Illinois town replaces deteriorated redwood structure with precast concrete building
Buildings often are looked at for what they contain, not for what they are. In March 2016, a precast concrete Easi-Span building accomplished an unusual feat—it became a spray aerator for the residents of Carpentersville, Ill. This new system replaced one that was constructed in the 1960s and improved over the years but had reached the end of its useful life. Carpentersville’s water treatment system consists of aeration, filtration, ion exchange softening, chlorination and fluoridation.
The original aerator sat on top of a detention tank, and the new aerator had to be in the same location. The 20-ft-by-20-ft-by-8-ft Easi-Span building was placed on top of the existing concrete foundation, approximately 20 ft tall. The contractor’s crew accomplished the installation in just one day. McCann Concrete Products—a Dorsey, Ill., licensed Easi-Set building producer—worked with project engineer Baxter & Woodman Inc. of Crystal Lake, Ill., and general contractor Boller Construction of Waukegan, Ill.
“The upgraded aerator has two parts—the internal items that distribute the water so it can absorb oxygen from the air, and the exterior structure that enclose internal items and protect the sanitary condition of the water inside,” said Harry D. Harman P.E., senior project manager with Baxter & Woodman. “So the Easi-Span Building does not just enclose or house the aerator; it is an integral part.
“The existing aerator was installed in the 1960s and could no longer be maintained. Also, the aerator did not have the capacity to meet the needs of the village. Spray aerators for iron removal are a relatively easy design but not commonly thought of first by most engineers. The design criteria of common aerators are complicated. The design criteria for a spray aerator is simple, lower profile and easy to control.”
The previous aerator was constructed of redwood with metal siding. Although the siding lasted, the interior redwood structure had begun to deteriorate. The village wanted a replacement structure that was strong and long lasting. A precast concrete building provided the right characteristics—a long lifespan, low maintenance, appealing appearance, cost competitiveness and ease of installation.
Easi-Span is a large clear-span all-precast concrete building system. The building has a simple broom finish texture on the exterior with a white concrete stain to match existing buildings onsite. The roof consists of two Easi-Span building roof panels. Customization is an option for every Easi-Set building, and this one required specific features. The structure was fitted with 12 24-in.-by-12-in. air exhaust openings, four 24-in.-by-24-in. air inlet openings and one 24-in.-by-36-in. steel entry hatch. McCann also was able to cast an exterior flashing reglet in the lower wall section, saving the contractor significant time and labor.
“The project required locating and casting precise openings for existing equipment that remained in place during installation,” said Chris Reese, an engineering manager for Easi-Set Buildings. “The south wall panel had to set around an existing 20-in. aerator inlet.”
Now that this upgraded system includes a long-lasting building, the village can continue to supply quality water to its residents for years to come.