of  claim 42  further comprising:
 a subgrade layer below and in contact with said base layer. 
 
     
     
         44 . The system of  claim 41  further comprising:
 one or more temperature sensors in said system and 
 a controller coupling said one or more temperature sensors to said power supply, wherein, said controller causes said power supply to supply current to said electrodes in response to said temperature sensors. 
 
     
     
         45 . The system of  claim 41  further comprising:
 an alternative current in contact with said upper layer. 
 
     
     
         46 . The system of  claim 41 , wherein the upper layer and lower layer are installed in a paved surface. 
     
     
         47 . The system of  claim 41 , wherein the upper layer and lower layer are isolated from a paved surface.