Reinforcement Of Old Bridge

PROJECT

A bridge project has a total length of 241m and a bridge deck width of 26m. It is an integral part of the highway project with a design speed of 60km/h. It was completed and opened to traffic in June 2003. During the quality inspection of the bridge project in June 2015, it was found that the left and right wing slabs of the bridge had quality defects, and a large area of concrete peeled off and exposed reinforcement. It was necessary to take timely repair and reinforcement measures.

Combined with the specific conditions of the bridge project, in order to maximize the overall performance of the bridge structure and enhance the safety and stability of the structure, on the basis of comparing the technical and economic aspects of different maintenance and reinforcement schemes, it was decided to use prestressed carbon fiber laminates for reinforcement.

REINFORCEMENT PLAN

During the reinforcement construction of the old bridge, the spalled concrete was first cleaned up. Then stretch the carbon fiber board on the bottom of the T-beam horseshoe, and construct it as required, strictly following the steps to carry out various operations, thereby enhancing the concrete crack resistance and improving the bearing capacity of the bridge structure. The comprehensive performance indicators of the prestressed carbon fiber board: tensile strength 4560MPa, elastic modulus 266GPa, elongation 1.8, and tensile bonding strength 4.3MPa. After testing and testing, all indicators are qualified, and the material quality meets the requirements of construction specifications. On this basis, follow the technological process to carry out the reinforcement operation to restore the comprehensive performance of the old bridge, improve the structural bearing capacity, ensure the stability and reliability of the bridge project, and promote the improvement of the construction effect of the old bridge.

REINFORCEMENT EFFECT

The task of strengthening the old bridge was completed in August 2015. In order to understand the reinforcement effect, objectively evaluate the reinforcement quality of the prestressed carbon fiber board, and carry out continuous follow-up monitoring after the completion of the construction. The monitoring indicators include the concrete surface cracks, the color of the carbon fiber board protection layer, and the sealing performance. After nearly 2 years of tracking and monitoring, detailed data indicators were obtained, and then the appearance of the bridge structure was integrated for quality judgment and assessment. The results show that the bonding performance of the prestressed carbon fiber board and the surface of the old bridge structure is good, and there are no quality problems such as peeling and detachment. At the same time, the entire structure of the old bridge is stable and reliable, and the bearing capacity of the bridge has been significantly improved, realizing the purpose of effectively strengthening the old bridge, providing guarantee for the safe and smooth passage of vehicles, and winning the praise of drivers and people around.

CONCLUDING REMARKS

In short, the prestressed carbon fiber board is not only light in material, but also high in strength and has good corrosion resistance. It can be used to reinforce the old bridge to achieve good results. As a bridge maintenance and construction unit, we should fully understand the important role of prestressed carbon fiber board and use it in the reinforcement of old bridges in combination with engineering examples. At the same time, it is necessary to strictly follow the construction process, grasp the technical points, strengthen quality control, promote the better application of prestressed carbon fiber boards in the reinforcement of old bridges, promote the improvement of reinforcement and maintenance effects, and also provide guarantee for the safe and stable operation of the bridge.