Research On Flexural Strengthening With CFRP And Its Application In The Reinforced Concrete Bridge

Structural retrofit and rehabilitation with Carbon Fiber Reinforced Plastic(CFRP) is a very hot strengthening technique which has a great market nowadays. When compared to traditional structure reinforcement technology it has many advantages such as high-strength efficient, convenient construction, durability and corrosion resistance, and apply a wide range, respect light, not to increase the size of structure, So it has a wide range of applications. CFRP used for bending beam, and other components of reinforcement is the most common form of reinforcement, from the experimental analysis and application monitoring indicate that through CFRP paste components can greatly increase ultimate capacity. In order to meet the applicability, durability and safety of members only pay attention to the bearing capacity is not enough, many cases also need to control the deflection of the structure, it was necessary to do research on the stiffness of the component after reinforcement; under sustained load bearing capacity also need further research .Although there are a great amount of experimental studies on flexural performance of RC beams strengthened with FRP, most of the test members are strengthened under initial state without crack , there is a great difference with the actual structural members. Therefore it has a practical significance to study the flexural performance of RC members strengthened with FRP which simulate the practical state .This paper conducted experiments of beams with cracks and real bridge static loading test, Analyse the bearing capacity of the members. At last, the FEM analysis of specimen were carried out, the analytical results are consistented with experimental results well, this research provide the basis for strengthening design, evaluation of the structural members serving capacity and lay the foundation for deflection.Through the experimental and theoretical analysis, the conclusion can be summarized as follows:1)The initial load hardly influence the flexural bearing capacity of CFRP-Strengthened RC beams;2) The stiffness of beams with CFRP Strengthening is greater compared with ordinary reinforced concrete beams3) carbon fiber-paste can effectively inhibit the concrete cracking and the expansion of existing cracks, and carbon fiber Later paste at the end of a significant reduction in concrete strain can improve the durability of the structure;4) the FEM analysis of specimen were carried out, the analytical results are consistented with experimental results well.