Toward resilient infrastructure: a critical review and roadmap for ultra–high–performance concrete (UHPC) design, performance and standards

Ultra–High–Performance Concrete (UHPC) represents a transformative advancement in the construction materials, offering exceptional mechanical properties (compressive strength exceeding 150–200 MPa) and potential durability performance along with a ductile behavior, outperforming the conventional concrete. Despite its proven performance in bridges, buildings, and rehabilitation projects, UHPC adoption remains limited due to systemic barriers. Existing literature and practice reveal critical gaps including non–harmonized standards, lack of prescriptive mix design guidelines, insufficient durability protocols, and inconsistent life–cycle assessment (LCA) frameworks. These shortcomings lead to project–specific testing, elevated costs, and uncertainty in sustainability claims. This review consolidates the evolution of UHPC technology, mix design strategies, durability mechanisms, nanotechnology integration, while critically benchmarking prior reviews to expose knowledge fragmentation, and identifying the gaps and needs in the existing design and materials UHPC standards. Unlike previous review studies, this work synthesizes technical, economic, and environmental dimensions, highlighting interdependences between curing regimes, embodied energy, and cost implications. To overcome adoption barriers, the authors propose a roadmap prioritizing global harmonization of standards, open-access mix design guidelines incorporating regional supplementary cementitious materials (SCMs) and recycled fine aggregates, standardized LCA templates, and performance–based procurement practices. This integrated approach aims to reduce uncertainty, foster innovation, and position UHPC as a mainstream solution for resilient and sustainable infrastructure.