Concrete - Encased Steel Joist Composite Structures for Seismic Resistance

该项目的主要目标是开发一种创新的复合结构系统，利用先进的纤维增强混凝土材料包裹开腹板钢托梁，以提高经济和抗震性能。分析和实际设计程序将制定。人们普遍认识到，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系统抵抗地震力。最近的研究表明，由纤维钢筋混凝土包裹的开腹板钢托梁组成的组合构件结构体系具有很大的前景，特别是在抗震方面。在这种构件中，复合作用是通过混凝土和开口腹板钢托梁之间的联锁作用来实现的，而不需要剪切连接件，纤维增强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。连接是通过从周围的混凝土中伸出的钢板来实现的。因此，该系统既适用于现浇，也适用于预制混凝土。本研究将从半至三分之一比例的梁柱试件在轴向联合荷载和反向循环弯曲作用下的试验开始。测试结果将用于开发构件行为的分析模型。这项工作之后，将对选定的主题结构进行分析研究。最后一个阶段将包括对取自主题结构的关键子组合的测试和分析工作。重点将放在梁柱连接行为的研究上，并为连接细节提出建议，以实现预期的性能。这是一个由土木基础设施系统（CIS）招标NSF 94-154的第一年项目支持的项目。＊＊＊

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. ***