Project Overview

A bridge project has a design mileage of 241m, a width of 26m, and a design maximum speed of 60km/h. It was officially put into use in June 2003. In June 2015, during the inspection of the bridge's quality by the relevant unit, it was discovered that the wing structure on the left and right sides had serious quality problems. The concrete falls off in a large area, exposing the reinforced structure, and it is necessary to take immediate measures to repair and strengthen. According to the actual situation of the project, to maintain the overall performance of the bridge, improve its safety and stability, and comprehensively consider various construction plans and economic requirements, choose to use prestressed carbon fiber laminates for reinforcement construction.

Reinforcement plan

In the process of strengthening the bridge, the concrete that has fallen off should first be cleaned up, and then the prestressed carbon fiber laminate should be used for reinforcement at this position. According to the requirements of the project, follow the construction process to improve the performance of the structure in an all-round way to ensure that the bridge has more bearing capacity. HM-2.0T carbon fiber laminate is selected according to the needs of the project. Then use glue to paste, perform performance testing after the completion of construction, and meet the following requirements. The tensile strength is 4560 MPa, the elastic modulus is 266 GPa, and the elongation is 1.8.

After inspection and comparison, it is found that the performance of each part can meet the requirements of the project, and the bearing capacity has also been greatly improved, which ensures that the bridge is more stable and reliable, and the reinforcement performance is very obvious

Reinforcement effect

The reinforcement construction in this project was carried out after August 2016. In order to comprehensively improve the effect of reinforcement construction, and to test the reinforcement effect objectively, follow-up inspections are carried out after construction. Including concrete structure cracks, overall structural sealing performance, etc. Implementation monitoring was carried out within two years after the completion of the reinforcement construction, very accurate data information was obtained, and quality inspection and evaluation were carried out.

The research results show that the prestressed carbon fiber laminate is well bonded to the old bridge structure without any shedding or quality defects. On the whole, the performance of the bridge structure is very good, the bearing capacity has been greatly improved, the effect of reinforcement is achieved, and the safety of traffic operation is guaranteed.

Conclusion

The prestressed carbon fiber laminate itself has the characteristics of light weight, high strength, and excellent corrosion resistance. The application of this material to the reinforcement of the old bridge can greatly improve the structural performance of the bridge and ensure the safety and stability of the bridge. However, the construction should be carried out in strict accordance with the requirements of the construction specifications, control all key links, improve the quality of the bridge, and provide reliable conditions for the normal use of the bridge project.