1 carbon fiber reinforced structural components technical principles
Externally bonded fiber reinforced composites reinforced concrete technology is paste in the concrete structure of the external fiber-reinforced composite sheet, the two together by force, to achieve the purpose of reinforcement of carbon fiber material with high strength, high elastic modulus, light weight and corrosion resistance good characteristics, its tensile strength is about ten times the ordinary steel, ordinary steel modulus of elasticity higher than the modulus of elasticity. reinforced concrete structure repair all carbon fiber materials are mainly two: carbon fiber materials and supporting resin. The tensile strength of carbon fiber which is ten times that of steel construction, and very elastic modulus of steel, some (such as high elastic modulus carbon fiber and even more than twice in the steel, and good workability and durability is a kinds of good reinforcement and restoration materials, supporting the bottom of the resin include resin, leveling resins and adhesive resins, the role of the first two is to improve the quality of bonding of carbon fiber, while the latter's role is to make carbon fiber composite and concrete to form a of the whole, and work together to improve the structural elements of the bending, shear strength, to reinforce the structural elements, reinforcement purposes.
2 the use of CFRP has advantages
The use of CFRP structure has the advantages of high strength due to the carbon fiber material superior physical and mechanical properties, in the repair of concrete structures reinforced concrete structures and components can improve the bearing capacity and scalability, improve the performance of its force, to achieve efficient reinforcement patch the purpose. construction convenient, high efficiency, no wet work, no large-scale construction equipment, construction, less space occupied, according to the statistics, the same construction method for the reinforcement paste, paste, paste carbon fiber material is steel construction efficiency of 4-8 times with a very excellent corrosion resistance and durability. tests showed that carbon fiber reinforced concrete structure with good corrosion resistance and durability, can often encountered in the building to resist acid, alkali and salt corrosion on the structure. wide range of applications. Bonding carbon fiber reinforced concrete structure repair can be widely applied to various structural types (such as buildings, structures, bridges, tunnels, etc.), a variety of structural shapes (such as rectangular, circular, surface structure, etc.), various structural parts (such as beams, plates, columns, nodes, arch, shell, pier, etc.) of the reinforcement patch, and does not change the structure and shape, which is any kind of structure reinforcement method match. It is particularly important, for some large-scale bridge piers, bridges, bridge plate and the tunnel, tube and shell structure of large projects, use the old reinforcement means almost impossible to implement, while the use of the reinforcement techniques can be successfully resolved, construction quality assurance due to the carbon fiber material is flexible, even The structure is reinforced not very smooth surface can be achieved basically paste the effective rate of 100%, and paste the steel is difficult to achieve 100% effective paste surface, the corresponding acceptance criteria requiring only 70% on it. carbon fiber light weight and thin, less than the weight per square meter after you paste 1.0kg, paste the layer thickness is only 1.0mm or so, reinforced repair the original structure would not increase after the weight and size of the original components(France Paper).
3 carbon fiber reinforcement in the structure's use
3.1 Structure of carbon fiber reinforced Scope
Carbon fiber materials are suitable for a variety of structural types, various structural parts of the reinforcement patches, such as beams, plates, columns, roof trusses, piers, bridges, chimneys, cylinder, shell structure, etc. In addition, some mechanical properties of brick masonry can also be reinforced with carbon fiber. Specifically, you can, but not limited to: the use of carbon fiber reinforced London road bridge structure, the reinforcement of existing reinforced concrete chimney, component flexural reinforcement, shear reinforcement beam elements, concrete pillars bracket broken reinforcement, masonry seismic reinforcement, lack of capacity strengthening, building by-layer reinforcement, axial compression ratio overrun frame reinforcement, slab cracking reinforcement, shear reinforcement openings, floor load increases reinforcement, bridges broken, the old Bridge repair and reinforcement reinforcement towers and so on.
3.2 carbon fiber sheet reinforced concrete structure repair specification
Bonding carbon fiber sheets using reinforced concrete structure, bonding materials, through supporting carbon fiber sheets pasted together to make carbon fiber sheets under tension, and coordination with the deformation of concrete, a common force.
3.3 carbon fiber sheets can be used in the following ways to reinforce concrete structures:
In the beam, board member of the tension zone paste carbon fiber sheets for flexural reinforcement, fiber direction and reinforcement at the tension in the same direction; the use of closed paste, U-shaped paste or paste on the side of beam and column elements for shear reinforcement, axial and vertical components Fang Xiangyi fiber, the use of closed paste for seismic reinforcement of the column, the axial fiber direction and the vertical column, when there is a reliable basis, the carbon fiber sheets can also be used other forms of force or other condition of the concrete structure reinforcement, the use of bonding carbon fiber sheets reinforced concrete structure, with existing national standards should be used in probability theory-based limit state design method for calculating the carrying capacity limit state and limit state checking, steel and concrete materials, according to the test to be The actual strength, according to existing national standards to determine the appropriate strength of the material design specifications, carbon fiber sheets should be based on component to the limit state of strain, according to the linear elastic stress-strain relationship to determine the corresponding stress, carbon fiber sheets shall be taken as the production plant provide not less than 95% of the guaranteed ultimate tensile strength as the tensile strength ratio of the standard value, when using the paste of carbon fiber sheets to reinforce the structure or component should be considered when, after reinforcement of the structure of other components or performance of other components may impact of the use of bonding carbon fiber sheets for structural reinforcement, should be removable role in the structure of the live load, such as can not be uninstalled completely under the conditions of reinforcement, should consider the impact of the second force in the flexural reinforcement and by the shear reinforcement, reinforced concrete structures and components are the actual concrete strength not less than Cl5. the use of closed bonding carbon fiber sheets reinforced concrete columns, concrete strength not less than C10.
With the carbon fiber processing technology to the public, our wide range of applications of carbon fiber rate demand ratio rising from this point of view has been indicate the carbon fiber in engineering broad application prospects, perhaps in the future of human society in the material application from the steel era into the a carbon fiber material widely used era.