RESEARCH OF THE PHYSICOMECHANICAL PROPERTIES CEMENT-SAND SOLUTIONS EXPOSED TO THE SUPER-FREQUENCY OF ELECTROMAGNETIC RADIATION
The durability of the used cement-based construction materials can be improved by modifying them with electromagnetic radiation. Thus, in a number of research papers it is noted that magnetic and microwave radiation intensifies the processes of dissolution and hydration of cement at earlier times, that leads to the formation of fine crystalline structures, a decrease in porosity, an increase in density, strength, frost resistance and durability in general. In the course of the research, physical and mechanical tests of samples of cement-sand solutions irradiated with ultrahigh-frequency electromagnetic radiation were carried out and the results compared with those not irradiated were analyzed. The research was carried out both on samples of low-quality cement-sand mortars from dry mixes and on high-quality samples of cement-sand mortars used for the repair of concrete and reinforced concrete structures - for clarity of the obtained results. The structure of the samples was studied by means of a scanning electron microscope with an energy-dispersive spectrometer. As a result of the studies, an increase in the basic physicomechanical parameters was observed in comparison with the unirradiated samples at the age of 28 days. According to the results of physical and mechanical tests of irradiated samples and comparison of data with unirradiated microwave EMI samples of the CRP, it can be concluded that the maximum effective irradiation time is mainly 2 days after mixing both low and high quality compounds. At the same time, there was an increase in the main physicomechanical parameters in comparison with unirradiated samples. It is noted that in the irradiated compositions, the hydration process runs more intensively, that leads to an accelerated set of strength in the early stages, as well as an increase in strength and density at the age of 28 days.