The Behavior Research Of New-to-old Concrete Composite Components

Concrete structures will appear anything inevitably by artificial action or entironment, especially a large amounts of bridges go into the period of maintenance or reinforcement in the near future. A lot of concrete structures need to be maintained or reinforced, in order to resume or enhance their bearing capacity or using function. The cohesion problem of New-to-old concrete and the problem of the behavior of composite components have to become the key factors. In the criterions about maintenance&reinforcement in print, the reinforcement method of augmented section has already became an important and independent capture, and to be an important tool to guide the design and construction of new-to-old concrete composite components. But the faultiness in theory and rigid restrictor in using formulas have restricted severely its using and development. Most structures are designed by self-experience. The paper collects and tides up abroad research information, and deduces the shearing strength formulas for joint surface by the criterions up to the minute, recites the analyse method for new-to-old components and the cohesion behavior research results of the joint surface, and summarizes the methods of controlling and checking the joint quality of new-to-old concrete. In the end, checking out the theory narrated forward by the case of a practical bridge reinforcement design and construction.