New research is offering insight into how climate change could adversely affect concrete structures. A team from Northeastern University in Boston, led by civil engineer Matthew Eckelman and graduate student Mithun Saha, found concrete buildings could face structural deterioration much sooner than anticipated, due to environmental changes. Their work was published in the September 2014 issue of Urban Climate.
Kevin Hartnett wrote about the findings for the Boston Globe.
... findings, published in September in the journal Urban Climate, suggest that both [Boston] and many [other cities] are likely to face huge repair bills long before anyone anticipated. “Starting in 2025 is when [we expect] to see the concrete cover on buildings start to fail, assuming they were built to code,” Eckelman says. With accelerated warming added to existing rates of decay, they predict that 60 percent of Boston’s concrete buildings will face structural deterioration by 2050 ... Eckelman and Saha’s study focuses on two processes that slowly eat away at concrete: carbonation, in which carbon dioxide diffuses into concrete, and chlorination, in which chloride ions, dissolved in water, are absorbed into concrete (especially a problem near the ocean, where chloride-rich salt spray coats buildings). Eventually the carbon dioxide or chlorides reach the rebar inside, causing it to corrode and expand. The process is largely invisible until a building’s façade cracks or chunks of concrete fall from a highway overpass.
This isn't the first research on the impact of climate change on concrete, and while not everyone agrees on the level of urgency, the new findings lend more credence to calls to update some building codes. Increasing the thickness of concrete could offset some of the affects of climate change, and the American Concrete Institute, is currently reviewing standards for concrete thickness in light of global warming. And other researchers, including Nemkumar Banthia, an engineer at the University of British Columbia and an ACI committee chair, are exploring other options. Read More