Expansion of the landmark 1917 Kelly Springfield Building preserved the façade and some interior elements while incorporating materials and architectural features that accentuate the area’s historic auto row vernacular. In collaboration with the design team, we developed an alternative design option based on research compiled from multiple national and international sources.
Because of the landmark status of the framing, conventional methods of reinforcing the beams were not possible. Our team explored the notion of combining concrete topping in conjunction with the existing wood beams using mechanical connectors. This Timber Concrete Composite (TCC) method is used in Europe and in other international countries but is not addressed in US building codes.
Pursuing an alternate means and methods process with SDCI for approval, the team avoided expensive in-situ full scale testing by extracting university-level composite fastener testing research and guidance from the European building code. The project was successfully granted a code alternate variance to replace the ceiling with repurposed heavy timber attached to a concrete structure above for structural integrity.
The timber framing was disassembled and shipped offsite for restorative work. After new building levels were installed, the timber was reinstalled piece by piece in the first floor ceiling. We worked closely with the contractor for the proper installation of the composite fasteners, given realistic construction tolerances and limitations.
This hybrid timber-concrete composite solution was an exceptional way to repurpose heavy timbers for large loads and was one of the first North American projects to use the TCC system.
