Large-Scale Production and Quality Control/Assurance of Electrically Conductive Concrete

Abstract

While electrically conductive concrete (ECON) heated-pavement systems (HPS) offer an innovative solution for ensuring year-round mobility in cold climates, comprehensive guidelines for large-scale ECON production in concrete plants are still lacking. This study addresses transit-mixed ECON’s production, transportation, and quality control/assurance processes. Through a series of nine laboratory trials and ten plant trials, the study establishes standards, identifies optimal mixture proportions for ECON, and highlights the fragility of carbon fiber that leads to its degradation during large-scale production. To minimize the effects of this degradation, the optimal method involves adding carbon fiber to the truck mixer at the job site with 30% of the batch water and mixing for 3.5 min at a speed of 18–20 rpm, effectively producing carbon-fiber-reinforced ECON. The study finds that the electrical resistance of ECON remains relatively stable despite variations in carbon fiber length or batch volume as long as the fiber dosage rate is consistent. A statistical prediction model was created to estimate the 28-day electrical resistance from the electrical resistance measurement of fresh ECON immediately after production. Given that the electrical resistance of ECON stabilizes after 28 days, establishing a target for a design 28-day electrical resistance and back-calculating the corresponding fresh-stage electrical resistance range can serve as an effective quality control/assurance tool during large-scale ECON production. The findings will enhance the practical implementation of ECON HPS technology and increase production reliability, enabling design engineers to confidently determine electrode configurations and electrical wire designs for constructing efficient and safe ECON HPS.