Electrical performance of conductive cementitious composites under different curing regimes: Enhanced conduction by carbon fibers towards self-sensing function

Electrical performance is a significant indicator for conductive self-sensing cement-based composites, while the application of the composites is largely restricted in cold region due to the harsh environment. In this work, the electrical performance of carbon fibers reinforced conductive cement-based composites (CFR-CCBC) was evaluated, aiming to disclose the potential of ohmic heating (OH) cured conductive composites for structural health monitoring at cold region. Results showed that both OH curing and freezing condition were detrimental to the electrical conductivity, while the increase of CFs was an effective strategy to stabilize the electrical performance. However, the increasing CFs fraction was not economical and may induce strength degradation for concrete. At this time, the use of antifreeze could significantly stabilize the electrical conductivity by lowering CFs contents in CFR-CCBC with comparable electrical performance, even in severely cold environment. Piezoresistive property indicated that the combined use of 0.75 vol% CFs and antifreeze significantly increased gauge factor and linearity, indicating the improved self-sensing ability. Further, the fully connected neural network (FCNN) was employed to establish a model to systematically analysis the multiple factors on the electrical performance of CFR-CCBC.