Abstract: To solve the problems of poor toughness and high temperature sensitivity of traditional cement-based conductive materials, graphene and carbon nanotubes were used as composite conductive fillers. Combined with waterborne epoxy resin modification technology, a new multifunctional cement-based conductive coating was prepared. The influence of different carbon nanotube/graphene doping ratios on the thermal decoupling performance of composite coatings was studied. The pressure-sensitive performance of the coatings were evaluated through deflection-resistance testing. The results show that carbon nanotubes exhibit negative temperature coefficient characteristics, while graphene exhibits positive temperature coefficient characteristics. When the mass ratio of the two materials is 1∶2, the composite material achieves the best thermal decoupling effect. The incorporation of waterborne epoxy resin forms an interpenetrating network structure, which enables the maximum deflection angle of composite coating up to 35°, significantly improving the toughness of material. The composite coating has good pressure-sensitive performance, and the deflection and relative resistivity follow a quadratic function relationship ΔR/R₀=-0.002 93+0.012 03γ-1.423 5×10^-4γ², exhibiting excellent stability under cyclic loading. This study provides a theoretical basis and technical path for the development of intelligent cement-based conductive coating materials with high toughness, low temperature sensitivity and high stability.

Key words: carbon nanotube, graphene, waterborne epoxy resin, cement-based conductive coating, thermal decoupling performance, pressure-sensitive performance