STRUCTURAL SELECTION COSTS AND SCHEDULING
The project's technical success and the spirited character of
its architectural interior demanded the use of reinforced structural concrete for these
reasons:
"Matching existing floor to floor heights" to the
adjacent 1932 building. These heights are as low as 11'-3" in the first three floors.
A reinforced concrete structural system was the only solution for matching these heights
while also satisfying the structure's many other complexities.
"Schedule and Budget" Architectural concrete's ability
to provide a fire-proof, permanent finish structural system offset a host of costs
associated with steel: fire-proofing, column covers and finished ceilings. While a steel
system required four months' lead time, the concrete superstructure was under construction
immediately after foundations were placed. The project was completed on time despite
inclement weather.
With this size of building, 3 or 4 concrete pours occurred
simultaneously while reinforcing or forms setting occurred in other areas.
STRUCTURAL INTEGRATION
Structurally, the engineers and architects teamed
together to maximize the economy and design characteristics for this cast-in-place
reinforced concrete structure.
The structural frame is a wide-module, one-way joist
system using 21" and 30" deep pans with a 4-1/2" slab and typical spans of
35'-0. The space between the joists houses the heat pumps and conduits for the HVAC
system. The system provided great flexibility for coring floor openings between joists to
integrate the HVAC requirements and other field changes during construction.
Exposed concrete was also used as an integral part of the following
architectural elements: interior finish for floors, columns, stairs and ceilings, exterior
cornice details and walls. In addition, concrete met all required fire ratings without
additional treatment or cost.
