Development of Alternative Composite Concrete Bridge Systems for Short and Medium Span Bridges

A total of four new bridge systems for short and medium span bridges are presented. These bridge systems are lightweight, efficient in flexure and shear and can be used in sites with stringent vertical clearance requirements while being able to accelerate construction by eliminating the need for site installed formwork. The investigated systems consists of adjacent hollow precast concrete beams with and without concrete topping. The proposed configurations are compared with traditional adjacent box beam and decked bulb tee systems for spans that range from 80 ft to 150 ft. Both normal weight and lightweight concrete options are investigated. The comparison is made in terms of span to depth ratios, weight, number of strands, live load deflection and camber. It is demonstrated that the two proposed systems (PS1 and PS2) that feature concrete topping are lighter than the adjacent box beam system for all spans considered. Additionally, PS2 requires fewer strands. The proposed topped systems feature lower camber when compared to the adjacent box beam system. PS2 provides shallower superstructure depths for a given span compared to the adjacent box beam system. While the proposed systems that feature concrete topping (PS3 and PS4) are heavier than the decked bulb tee system, they require a smaller number of strands for a given depth. Additionally, the live load deflection and camber for both PS3 and PS4 is generally less than that for decked bulb tees. PS4 provides shallower superstructure depths for a given span compared to the decked bulb tee system. PS2 and PS4 appear to be more competitive than PS1 and PS3. Live load distribution factors (LLDF), for PS1/PS2 and PS3/PS4 can be conservatively estimated using American Association of State Highway and Transportation Officials (AASHTO) provisions for adjacent box and decked bulb tee systems, respectively. Also, LLDF for adjacent box and decked bulb tee systems computed from finite element analysis were lower than those calculated based on AASHTO provisions.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Figures; References; Tables;
  • Pagination: 83p

Subject/Index Terms

Filing Info

  • Accession Number: 01835896
  • Record Type: Publication
  • Report/Paper Numbers: FHWA/LA.16/16-1TIRE, LTRC Project Number: 16-1TIRE, State Project Number: DOTLT1000069
  • Files: NTL, TRIS, ATRI, USDOT, STATEDOT
  • Created Date: Feb 11 2022 5:15PM