LABORATORY: CNR ISPC

NAME OF THE INSTRUMENT

Matest C369N equipped with 55kHz probes

 

GENERAL DESCRIPTION

Ultrasonic measurement is a non-invasive method to assess the state of conservation and identify internal defects of concrete structures. It is also possible, with appropriate instrument configurations, to detect the presence of layers with a different state of conservation and to determine the extent of a crack visible from the surface.

TECHNICAL DESCRIPTION

Ultrasonic measurement was also applied on stones for the evaluation of consolidating treatments. The speed of the ultrasonic pulse depends on the properties of the medium it passes through, in particular density and elastic characteristics. The pulse is sent by a transmitting probe and acquired by the receiving probe. The probe is coupled to the surface with a material such as vaseline, ultrasound gel, plasticine such as to minimize the presence of air at the interface between the probe/surface and fa. The ultrasonic measurement can operate with different instrument configurations both for investigative reasons and for surface morphology. For example, the indirect method realized with increasing distance distances can be useful to identify any changes in the properties of the cement (from healthy to altered or vice versa) this change is identified at the point where the slope of the ultrasonic value curve varies as a function of the distance. There are different types of ultrasonic probes that operate with different frequencies and that allow to investigate different path lengths.

 

Referent

Silvia Rescic silvia.rescic@cnr.it

 

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