NCHRP 12-121 [Anticipated]
Developing AASHTO Specifications for the Use of FRP Auxiliary Reinforcement in Prestressed Concrete Beams and Girders
| Project Data
||Florida Department of Transportation|
|This project has been tentatively selected and a project statement (request for proposals) is expected to be available on this website. The problem statement below will be the starting point for a panel of experts to develop the project statement.
The objective of this research is to develop a methodology and AASHTO specifications for the design of Fiber Reinforced Polymer auxiliary reinforcement in prestressed concrete beams and girders. This research includes confinement, splitting, transverse shear, and interface shear.
Fiber Reinforced Polymers (FRPs) have made significant progress in highway structures as corrosion mitigation to extend the service life of structures, especially in aggressively corrosive environments. In the effort to further facilitate the use of these materials, AASHTO developed the AASHTO Guide Specification for the Design of Concrete Bridge Beams Prestressed with CFRP Systems (AASHTO-PBCFRP) and the 2nd edition of AASHTO LRFD Bridge Design Guide Specifications for GFRP Reinforced Concrete (AASHTO-BDGFRP).
The design of prestressed beams and girders includes prestressing and auxiliary reinforcement for confinement, splitting, interface shear, and transverse shear. Currently in the design of durable (corrosion free/corrosion-resistant) prestressed concrete beams and girders, engineers could use Carbon Fiber Reinforced Polymers (CFRP) prestressing according to the AASHTO-PBCFRP or Stainless-Steel Reinforcing according to the AASHTO LRFD Bridge Design Specification (AASHTO-LRFD) or shear in accordance with ACI 440. Engineers do not have specifications to guide them in the design of FRP reinforcement auxiliary reinforcement.
While stainless steel reinforcing is durable and can meet the load and durability demands, Carbon Fiber Reinforced Polymer(CFRP), Glass Fiber Reinforced Polymers (GFRP) Bars and Basalt Fiber Reinforce Polymer (BFRP) reinforcing could provide a more economical solution. However, the behavior and the mechanical properties of CFRP, GFRP and BFRP bars are different from the traditional steel bars which are the basis of the current specifications, design methodology and procedures. Therefore, there is an urgent need for research and development of specifications and guidance for the use of FRP bars for auxiliary reinforcement in prestressed concrete beams.
The research results will be implemented within the AASHTO Guide Specification for the Design of Concrete Bridge Beams Prestressed with CFRP Systems (AASHTO-PBCFRB) and/or the 3rd edition of AASHTO LRFD Bridge Design Guide Specifications for GFRP Reinforced Concrete (AASHTO-BDGFRP). This implementation is expected to improve durability, economy, and efficiency.