The thought of precast concrete as a foundation material for major sports facilities was--until recently--an idea that did not enter the minds of most designers. Precast concrete was usually ruled out due to the perception that it could not provide the structural integrity necessary for a large structure in which seismic considerations were important. However, recent technological innovations, such as mechanical rebar splicing systems, have addressed the issue of continuity and in many cases provided designers with a low-cost, structurally sound alternative.
The Olympic Stadium in Atlanta uses precast concrete elements in structural applications as well as in traditional applications such as seating and vomitory walls. The selection of a rebar splicing system was an important decision that affected the appearance, installed cost, and maintenance requirements of the facility. The system consists of a tapered-thread coupler and high-strength grout. The splice is completed on-site by inserting the exposed dowel of the adjoining structural member into the sleeve and filling the coupler cavity with grout.