FRP Structural Reinforcement

FRP reinforcement is a fiber reinforced polymer (FRP) (or fiber reinforced plastic) that is used as internal reinforcement, such as rebar, or externally bonded reinforcement used to strengthen concrete, masonry, steel, and timber structures.

​​FRPs used for internal reinforcement and strengthening of structures use synthetic fibers in a polymeric matrix to provide excellent tensile strength in the direction of the fibers. The fibers are set in a straight, parallel and continuous arrangement within the matrix. These FRPs are sometimes known in the civil engineering community as high-strength composites.

A Brief History

One of the first known uses of FRPs as reinforcement occurred in 1975 in Russia. There, glass fiber reinforced polymer (GFRP) prestressing tendons were used to reinforce a 30 ft (9 m) long, glued timber bridge. ​Significant studies of using FRPs as reinforcement began in Europe in the 1980s as an alternative to steel plate bonding for bridge repair and strengthening. FRP reinforcements gained significant support during the 1990s from research of magnetically levitated (mag-lev) train support structures in Japan. The Japanese in 1996 were the first to introduce design guidelines for FRP reinforced concrete.[2]​  Since then, the use of FRP as structural reinforcement has increased exponentially and design guidance has been authored by organizations from around the world.

Advantages & Disadvantages

Advantages

  • High Strength and Lightweight
  • Corrosion Resistant
  • Dimensionally Stable
  • Low Thermal Conductivity
  • Nonconductive
  • Electromagnetically Transparent
  • Impact Resistant
  • Low Lifecycle Costs

Disadvantages

  • High Initial Cost (compared to steel reinforcement)
  • Susceptibility to Mechanical Damage
  • Susceptibility to Fire (without insulation)
  • Inability to Bend in the Field
  • Longer Load Transfer (Lap) Lengths
  • Poor Shear Strength
  • Low Strain to Failure (Lack of Ductility)

Note:  This website is about FRPpro, a software tool coming soon to assist engineers with the design of FRP reinforced concrete.  Until then, we have included some basic information about FRPs.  More information can be found on our engineering website.