X-BRIDGE Program
(Photo by University of Maine)
The ARPA-I eXceptional Bridges through Innovative Design and Groundbreaking Engineering (X-BRIDGE) program is revolutionizing national infrastructure by developing transformative materials and construction techniques designed to deliver bridges at half the cost, in half the time, and with twice the lifespan. With a $125 billion bridge repair backlog in the United States, much of that due to deterioration from corrosion, this initiative addresses the critical gap between laboratory innovation and large-scale deployment. Through a landmark $23 million partnership between ARPA-I and the University of Maine’s Advanced Structures and Composites Center (ASCC), the program is pioneering a bridge design approach that utilizes high-performance, corrosion-free materials to replace traditional corrosion-prone construction.
X-BRIDGE is a focused initiative to engineer and commercialize a new Composite Bridge System (CBS) featuring Fiber-Reinforced Polymer (FRP) girder bridges spanning up to 100 feet. This research is advancing technologies such as field-bendable thermoplastic rebar, non-metallic fiber-reinforced concrete decks, and steel-free, quick-disconnect girder-deck connectors that allow for easier maintenance and future deck removal without damaging the girders. To drive down initial costs, the team is evaluating three advanced manufacturing methods: semi-automated fabric placement with resin transfer molding (RTM), thermoset pultrusion, and a Continuous Forming Machine (CFM) for thermoplastic pultrusion.
The program is rapidly transitioning from theoretical design to real-world validation through full-scale prototypes and milestone demonstration projects. Rigorous durability evaluations, including accelerated aging and full-scale fatigue testing, are underway to validate a 150-year service life. Demonstration projects are planned to be built over the next five years. X-BRIDGE is collaborating with state DOTs and the composite industry to explore and overcome barriers to implementation. By partnering with AASHTO to establish new design and inspection specifications, X-BRIDGE is clearing the regulatory and technical roadblocks necessary to make advanced composite bridges a mainstream solution for modernizing the American transportation network.