Design Recommendations for Precast Concrete Structures

Reported by ACI-ASCE Committee 550. © 2001, American Concrete Institute.

In design of precast members and connections, all loading and restraint conditions from casting to end use of the structure should be considered. The stresses developed in precast elements during the period from casting to final connection may be more critical than the service load stresses. Special attention should be given to the methods of stripping, storing, transporting, and erecting precast elements.

When precast members are incorporated into a structural system, the forces and deformations occurring in and adjacent to connections (in adjoining members and in the entire structure) should be considered. The structural behavior of precast elements may differ substantially from that of similar members that are monolithically cast in place. Design of connections to transmit forces due to shrinkage, creep, temperature change, elastic deformation, wind forces, and earthquake forces require special attention. Details of such connections are especially important to insure adequate performance of precast structures.

Precast members and connections should be designed to meet tolerance requirements. The behavior of precast members and connections is sensitive to tolerances. Design should provide for the effects of adverse combinations of fabrication and erection tolerances. Tolerance requirements should be listed on contract documents, and may be specified by reference to accepted standards.

The shop drawings should show, as a minimum, all details of the precast concrete members and embedded items. The contract documents may specify that portions of connections exterior to the member are also to be shown on the shop drawings. The contract documents may also require the contractor to provide designs for the members and/or connections. The contract documents should show the loads to be considered in design of the precast concrete elements of the structure, and they should indicate any special requirements or functions (for example: seismic loads, allowance for movements, etc.) that should be considered in design assigned to the contractor. In this case, the shop drawings should include complete details of the connections involved.

Recommended references

American Welding Society

American Concrete Institute

Cited references

Jones, H.I., and Boaz, I.B., “Skewed, Discretely Connected Multibeam Bridges,” Journal of Structural Engineering, ASCE, V. 112, No. 2, 1986, pp. 257-272.

PCI Design Handbook-Precast Prestressed Concrete, 4^th Edition, MNL-120-92, Prestressed Concrete Institute, Chicago, 1992, 580 pp.

PCI Manual for the Design of Hollow Core Slabs, MNL 126-85, Prestressed Concrete Institute, Chicago, 1985, 120 pp.

Speyer, Irwin J. (for PCI Committee on Precast Concrete Bearing Wall Buildings), “Considerations for the Design of Precast Concrete Bearing Wall Buildings to Withstand Abnormal Loads,” PCI Journal, V. 21, No. 2, Mar.-Apr. 1976, pp. 18-51.

Design of Concrete Structures for Buildings, Canadian Standard Association, Ontario, Canada, 1984, 281 pp.

Salmons, J.R., “Bond Characteristics in Untensioned Prestressing Strand,” PCI Journal, V. 22, No. 1, Jan.-Feb. 1977, pp. 52-65.

PCI Manual on Design and Typical Details of Connections for Precast and Prestressed Concrete, 2^nd Edition, MNL-123-88, Prestressed Concrete Institute, Chicago, 1988, 270 pp.

PCI Committee on Quality Control Performance Criteria, “Fabrication and Shipment Cracks in Precast or Prestressed Beams and Columns,” PCI Journal, V. 30, No. 3, May-June 1985, pp. 24-29.

PCI Committee on Quality Control Performance Criteria, “Fabrication and Shipment Cracks in Prestressed Hollow-Core Slabs and Double Tees,” PCI Journal, V. 28, No. 1, Jan.-Feb. 1983, pp. 18-39.

Martin, L.D., and Korkosz, W.J., “Connections for Precast Prestressed Concrete Buildings-Including Earthquake Resistance,” Technical Report No. 2, Prestressed Concrete Institute, Chicago, 1982, 297 pp.

Manual for Quality Control for Plants and Production of Architectural Precast Concrete, MNL-117-77, Prestressed Concrete Institute, Chicago, 1977, 226 pp.

Manual for Quality Control for Plants and Production of Precast Prestressed Concrete Products, MNL-116-85, Prestressed Concrete Institute, Chicago, 1985, 123 pp.

PCI Committee on Tolerances, “Tolerances for Precast and Prestressed Concrete,” PCI Journal, V. 30, No. 1, Jan.- Feb. 1985, pp. 26-112.

Johnson, T., and Ghadiali, Z., “Load Distribution Test on Precast Hollow-Core Slab Construction with Openings,” PCI Journal, V. 17, No. 5, Sept.-Oct. 1972, pp. 9-19.

Lague, D. J., “Load Distribution Tests on Precast Prestressed Hollow-Core Slab Construction,” PCI Journal, V. 16, No. 6, Nov.-Dec. 1971, pp. 10-18.

Pfeifer, D. W., and Nelson, T. A., “Tests to Determine the Lateral Load Distribution of Vertical Loads in a Long-Span Hollow-Core Floor Assembly,” PCI Journal, V. 28, No. 6, Nov.-Dec. 1983, pp. 42-57.

Stanton, John F., “Proposed Rules for Load Distribution in Precast Concrete Decks,” ACI Structural Journal, V. 84, No. 5, Sept.-Oct. 1987, pp. 371-382.

Spindel, J. E., “Study of Bridge Slabs Having No Transverse Stiffness,” PhD thesis, London University, 1961.

Buettner, D., and Becker, R. J., “Concentrated Loads on Spancrete Assemblies,” Computerized Structural Design, Final Report to the Spancrete Manufacturers’ Association, Milwaukee, 1980, 10 pp.

Venkataswartu, B.; Shanmugasundaram, J.; and Shanmugam, V., “Roof and Floor Slabs Associated with Precast Concrete Cored Units,” ACI JOURNAL, Proceedings V. 79, No. 2, Jan.-Feb. 1982, pp. 50-55.