A superstructure can be thought of as the conduit which carries a roadway over a crossing. Like any other bridge component, the superstructure is comprised of many elements. In the bridge design profession, no other component elicits so much discussion, and even downright controversy, as to the type of elements to be utilized in construction. The structural and geometric complexities of the superstructure component make it one of the most challenging design problems in a bridge engineering project | Source Bridge Engineering 3 Design of Superstructure Elements A superstructure can be thought of as the conduit which carries a roadway over a crossing. Like any other bridge component the superstructure is comprised of many elements. In the bridge design profession no other component elicits so much discussion and even downright controversy as to the type of elements to be utilized in construction. The structural and geometric complexities of the superstructure component make it one of the most challenging design problems in a bridge engineering project. In this section we will examine the various types of superstructures and the different elements which comprise them. While it would be impossible to cover every permutation of superstructure types that are in use this section will attempt to provide the reader with fundamentals behind several of the common superstructure configurations presently being used in highway networks around the world. Section Overview This section provides a detailed look at the various elements that compose a highway bridge superstructure. Different types of superstructures are discussed along with many of the design maintenance and rehabilitation issues affecting them. Design examples for commonly used superstructure elements are provided to give the reader an understanding of principal superstructure design fundamentals. SUPERSTRUCTURE TYPES The type of superstructure chosen for a bridge can be based on a variety of factors ranging from maintenance considerations to personal preference. Specifically some of the commonly used criteria in selecting the type of superstructure to be used are Material function and availability Construction cost Speed of construction and constructability Design complexity Maintenance costs and life expectancy Environmental concerns Aesthetics Where there are no steadfast rules governing which of the factors listed above is more important than the other one certainty is that the use of Downloaded from .