ABSTRACT

Reinforced concrete (RC) structures are widely used. Nowadays, many existing RC structures, including some reinforced concrete offices, department stores and plants built in some big cities in China before 1949, have already been repaired. And after the foundation of P. R. China, a great number of civil and industrial buildings and a few office buildings were designed as reinforced concrete structures during the 1950s to 1960s. For those structures of that period, deficiency in construction quality and failure in proper use and maintenance caused problems to their service and even safety. Owing to the expensive cost of structures, it is not economical to replace buildings with new construction because of the insufficient bearing capacity. Retrofit strategies, which require less cost to the buildings, remain the most viable alternative approaches. Additionally, some buildings need to be retrofitted for such requirements such as changing their function or adding new stories. Therefore, retrofit demand will be around for a long period.