Carbon fiber reinforcing fabric has the characteristics of environmental protection and wear resistance, and it is often used in room decoration or renovation nowadays. When a homeowner doesn't like the construction of a house, he can design the house according to his own idea, but it's dangerous to tear down a load-bearing wall, and carbon fiber fabric can solve the problem.

When the room is decorated, carbon fiber fabric are used in the following places. The first is a curtain panel that can be used as a non-load-bearing wall. It is a lightweight, mechanical, and not easy to age. It is usually used in high-rise buildings or coastal buildings. The second is as a roof waterproof coating, usually applied to the roof surface, which will prevent the roof weathering and effectively reduce the occurrence of dew in the house, and our house is also beautiful. The third is the electromagnetic shielding plate and conductive plate, generally using carbon fiber high conductivity to quickly eliminate some static electricity, mainly from the atmospheric discharge and lightning strikes of static electricity. The fourth is that it can be used to prevent the wall from being corroded, and to enhance the use time of the floor. The fifth is in the application of open door, and the carbon fiber fabric is not further fixed.

1. Application example of carbon fiber fabric in interior decoration and strengthening

1.1  Engineering survey

Siping station front residential building, built in the early 1990s, the bottom frame shear wall structure, the bottom frame, the upper four-storey housing. The original design 1 - 2 storeys for restaurants (live load of 2.5KN/m), the kitchen (live load of 4.0KN/m) is located on the first floor. It is now planned to redecorate and open a KFC chain store, moving the kitchen to the second floor and setting up a table in the original first floor kitchen. Due to the increase of load caused by functional changes, the original 2 story partial beam will not meet the design requirements and needs reinforcement. After the demonstration of the scheme and the comparison of economic and technical feasibility, carbon fiber reinforced polymer (CFRP) fabric was chosen to reinforce it.

1.2 Basic assumptions

The ultimate bearing capacity of concrete beams strengthened with CFRP fabric is calculated on the basic assumption that the effect of concrete in tension zone is neglected. After bending, the strain of concrete, steel bar and carbon fiber accords with the assumption of plane section. The carbon fiber fabric adopts a linear elastic stress-strain relationship: σcf=E cfxεcf and cf<0.01.

1.3 Reinforcement design

According to the "Technical Specification for Reinforcement and Repair of Concrete Structures with Carbon Fiber Reinforced Polymer Fabric" (CECSl46:2003), the limit design method based on probability theory is adopted for calculation. Considering that the live load acting on the reinforcement structure is basically removed, the effect of the two force is not considered. Taking the middle span of one of the axle beams as an example, the design value of the maximum bending moment is 463.6 kNm according to the original design, and the reinforcement design is to paste 300 m m wide CFRP fabric three layers at the bottom of the beam. According to the formula of the regulation, the design value of the maximum bending moment after reinforcement is 524 kNm, which is 13% higher than the original one.

1.4 Construction method and construction technology

In order to reinforce the anchorage of CFRP fabric at the bottom of the beam and increase the shear resistance of the beam, 160mm wide U-shaped hoop is pasted on each side of the beam end, and 160mm wide U-shaped hoop is pasted on each side of the main and secondary beams. U type paste paste height should take the section height of components. For U type paste, the longitudinal carbon fiber sheet should be pasted at the upper end. Considering the influence of the construction site on the multi-layer bonding of CFRP wrapping, it is suggested that the number of CFRP layers should not exceed 3 layers for flexural members.

1.5 Construction effect

The project has been put into use for less than two months from design to completion. It takes only 10 days for the project to be constructed by carbon fiber reinforcement. There is no quality problem and the construction effect is good. The project has been praised by the designers, supervisors and owners.

2. Application example of carbon fiber fabric in interior decoration and strengthening

2.1  Engineering survey

The main building of a building is a 4-storey reinforced concrete frame structure (the office part is a 5-storey brick structure), with a floor area of 2602 m2, an auditorium on the ground floor, a garment factory building on the second floor or above, and a 2-storey brick-concrete structure (a simple house is built on the roof). The building area is 725 m2. These two buildings need to be renovated and renovated, and a seismic appraisal committee of a construction project is also entrusted to carry out a comprehensive test of the two buildings, and make technical appraisal and reinforcement plan.

