Prestressing Concrete Structures with FRP Tendons (ACI 440.4R-04)

Fiber-reinforced polymers (FRP) have been proposed for use instead of steel prestressing tendons in concrete structures. The promise of FRP materials lies in their high-strength, lightweight, noncorrosive, nonconducting, and nonmagnetic properties. This paper provides an overview of the ACI 440.4R-04 document on "Prestressing Concrete with FRP Tendons" reported by ACI Committee 440 on "Fiber-Reinforced Polymer Reinforcements". The document is one of the Emerging Technology Series published the American Concrete Institute. The paper outlines the content of the document and the philosophy of applying FRP technology as opposed to conventional steel for prestressing. The document offers general information on the history and use of FRP for prestressing applications, and a description of the unique material properties of FRP. It also focuses on the current state of design, development, and research needed to characterize and ensure the performance of FRP as prestressing reinforcement in concrete structures. The proposed guidelines are based on knowledge gained from worldwide experimental research, analytical work, and field applications of FRPs used as prestressed reinforcement. The current development includes a basic understanding of flexure and axial prestressed members, FRP shear reinforcement, bond of FRP tendons, and unbonded or external FRP tendons for prestressing applications. The document concludes with a list of research needs.