When the Joseph Corp., Aurora, Ill.—a nonprofit organization that helps people with limited means find housing—was demolishing some homes that were too run down, it was suggested that they build a concrete home.

Brian Bock, vice president for Dukane Precast, working with the American Red Cross and the Portland Cement Association (PCA), persuaded the Joseph Corp. to build a concrete home using Dukane's precast double-wall panel system at one of the sites. Together they enlisted an army of volunteers and organizations to help with the project.

Panel exterior faces were cast with brick-patterned formliners. Photo: Dukane Precast

The organizations involved include the PCA, the American Red Cross of Greater Chicago, the Illinois Emergency Management Agency (IEMA), The Pre-cast/Prestressed Concrete Institute (PCI), the Institute for Business and Home Safety (IBHS), and the construction vocational trade programs of three high schools in the area. The Red Cross and IEMA are involved through their “Safe Home Illinois” initiative. The IBHS is involved through its “Fortified...for safer living” program.

Together, their goal was to build a reasonably priced 1500-square-foot home that would keep its new owners safe in the event of a natural disaster, significantly reduce heating and cooling bills, ensure low maintenance cost, and be fire resistant.

Life safety issues focus on construction methods and materials that will prevent the collapse of a building in the event of a disaster.

The fundamental concept of sustainability is simple: to use products made with recycled materials, and build structures with long-service lives that also can withstand disasters.

Energy-efficiency goals are achieved when there are few air leaks in a building envelope and when insulation with high R-values is installed. Sometimes the ability of a structure to store energy in its thermal mass, which concrete does well, and to release it at times when it is needed, can reduce energy bills.

Bock says this house was originally going to be a wood-frame house. For the student's educational and training purposes, it was decided to keep the breezeway and the garage as wood-frame structures with brick as the finished surface. To more easily achieve the fortified designation and provide an energy-efficient sustainable home, Dukane decided to make their precast concrete double-wall panels with a brick formliner pattern the same size as the bricks.

The house has cast-in-place footings and foundation walls except for one wall. “We left the foundation wall out for the area closest to the street for crane access to the back of the house,” says Bock. “Afterward, we installed a precast foundation wall and then placed the first story wall on top of that.”

The 6000 psi precast panels are made with 38% recycled material including fly ash, ground granulated blast furnace slag (GGBFS), and expanded slag lightweight aggregate. The lightweight aggregate is trucked dry to reduce transportation costs and then saturated with water in a vacuum saturation tank just before it is used. A typical wall panel is 8 inches thick consisting of two concrete panels joined together by a wire truss. Each concrete panel is 2½ inches thick with the 3-inch section in the center used for insulation, rough electrical, and plumbing. Bock says they use a biobased foam insulation product made from soybean and castor oil that provides R-7 insulation per inch of foam or R-21 for the panel. Though they still place steel rebar in the panels, Dukane also uses prestressing strands set every 2 feet.