Windsor probe
The Windsor probe (in English Windsor sample ) is a halbdestruktive (sometimes called nondestructive unclassified) In-situ method of measuring the compressive strength of concrete , and other materials (such as bricks).
A standardized metal probe (around 8 millimeters in diameter, hardened metal) is shot at the concrete surface with a special pistol that is placed on the concrete and the penetration depth of the projectile is measured. The result also depends on the surface hardness ( Mohs scale , depending on the aggregate of the concrete) and there are digital devices that determine the compressive strength from the penetration depth and input of the surface hardness. Measurements are made at three points with a minimum distance, for which a triangular template is used.
The result is based on empirical correlations between compressive strength and the measurement results with the Windsor probe.
The procedure is used in the Anglo-Saxon area and beyond. It is specified in an ASTM standard .
literature
- ASTM C803 / C803M - 03 (2010) Standard Test Method for Penetration Resistance of Hardened Concrete