JGP provides the full range of Concrete Testing for Mundic, from structural inspections to laboratory-based analysis. Mundic services are carried out in accordance with the Guidelines published by the Royal Institute of Chartered Surveyors (RICS).
Mundic concrete is an historic problem in many areas of Devon and Cornwall. Affected concrete was made with unstable aggregates from old mine waste tips found throughout the region. The problem with mundic came to light in the 1980s. Some minerals in the waste, mainly sulphides such as iron pyrites, can oxidize, decompose and expand. Mundic is the Cornish name for iron pyrites. Deterioration can occur to the extent that can disintegrate the concrete and trigger major structural damage.
Concrete testing for mundic or “mundic screening” identifies any potentially unstable aggregates, as well other concrete quality problems. It assesses the stability of the concrete and its structural integrity.
Following the assessments, the concrete will be classed as follows:
The testing uses a staged approach….
A qualified engineer will inspect the property. Concrete cores will be taken from representative walls and then visually examined within our laboratory. The aggregate type is identified as well as the condition of the concrete. A report is compiled based on both physical evidence from the building inspection and the Stage One petrographic assessment.
Only if the concrete contains suspect ‘mundic’ aggregates will a Stage Two be requested. This usually involves the microscopic assessment of the concrete and levels of microscopic sulphides. Again a report is compiled classifying the concrete based on aspects such as aggregate stability and any concrete deterioration.
The Stage Three Assessment is for ‘mundic’ concrete that appears to be stable but cannot be confirmed during a Stage Two. It is an accelerated weathering test designed to assess if any expansion would be at a rate that would affect structural integrity.
