Carbon fiber CFRP strengthening

At the end of the 1980s, based on the idea of bonding steel reinforcement, a fiber reinforced plastic (FRP) reinforcement method appeared. In recent years, it has been gradually promoted and applied at home and abroad and has been fully industrialized. Carbon fiber cloth reinforcement technology is suitable for the reinforcement and repair of various structural types and various structural parts. Carbon fiber cloth reinforcement technology is a new technology for external reinforcement of structures that is more commonly used and has better performance in the application of fiber reinforced plastics.

The failure form of concrete beam

Detection of beam damage

Carry out carbonization test on concrete, or test the strength of concrete with a rebound tester, and get the cubic compressive strength of concrete after conversion according to the method specified in the specification. The failure form of the beam is shown in Figure 1.

Carbon fiber CFRP reinforcement method

Reinforcement of reinforced concrete beams can be divided into different CFRP paste positions:

1) Paste reinforcement on the tensile surface of RC beam;

2) Paste U-shaped CFRP reinforcement on the tension surface and both sides of the RC beam (see Figure 2);

3) RC beam wrapping and strengthening;

4) Only paste reinforcement on both sides of the beam.

Carbon fiber procedure for reinforcement of RC beam

Reliability appraisal-reinforcement plan selection-reinforcement design-construction organization design-+ construction-+ acceptance.

Sum up of CFRP strengthening

The ultimate strength and ultimate deformation of concrete confined by carbon fiber cloth are greatly improved compared with those of unconstrained concrete, and the greater the reinforcement rate of carbon fiber cloth, the greater the degree of improvement. After reinforcing the concrete beam with carbon fiber cloth, its flexural and shear bearing capacity is significantly improved. Carbon fiber cloth can effectively inhibit the development of cracks, making the width and spacing of cracks significantly smaller. Compared with the original reinforcement method, the technical advantages of carbon fiber reinforcement method make it have broad development prospects.