Research on the Solutions to the Concrete Durability of Newly-built Tunnel Structure

摘要

Through the survey about the durability of existing railway and road tunnels, it is found that there are different kinds of defects in most tunnels concerning poor durability. This phenomenon exists for a number of reasons among which the main ones are geological conditions , hydrological conditions, types of concrete structures, poor grading, larger second lining thickness, excessive larger stiffness and the poor quality construction. Solutions of these problems are provided in this paper. Specific measures are using multiple composite cementitious materials (the cocktailtreatment), providing composite cementitious materials with mixing station mode, using effective superplasticizer with low water-cement ratio and small water usage, adding appropriate amount of cellulose fibers in concrete, emphasizing the initial support and belittling the secondary lining, using reasonable maintaining technology, using new technology of Waterproof Plate.