A thin section is a 0.025 mm thick sample of mineral-based material which is made in a special laboratory using diamond grinding techniques. Thin sections can reach up to 100 mm long, meaning it can span a balcony wall and provide samples of the structure's external and internal surfaces. Microscopic analysis of a thin section provides an invaluable amount of information about the condition of the concrete and above all, the reasons for any damage. Without this information, the planning and implementation of repairs would be a gamble.
Regulations and recommendations related to thin section research can be found, for instance, in the guidebooks published by the Concrete Association of Finland (Suomen Betoniyhdistys ry) and are available in Finnish only.
Picture: Long (75 mm) thin sections from various facades.
Picture: In a condition survey, testing often extends
throughout the entire external layer using a 75 mm
long thin section.