As a new material, FRP has high specific strength and high specific stiffness, high design, good fatigue fracture resistance, corrosion resistance, good structural dimensional stability and special electromagnetic properties. And unique advantages such as bite invisibility.
FRP pultruded profiles are widely used in construction and civil engineering, transportation, chemical corrosion protection, electrical and electronic, aerospace and military equipment, and play an important role. FRP has become an important technology industry. Its market distribution is 40% for buildings, 24.4% for tubular storage tanks, 12% for industrial equipment, 6% for transportation, 4% for ships and 14% for other ships.
FRP/composite is a new type of composite material with resin as matrix material and glass fiber reinforced. The reinforcing material glass fiber is made of glass balls made of ore and drawn into filaments. Since the main component of the profile is natural mineral material (more than 60%), FRP has good mechanical and physical properties. FRP is an anisotropic (short fiber composite material and other isotropic) materials, the strength changes with direction, the texture of the structure is discontinuous, and it is viscoelastic.
FRP reinforced concrete beams, FRP/composite materials, as structural reinforcement materials, have the foundation to work with concrete and can adapt to various working environments. The linear expansion coefficient of FRP is similar to that of ordinary concrete, so there will be no bond failure between the two due to temperature changes. After properly treating the concrete surface, glue FRP to ensure a good bond between the two. Adhesion. As a reinforcing material, FRP sheets and sheets have the advantages of high strength, convenient structure, short cycle, good impermeability and corrosion resistance.
The reinforced concrete beam is covered with glass fiber cloth, and epoxy resin is used as a binder. There is no sliding joint between the glass fiber cloth and the concrete joint surface, and the joint surface can effectively transmit stress. In the initial stress stage of the glass fiber reinforced beam, the number of glass cloth layers has little effect on the stiffness and deformation of the beam. After the tensile steel yields, the influence of the outer glass fiber reinforced plastic on the stiffness of the beam is obvious, thereby reducing the deformation of the beam. It can be seen that concrete beams reinforced with FRP can significantly improve the stress characteristics of concrete beams, extend the service life of long beams, and have broad application prospects.