
The issue of mica, pyrite and pyrrhotite in concrete blocks in properties in County Donegal and County Mayo has been prominent in the news in Ireland over the last few years, associated with concrete blocks crumbling and losing strength. Long term exposure to the moisture ingress, coupled with lower durability and strength, moisture-sensitive aggregates and a hindered response to freeze-thaw cycles, are common factors in the deterioration and loss of integrity of the concrete blocks.
The Irish Standard, IS 465, sets out a methodology for investigating concrete blocks containing mica and pyrite-bearing aggregates. Sandberg can undertake testing in accordance with IS 465: 2018+A1: 2020, in particular Test Suites A, B and C, including simplified petrography, XRD, chemical analysis, strength testing and SEM analysis to provide data for the assessment of the condition of the damaged blocks.
Sandberg has developed expertise over many years of working with organisations in Ireland and is UKAS accredited for the procedures specified in IS 465 that include:
- Visual examination and measurement of cement
- Petrographic examination of thin sections for the detailed evaluation of causes of deterioration
- Classification of risk potential for future damage according to IS 465
- Measurement of free mica content by X-ray phase mapping using the scanning electron microscope
- Chemical testing for cement content, total sulfur and acid-soluble sulfate content




For more information contact our in-house expert: