In building reinforcement, bonded steel reinforcement and carbon fiber reinforcement have the same reinforcement method, and both are reinforced by bonding, but the reinforcement materials used are different. Bonded steel reinforcement uses steel plate, and carbon fiber reinforcement uses carbon fiber cloth or carbon fiber plate. All of them can improve the bearing capacity of the original building structure, so the question is, is it better to increase the bearing capacity of the original component with more layers of reinforcement and paste? Can the bearing capacity of the original components be infinitely increased?

When evaluating or reinforcing existing structures, bearing capacity is one of the important indicators to determine the safety of load-bearing structures. When the bearing capacity of the building is insufficient, it will affect the performance of the entire building, and it is easy to cause some safety problems. In this case, we need to take corresponding reinforcement measures.

And how much can the bearing capacity of the building be improved? This needs to be checked when formulating the reinforcement design scheme.

The national code has made relevant restrictions on the reinforcement of bonded steel and carbon fiber cloth to improve the bearing capacity of the structure. After the reinforced concrete structural members are reinforced, the increase of the flexural bearing capacity of the normal section should not exceed 40%, and the shear bearing capacity should be checked. To avoid the occurrence of shear failure of components prior to bending failure after the flexural bearing capacity is increased.

While considering the bearing capacity, there are also certain requirements for the thickness of the reinforcement and the number of layers:

Bonded steel reinforcement steel plate thickness:

To determine the thickness of the steel plate by bonding steel reinforcement, it is only necessary to obtain the height of the concrete compression zone through the bending moment value of the reinforced part, and then calculate the cross-sectional area required for the reinforcement steel plate through the height of the compression zone. Then determine the reasonable steel plate width according to the beam width, and calculate the required steel plate thickness. After the above calculation process, the thickness of the steel plate can be verified. When the calculation requires a steel plate with a thickness exceeding a certain thickness, it can be carried out by layering and pasting, but the total thickness of the overall steel plate should not be greater than 10mm.

During construction, high-quality adhesive steel that is easy to construct and ensure the quality of reinforcement should be selected.

Carbon fiber cloth paste layers:

It is recommended that the number of layers of carbon fiber cloth to be pasted should not exceed three layers when carbon fiber cloth is reinforced.

It can be seen that the number of layers of reinforcement and paste is not as much as possible. The structural bearing capacity cannot be infinitely improved by pasting steel plates or carbon fiber cloth. Bonded steel reinforcement or carbon fiber cloth reinforcement should be determined according to the specific situation. Some can obtain specific values through calculation, and some can take corresponding measures based on practical experience. However, no matter what kind of reinforcement and pasting method is used, it should not exceed the limit value specified in the construction regulations.