Comparative life cycle assessment of UHPFRC bridge deck overlays

This study compares the environmental impact of Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) and conventional Steel Fiber Reinforced Concrete (SFRC) in hypothesized bridge deck overlay applications through comprehensive Life Cycle Assessment (LCA). Despite UHPFRC's higher initial material cost, an analysis that uses the function of overlaying 1 m 2 area of a bridge deck and maintaining a specified structural performance, specifically the load-bearing capacity against design live loads, for a period of 100 years, demonstrates the UHPFRC superior environmental performance across multiple categories. UHPFRC achieved significant reductions in energy consumption (39 %), fossil resource usage (oil: 53 %, coal: 26 %), CO₂ emissions (34 %), and most air pollutants (approximately 30 %). The material superior strength properties enable thinner overlays, resulting in substantial environmental benefits throughout the entire life cycle. Using the LIME3 methodology, UHPFRC demonstrated net environmental benefits 1.76 times higher than conventional SFRC, with particularly notable improvements in fossil fuel consumption (46 %), mineral resources (56 %), and water resources (71 %). These advantages also stem from UHPFRC's extended service life due to enhanced fatigue life endurance, significantly reducing major maintenance frequency and environmental impact per functional unit. The findings support UHPFRC as a more sustainable solution for infrastructure rehabilitation. • UHPFRC overlay reduces CO₂ emissions by 34 % compared to conventional SFRC. • 40–67 % less energy is used in UHPFRC due to thinner overlays and longer service life. • Major environmental gains arise from reduced material use in UHPFRC production. • UHPFRC improves circularity via efficient by-product use and less waste generation. • Environmental burden cost of UHPFRC is 1.76 times lower than that of SFRC overlay.