Wafeek Mohamed Ibrahim, Mohamed Hechmi El Ouni, Nejib Ghazouani
Multifunctional nanoengineered cementitious composites are emerging as smart construction materials capable of providing structural performance, self-sensing, electrothermal functionality, thermoelectric energy conversion, and electrochemical energy storage simultaneously. Conductive nanomaterials including carbon nanotubes, graphene nanoplatelets, graphene oxide, carbon nanofibers, and carbon black form interconnected conductive networks within cement matrices through percolation, tunneling, and interfacial conduction mechanisms. These networks enhance electrical conductivity while enabling piezoresistive sensing, self-heating, thermoelectricity, and structural supercapacitive behavior. This review summarizes recent advances in conductive mechanisms, microstructural evolution, mechanical properties, and electrical transport behavior of multifunctional cementitious composites. Particular attention is given to structural health monitoring, electrothermal deicing, thermoelectric energy harvesting, and cement-based energy-storage systems. Challenges including filler agglomeration, moisture sensitivity, durability degradation, and strength-functionality tradeoffs are discussed, together with future directions involving hybrid nanofillers, optimized conductive architectures, additive manufacturing, and scalable fabrication strategies. Potential applications in intelligent pavements, self-diagnostic infrastructure, and sustainable self-powered systems are also highlighted comprehensively.