Zero Void Monostrand System Stabilizes Modern Transportation Hub at Miami Airport
Located next to Miami International Airport (MIA), the Miami Intermodal Center (MIC) is a massive ground transportation hub that is currently being developed by the Florida Department of Transportation and scheduled for completion in spring 2010. The complex will provide connectivity to the airport for residents and visitors of Miami-Dade County and the South Florida region. In addition, the transportation hub was created to reduce congestion in the streets around the busy airport.
The first sub-project was the Rental Car Center (RCC), an approx. 315,870m² (3.4 Million ft²) large building that will provide customers arriving through Miami International Airport (MIA) convenient access to approximately 20 participating rental car companies.
The next sub-project will be the construction of Miami Central Station, a rail hub. An automated people mover between the MIC and MIA will also follow the completion of the RCC. The completed center is expected to serve approximately 150,000 commuters and travelers each day.
The MIC rental car facility is a 4 level beam/girder and slab parking structure. Each floor is approx. 16,190m² (174,240ft²) in size and was built in 2009 using the 0.5" Zero Void Unbonded Monostrand System. The fully encapsulated system provides excellent water tightness and corrosion protection.
The fixed ends were also encapsulated Zero Void anchorages. On the stressing end, only the tendon tail necessary for prestressing had to be removed once stressed, leaving no bare strand exposed inside the concrete.
Additionally, intermediate Zero Void Monostrand System couplers were used at construction joint locations where no deck was available to support the remaining length of the tendons for the next pour. The coupler system was installed as a temporary stressing end in the completed section. This anchorage has an exterior thread and can be capped and protected for a long period of time. Once it was time to construct the adjacent pour, a new tendon with an end consisting of a coupler sleeve with interior thread and integrated fixed anchorage was inserted at the “temporary” stressing end, creating a monolithic connection once the adjacent pours had been stressed.
Thanks to this solution, very long tendons could be manufactured in sections and did not have to be rolled up at the construction joints and temporarily stored. More importantly, this procedure also eliminated the need to build support platforms and allowed the contractor to reduce construction time by two months. In addition, the Zero Void Nail-Less Pocket Former made the use of nails for fastening the anchorage to the edge form unnecessary, which eliminated staining of the concrete surface and reduced installation cost and time.
The Zero Void Plasma Cutter was used to cut tendon tails after stressing. In contrast to an oxyacetylene torch, the Plasma Cutter only generates a minimal amount of heat during cutting and has no effect on strand and wedge material. The Plasma Cutter quickly cuts the tendon tails to a precise length so the grease caps can be easily installed. The lock-on grease cap allows a tighter connection with the anchorage and a better protection of the wedges.