INFLUENCE OF LASER RADIATION ON CONCRETE

In many countries (Japan, USA, China, Poland, etc.) the studies of the influence of laser radiation on the surface of various building materials are being carried out for a long time, including the military purposes. Most attention has been paid to the interaction of laser radiation with the surface of metals. In recent years, considerable attention has been paid to the study of the influence of laser radiation on the surface of concrete: the temperature fields, chemical reactions and stressed-deformed state in the field of heating, the possibility of technological influences on the surface of such building materials as brick, gypsum and cell concrete, confirming the possibility of application laser for processing their surfaces. As a result of studies of concrete cube samples on the influence of pulsed laser radiation, conducted on the Department of building construction and bridges, the fifth stage of the interaction of a laser beam with concrete was obtained – a cold plasma on the surface of water-saturated specimens. Dried specimens and samples with natural moisture up to two years age have also been studied. The emergency mode of work of protective structures at high-temperature local influence was modeled. The distribution of temperatures on the surface and in the thickness of the samples, the zones of influence and the destruction of the surface during five minutes of heating have been studied. The features of contact surface destruction are revealed. With the
help of acoustic emission control, the formation of normal macro crushes in concrete in the vicinity of heating was found. The possibilities of application of available theoretical dependences for the description of temperature fields in concrete samples, application of the coefficient of thermal diffusion obtained by other authors in the investigation of cellular concrete have been analyzed.
 

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