Retrofit method with carbon fiber for reinforced concrete structures

Some existing reinforced concrete structures do not have sufficient seismic capacity, therefore, various retrofitting techniques are proposed. However, such techniques are not always adequate from the viewpoint of the increase in weight and the maintenance of the function. In order to overcome these problems, the authors have developed a new method using carbon fiber, which is a material of high strength, light weight and good durability, and recently developed as a 'high-tech' material. In this paper, basic properties, application techniques and durability of carbon fiber are introduced. This reinforcing system is more economical than conventional ones, and it has been used to improve the earthquake resistance of concrete chimneys. This system is also applicable to reinforcing buildings and freeway piers.