Method and apparatus for the non-destructive measurement of the compressive strength of a solid
AssigneeMarco Brandestini
InventorMarco Brandestini
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Abstract
An apparatus and a method are described that determine the compressive strength of a solid by rebound. The method and apparatus have a reduced sensitivity to error sources, i.e. gravity, internal friction and operator interference (unsteady holding of the instrument). The improvements are achieved by contactless measuring of the quotient of rebound to inbound velocity recorded immediately before and after the impact. Matching the mass of the mallet (3) to the plunger (5) yields higher efficiency, less angular variation of the impact energy and lighter weight. Added benefits of the invention are: Extended range of measurement and simplified mechanical adjustments, calibration and maintenance.
Claims16
An apparatus for the non-destructive measurement of the compressive strength of a solid, in particular of concrete, comprising
- a plunger displaceable along an axis and having a front end for probing the solid,
- a mallet displaceable along said axis to impact against said plunger,
- a drive mechanism for driving said mallet against said plunger, thereby causing said plunger to impact against said solid and to generate a rebound of said mallet,
- a sensor measuring at least two rebound velocities of said mallet at different times during said rebound, and
- a control unit calculating a parameter indicative of the compressive strength of said solid depending said at least two rebound velocities
- comprising a plurality of projections on a surface of said mallet and wherein said sensor comprises a light barrier generating at least one light beam interrupted by said projections.
Dependencies are inferred from the claim text.