Greetings from Bridging Solutions!

New Generation Composite Tub Girders Provide Opportunity for Precasters

This installment of “A Bridge Moment” describes a potential opportunity for precast concrete manufacturers to produce and sell a bridge product that can compete with the Inverset™️ steel beam/composite deck product and the prestressed concrete slab, box, NEXT and AASHTO beams.  The GBeam™ Composite Bridge System is AIT Bridges’ newest composite bridge system that is available in span lengths up to 120 feet. The GBeam™ was developed in conjunction with the University of Maine’s Advanced Structure and Composite Center.  

The GBeam™ composite bridge system consists of lightweight FRP tub girders with a partial depth or full depth precast concrete bridge deck. The decks are cast on a single GBeam™ or on a pair of GBeams™ to form a single or double tee beam configuration. The photos below show the GBeams™ for an entire bridge being shipped in one truck load to the casting yard and in the process of forming the decks.

The bridge deck could be poured cast-in-place on site, however, casting the deck with the beam shored in a precast plant yields a more efficient composite beam design and overall cost-effective product. Other benefits of the precast deck approach are the reduced construction duration on site and the quality advantages gained by casting in a controlled environment.

The primary advantage over other competing bridge systems is the 100-year design life with minimal or no maintenance. This long design life is possible because the GBeam™ system is designed and fabricated using no carbon steel. The corrosion of carbon steel reinforcing embedded in reinforced concrete beams and decks is the primary cause of premature deterioration of bridges.

For more information on the opportunities for precasters anywhere in the USA,

contact Ken Sweeney, PE, President of AIT Bridges at 207-573-9055 or Ken@aitcomposites.com