Pyrrhotite disaster in the northeastern United States – CCACB Guest Post

Pyrrhotite disaster in the northeastern United States

The following article is a guest post by the Connecticut Coalition Against Crumbling Basements on the pyrrhotite disaster in the northeastern United States.

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

Research paper: pyrrhotite in concrete aggregate

Pyrrhotite in Concrete Aggregate

Izelman Oliveira and others at the University Politecnica de Cataluna, Barcelona have published a paper on the oxidation of pyrrhotite in concrete aggregate in Spain. The authors report that the nature of pyrrhotite (in bands) creates planes of weakness that act as preferential paths for oxygen ingress.

The paper, titled “Evolution of pyrrhotite oxidation in aggregates for concrete” follows prior research by Oliveira et al., (2012): Olveira, I., Cavalara, S.H.P., and Aguado, A. (2012). New Unreacted-Core Model to Predict Pyrrhotite Oxidation in Concrete Dams. Journal of Materials in Civil Engineering. 25 (3), 372-381.… Read the rest

Pyrrhotite judgement: SNC-Lavalin to appeal

pyrrhotite Judgement

Despite pleas from Coalition of Victims of Pyrrhotite (CVAP) in Canada, SNC-Lavalin (the main defendant in the recent pyrrhotite trial) have stated that they will appeal the pyrrhotite judgement, Le Nouvelliste reported yesterday (10.07.14).

In the Superior Court judgement, SNC-Lavalin along with their geologist Alain Blanchette, had been found responsible for 70 % of the pyrrhotite problem. Le Nouvelliste reports that the CVAP spokesman, Yvon Boivin, was “bitterly disappointed” by the decision to appeal, but was continuing with plans to promote the boycotting of SNC-Lavalin. Disappointment was also expressed at the news on the CVAP Facebook page.Read the rest

Canadian pyrrhotite problem: verdict delivered

The Canadian pyrrhotite problem

In the early 2000s around 30 homes suffered pyrrhotite problems in the Trois Rivieres area of Quebec, relating to aggregates from a small quarry that only operated for a short time (Maher, 2013). New problems came to light in the late 2000s, with around 1700 residential buildings now suspected of having pyrrhotite problems.  A major legal case relating to the more recent events has concluded and the judge has delivered the verdict.

Canadian pyrrhotite problem historical summary

A summary of the events related to pyrrhotite in Canada can be found here.… Read the rest

Pyrite in masonry blocks: ACEI publish advice

pyrite in masonry blocks – ACEI Guidance note

The Association of Consulting Engineers Ireland (ACEI) have published, on 15th May 2014, an interim advice note on the presence of pyrite in masonry blocks stating:

“It has come to the attention of the ACE that there have been recent instances of apparent pyrite content in concrete blocks provided by block manufacturers.

In cases reported the affected blocks were noted to have a brown discoloration. The physical strength characteristics diminished over short period of time, particularly when exposed to moisture.

The ACEI are concerned about these occurrences and recommend all member firms request assurance from suppliers that materials are free of deleterious materials and that a representative sample of blocks be tested for pyrite content by chemical analysis.”

RIAI Guidance issued

An email sent to members of the The Royal Institute of The Architects of Ireland (RIAI) on the 29th May 2014 was posted on the Pyrite Action Facebook group and adds more detail to the pyrite problem

“A number of RIAI Practices have brought to the attention of the RIAI problems encountered on projects in the Leinster region with conrete blocks that contain pyrite.

Read the rest