9502470 Goel The primary objective of this project is to develop an innovative composite structural system utilizing open web steel joists encased in advanced fiber reinforced concrete materials for improved economy and performance for seismic resistance. Analysis and practical design procedures will be formulated. It is widely recognized that innovative uses of two or more different materials generally leads to more efficient systems for resisting seismic forces. Recent studies show that structural systems consisting of composite members made of open web steel joists encased in fiber reinforced concrete hold great promise, especially for seismic resistance. In such members composite action is achieved through interlocking effect between concrete and open web steel joists without shear connectors, and the use of fiber reinforced concrete eliminates the need for conventional reinforcement which is quite labor intensive. Connections are made through steel plates sticking out of the encasing concrete. Therefore, this system can be suitable for cast-in-place as well as precast concrete. The research will begin by testing half to one-third scale beam-column specimens under combined axial load and reversed cyclic bending. The test results will be used to develop analytical models for the member behavior. This work will be followed by analytical studies of the selected theme structure. The last phase will include testing and analytical work on critical subassemblages taken from the theme structure. The focus will be on study of beam-to-column connections behavior and development of recommendations for connection details in order to achieve desired performance. This is a project supported under the year 1 program of the Civil Infrastructure Systems (CIS) solicitation NSF 94-154. ***
