Cut some windows, install some floors, and you're well on your way to converting 36 retired silos into a 200-room luxury hotel. That's what happened in the center of Akron, Ohio. The overall architectural approach was to produce a contemporary building by retaining the round shapes, cutting openings for windows and curved balconies, and leaving visible the aggregate exposed by sawing. The architects concluded that it was best to use diamond-tipped saws to cut through the 7-inch concrete containing horizontal and vertical steel and thereby achieve the clean, finished cuts they wanted. The silos had been built by slipforming in 1932 and they were still structurally sound with no spalling or cracking. Strength of the concrete as determined by hammer, probe and core tests, averaged 6250 psi. The thick walls offered energy-saving heating and cooling advantages.
Before any interior construction could begin, large openings had to be cut in the rounded exterior walls for doors and windows. The curvature of each silo required that precise cuts be made so as not to damage the building. Thousands of feet had to be cut. Water-cooled high-cycle wall saws with 24-inch diamond-edged blades did the bulk of the work but 30-inch and occasionally 42-inch blades were used on difficult spots where cutting was on the radius. For most of the project, sawing was done from the interior on scaffolding. Workmen had to take care of jack rods that had been embedded in the concrete during slipform construction. To keep these from dropping and shattering the equipment, the workmen first drilled holes in the walls and used an anchoring device to pin the jack rods in place.