The PR330 system is able to perform non-destructive mechanical measurements in masonry, allowing to determine the state of stress present in the structures, as well as to determine its deformability characteristics.
The test is based on the measurement of the stress state in a point of the structure due to a cut performed on the analysis part. The release of tensions causes the cut to close. By initially positioning the heating rods, in a symmetrical position with respect to the cut, the relative distance is measured before the cut and immediately after using a displacement sensor. Inside the cut is inserted a flat jack (made of a thin steel sheet) which, managed by a hydraulic pump, will restore the initial state of the masonry, canceling the failure previously measured by the displacement after the cutting operation.
In these conditions, the pressure inside the jack, measured by means of a precision manometer, is equal to the pre-existing stress in the masonry.
SIM STRUMENTI offers as an alternative to the mechanical measuring system (displacement sensor – pressure gauge) an automatic system, consisting of displacement meters and a pressure meter, connected to a data acquisition system.
Finally, the flat jack can be left inside the walls during the the restoration of the structures, in order to detect any overloads induced in the structures by means of special pressure gauges.