Khosro Shabani

High-performance and ultra-high-performance fiber-reinforced concretes (HPFRC/UHPFRC) have emerged as advanced cementitious composites capable of achieving superior mechanical performance, durability, and structural efficiency compared with conventional concrete. However, their widespread adoption remains challenged by relatively high material costs and significant embodied environmental impacts associated with elevated binder and fiber contents. This study presents a comprehensive life-cycle review of advanced high-performance cementitious composites, evaluating their sustainability from raw material extraction and mix design to structural application, service life, and end-of-life considerations. The review synthesizes current knowledge on material composition, production processes, structural performance, durability characteristics, and environmental impacts through the framework of life-cycle assessment (LCA). Particular attention is given to the influence of mix-design parameters, including binder composition, supplementary cementitious materials (SCMs), aggregate systems, and fiber type, on embodied carbon, energy demand, and mechanical performance. A dataset compiled from published experimental studies covering high-performance and ultra-high-performance concrete mixtures is analyzed to examine relationships between compressive strength, embodied energy, and carbon footprint, highlighting the dominant role of cementitious binders and fiber production in environmental impacts. Although advanced fiber-reinforced concretes generally exhibit higher cradle-to-gate emissions than conventional concrete, their superior mechanical properties, improved durability, reduced material demand, and extended service life can substantially reduce life-cycle environmental impacts at the structural level. The review further discusses emerging strategies for developing low-carbon high-performance cementitious composites, including clinker reduction, recycled and alternative fibers, optimized particle packing, and AI-assisted mix design. Finally, key research gaps are identified, particularly regarding standardized LCA methodologies, long-term durability data, harmonized performance-based functional units, and circular-economy strategies for material recycling and reuse. The findings highlight that performance-based life-cycle evaluation is essential for accurately assessing the sustainability potential of advanced high-performance cementitious composites in resilient and low-carbon infrastructure systems.

This study investigates the feasibility of incorporating recycled concrete aggregate (RCA) as a full replacement for fine aggregate in high-performance concrete (HPC). Five mixtures containing 0%, 25%, 50%, 75%, and 100% RCA were experimentally evaluated. Hardened density, compressive strength, splitting tensile strength, flexural strength, water absorption, microstructure (SEM), and carbon footprint were analyzed. Results showed a near-linear density reduction of 5.8% at 100% RCA due to lower specific gravity and higher porosity of RCA. Mechanical performance decreased with RCA content: compressive strength reduced from 78 MPa to 53 MPa (−32%), splitting tensile strength from 6.2 to 4.2 MPa, and flexural strength from 7.6 to 5.0 MPa. Water absorption increased by 42%, indicating increased permeability. SEM analysis revealed a weakened and porous interfacial transition zone (ITZ) surrounding RCA particles, explaining strength reduction. Carbon footprint analysis showed a slight increase in emissions with RCA due to cement dominance and RCA processing energy. Results confirm that RCA enhances material circularity but introduces a performance–durability trade-off, requiring optimized mix design and SCM integration for structural applications.