In 2014, the Glenstone Museum embarked on a major expansion project, adding a 204,000 ft2 building to its already spacious campus. The designers wanted materials of the new structure to evoke a direct connection with the surrounding landscape, while providing a lasting structure that reflects the modern art within the museum, says Travis Fox, vice president of operations for Gate Precast. “Precast concrete block was chosen for its durability and the natural variations and beauty exhibited in each specific panel.”
The new structure appears to emerge from the hilly landscape and features a ring of gallery rooms surrounding a large, central water court. The exterior of each room is made of stacked blocks of precast concrete, individually poured to measure 6 ft long, 1 ft high, and 1 ft deep. No color-altering pigment was used in the design, Fox notes. Instead, the pouring method and mixture of cement and sand were chosen to produce slight variations in the light-gray color and texture, creating a beautiful, naturalistic design. This finish deliberately contrasts with the smooth precision of the windows, which have been specially engineered using glass panels that are set flush into stainless steel mullions.
The biggest challenges on the project were related to the size, quantity, and delicacy of the individual panels. Because the structure features an as-cast form finish, there could be no imperfections, says Chris Cruze, project manager for Gate Precast. Form parts were made of double-layered, 1-in.-thick plywood and were slightly undersized to allow room for adjustability, fiberglass resin, and surrounding foam weather stripping. The mold faces were closely monitored throughout production and replaced as soon as any bowing or excessive wear of the buildup was noted.
Gate’s team was also highly cognizant that panels might be damaged if blocks moved during shipping. To protect the panel edges and prevent breaking, the plant team devised a pallet system whereby exterior blocks, which weighed up to 900 pounds each, were individually placed on their own shoring to raise them off the 53-ft-long trailer’s surface. Layers of pressure-treated shoring were attached between stacked blocks to prevent sliding, and then each block was secured with ratchet straps. The interior pieces, weighing up to 300 pounds each, were also all custom stacked and arranged on pallets. To further minimize the risk of having to replace a damaged piece, Gate’s team developed a technique to reface any piece in the project. “Close coordination between the erector, project manager, and shipping supervisors enabled the yarding crew to stay ahead by loading the most-needed blocks in sequence so they would be available to meet erection schedules,” Cruze says.
Organizing the panels was also a constant challenge. Of the 23,000 panels, 1400 pieces had unique markings, which required considerable coordination in detailing, production, tracking, delivery, and installation.
The result is a beautiful, modern structure that is a unique example of the function and attractiveness of precast concrete. “Aesthetics were the primary objective of the architect as it related to precast concrete because the owners wanted to build something lasting and of enduring value,” Cruze says. Through careful coordination and planning, this precast concrete design fit the bill.