This project will develop a cost-effective, sustainable ultra-high-performance concrete (UHPC) using recycled steel fibers from scrap tires for highway bridge applications. Work in Stage 1 will focus on procuring and characterizing raw materials, followed by UHPC mixture formation and assessments of fresh properties, fiber distribution, and microstructure. An extensive material characterization of all raw materials needed to formulate the UHPC mixture will be performed. A micromechanics guided design approach will be utilized to design reliable and quality UHPC mixtures with 100% recycled steel fiber (RSF). The bond behavior between RSF and a typical UHPC matrix will be characterized and the bonding properties between RSF and UHPC matrix will be utilized to establish a fiber pullout constitutive model for RSF, which will then be integrated into a mesoscale model for fiber reinforced concrete materials to predict the tensile and cracking properties of resulting UHPC mixtures. The fresh properties of various UHPC mixtures, including the rheological characteristics, will also be measured. The fiber distribution and dispersion quality in UHPC will be studied using X-ray computed tomography (CT). The influence of the adhered rubber on the microstructure of UHPC mixtures will be observed via optical microscopy using thin section specimens. In Stage 2, the UHPC mechanical performance will be evaluated. After high-quality UHPC mixtures are formulated, their mechanical properties will be experimentally determined. For life cycle assessment, a hypothetical highway bridge case using the final optimum UHPC material will be created and a life cycle inventory analysis covering all phases of the structure life cycle will be performed. A comprehensive life cycle assessment study will be subsequently carried out to quantify the economic, social, and environmental benefits for the new UHPC structure. Recommendations for future research and implementation will be proposed. The final report will include all relevant data, methods, models, and conclusions along with recommendations, guidelines, and implementation plans.