Summary of Bridge Strengthening Technology

In recent years, with the development of materials science and technology, many high-tech fiber materials have been developed. Among them, carbon fiber is by far the earliest and most mature technology used in the field of civil engineering, and it is also the most widely used high-tech material.

Carbon Fiber Reinforcement

The characteristics of carbon fiber is made of polyacrylonitrile or mesophase pitch fiber after high temperature carbonization. There are many types of carbon fiber used for the reinforcement of concrete structures, which can be classified according to different classification methods. According to the shape, it can be divided into sheets (including cloth and plate), rods, profiles, and staple fibers. According to the mechanical properties, it can be divided into high elastic modulus fiber, high strength fiber and medium elastic modulus fiber.

In structural reinforcement, carbon fiber cloth, plates and rods are used more often. All are bonded to the concrete with a structural adhesive with a certain strength, so that it can work together with the concrete to achieve the purpose of structural reinforcement.

Technical characteristics of carbon fiber reinforced bridges

Because the strength and elastic modulus of carbon fiber materials are very high, compared with other reinforcement materials in the reinforcement of bridges and beams, it has the following advantages.

(1) High strength and high efficiency

Due to the excellent physical and mechanical properties of carbon fiber materials, in the process of strengthening and reinforcing concrete bridges, they can make full use of the characteristics of high strength and high elastic modulus to improve the bearing capacity of the bridge or its members, improve its bearing performance, and achieve the purpose of efficient reinforcement.

(2) Good corrosion resistance and durability

The chemical properties of carbon fiber materials are stable and do not react with chemical substances such as acids, bases and salts. Therefore, reinforced concrete members reinforced with carbon fiber materials have good corrosion resistance and durability, which solves the chemical corrosion problems encountered by other reinforced materials. In particular, it is more advantageous to perform reinforcement in a corrosive environment.

(3) Without increasing the weight and volume of components

The carbon fiber cloth is light in weight and thin in thickness. The reinforced and repaired member basically does not increase the weight and size of the structure, nor does it reduce the space used by the building. This is particularly important for the reinforcement of old bridges under the bridge that require navigation or have access requirements.

4) Wide application

Because carbon fiber cloth is a flexible material, it can be cut arbitrarily, so this reinforcement technology can be widely applied to various structural types, various structural shapes and various parts of the structure, and does not change the structural shape or affect the appearance of the structure. For bridges, abutments, beams and slabs and other structural members can be smoothly reinforced.

5) Easy construction

The use of carbon fiber materials for the reinforcement of concrete bridge beams does not require large-scale mechanical equipment during construction, occupies less construction site, and has extremely high efficiency.

In conclusion

Reinforcing the bridge beam with carbon fiber, no matter whether it is sheet or bar, has the advantages of clear stress and simple and convenient construction. It can be easily reinforced for the stress members of different parts of the bridge, which is a new technology that can be widely applied.