The Irish Examiner and the Independent report that six new homes in the Moneymore area of Drogheda, Co Louth are scheduled for demolition as a result of pyrite. The online news stories state testing is ongoing for 19 other houses in the estate. The problem at this site is supposedly the presence of pyrite in building blocks and the news comes just weeks after the ACEI and RIAI published a warning on pyrite in concrete blocks in the Leinster area.
Following guidance from the The Royal Institute of the Architects of Ireland (RIAI) and Association of Consulting Engineers of Ireland (ACEI) (see previous post), RTE news reports that local authorities are starting investigations into concrete blockwork with possible pyrite problems at a number of sites, including areas in Leinster.
RTE news, describing a statement issued by the Department of the Environment, suggests that the “allegedly defective blocks” supplier had been co-operating with the investigation. The block manufacturers have not been named.
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.
Peter Finnegan (Dublin City Council), Paul Forde (DBFL Engineers) and Brian Hawkins (Engineering Geological Consultant) have published a paper on the structural effects of sulfate generated heave, with particular reference to the problems in Dublin, Ireland.
The paper, titled “Sulphate-generated heave – the effect on structures in Dublin” adds to existing information published by the authors in their respective chapters of the 2013 book, Implications of Pyrite Oxidation for Engineering Works. Finnegan et al (2014) describe the typical mechanisms and types of damage that can occur due to expansion of sub-floor aggregate. The authors also discuss methods and planning of remediation, including consideration of the potential for differential stresses in adjacent structures during remediation.… Read the rest
On April 20th 2012, Trinity College Dublin (Ireland) hosted a one-day research conference considering engineering problems related to the use of pyritiferous fill as under-floor aggregate. The conference was organised by Dr. Brian Hawkins.
The original flyer from the 2012 Pyrite Symposium
The Pyrite Symposium aimed to aid and inform all involved with pyrite problems by reviewing and discussing the issues associated with pyrite heave, as well as the causes, assessment and solutions, in the context of current research and case studies.
The conference included eight presentations by engineers and academics and ended with a panel discussion considering current standards and guidance pertaining to aggregates.