Bridge girders are large horizontal beams that support bridge decks and transfer loads from the structure and traffic to piers, abutments, and foundations. As primary structural elements in many bridge systems, and vital components in truss, arch, and cable-stayed bridges, girders are designed to resist bending and shear forces from both static and moving loads.
Every day, bridge girders help support vehicles traveling on major transportation routes across the country. From interstate river crossings and airport access bridges to heavily traveled commuter corridors, girders provide the structural strength needed to safely carry traffic while maintaining long-term performance.
Prestressing further enhances the structural capabilities of concrete girders. Tensioned steel strands introduce compressive forces into the concrete, helping the girder efficiently resist the forces it will experience in service. For engineers, this combination of concrete and prestressing supports demanding load and span requirements while providing the advantages of precast construction.
Girder selection can influence more than the bridge superstructure. Engineers consider span requirements, anticipated loading, bridge geometry, site constraints, foundation conditions, constructability, environmental exposure, and applicable agency specifications when developing the structural system.
Prestressed concrete girders can provide the load-bearing capacity needed for long spans, allowing engineers to optimize span layouts and, where appropriate to the design, reduce the number of intermediate piers and foundations. This can be particularly valuable when bridges cross active roadways, waterways, rail corridors, or other locations where additional supports can increase construction complexity.
Precast bridge girders are designed for demanding transportation environments. Producing girders off site in controlled PCI-certified manufacturing facilities allows production and quality processes to be consistently managed before structural components reach the jobsite. Manufactured from high-strength, durable concrete to applicable project and DOT standards, prestressed girders provide consistent quality in municipal, highway, and transportation infrastructure projects.
With a history of proven performance on state, county, and local bridge projects, prestressed girders offer a variety of construction advantages. Since they are produced off site, they can be manufactured simultaneously with site preparation, which simplifies construction schedules. Because they arrive ready for installation, precast girders also reduce the amount of field forming, reinforcing, and concrete placement required on-site.
These advantages align with accelerated bridge construction (ABC), an approach used to reduce construction time and site impacts through strategies that include prefabricated bridge elements. PCI identifies precast concrete components as a means of reducing bridge schedules, traffic impacts, and onsite construction activities.
Prestressed concrete girders provide an enhanced load-bearing capacity that allows for long bridge spans, which can reduce the number of piers, foundations, and intermediate supports required, depending on the bridge design. Reduced field construction and fewer intermediate supports can also help project teams address construction duration, site activity, safety, and traffic-management objectives.
Bridge projects require careful planning, coordination, and transportation, which is why County Prestress & Precast employs a well-organized fleet strategy to transport girders from plant to jobsite. Designed to meet narrow delivery windows, this approach emphasizes proactive communication, detailed route planning, and flexibility on site. Additionally, drivers are trained to navigate job site constraints and coordinate closely with site crews, ensuring a seamless offloading process.
According to ACI, girders made of high-strength prestressed concrete can have an extended service life of 75 years “in harsh environmental conditions,” minimizing bridge replacement frequency. Bridge durability depends on the interaction of material selection, structural design, environmental exposure, drainage, maintenance, and other project-specific conditions. Prestressed concrete girders are engineered for demanding transportation environments, with durability considerations evaluated against the exposures anticipated for each project. The FHWA provides engineers with guidance on the variables to consider when designing a bridge for durability.
Customizable sizing options allow bridge girders to meet project specific requirements, supporting efficient design, optimized span layouts, and site-specific performance needs. Depending on the infrastructure system, precast bridge girders can also be incorporated alongside other concrete products from the County Materials Family of Companies, including wingwalls, endwalls, end treatments, box culverts, and reinforced concrete pipe.
County Prestress & Precast manufactures prestressed concrete bridge girders for tunnel projects, highways, railroads, airports, urban and local roads, and other specialized infrastructure projects. An excellent solution for accelerated bridge construction (ABC), they provide dependable strength, long-term durability, and consistent results to contractors, engineers, municipalities, and project stakeholders.
Major transportation infrastructure projects across the Midwest incorporate County Prestress & Precast's Bridge Girders:
Prestressed girders were specified for the Mile Long Bridge southwest of Chicago, Illinois, because they provide high-performance strength and reliability, an essential consideration as more than 150,000 vehicles traverse the bridge each day.
The contractors for the Eisenhower Bridge of Valor in Red Wing, Minnesota, selected County prestressed concrete girders for a portion of the bridge with a long span because of their reliable strength, cost-effectiveness, and construction efficiency.
The MidAmerica St. Louis Airport Taxiway and Bridge outside St. Louis, Missouri, spans a small stream. That necessitates the structural strength of low-maintenance prestressed girders, which can support heavy loads from aircraft and other airline machinery.
Planning a bridge or transportation infrastructure project?
Discover how County Prestress & Precast's prestressed concrete girders can help address your project's span, schedule, performance, and delivery requirements. Explore our bridge girder capabilities or contact our Customer Service Team at (708) 562-7700.