Four advantages of using YuNiu glass fiber reinforced composites

With the use of the existing buildings in the world, the growth of the age and the deterioration of the environment, there are more and more building structures with "disease" and "service". In order to ensure the safety of the building structure and prevent the occurrence of building accidents, it is necessary to timely detect and reinforce the structure of the disease. Therefore, strengthening the industry has become a new direction, has been paid more and more attention has aroused widespread concern in the industry, strengthening the industry development is more and more rapidly to the rapid development of reinforcement materials and the construction method of new emerging methods of structural reinforcement are also more and more.

The structural strengthening methods can be divided into two categories: direct reinforcement and indirect strengthening. The direct reinforcement includes the method of increasing section reinforcement and the method of strengthening with bonded fiber composite. The indirect reinforcement includes external prestressing strengthening method and prestressed glass fiber composite plate strengthening method. Bonded glass fiber composite material in direct reinforcement reinforcement method, as an advanced structure of a kind of high efficiency and low cost method to repair, since 1980s, has been in the civil engineering has gained great attention and extensive research and application.

The FRP composite material reinforcement method is the most commonly used glass fiber cloth, glass fiber board (hereinafter called glass fiber material) compared with the traditional reinforcement methods, has many obvious advantages such as glass fibre reinforced composite materials.

1) glass fiber material is light in weight, superior in mechanical properties, high strength, and has excellent corrosion resistance. The damage of the original structure is small, and the integrity of the original structure is not destroyed.

2) glass fiber reinforcement construction method is convenient, low cost, high efficiency, site construction without large mechanical equipment, repair time is short, small space can also be construction.

2) glass fiber materials have formability, and they have special advantages for complex surface structures and anisotropic structures, such as tunnels.

3) glass fiber material itself has high corrosion resistance to acid, alkali and salt.

4) glass fiber reinforcement construction method is convenient, low cost, high efficiency, site construction without large mechanical equipment, repair time is short, small space can also be construction.

So it seems "universal" glass fiber composite materials in strengthening field invincible, invincible, but in many projects, it will be in a position where it is useless, this would like to discuss today.

First of all, glass fiber reinforcement for reinforcement of the original structure strength is a certain requirement. The reinforcement method of glass fiber material is not applicable to plain concrete members, and it is not applicable to the reinforcement of the side of the longitudinal tensile steel bar with a reinforcement ratio of less than 0.2%. In addition, the strength level of the concrete of the original structure needs to be determined by field measurement. The strength grade of the concrete determined shall not be less than C15, and the tensile strength of the concrete surface shall not be less than 1.5MPa.

Second, the use of glass fiber reinforced material, the original structure of the stress state also requires. The tensile strength and modulus of elasticity of glass fiber materials are higher than those of steel bars, and they can also be combined with concrete as a whole. However, glass fiber material is soft and low compressive strength, therefore, glass fiber material is applicable to reinforced concrete bending, axial compression, large eccentric compression and strengthening of tension members, such as beams and columns. For compression structures, such as walls, the results are minimal.

Third, for a long time in high temperature, high humidity, concrete structure erosion structure, if a fiber glass reinforcement construction, need to pay special attention to the corresponding protective facilities and caking agent by adhesive specially made, construction should pay attention to the need for specialized operation process in accordance with the construction process specification.

Finally, the glass fiber material can form a whole with the concrete structure, largely depending on the adhesive. The use of impregnated glass fiber material has a strong effect on the concrete bond, but for the steel structures, should be used with steel as substrate supporting adhesive for construction, otherwise it will reinforce effect will be greatly reduced.

Application of glass fiber composite materials, is dependent on material properties and strength were determined, rather than the human will "universal" tell us using the above four points, the reinforcement method of pasting fiber is not a panacea. For different structural members, we should combine the material characteristics, which should be flexibly applied to the appropriate situation and different methods can be used to achieve the best reinforcement effect.