Design and Analysis of Precast, Prestressed Concrete, Three­ - Wythe Sandwich Wall Panels

Abstract

Precast concrete, three-wythe sandwich wall panels were developed with potentially improved thermal and structural performance compared with that of traditional two-wythe panels. A three-wythe panel has three concrete wythes and two insulation layers. All three concrete wythes are connected by solid concrete regions, and the connections between successive concrete wythes are staggered in location so that no concrete path extends directly through the entire thickness of the panel. This paper describes the design and analysis of the three-wythe panels. A series of two- and three-wythe panels were designed, and examination of the resulting panels' behavior provides insight into the anticipated capabilities of the three-wythe panels. Finite element analyses were performed to anticipate the behavior of the three-wythe panel at both the transfer of prestressing force and under service loads. It was found that three-wythe panels can be designed using current design codes with special consideration of stresses that develop at the panel ends. A three-wythe panel can be treated as a composite panel and is suitable for longer spans compared with spans typical for a two-wythe panel. Transverse bending occurs in a three-wythe panel at the panel ends, and several approaches to reduce the transverse bending were introduced and evaluated, such as using partially debonded strands and shear connectors.