Pyrrhotite Foundations
PYRRHOTITE FOUNDATION FAQs WHAT IS PYRROTITE? Expand As the name suggests, Pyrrhotite (/ˈpirəˌtīt/) is a naturally occurring iron sulfide (Fe1-xS). According to the Geological Society of America, “rock aggregate in the failing concrete foundations was largely mined from a single quarry, working a stratified metamorphic unit in eastern CT mapped as Ordovician Brimfield Schist. The gray, rusty brown to orange yellow weathering rock, is a medium to coarse grained, interlayered schist and gneiss, composed of oligioclase, quartz, K-feldspar, biotite and commonly garnet, sillimanite, graphite, and pyrrhotite.” WHAT IS A CRUMBLING FOUNDATION OR CRUMBLING BASEMENT? Expand “Crumbling Foundation” and “crumbling basement” are terms commonly used to describe concrete foundations that have begun to deteriorate because of the presence of pyrrhotite aggregate. Aggregate is composed of mineral crystals of one or more kinds or of mineral rock fragments. Concrete is made by mixing Portland cement with aggregate, including small rocks and sand. According to Trinity geologist Dr. Jonathan Gourley, in the presence of moisture/air and calcium, the sulphur in the pyrrhotite reacts and transforms to several secondary minerals, and associated changes in volume lead to a loss of structural integrity. While current science is unable to predict whether any given concrete foundation …