Pull-out tests on concrete

The pull-out test is an investigation technique that allows to assess the average compressive strength of concrete by extracting a bar or an expansion plug pre-embedded or post-inserted into the conglomerate. The dowel or bar is inserted by hammering, thus allowing the internal radial part to widen for perfect adhesion to the walls. A hydraulic jack is then applied which rests on a circular surface; the pull of the anchor causes the breaking of a concrete cone. The force that causes the concrete to break is then correlated, using experimental calibration curves, with the characteristic resistance of the concrete. The pull-out test is carried out in the areas without reinforcing bars, appropriately identified using a covermeter. Three extraction tests are carried out for each area under investigation.

Reference standards: UNI EN 12504-3:2005; UNI 10157/1992.