Credit: Matt Melrose

Columbia University’s new Medical and Graduate Education building emphasizes the beauty and strength of concrete. The 15-story concrete building with embedded steel features an innovative post- tensioning system with a Cobiax voided slab system to lighten the loads. On a floor-by-floor basis, architecturally challenging elements within the lower floors caused average slab duration to be 13 days. Post-tensioning, double-story exposed concrete columns, and larger footprints contributed to this construction pace. On the upper floors, the pace increased to about seven days, despite the challenging formwork, heavy rebar, post-tensioning, and Cobiax. Superstructure concrete strengths using self-consolidating concrete were from 8,000 to 10,000 psi. The concrete was designed and provided by Jenna Concrete Corp. with admixtures from Euclid Chemical.

On a very congested and narrow site, crews had to work with limited staging areas for concrete trucks, pumps, rebar fabrication areas, formwork makeup, and debris removal. Doka USA provided the formwork solution on this project, which was awarded the top honor at the Concrete Industry Board of New York’s 53rd Annual Roger H. Corbetta Awards dinner. The project team includes Urban Foundations/Engineering for the foundations and DiFama Concrete for the superstructure.