320 North Sangamon

13-STORY OFFICE BUILDING

Chicago, Illinois

Identifying the need for more office space in Chicago’s once industrial Fulton Market neighborhood, developers Tishman Speyer and Mark Goodman & Associates partnered to redevelop a former propane fueling and tank exchange station into an amenity-packed, 13-story office building.

Tribco Construction Services, a wholly owned subsidiary of Ceco Concrete, provided the full concrete frame plus the tower crane. The structural design originally called for a band beam and one-way post-tensioned (PT) slab system. The structural engineer worked with Tribco to provide a less costly solution that was a better fit for the building’s loft-style floor plans with widely spaced columns: a band beam and two-way PT system.

The band beams and slab on each floor required a significant amount of concrete, which made placing a complete floor in one pour extensive and costly. Single-floor pours would also stall the formwork, as crews would have to stop and wait between installing deck formwork and stripping decks. Therefore, slabs were installed in two pours. To keep deck formwork moving at an even, consistent pace, the Tribco team would first frame the south half of a slab and install rebar and PT. As the south half of the slab was being poured, the crew finished forming the north half of the deck.

Formwork systems included Tribco panelized beam bottoms and slabs on Tribco-owned CEFCO towers. Once the Tribco team moved to Level 4, they switched to Tribco HV formwork to form slabs north of the core to further expedite the process.

The project remained on schedule prior to the COVID-19 pandemic taking hold in March 2020. As socially distanced work crews became a necessity on project sites, the pace of work was forced to slow. Regardless, Tribco was able to top out August 2020.

Project Documents

Project Sheet