Development of Novel Connections for Pre-cast Composite and Pre-cast Concrete Frames

Abstract

In some applications, the conventional steel pipe racks were encased with concrete to protect the frame from fire. However, the concrete encasing steel is not considered to contribute to structural capacity at all. This paper proposed pipe rack frames encased by precast concrete, but with functions both as a part of structural elements contributing to flexural load bearing capacity and to fire proofing. The new steel-concrete composite structural system consisting of steel, concrete with reinforcements, extended steel plates with bolts designed based on inelastic finite element method provides efficient structural performances, reducing material quantities with the protection from fires. Additionally extended plate with bolts introduced for column-beam joint assembly played important roles in providing moment connections. AISC 358 introduced the use of extended plate similar to the proposed connection. Significant experimental and analytical investigations were performed to verify structural behaviour of the composite frame. Material quantities were also compared to demonstrate economy of the new frames compared with conventional pipe rack frames.