ACI 533.1R-20 Guide for Design and Construction Responsibilities for Architectural Precast Concrete.
3.2.1 Instructions to precast specialty structural engi- neer—The architect or structural engineer of record may specify in the contract documents that a portion of the design is supplied by the precaster. Typically, design services are performed for the precaster by a licensed specialty struc- tural engineer, who can be an employee of the precaster or be an independent specialty structural engineer or specialty structural engineer frm. The contract documents should clearly defne the scope of the architectural precast concrete design requirements and submittal review responsibilities, as well as the responsibilities of other parties providing design services. 3.2.2 Contract drawings—The contract drawings prepared by the architect and structural engineer of record should detail desired aesthetic, functional, and structural require- ments. Provide the overall geometry and dimensions of the structure, member or unit dimensions and cross sections, typical connection locations and details, and concepts so that all precasters are estimating and bidding based on the same information. The architect’s drawings may only show reveals or design articulation, allowing the precaster to determine panel sizes suitable to their handling and erection capabili- ties. In the prebid process, the precaster and erector should discuss their approach to panelization and subsequently how to connect the units to the building frame within the archi- tectural and structural concepts of the project. In addition, the structural drawings prepared by the structural engineer of record should provide the general performance criteria, design loads, concrete strength requirements, defection requirements, temperature considerations, and any tolerance or clearance requirements for proper interfacing with other elements of the structure.
3.2.3 Precast drawing review—The architect should review precast shop drawings for conformance to the contract drawings. The structural engineer of record should review designs, calculations, and shop drawings submitted by the precaster for conformance with design criteria, loading requirements, connection points, and design concepts as specifed in the contract documents. This review, however, does not relieve the precaster and the precast concrete engi- neer of their design responsibilities. 3.2.4 Architectural mockup samples—Architectural precast concrete approval typically includes producing mockups to show the completed façade, feld-construction techniques, and material interface issues. If the units have returns, the same-size return should appear in the mockup panels. The architect establishes the criteria of acceptability for surface fnish, color range, and remedial procedures for production and construction blemishes and damage. This can be best accomplished by the precaster producing at least three sample panels 15 to 20 ft 2 (1.4 to 1.9 m 2 ) each, before the initial production to establish the range of accept- ability with respect to color and texture variations, surface blemishes, and overall appearance. In addition, the architect should visit the precaster’s plant early in production to eval- uate conformance with approved samples.ACI 533.1R pdf download.