To talk about the life of carbon fiber strengthening, we must first look at the factors that affect the durability of carbon fiber cloth. Horse believes that there are the following points:

1. The quality difference of carbon fiber yarn.

The fibers used for carbon fiber composites must be continuous fibers. Among them, the carbon fibers used for the strengthening of load-bearing structures must be selected from polyacrylonitrile-based (PAN-based) small bundle filament fibers of 24K and below. Large bundle filaments are strictly prohibited. The quality of carbon fiber yarns varies from manufacturer to manufacturer.

2. In addition to the differences in the quality of carbon fiber yarns, the quality of the braided wires used to weave carbon fiber fabrics also varies greatly.

At present, the fixed and edge-knitted braided wires on the market include hot-melt wire, cotton wire, glass fiber, nylon wire and so on. The high-quality carbon fiber cloth uses hot-melt wire. (The hot-melt wire is a linear connecting material made of a polymer that can be melted by heating. The temperature can reach 150°C when bound. A good hot-melt wire can withstand a high temperature of four or five hundred.)

Some unscrupulous merchants use ordinary cotton thread instead of hot-melt thread to save costs. The difference in appearance is not big, but the difference in high temperature resistance and fatigue resistance is very different.

3. The impact of the severity of the reinforced environment on the material

The aging resistance of carbon fiber composites in a variety of typical environments (water environment, acid environment, environment with high alkali content) was tested. Test Carbon fiber cloth and carbon fiber cloth composite materials were immersed in a typical environment for 10d, 20d, 30d, 40d, 50d, and 60d, then taken out and dried, and then a tensile test was conducted.

The test results show that: under the premise of no protection, the carbon fiber cloth is immersed in water, acid solvent, alkali solvent for 60 days, its mechanical properties (elastic modulus, tensile strength, elongation) decrease value is very small, less than 5%. This shows that carbon fiber cloth has good durability in these media.

For the strengthening of buildings in offshore areas such as ports and docks, carbon fiber is inevitably subject to physical and chemical erosion by seawater because it has been exposed to the special environment of seawater immersion for a long time. In addition, the impact of wind waves, ice cubes, freeze-thaw cycles, etc., also caused a little damage to the carbon fiber cloth, less than 5%.

At the same time, the test shows that the durability of the carbon fiber itself to the medium is very good, and the durability of the carbon fiber strengthening to the medium mainly depends on the durability of the carbon fiber structural adhesive.

In summary, the durability of carbon fiber cloth is very strong, but it cannot be accurately estimated at present, and there is no clear test data in the industry that can indicate the service life of carbon fiber cloth.

However, the national standard sets the service life of carbon fiber structural adhesive as 50 years. As the main body of carbon fiber strengthening, carbon fiber cloth must have a life span of more than 50 years.