Retrofitting with Fiber Reinforced Polymers
FRP is comprised of a polymer (such as epoxy, vinyl-ester, or polyester), reinforced with a fiber (such as carbon, glass, Kevlar, basalt, etc.). The fibers are the main source of strength and stiffness in the combination of FRP.
The resin distributes the load among all fibers and protects them from environmental effects such as abrasion. FRP’s should only be considered as a secondary to pre-existing reinforcements and should be applied to a project as part of retrofitting.
FRP “are constructed with specially designed equipment. Sheets of carbon or glass fabric up to 60 inches (1.5m) wide are saturated with resin and passed through a press that applies uniform heat and pressure to produce the laminate. SuperLaminates shown below offer three major advantages over conventional laminates. First, by using unidirectional or biaxial fabrics, the laminate may provide strength in both longitudinal and transverse directions. This is a tremendous advantage that opens the door to many new applications. Secondly, they are much thinner than conventional laminate strips; with a typical thickness of 0.025 inches (0.66 mm), they can be easily coiled into a circle with a diameter of 12 inches (300 mm) or smaller. Lastly, the number and pattern of the layers of fabrics can be adjusted to produce an endless array of customized products that can significantly save construction time and money.”
An important part of FRP application process is to make sure the product is placed onto a properly prepared surface. To prepare the concrete prior to the FRP application, the surface of the concrete must have a sandpaper like profile. This process assures sound substrate to bond with the FRP.
QuakeWrap is a revolutionary product now available on the market, utilized recently to repair bridges in the United-States. Similarly, PileMedic offers a similar solution for retrofitting and restoring piles and pipes.
Additional information: http://www.epoxydesign.com/carbon-fiber-reinforced-polymers-cfrp/