UConn Engineers Seek to Validate Methods of Testing Pyrrhotite in Concrete

Distribution of concrete (Getty Images)
Distribution of concrete (Getty Images)

UConn is using its research and engineering acumen to create a method by which experts can determine the most accurate tests to measure pyrrhotite levels in concrete samples.

Pyrrhotite, a mineral that reacts when exposed to oxygen and water, is at least one of the factors causing a problem in which homeowners in about two dozen Connecticut municipalities have experienced cracking and crumbling in their concrete foundations.

UConn’s School of Engineering has been involved with the issue since 2015, conducting a study at the request of the Connecticut Attorney General’s Office to determine potential causes of the concrete problems that have plagued scores of homeowners.

That study determined pyrrhotite in the concrete and possibly other factors were at fault. Officials also found that the concrete company that poured the foundations used a specific quarry, which was later determined to be in a vein of rock containing significant amounts of pyrrhotite.

UConn announced this week that it is using its internal resources to fund a project in which the School of Engineering will review and validate methods to measure the amount of pyrrhotite in samples, with the intention of providing a rigorous technical framework by which standardized testing can be conducted.

While the research will not provide a rating system to determine a foundation’s potential for failure, it will provide a uniform test method that can be used when a rating system is developed in the future.

No state funds or insurance proceeds earmarked for homeowner remediation will be used in UConn’s work on validating the testing methods, which is expected to take about a year to complete.

The work will be complex, involving chemical and physical processes that depend on numerous parameters that are specific to each site. The researchers will also be in contact with others from Trinity College in Hartford and others.

Once the study is completed, UConn will share the results with key state stakeholders who can then take any necessary steps to:

  • Establish a standard methodology for quantifying the amount of iron sulfide in foundation materials;
  • Establish a standard methodology to assess the minimum amount of pyrrhotite that causes deterioration under certain conditions of porosity, water, and concrete strength;
  • Develop a rating system for homeowners and insurance companies to determine a foundation’s potential for failure;
  • Estimate the number of Connecticut homes impacted; and,
  • Develop an economic impact analysis of the problem to the entire state.