GUIDE SPECIFICATION FOR ARCHITECTURAL PRECAST CONCRETE
This document provides a basis for specifying in-plant fabrication including product design not shown on contract documents, and field erection of architectural precast concrete. It does not include structural precast concrete, coatings, or sealing the joints between units.
DRAWINGS AND SPECIFICATIONS
The Architect’s or Engineer’s drawings should show panel locations and necessary sections and dimensions to define the size and shape of the architectural precast concrete units, indicate location and size of reveals, bullnoses and joints (both functional and aesthetic) and illustrate details between panels and adjacent materials. When more than one type of panel material or finish is used, indicate the extent and location of each type on the drawings. The location and details of applied and embedded items should be shown on the drawings. Plans should clearly differentiate between architectural and structural precast concrete if both are on the same project. Illustrate the details of corners of the structure and interfacing with other materials. Identify the requirements for design and design loads, and indicate load support points and space allowed for connections. The Engineer of Record needs to be aware of the magnitude and direction of all anticipated loads to be transferred to the building structural framing and their point of application. These loads should be addressed in the bid documents. It is especially critical that the Engineer of Record provide stiffeners and bracing that are required to transfer precast loads to the structural frame.
Describe the type and quality of the materials incorporated into the units, the design strength of the concrete, the mix and finishes and the tolerances for fabrication and erection. In the event of a performance specification appropriate data should be included for the precaster to assess the scope and quality of the precast units to be fabricated.
Specifiers should consider permitting variations in production, structural design, materials, connection and erection techniques to accommodate varying plant practices. Specifying the results desired without specifically defining manufacturing procedures will ensure the best competitive bidding. Required submittals should also include range-bracketing samples for color and texture.