ACI 551.1R

Abstract

<strong>Introduction</strong> <br>According to ACI 116R, "Tilt-up construction is a technique for casting concrete elements in a horizontal position at the jobsite and tilting them to their final position in the structure," while ACI 318 and IBC 2000 establish "a structural concrete element cast elsewhere than its final position in the structure." ACI 318 further states that tilt-up concrete construction is a form of precast concrete. Several features make the tilt-up construction method unique. Tilt-up panels are generally handled only once. They are lifted or tilted from the casting slab and erected in their final position in one, continuous operation. Tilt-up panels are generally of such large size and weight that they can only be constructed on site and in close proximity to their final location in the structure. Panel gravity loads are supported directly by the foundation instead of being supported by a structural frame. Typically, tilt-up panels are erected before the structural frame. Tilt-up panels are usually load-bearing for gravity loads and lateral loads. In fact, a whole industry developed around the tilt-up construction method. Tilt-up concrete construction is a unique form of site-cast precast construction and, as such, has its own specialized set of design parameters and construction techniques. <br>This guide is not all-inclusive; it presents basic concepts, techniques, and procedures involved in tilt-up construction. The design of tilt-up wall panels is not addressed in this guide, although it is stressed that both designers and contractors can benefit from the contents. This guide includes a brief history of tilt-up concrete and a discussion of planning; foundation and floor slab construction; and wall panel forming, casting, and erection. It briefly describes typical connections used to attach the panels to the rest of the structure, and options for panel finishes are briefly described.