APPLICATION OF "FLOWABLE" CONCRETE IN A TUNNEL LINING

This article describes how highly durable, homogeneous, and labor saving concrete structures can be constructed with flowable concrete. Flowable concrete is high performance concrete that has enhanced ease of placement and high resistance to segregation. The project in which it was used consisted of the construction of a tunnel in Yokohama City, Japan, at a depth of 20 m to protect a residential area from flooding. Concrete mixture constituents and proportions are described. Transportation of the mixture and the quality control, as well as the construction are also described. It was found that the flowable concrete is a very effective construction material, especially for structures with congested reinforcement.