POSSIBILITY USING THERMOGRAPHIC CONTROL METHOD TO DETECT CRACKS IN REINFORCED CONCRETE STRUCTURES

Abstract

Abstract. The article presents the study results of the possibility of using thermographic non-destructive testing to search for cracks in reinforced concrete structures. The basis of non-destructive thermal control is the registration of changes in the thermal field that occurs when the thermodynamic equilibrium of object with the environment is disturbed, which appears on the surface, and the nature of which allows obtaining the necessary information. The thermal control method is based on the interaction of the object's thermal field with thermodynamic sensitive elements (thermocouple, photodetector, liquid crystal element, bolometer), which convert the field parameters (intensity, temperature gradient, contrast, radiance) into an electrical signal of the recording device. As a result of the experiment, it was confirmed that the thermographic control method can be used when examining reinforced concrete structures for a qualitative assessment of hidden defects and damages. Thermal imagers with different resolution of the IR image matrix, an infrared thermo hygrometer, and a luxmeter were used as measuring instruments for the experiment. During the experiment, no fundamental difference in the use of thermal imagers with different types of IR matrices was revealed. When using the more accurate Flir E8 thermal imager, the thermogram had a clearer definition of the surface temperature compared to the Flir C2. This feature can be useful for quantifying defects, for example, the depth and size of a crack under a layer of paint, but fundamentally, for high-quality detection of defects and damage, the use of more accurate equipment is not a prerequisite. The authors conclude that the method of thermographic control can be used when examining reinforced concrete structures for a qualitative assessment of the presence of cracks.