Rapid strength formation of on-site carbon fiber reinforced high-performance concrete cured by ohmic heating

In this paper, ohmic heating (OH) curing was proposed as a novel curing method for on-site high-performance concrete (HPC). With this method, constant electric power was applied to the carbon fiber reinforced high-performance concrete (CF-HPC) sample to generate ohmic heating, which aided to the rapid structural strength formation. Carbon fibers (CFs) were utilized to build the conductive network in the fresh CF-HPC sample and enhance the tensile strength and toughness of CF-HPC. A numerical and experimental study was conducted to dissect the bridging behavior of CFs and determine the optimal content of CFs. The CF-HPC-OH sample showed a stable electrical resistivity during the 3 d curing period, and numerical analysis of the thermal balance based on heat transfer theory was carried out to better describe the relationship between electric power and curing temperature. The CF-HPC-OH sample with constant electric power of 20 W showed mechanical properties comparable to the CF-HPC sample with high-temperature steam curing. This work provides insights into an efficient curing method to rapidly form the strength of HPC for achieving the objective of on-site construction through ohmic heating curing.