AAC Takes Off in the Midwest
When it comes to concrete, Jon Edwards of St. Louis based Building Products Group favors a more sustainable choice – AAC – and plenty of his company's clients are taking his advice. "We concentrate on durable, energy efficient building envelopes using autoclaved aerated concrete - the Aercon AAC block and structural panels," he said. "We’re seeing it gain increasing acceptance, especially with some of the bigger firms. They understand it and know how and where to use it."
Autoclaved Aerated Concrete (AAC) is supplied as a precast building block or panel made from a blend of 70% sand (with a high quartzite/silica content), 15% cement, 15% lime. It can be used in loadbearing or non-loadbearing applications, inside or out. It's fire resistant, mold resistant, and offers more effective insulation than CMUs while also offering superior acoustic properties. Thanks to the aeratation that takes place during its manufacture, it weighs about 80 percent less than a similar sized concrete product, which makes it easier and quicker to work with on the jobsite… and it also requires less energy during transport. AAC is eligible for credits towards certification under LEED and other green building programs.
That's produced some important converts in the commercial building industry. "We’re working with a retail developer who is using AAC to get a 3-hour code firewall they needed, because they’re putting some buildings pretty close together," he noted, in describing a current project. "HOK speced us for a new University of Missouri Health Care tower, and we’re going into an adjoining wall and some interior walls of the hospital there," he added.
But Edwards is also seeing some interest on the residential front. "In conjunction with the city of St. Louis, we just developed and build a house on South Broadway that is constructed of AAC panels, as part of their affordable housing program." The two story home utilized 20 foot AAC structural wall panels, and everything was set in place by crane. "We had two stories of walls up in a day and a half, and this was the first time the contractor had done that," said Edwards. "He told us later that he could probably do the job in a day next time."
The house was enclosed within a week, and the finished structure featured a ground-source heat pump. "That winter, I monitored the energy usage there every day," said Edwards. "There was a really cold winter that year, with temperatures in the teens and lower, but the heating bills never amounted to over $70 per month for a 1,656 square foot two story home. The combination of the AAC construction with the ground source heat pump turned out to be as efficient as you could ask for," he concluded. "I was proud to be a part of this project."
Building Products Group supplies AAC and related materials to building firms throughout the midwest.
www.buildingproductsgroupllc.com • 314-610-0331
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