Amir M Malek - Division of Structure Design, California Department of Transportation, USA

In recent years application of fiber composites in construction industry has significantly grown. Several advantages of fiber composites such as corrosion resistance, high specific strength and stiffness, easy fabrication and bonding, and formability have supported their application. Availability of different types of fibers and resins allow designers to select the constituents based on environmental conditions during the service life, desired physical and mechanical properties of the strengthening system, and cost-effectiveness. Despite superior structural properties, still several issues such as fire resistance, long-term performance under service conditions, and local debonding of the strengthening system from substrate need further studies. On the other hand, lack of unified design methodology and construction specifications have retarded industrial applications. Different components of a reinforced concrete bridge such as deck, girders, bent caps, and columns can be efficiently upgraded by bonding fiber composite laminates. The composite laminates will increase the flexural and/or shear capacity of the reinforced concrete superstructure. Fiber composites have been also used as fiber wraps or prefabricated jackets for seismic retrofit of reinforced concrete columns. In this application, the composite system applies lateral compressive stresses to the concrete column and the mechanical properties of concrete are improved by extra confinement provided by composite. In this paper, some of the recent applications of composites in strengthening of reinforced concrete bridges will be reviewed. Furthermore, different failure modes in the strengthened beams and design methodology will be discussed

Composite, fiber reinforced, flexural upgrading, FRP, reinforced concrete, repair, retrofit, shear strengthening