Preparation and Performances of Self-Compacting Concrete Used in the Joint Section between Steel and Concrete Box Girders of Edong Yangtze River Highway Bridge

Abstract

The joint section between steel and concrete box girders is the key localization of the super-long span hybrid girder cable-stayed bridge in the Edong Yangtze River, a high strength self-compacting concrete (SCC) was required to use in the joint section. This paper systematically investigated the performances of three types of C55 grade self-compacting concretes (SCCs), such as plain SCC, micro-expansion and polypropylene fiber reinforced SCC and steel fiber reinforced SCC. The results indicated that the steel fiber reinforced SCC had the best workability and mechanical properties. The flexural toughness of the steel fiber reinforced SCC was much better than that of the other two types of concretes. The addition of steel fiber, or polypropylene fiber and expansive agent improved the crack resistance of SCC, and the micro-expansion and polypropylene fiber SCC reinforced had better crack resistance than steel fiber reinforced SCC. The three types of SCCs have very high chloride penetration resistance and advanced freezing and thawing resistance. Moreover, the test achievement of concrete casting technology for the full-scale model of steel girder chambers in the joint section is introduced. The steel fiber reinforced SCC was preferred to be used in the steel-concrete joint section.