Nanotechnologies in Construction: A Scientific Internet-Journal

63-76

Authors: Avrenyuk A.N., Rusyaev E.V., Vilinchuk V.L., Abutalipova E. M., Mugallimov F.M.

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 cementsand 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.

91-107

Authors: Urkhanova L.A., Lkhasaranov S.A., Buyantuev S.L., Khardaev P.K.

The article presents the results of studies on the production of fiber-reinforced concrete with mineral fibers produced in a plasma reactor, composite binders and nanomodifying additives. For dispersed reinforcement of concrete, basalt mineral fibers obtained by the electrothermal method in a plasma-arc reactor were used. To reduce the negative impact of Portland cement, composite binders based on Portland cement and fly ash were used. Fly ash meets the requirements of standards and is suitable for using it as a part of building materials. The nanosilica produced at an electron accelerator was used for comparison. The introduction of nanosilica improves the mechanical properties of cement by accelerating the hydration processes of Portland cement, improving the microstructure and changing the phase composition of the cement stone. The optimal content of fly ash in the composite binder, which allows obtaining high mechanical properties, has been determined. To reduce water content in the binder super plasticizer polycarboxylate type was used.

124-155

Authors: Kudryavtsev P.G.

Porous materials are formed from dispersed particles of various shapes. The porous structure of such materials is determined by the shape and nature of the packing of their structural units. As a model for the analysis of the structure of porous materials, model-packing units were selected in the form of spherical particles and fibers. Separately, the pore structure in foam-like regular porous materials was considered. It is shown that the pore volume in such packages grows with the reduction of the coordination number of the packed spherical particles. To study this regularity, the structural types of crystal lattices of various chemical substances were analyzed. Examples of such packages are most metallic elements and all inert gases, except for helium. These substances crystallize in simple structural types. All of them can be considered as packing of balls of identical radii. Such regularities are observed strictly up to the coordination number 4. With coordination number 3, a very openwork, loose package is formed. When forming mixed packages, the coordination number can have fractional values. A special group is represented by structures with coordination number <3.