The main building is a four storey five storey building with a three storey building. Taking the main building as an example, this paper expounds the scheme of appraisal and reinforcement. The main building was built in 1981. The bottom floor and foundation were made of standard bricks with 100 mechanism and 50 mixed mortar. The floor was made of 85 bricks with 100 mechanism and 25 mixed mortar. The office part is brick structure, cross wall bearing, bearing wall thickness 370mm, inner wall thickness 240mm. The upper part of the original factory building is a regular multi-storey reinforced concrete frame structure. The cast-in-situ beams and columns are all made of concrete marked 200. No reinforced concrete columns are installed at the joints between the factory building and the office. The roof longitudinal connecting beams and perforated slabs of the factory building are directly placed on the cross-wall ring beams of the office. After checking the structure, material strength, relative non-uniform settlement trend and inclination of the main building, and checking the seismic performance of the structure, the reinforcement scheme of the auditorium on the bottom floor of the main building is proposed.

2.2 Frame column reinforcement with carbon fiber fabric

Reinforced concrete columns with excessive axial compression ratio below the bottom interlayer are strengthened by wrapping several layers of CFRP fabric or enlarging the section of columns. Reinforced concrete columns with axial compression ratios above the bottom sandwich and over the second floor are strengthened by sticking carbon fiber sheets. First, a layer of longitudinal carbon fiber fabric is pasted on the surface of the columns, and then several layers of circular carbon fiber fabric are wrapped around the outer surface according to the axial compression ratios of the columns.

2.3 Roof beam reinforcement with carbon fiber fabric

The roof beams are strengthened by pasting longitudinal carbon fiber fabric at the bottom of the beams and U-shaped carbon fiber wrap at the end of the beams.

2.4 Construction effect

After carbon fiber fabric reinforcement , the seismic performance of the structure meets the requirements and has been put into operation.

3. Technical and economic benefits by carbon fiber fabric reinforcement

Carbon fiber faric has the advantages of light weight, high strength and good shape-following. It can be used for repairing and reinforcing various complex structural shapes, and has little effect on structural weight. Carbon fiber repair and reinforcement process is simple and rapid, without any clamps, templates and support, although the cost of carbon fiber itself is higher than other materials, but the construction cost is greatly reduced. It eliminates the complicated procedures and auxiliary facilities such as anchorage, clamping and disassembling, erecting formwork, supporting, pouring concrete, maintenance and demolition formwork required by traditional methods such as steel plate reinforcement and concrete reinforcement, and occupies a small space. Even in high altitude operation, it only needs to set up a simple working platform. Therefore, the comprehensive cost of repairing and reinforcing concrete structures with CFRP sheet will be lower than that of traditional reinforcement methods. The economic benefits depend on the specific project conditions, and the more complex the structure, the more obvious the benefits.

4. Social results by carbon fiber fabric reinforcement

Because the construction of carbon fiber fabric repair and reinforcement is simple and rapid, the construction cycle is short, and the occupied space is small, the construction impact on the surrounding is reduced to the minimum. The social and environmental benefits will be enormous if carbon fiber fabric are used to repair the seismic damage of concrete structures caused by accidental disasters, especially the houses and other structures.

5. Summary of carbon fiber fabric reinforcement

The bonded carbon fiber fabric (CFRP) is a new type of reinforcement technology, which has been widely used and has produced great economic benefits. Compared with other traditional reinforcement technology, bonded carbon fiber fabric(CFRP) technology has the advantages of convenient construction, high efficiency, light and thin, and hardly increases weight and thickness after bonding. With excellent corrosion resistance and temperature resistance, and a wide range of applicability, regardless of the type of structure, structure shape, it can solve the problem of reinforcement smoothly. Construction quality can be guaranteed, even if the surface of the strengthened structure is not very smooth, bonded carbon fiber reinforcement can guarantee nearly 100% sticking rate. These advantages make it achieve the purpose of high strength and high efficiency, especially for seismic strengthening and other important, bonded carbon fiber reinforced concrete structure has obvious advantages.