Design and Construction of Post-Tensioned Sport Courts
|Publication Date:||1 January 2006|
A post-tensioned concrete court should be considered a "slab" rather than a "foundation." In other words, it is not intended to minimize deflections to protect a supported structure. ACI 318-052 does not cover the design of soil supported slabs. Values for allowable stresses and spacing of tendons are based on successful performance of post-tensioned concrete courts and are not to be compared to ACI 318 criteria. The use of a post-tensioned uniform thickness slab designed with the methods discussed in this document will not completely mitigate the effects of highly expansive or compressible soils. The use of a post-tensioned slab as described herein will minimize the effects of minor sub-grade defects, i.e. small voids can be spanned to a greater extent than with other types of courts, but it is not intended to be a slab that is stiffened to the point of completely resisting the movements of expansive or compressible soils.
If a stiffened slab, designed to mitigate significant soil movement, is desired, the designer should refer to the Post-Tensioning Institute's Design of Post-Tensioned Slabs-On-Ground3. A designer should, however, consider the additional costs that will be involved in constructing a stiffened slab and should carefully analyze any perceived benefits. Tor example, it may not be worth doubling the volume of concrete in a court just to limit deflections that will most likely not be noticed during normal use.
The intent of this document is to provide guidance for the design and construction of various types of post-tensioned sport courts. The geometry of a slab, and the various elements that can restrain a slab and prevent it from shortening under a preslressing force, play a critical role in the successful construction of post-tensioned sport courts. The possible configurations are too numerous to address on an individual basis. However, sound engineering judgment and experience should be used in conjunction with these guidelines.