What is a sandwich panel and why would you want your building’s panels to be sandwich?
A regular concrete panel in the walls of a tilt-up building consists of essentially nothing but concrete and rebar. Meanwhile, a sandwich panel is a panel that has concrete on both the inner and outer layers of the panel. Sandwiched between the inner and outer layers of concrete is foam insulation. This foam insulates the building and protects the interior of the building from extreme temperatures.
How is the foam placed in the concrete panels?
While pouring a regular concrete panel, the entire form is filled with concrete and structural rebar and completed in one pour. In sandwich panels, you separate it into two pours. On the first pour, foam is placed on top of the concrete and connected in with HK ties. These ties make the foam become part of the concrete. Then, on the second pour, concrete is poured over the foam. Once the concrete is dry, the panel now has a foam section in the middle creating a panel that is engineered to be more energy efficient and structurally sound.