Copyright Goodheart-Willcox Co., Inc. Chapter 18 Concrete Flatwork and Formed Shapes 403 Tilt-up panels can be cast as individual panels or as larger slabs that are sawed into smaller panels after the concrete has been placed. Tilt-up panels have a grid of reinforcing steel embedded within the panel to provide the necessary strength. Standard Grade 40 or 60 bars are used. Plastic chairs are used Goodheart-Willcox Publisher Figure 18-48. Typical footing and foundation wall used in tilt-up construction. to support re-bars instead of steel chairs to avoid rust on the panel face. Concrete must meet all mix specifications for the application. Many panels are cast with a textured surface or pattern. The surface treatment must be planned carefully, but the results are impressive. Other finishes such as exposed aggregate, sandblasting, and brick or stone facings are commonly used with tilt-up panels to “dress up” the building. The erection process should be well-planned for efficiency and safety. Braces should be attached before the panels are lifted and not removed until the roof and decking are installed. See Figure 18-49. Installing braces once the panels are in the vertical position is difficult and dangerous. The result of a well-planned erection process is a spectacular finished structure. Tilt-up panels are set in place similar to erecting building blocks that were played with as children except on a larger scale. As panels are set, depending on the type, a certain amount of space is left between the panels for insulating and sealing. As panels are erected, they need to be braced similar to concrete block walls under construction. See Figure 18-50. Once wall panels are in place and braced, construction can begin on the roof. Goodheart-Willcox Publisher Figure 18-49. Proper bracing of tilt-up panels is important for both safety and efficient erection of the structure. The diagonal braces attached to the wall panels are not removed until the roof decking is installed to tie the structure together.