Application

The recorder is used for determining  mechanical strength of concrete

• in construction industry - in productioin  and erection of  concrete components;
• in public service - in assessment of technical state  of exploited constructions;
• in other industries where concrete components are used.

Depending on problems  to be solved, the recorder can be used for defectoscopy of materials and articlesm flaw location, and non-destructive tests of materials' strength and quality.

At present the "Prochnost" recorder is successfully used for assessment of state of road bridges in Tomsk, Tyumen', Novosibirsk, Kemerovo, and Amur oblasts, as well as in Altay and Krasnoyarsk krai.

Function

To record, store, and analyze shape of electromagnetic emission pulses (EEP) arising  in materials under mechanical shock-excitation

Complete set: 1 - a mechanical striker, 2 - EEP receiver, 3 - an indicator.

Specifications

• Error  of concrete strength determination does not exceed 10%;
• Volume inspected in single measurement - 0.4 m³;
• Measurement time for one point - less than 5 s.

Principle of operation

Defects  of material structure such as micro- andmacrocracks, disintegrations, foreign inclusions, interfaces between aggregate and matrix are the sources  of electromagnetic emission. A shock-induced elastic wave sets in motion electric charges existing on such defects. An external pulsed electromagnetic field arises that is recorded with the device. Analysis of a shape of the electromagnetic emission pulses according to the preset algorithms allows one to evaluate physical and mechanical properties of material. This method comprises the advantages of acoustic methods and gives supplementary unique information on electrical structure and defectiveness of concrete, allowing to obtain more precise data on it strength.

Merits

• There is no need in special surface preparation because the sensor does not contact the material  surface. Measurements are possible  at one-sided access.
• Unlike sclerometry methods, the method suggested detects concrete structure defects and measures an integral strength in some volume and not  just on its surface.
• Analysis of measurement results has shown that accuracy in determining concrete strength with the 'Prochnost' recorder is two times higher  as compared to one obtained with sclerometers of different  types  and by 30% higher  as compared  to ultrasonic defectoscopes.