The Pull-out testing is a standardised partially-destructive testing method to evaluate the mean compressive strength of concrete. It is typically adopted on decayed structures for which the actual static conditions are being assessed. Similarly, it is used on buildings located in riskful areas according to classification of national seismic hazard mapping and also on those buildings to be consolidated or restored for their due preservation, wherever the evaluation of the materials mechanical characteristics is essential.
The equipment consists in an aluminium hydraulic jack with a central hole whose function is to extract (or pull-out) some special steel anchors (a kit of 20 pcs. is included) by using a manual hydraulic hand pump with a maximum pressure pointer manometer and relative tubing length, and some drilling tools.
The concrete compressive strength is determined on site by measuring the pressure applied to the oleodinamic jack converted into the force requested to pull out a metallic anchor from a hole purposely drilled in the concrete. The pressure readings are then referred to specifically drawn calibration curves and compressive strength assessed, sometimes together with data from other non-destructive methods.
Boviar is currently cooperating with University of Genoa (DISEG) to further improve this methodology by the use of new anchor models with new calibration diagrams.