Ultra-high-performance concrete (UHPC) is redefining what is possible in structural design through its exceptional strength, durability, and longevity. As the industry pushes toward more resilient and sustainable infrastructure, UHPC offers unique opportunities to reduce material usage, extend service life, and lower life-cycle environmental impacts. However, quantifying the full sustainability benefits of UHPC remains a complex challenge—particularly when balancing embodied carbon with long-term performance. This session will explore the holistic role of UHPC in advancing sustainability and resilience in the built environment. Presenters from academia, government, and industry will share case studies, research insights, and practical examples demonstrating how UHPC contributes to more efficient construction, reduced maintenance cycles, and improved environmental performance. The session will also open the floor for discussion on metrics, trade-offs, and future pathways to better integrate UHPC into sustainable construction strategies.
Comparative Life Cycle Assessment of Ultra-High Performance Concrete and Performance-based Concrete for Sustainable Overlays Design
Presented By: Asmita Mankar
Affiliation: Texas State University San Marcos
Description:
Sustainable Ultra-High-Performance Concrete with Magnesium–Iron Silicate (MIS) from Mine Waste
Presented By: Nancy Soliman
Affiliation: Texas A&M University-Corpus Christi
Description: Ultra-high-performance concrete (UHPC) exhibits outstanding strength, ductility, and durability; however, its dependence on cement and quartz-based materials poses sustainability and health concerns. This study introduces, for the first time, magnesium–iron silicate (MIS) derived from mine waste, engineered with controlled particle-size distributions, as a multifunctional replacement for cement (0–50%), quartz powder (0–100%), and quartz sand (0–100%) in UHPC. The research investigates how varying particle sizes and their synergistic effects influence UHPC’s synthesis, physicochemical behavior, and mechanical performance. Results show that coarse MIS with a mean particle size of 400 µm (MIS400) provides the best flowability–strength balance and enhances macro-mechanical properties across all replacement levels and curing regimes. Fine MIS powder (mean ˜ 14 µm) can replace up to 50% of cement with only ~10% strength reduction relative to the reference mix and can fully substitute quartz powder. Depending on mix composition and curing temperature, MIS-UHPC achieved compressive strengths between 130 and 184 MPa and tensile strengths up to 10 MPa. The strength enhancement arises from the hard-inclusion effect of MIS, confirmed by nanoindentation results showing a high-stiffness cluster (M ˜ 250 GPa, H ˜ 19 GPa). Although the angular morphology of MIS introduced localized interfacial microporosity (SEM) and increased total porosity by ~29%, its high density preserved a favorable binder-to-aggregate ratio, maintaining workability and improving cohesion and ductility through enhanced energy dissipation. MIS demonstrates strong potential as a sustainable replacement for cement, quartz powder, and quartz sand in UHPC, advancing eco-efficient infrastructure materials.
Resource-efficient UHPC
Presented By: Kay Wille
Affiliation: University of Connecticut
Description: This presentation discusses the use of the resource-efficiency factor (R-factor) to develop non-proprietary UHPC, focusing on workability, compressive strength, cost, and carbon footprint (CFP). Using locally available materials from New England, the research designed 30 UHPC matrices and evaluated their resource efficiency, achieving a 67% increase in R-factor compared to typical non-proprietary UHPC mixes in the U.S. The study further refined the matrix by adjusting aggregate-to-cement ratios and incorporating silica fume and slag, with resulting compressive strengths ranging from 156 to 233 MPa. These findings are compared to existing commercial and non-proprietary UHPC mixes, highlighting the R-factor’s potential as a tool for creating sustainable, high-performance concrete.
Alternative Binders and Fibers for Sustainable Ultra-High Performance Concrete Mixtures
Presented By: Behrouz Shafei
Affiliation: Iowa State University
Description: Ultra-high performance concrete (UHPC) offers superior mechanical and durability properties when compared to conventional concrete. However, the high cement content commonly used for UHPC mixtures poses significant environmental concerns. To address this issue, there has been a growing movement toward sustainable UHPC mixtures, leveraging alternative binder ingredients and fiber products. This has motivated the current study to investigate the potential use of waste glass powders and recycled plastic fibers in UHPC. The experimental program consists of various tests designed to evaluate key fresh and hardened properties of the developed sustainable UHPC mixtures. The obtained macro-scale investigations have been paired with micro-scale analyses to further understand how the inclusion of waste glass powders and recycled plastic fibers affects the main properties of the tested UHPC mixtures. The obtained results have been studied individually and in comparison to each other. The outcome is expected to facilitate the use of alternative binder ingredients and fiber products with the ultimate goal of reducing the UHPC’s carbon footprint.
UHPC Sustainability at Scale: From Recycled Fibers Implementation Strategies to Bridges Carbon Footprint Reduction Case Studies
Presented By: Mohamed Moustafa
Affiliation: New York University Abu Dhabi
Description: With a growing interest in the structural and large-scale applications of UHPC, the issues of material economy and carbon footprint become more relevant and significant. The objective of this presentation is to look into sustainable strategies for scaling-up UHPC for full structural components and applications such as incorporating local materials and recycled tires wires and fibers in precast UHPC construction. To further look into the sustainable impact of UHPC, a comparative analysis of the carbon footprint of archetype conventional concrete and UHPC bridges is provided.
Development and Performance Evaluation of Non-Prestressed UHPFRC Railway Crossties as a Sustainable Alternative to Prestressed Concrete Crossties
Presented By: Raafat El-Hacha
Affiliation: University of Calgary
Description: Modern railway systems demand higher performance under heavier axle loads, faster train speeds, and stricter durability standards. Conventional prestressed concrete crossties, though widely used, suffer from prestress losses, fabrication complexity, and high embodied carbon. This study introduces non-prestressed railway crossties made from Carbon Nanofibre Ultra-High-Performance Fibre-Reinforced Concrete (CNF-UHPFRC) reinforced with high-strength ChromX steel as a sustainable and resilient alternative.
Two full-scale designs were developed—a solid rectangular tie and an inverted U-section with internal voids to reduce weight. Analytical and experimental evaluations demonstrated that CNF-UHPFRC ties meet or exceed AREMA design requirements, achieving up to 64% higher negative moment capacity and 37% higher rail seat capacity while reducing weight by approximately 140 lb per tie.
Finite element simulations validated these findings, confirming that CNF-UHPFRC’s tensile ductility eliminates the need for prestressing without compromising flexural capacity or serviceability. The results highlight a simplified, low-maintenance, and low-carbon alternative to conventional crossties, advancing the next generation of eco-efficient and high-performance railway infrastructure.