Precast concrete sandwich wall panels are commonly constructed of two wythes of concrete separated by a layer of thermal insulation. In these two-wythe panels, solid concrete regions which extend directly through the entire thickness of the panel are often provided with embedded hardware for lifting, handling, and connections, or to provide composite action. These solid concrete regions have a significant adverse impact on the thermal performance of the panels. This research was directed towards the development of precast concrete three-wythe sandwich wall panels with improved thermal and structural performance. A three-wythe panel has three concrete wythes and two insulation layers, and all three concrete wythes are connected by solid concrete regions that are staggered in location so that no concrete path extends directly through the entire thickness of the panel. Practical panel configurations of three-wythe panels were developed, and their thermal performance was evaluated by estimating thermal resistance (R-value) using finite element method.
