Materials Science Forum Vol. 945

Abstract: The article presents experimental data on the improvement of physical and mechanical properties and structure of fine-grained concrete by mechanical activation of sticky cement in various apparatuses. It is established that the use of mechanoactivation technologies allows controlling the surface characteristics of cement in a wide range, its granulometric composition, as well as the physical and mechanical characteristics of concrete products. It is revealed that the efficiency of grinding machines that realize various mechanisms of disperse action is not the same. The highest indexes belong to the concrete containing cement, which is mechanically activated on the planetary ball mill AGO-2.

Abstract: The article contains the results of research on the development of optimal in terms of time and complexity of work, energy intensity, consumption of materials and cost, the design of the roadbed for use in the construction of oilfield roads in wetlands. Trunk oil and gas pipelines in Western Siberia and north of the European part of Russia began to be built approximately from the mid-1960s. From the very beginning, designers faced serious problems: complex natural and heavy ground and hydro geological conditions, namely, permafrost soils and swamps. The length of the swamp sections is tens and hundreds of meters, and in some cases – tens of kilometers. Road construction in wetlands is a very difficult engineering task. Conditions of excessive moisture, extremely low load-carrying capacity of marsh soils, a characteristic deficiency of quality mineral materials - all this creates obstacles, the overcoming of which is associated with significant material costs. The average cost of road construction through the swamp is 3-5 times higher than in normal conditions. A constructive solution for the roadbed using a layer of non-woven synthetic material in the cage to ensure year-round and uninterrupted movement of technological transport for maintenance of oil facilities was chosen.

Abstract: The issue of ice reinforcing by lattice anisogrid composite structures is considered in order to obtain new materials for Arctic use. The results of laboratory tests of breadboard models are obtained, the possibility of using an ice-composite construction material in conditions of the Far North is shown in principle. The questions of applicability of a new type of structures and possible directions of further research are touched upon.

Abstract: We adduce the information about methodology of decision-making on conformity of quality of the painted surface of building products and constructions to the established requirements. General methodology consists of obtaining, analyzing the facts on the normalized indicator and calculation and establishment of the norm.When calculating the allowed value of the adhesive strength can be determined for 3-σ deviation from mathematics expectation. The maximum permissible values of average-quadratic deviation should be determined by standard value coefficient of variation. Formulas are given for determining the permissible value of the coefficient of variation. The normative values of the coefficients of variation for some protective and decorative coatings are given

Abstract: The question of adhesion of fibers with a cement matrix is considered. Under certain conditions the fibers connect and hold the places of potential breaks. The important characteristics of fibre fibers are: surface texture, cross-sectional shape and construction in the longitudinal direction of the fiber. A sufficient number of fibre fibers located in the direction of the acting force can take the tensile force after the rupture of the matrix. The question of the fiber content in the percentage of the volume, which is sufficient to increase the strength, is considered. The properties of the finished concrete mixture and the adhesion of the fiber and the concrete matrix depend on the parameters. As a rule, there is a poor adhesion of smooth steel fibers in the cement stone.

Abstract: The influence of heat treatment (burning) of building materials on the effective specific activity of natural radionuclides was investigated. Analysis and processing of the obtained results allowed to obtain a consistent pattern of this process for each material. It has been established that the effective specific activity of natural radionuclides decreases along with growth of temperature of building rocks treatment. The results showed that it is possible to reduce the effective specific activity of natural radionuclides managing technological production modes and, consequently, to reduce the radiation doses of the population from these materials.

Abstract: As a result of the influence of the corrosive environment, the construction materials have a decrease in performance. To increase the service life of the structures, continuous monitoring and, if necessary, restorative repairs are carried out. One of the ways to maintain the initial properties for materials is to give them a self-healing effect by introducing a specially developed additive containing a bioactive component in the manufacturing process. The article presents the results of research on the ability of building materials based on mineral binders to self-repair. Mixtures containing nutrient medium for the biomass of aerobic bacteria were used as bioadditives. Portland cement and gypsum binder were used as mineral binders. The obtained results allow to make a conclusion about a significant change in the rheological properties of cement-sand mortars due to the presence of biological surface-active substances that are part of the cells of microorganisms. The effect of changing the concentration of cells on the setting time and on the strength characteristics of cement-sand mortars was established.

Abstract: The paper presents the results of the study dealing with improving the physical and mechanical properties of building ceramics samples: mean density, compressive strength, wear resistance, impact resistance, water absorption, thermal conductivity coefficient, and frost resistance. In the study the organic-mineral additive based on industrial wollastonite with the superplasticizer S-3 was used. The most functional amount of the applied additive, as well as the optimal volume of water in the molding mixture and the firing temperature were determined with the method of experiment mathematical planning. In the course of the studies the specifics of the organic-mineral additive influence on the properties and structure of building ceramics are revealed. The findings are attested by electron microscopy data. The application of the organic-mineral additive improves the performance characteristics of building ceramics samples.

Abstract: Modern trends in the development of the oil and gas infrastructure of the Russian Far East are considered. The main threats in the operation of oil and gas pipelines are described. The technology of complex protection of pipeline surfaces is proposed. Protection of the inner surface is achieved through the use of silicate enamel coatings, protection of the external surface – through the use of foam glass. On the basis of local silicate raw materials the technology of the described materials is developed, and their main properties are determined. Recommendations on the application of the developed technology for the protection of pipelines are given.