In recent years, people's requirements for the safety, applicability and durability of buildings have continued to increase, and buildings have suffered various types of damage, which has led to the continuous decline in the safety of buildings and brought people's lives and property. potential threat. Therefore, the structural maintenance and reinforcement of existing buildings has aroused widespread attention.

At present, the commonly used methods of reinforced concrete structure reinforcement in engineering include: increasing section reinforcement method, outsourcing steel reinforcement method, sticking steel reinforcement and so on. These reinforcement methods have certain defects in practical applications, such as chemical corrosion, increasing the weight of the structure, difficult to handle joints, and difficult construction. Carbon fiber fabric reinforced concrete structure technology has been widely used in engineering applications as a new and high-tech building reinforcement method.

Carbon fiber cloth is used as a reinforcing and repair material, and its strength is generally many times that of steel for construction. Its elastic modulus is also higher than that of steel used in ordinary construction. It is an excellent reinforcing and reinforcing material. In addition to these characteristics, it has been observed that the use of carbon fiber cloth to reinforce concrete members can also provide effective protection measures for concrete members, prevent concrete corrosion, and improve the durability of concrete while increasing the bearing capacity of concrete structures.

Design principles and treatment methods of carbon fiber fabric in beam and slab reinforcement engineering:

When the carbon fiber cloth is used to strengthen the reinforced concrete beam and slab, the average strain of the cross section still conforms to the principle of the flat section assumption, which can be used as a basic assumption in the calculation analysis. Based on the flat section assumption, the strain of the carbon fiber should be slightly greater than that of the reinforcing bar. In order to simplify the calculation, the tensile strain of carbon fiber can be approximated to the tensile strain of steel bar. According to the principle of equal tensile force, the area of carbon fiber cloth can be converted into the equivalent steel bar area. Then, the calculation formula is based on the design formula of the normal section bearing capacity of the reinforced concrete single-reinforced rectangular section bending member.

The construction process of carbon fiber fabric in the beam and slab reinforcement project:

Before construction, the reinforcement and reinforcement scheme is determined according to the reliability rating of the building structure, and then the design is based on the reinforcement and reinforcement scheme. The characteristics of the carbon fiber cloth reinforcement construction method and reasonable construction measures should be considered while designing. To ensure the quality of construction, construction and acceptance should be carried out in accordance with relevant regulations. The specific construction technology is as follows:

1. Preparation and surface treatment before construction

Deteriorated concrete such as spalling, loosening, honeycomb, and corrosion on the surface of the reinforced concrete member is removed to expose the concrete structure layer, and the large holes and recesses are repaired and leveled with the card repair material. Because the carbon fiber cloth is bent along its fiber direction, it will generate a large concentrated stress, which will cause the fiber filament to break and affect the reinforcement effect. Therefore, when carbon fiber cloth is pasted at the corner, the corner of the concrete needs to be chamfered and polished into a circular arc, and the radius of the arc should not be less than 20mm. It is proved by experiments that the problem of stress concentration of carbon fiber cloth can be effectively alleviated when the arc radius is 20mm.

2.Brush the primer resin glue

The purpose of painting the primer is to strengthen the adhesion between the carbon fiber cloth and the concrete surface. It is particularly important to give full play to the high-strength characteristics of the carbon fiber cloth and the reinforcement effect. This requires strict construction according to the instructions of the primer manufacturer.

3. Bonding carbon fiber fabric

After the primer application is completed, the carbon fiber cloth cut according to the design requirements is pasted. The carbon fiber cloth is lightly pressed by hand to the part to be pasted, and a special roller is rolled in the direction of the carbon fiber cloth for multiple times to exclude the pasted carbon fiber. The air bubbles in the cloth make the carbon fiber cloth fully adhere to the concrete surface. Keep in mind that when rolling, you must roll in one direction to prevent the carbon fiber wire from being damaged. Finally, a layer of adhesive is applied on the carbon fiber cloth, and a plastic film is used for protection.