Carbon fiber can be used to strengthen the normal section bearing capacity of bending members and shear members when used in the reinforcement of bridges. Strengthen the bearing capacity of the inclined section. Strengthen the shear of the cross section. In addition, the use of carbon fiber cloth can also strengthen the compression member.

(1) Enhanced cross-sectional bearing capacity

When carbon fiber cloth is used to strengthen the bearing capacity of the normal section of the bending member, the pasting method as shown in Fig. 1 is generally adopted.

Paste one or more layers of carbon fiber cloth on the bottom of the beam, and its cross-sectional form can be made into the form of Figure 1. If possible, the carbon fiber cloth should be pasted into the U-shaped cross-section in the figure. The load-bearing capacity of the front cross-section of this kind of cross-section is increased even more.

(2) Inclined section bending resistance and cross-section shear strengthening

When the carbon fiber cloth is used to reinforce the bending resistance of the inclined section or to improve the shear resistance of the section, the pasting method shown in Figure 2 can generally be used. Cut the carbon fiber cloth into strips and stick it to the side of the beam. The sticking direction should be consistent with the main tensile stress trace in the beam body. In this way, the carbon fiber cloth can fully exert its tensile strength, prevent the cracking of the concrete, and can also improve the shear resistance of the beam.

(3) Reinforcement of compression members

When the compressed concrete column is reinforced with carbon fiber, the pasting method shown in Figure 3 can generally be used.

In the reinforced concrete members after compression, the function of carbon fiber is similar to that of the stirrups in the concrete column. In addition, the column can be completely wrapped with carbon fiber, or it can be partially wrapped. Initial studies have shown that partial wrapping may be more advantageous, as shown in the elevation of Figure 3.

The column of concrete reinforced with carbon fiber cloth can not only increase the bearing capacity, but also increase the ductility of the column of concrete. Therefore, carbon fiber reinforced bridges have more advantages in areas where seismic activity is more frequent.