Next-generation multifunctional concrete for future intelligent transportation infrastructure: mechanisms, performance and perspectives

Multifunctional concrete, as a promising material platform for intelligent transportation infrastructure, expands the use of traditional concrete beyond passive load-bearing applications. By integrating multiple functions, cement-based materials can enhance the mechanical strength, durability, monitoring capabilities, and sustainability of transportation systems. This paper provides a comprehensive overview of multifunctional concrete technologies related to transportation infrastructure, focusing on self-sensing, self-healing, photocatalysis, phase-change-material (PCM)-based thermal regulation, and energy harvesting functions, including thermoelectric, piezoelectric, and triboelectric methods. From a system design perspective, the review explores integrated multifunctional coupling strategies and analyses potential synergistic effects and performance trade-offs. Furthermore, it reviews typical engineering applications such as bridges, pavements, tunnels, and roadside facilities to assess their field feasibility under actual traffic loads and environmental exposure. Although existing demonstration projects have confirmed the technical feasibility of multifunctional concrete, its large-scale application remain constrained by factors such as durability uncertainty, construction complexity, economic considerations, and the lack of standardised evaluation methods. This review highlights key challenges and outlines future research directions aimed at developing system-oriented, application-specific strategies that enable concrete multifunctionalities to deliver significant life-cycle benefits, thereby promoting the development of strong, durable, resilient, sustainable, and intelligent transportation infrastructure.