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An international expert investigating the so-called mica crisis in Donegal has said his three-day trip had confirmed his findings that the defective block crisis expected to cost the State billions of euro is not caused by mica, but by pyrrhotite.
Dr Andreas Leemann, a leading scientist at the Swiss Federal Laboratories for Material Science and Technology (EMPA), said he was “repulsed” by the condition of some of the homes.
“It is one thing doing the laboratory research, but actually visiting the homes, going inside, smelling the mould, seeing the disastrous conditions, these people waiting for decisions. They are trapped in their houses, they cannot move out. It is really tragic,” he said.
“I can’t believe that homeowners are waiting months and months in a house that is just falling apart. I was coughing after 20 minutes in the houses, because of the mould. These people have kids and they cannot move out.”
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Dr Leemann, who earlier this week warned engineers assessing damaged homes they have “been looking for the wrong thing for years” said his visit to about 100 properties was “clear confirmation” of his laboratory findings.
Mica, a component in blocks long blamed for the scandal impacting on thousands of homes, is not to blame, but the high presence of another iron sulphide known as pyrrhotite, he has found.
“It has nothing to do with frost,” he added.
“What I have seen now is three very unfortunate conditions: the very poor quality aggregate (in blocks), very poor quality concrete and in addition to this iron sulphides which are causing an internal sulphate attack. It is a very bad condition.
To me it was confirmation of the results I got from the microstructural analysis.”
Dr Leemann said the “entire” defective blocks remediation scheme needs to be “streamlined considerably”.
“The entire process is far too complicated,” he said. “It is a several step process and everything seems to be put together to delay everything instead of accelerating everything.
“These people need help – it is obvious. I seriously doubt whether decision makers have ever gone to see these houses, had the smell of them in their noses, felt repulsed – people are living there for heaven’s sake.”
Dr Leemann said it would be “impossible” for a similar situation to be allowed to happen in Switzerland.
“Such a problem would be handled completely differently. This problem has been known for the last ten years at least. My question is why has there not been a major research project launched into it? The damages are estimated to be in the region of 2 or 3 billion euro. A decent research programme would cost around €1 million. What is that compared to €3 billion – it is nothing. The research should have started 10 years ago.”
Many other important questions remain unanswered around the crisis, he added.
“In Switzerland, if we knew we had this problematic aggregate, we would be asking are quarries still producing them? Does it still go into concrete blocks and foundations? This would be immediately addressed,” he said.
“Another thing that would be looked at is do we know where the problematic concrete is produced and sold, where has concrete gone to? We would like to know the magnitude of the future problems that we don’t know at the moment, a forecast of what to expect.”
He said it should be established if any of the affected concrete was exported.
At the invitation of Prof Paul Dunlop at the University of Ulster, Dr Leemann has been analysing defective concrete blocks from four affected homes in Co Donegal over the past year.
His microscopal laboratory testing made “very clear” there is “pyrrhotite oxidation” occurring in the cement – which acts as the “glue” for the blocks – which then releases a sulphur that causes expansion, stress and cracking.
Irish regulations for determining whether a building has been damaged by defective concrete blocks – IS 465, a 46-page guideline for the so-called mica crisis by the National Standards Authority of Ireland – do not mention pyrrhotite.
European Union standards set down in 2002 “clearly state” if pyrrhotite is present in blocks then it has to be weighted against the content of sulphur. Dr Leemann said the sulphur content of tested houses had values exceeding the EU limits by a factor of four to seven.
“In principle, the aggregates are not according to European standards. You could even say they are a violation of European standards on concrete aggregates,” he said earlier this week.