In New England in the United States, homes are crumbling from pyrrhotite. Nearly twenty towns in northeastern Connecticut are affected, as well as towns across the border in neighboring Massachusetts. The scope of the problem is unknown, but after a state investigation, a single quarry within a driving radius of these homes is believed to be the culprit.
Homes with visible damage were built between the early 1980s and 2003; however, this quarry has been used for building projects up until early summer 2016 when the quarry owners agreed to cease pouring residential properties for one year.… Read the rest
Thaumasite Damage to M5 Bridge Foundation Concrete
This month’s issue of New Civil Engineer (May 2016), the magazine of the Institution of Civil Engineers, features the long-term remedial works to the concrete foundations of overbridges along the M5 in southern England, UK, as a result of thaumasite damage.
In the article, titled “Concrete Concern – Long term rescue effort underway for M5 bridges with crumbling foundations”, Dave Parker (of NCE) discusses the background to the UK thaumasite problem, the extent of damaged bridges and the on-going remedial programme. The full article can be found on the NCE website by clicking here.… Read the rest
According to the Wikipedia page on the topic, Chinese Drywall refers to “…an environmental health issue involving defective drywall manufactured in China and imported to the United States starting in 2001”. Drywall is also known as plasterboard and is comprised predominantly of gypsum plaster.
“Most of the homes that have Chinese drywall were built between 2001 and 2008”
“Testing of Chinese drywall has found unusually high instances of pyrite.”
“There is speculation that the pyrite oxidation results in sulfur compounds being released by the drywall during periods of high heat and humidity.”
“Reports show that homeowners typically complain of corroding copper in their homes, and a rotten egg odor emanating from copper surfaces that, in turn, turn black and exhibit a powdery ash type substance.
Two new summaries/case history pages have been added to the website. These summaries concern the UK Thaumasite and Mundic problems. The pages are work-in-progress so do please check back for updates. Click the links below to find out more:
SRK Consulting have uploaded a seminar from their second Mining Seminar Series held in January 2015 in Vancouver, British Columbia, Canada. Stephen Day (Principal Geochemist) presented a talk titled “Segregating waste rock to prevent acid rock drainage”. Acid rock drainage is a major problem principally linked to the oxidation of pyrite.
“Mines have been proactively managing waste rock to address acid rock drainage (ARD) potential since the 1990s. The typical management approach leads to segregation of rock that has potential for ARD generation (PAG) from rock that is non-PAG.”
“The PAG rock is then disposed of appropriately to limit ARD (for example, underwater in an impoundment or completed pit), whereas non-PAG rock may be suitable for conventional disposal or use as construction fill, such as for a tailings dam.
The first guest post on pyriteproblem.com comes from Dr. Víctor Cárdenes Van den Eynde. Victor started his career in the slate industry of Galicia (Spain), later moving to the Slate Technology Center Foundation (Galician Association of Slate Producers). There, he developed various methods of inhibiting oxidation of iron sulfides in roofing slates.
He later moved to the University of Oviedo, working as a reseacher and completing a Masters in Geological and Geotechnical Resources in 2010 and a PhD in roofing slate in 2012. He currently researches the petrophysics and weathering of building materials. Further information about Victor’s research and publications can be found at the end of this post.… Read the rest