As a transportation hub such as roads and railways, bridges play a vital role in transportation. The main building material of the bridge-reinforced concrete will cause the following main problems with the extension of use time:

First, due to material aging, corrosion and man-made factors, the structure cracks, which reduces the load-bearing capacity of the structure;

Second, in reinforced concrete structures, there is a widespread problem of corrosion of steel bars. The corrosion of steel bars, especially prestressed steel bars, leads to a significant reduction in the load-bearing capacity of the structure, which can seriously cause structural failure and eventually lead to collapse.

How to improve the durability of the structure and extend the service life of the structure is a problem that needs serious research and urgent solution. Structural reinforcement and reconstruction technology can not only improve the durability and service life of the building, but also play a role in reinforcement and reinforcement.

The prestressed carbon fiber plate reinforcement system is one of the few reinforcement methods that can be effectively reinforced without unloading or blocking traffic. At the same time, the materials used have the characteristics of light weight, high strength and aging resistance of high-strength fiber composite materials, and hardly increase the weight and volume of the original structure after reinforcement, which is a very ideal bridge reinforcement solution.

Prestressed Carbon Fiber Laminate

Prestressed carbon fiber plate reinforcement technology is an active reinforcement technology, which is a new type of carbon fiber reinforcement technology. Combining the high strength of the carbon plate and the characteristics of prestressing, it has a high utilization rate of the strength of the carbon fiber plate, which can significantly increase the strength and rigidity of the structure while reducing the deflection deformation of the reinforced concrete structure, and can reduce and close the cracks. Light weight, little damage to the structure, easy construction, and good reinforcement effect.

The prestressed carbon fiber plate reinforcement system includes carbon fiber plate, tensile anchoring unit, supporting adhesive, etc. It is mainly used for bending reinforcement of beam and slab structure, and crack control reinforcement.

For bridges with larger section stiffness, the increasing section method has a more obvious improvement effect on section stiffness and bending strength, but the improvement of crack resistance is relatively low. The method of pasting steel plate (or clad steel) or fiberplate method improves the bending strength more obviously, but the rigidity of the reinforcement material itself is relatively small, so the improvement of crack resistance is limited. The external prestress method is an active reinforcement method, which can realize the redistribution of the internal stress of the beam and is an effective method for improving the crack resistance of the bridge structure.

In the stretching process of the prestressed carbon plate, the full-section carbon fiber tows are involved in the force, and when the maximum tensile stress is reached, "explosive" failure occurs.

Compared with carbon fiber cloth, the carbon fiber plate that has been impregnated and cured by resin has better structural integrity and material uniformity. When bearing the tensile load parallel to the fiber direction and the extrusion load perpendicular to the fiber direction, the carbon fiber plate is easier to ensure the uniformity of the fiber force in the full section. Therefore, the tensile strength of the carbon fiber material can be fully exerted, and the reinforcement efficiency is also higher. Therefore, generally, carbon fiber sheet is selected as the material for external prestressing.