Self consolidating concrtete
The Eli & Edythe Broad Museum at Michigan State University, Columbia University Medical and Graduate Education Building, and the United States Mission to the United Nations (USUN) are good examples of the use of SCC in successful architectural concrete projects.
None of these projects had form pressure problems of significance that required concrete removal and replacement.
Before the start of each new project, the contractor and design team should conduct a pre-concrete construction meeting to review the proposed mix designs and to discuss the required methods and procedures to achieve the specified concrete construction.
The contractor should require responsible representatives from all stakeholders concerned with the concrete work to attend the conference, including but not limited to the following: The concrete contractor should state that the proposed mix designs will enable proper placement, pumping, and finishing, and will achieve the concrete quality required by the specifications.
Maximum rental space is the goal in many buildings.
Columns and walls are heavily reinforced and are as narrow as possible. Example projects include a 14,000 psi concrete at Tower One at the World Trade Center in New York City.
In heavily reinforced members, the design/contracting team often requires a target spread of 28 inches /-1 inch.
Setting times and spread targets are adjusted as necessary for the change of seasons.Almost all of New York City’s tall buildings are using 14,000 psi concrete in their vertical members at the lower floors. A lower spread could have resulted in a blockage, and that would have been disastrous.An 8000 psi SCC mix was pumped blindly into a heavily reinforced elevated slab under the active Number 1 subway line at the World Trade Center. The Port Authority made a video of the early placements so that the team could see the SCC mix move easily into place., has included guidance for determining form pressure.A high-range water reducer plus a hydration-control admixture may be used.A hydration-control admixture can extend proper plasticity for several hours.