Concrete - Encased Steel Joist Composite Structures for Seismic Resistance

9502470 Goel该项目的主要目标是开发一种创新的组合结构系统，利用先进的纤维混凝土材料包裹的空腹钢龙骨，以提高经济性和抗震性能。将制定分析和实用的设计程序。人们普遍认为，两种或两种以上不同材料的创新使用通常会导致更有效的抗震系统。最近的研究表明，由空腹钢龙骨包裹在纤维混凝土中的组合构件组成的结构体系具有很大的应用前景，特别是在抗震方面。在这种构件中，组合作用是通过混凝土和空腹钢龙骨之间的连锁作用实现的，没有剪力连接件，纤维混凝土的使用消除了对传统钢筋的需要，这是相当劳动密集型的。连接是通过从外围混凝土中伸出的钢板来实现的。因此，该系统既适用于现浇混凝土，也适用于预制混凝土。这项研究将首先测试一半到三分之一比例的梁柱试件在轴向荷载和反向循环弯曲组合作用下。试验结果将用于开发构件行为的分析模型。在这项工作之后，将对选定的主题结构进行分析研究。最后阶段将包括对从主题结构中提取的关键部件的测试和分析工作。重点将集中在研究梁柱连接的性能和制定连接细节的建议，以达到预期的性能。这是一个在民用基础设施系统(CIS)征集NSF 94-154的第1年计划下得到支持的项目。***

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. ***