'Virtually indestructible': Utah architect applies thin-shell dome concept for safer schools
At $94 a square foot and "virtually indestructible," some school districts in Utah are opting to build concrete dome schools in lieu of traditional structures.
In the wake of natural disasters and school shooting incidents, education professionals across the country are looking for innovative ways to better protect children while they learn. A new building approach from Salt Lake City, Utah-based Leland A. Gray Architects is designed to contribute to that goal.
The domed building, which the architect calls "virtually indestructible," uses an air-formed thin-shell concrete dome, along with a concrete stem wall. The system was created for assembly buildings such as schools, churches, and arenas, but some school disctricts are finding that it works well for K-12 school buildings, as well.
To build one of these structures, the roofing membrane is formed into a dome shape with a 31-ounce PVC material. A concrete ring on the stem wall is attached to an air form, and the membrane is inflated by air pressure to the size of the dome. Then, the underside of the membrane is sprayed with a urethane insulation to a depth of 3 inches over the entire surface of the membrane.
Steel reinforcing bars are then placed in an interlocking pattern across the dome's underside. Finally, according to Leland Gray's website: "The reinforcing steel is built up to 4 feet high around the base of the dome and sprayed with shot-crete. This process continues in 4-foot-wide bands from the base to the top of the dome. The concrete will be 8 to 10 inches thick at the base, tapering to 3 to 4 inches thick at the top."
Schools like this have already been built in Utah and in other places across the country, in part, because they are relatively inexpensive to build and they can save school districts money in utilities.
According to KSL, which did a story on dome schools in Locust Grove, Utah, "both the elementary and the high school in Locust Grove cost $94 a square foot to build. That's a deal, considering the price for school construction in the U.S. ranges from $150-$250 a square foot." In addition, the superintendent of the district told reporters that these buildings cut utility costs by 40%.
Read the full KSL story here.
Check out the video below to see what goes into a concrete thinshell dome, and what one looks like from the inside.