Ohmic heating curing of electrically conductive carbon nanofiber/cement-based composites to avoid frost damage under severely low temperature

This study reports a novel ohmic heating curing method, in which alternating voltage was applied to the fresh carbon nanofiber/cement-based composite to generate ohmic heating, in order to accelerate the hydration reaction and prevent the early frost damage of cement-based materials under severely low temperature. Carbon nanofibers (CNFs) were utilized to form a conductive path in the fresh cement-based composite, thus the electrical resistivity was reduced. A numerical model was constructed to simulate the bridging behaviour of CNFs comparing with the experimental observation. An internal temperature rise was observed with the carbon nanofiber/cement-based composite cured under the ohmic heating condition at -20 degrees C, and the cured sample showed excellent mechanical property and structural homogeneity. This work provides insights into the quality control of cement-based materials by means of ohmic heating curing, providing a convenient and energy-efficient solution for construction in cold regions.