Strengthening of Old Wood with New Technology

ABSTRACT

The retrofi t of existing structures is always challenging from an engineering perspective. Constraints of accessibility, existing load capacity and project budget loom large when an older facility needs an upgrade. With existing wood structures, the options available for strengthening members are often limited. However, the growing use of Fiber Reinforced Polymers (FRP) in repair and retrofi t of concrete and masonry structures has opened the door for similar applications in wood. The advantages of FRP materials lie in their high tensile strength, low weight, and their ability to conform to varying shapes. Many carbon FRPs, for example, have tensile strengths in excess of 300 ksi while their density is less than 3 that of steel. FRP materials have been used successfully to strengthen existing concrete columns for higher seismic loads, as well as concrete and masonry walls that lacked adequate steel reinforcement. The versatility and ease of installation make FRP retrofi t solutions extremely effective.

The materials, design and installation of the FRP system discussed in this article was provided by QuakeWrap, Inc., Tucson, Arizona. Other team members included the architect of record, HDA Architects, the structural engineer, Paragon Structural Design, Inc., and Adolfson & Peterson Construction, as general contractor.