Abstract: The values of the system energy change caused by the structure formation of coatings based on paints using mineral binders are given. It is established that the process of curing coatings can be described using the first law of thermodynamics and thermodynamic potential - enthalpy. The main regularities of changes in thermodynamic parameters in the process of curing coatings on cement concretes depending on the curing time, the porosity of the substrate is revealed. It has been established that, depending on the type of coatings, there is an unequal change in the energy of structure formation, which allows predetermining the different operational durability of coatings. It is shown that the smallest change in entropy during the curing process is characteristic of coatings on substrates characterized by lower surface porosity. The increase in entropy in the process of curing coatings on substrates with high porosity suggests that the coatings are characterized by a greater defectiveness and, consequently, a greater probability of their destruction during operation. The increase in the surface porosity of the cement substrate reduces the adhesion strength of the coatings and reduces its durability during exposure to the environment.
Abstract: One of the urgent problems of modern concrete science is the use and improvement of high-quality concrete. The emergence of such concretes has opened a new era in construction. Their unique properties are: high strength and corrosion resistance, water resistance and frost resistance, adjustable deformability. High-quality concretes provide high guaranteed parameters of the operational reliability of buildings and structures under the conditions of complex environmental effects and loads, significantly reduce construction time and reduce investment risks. One of the promising materials that allows you to ensure all of the above characteristics is fine-grained concrete based on a composite binder.
Abstract: The development of modern construction technologies requires the development of efficient building materials with a unique property set and the improvement of existing ones. Fiber-reinforced concrete is one of the types of effective composites that meets the specified requirements, ensuring the structures operation reliability. The difficulty of achieving its maximum physical and mechanical characteristics is due to the complexity of the fiber equal distribution in the concrete matrix. Studies aimed at the optimization of the formulation and technological manufacture parameters of fiber-reinforced fine concrete, have revealed that from the perspective of obtaining products with optimal physical and mechanical characteristics, it is most feasible to introduce the agglutinant sand (cement + sand) of pre-prepared suspension from fibers, water of mixing and naphthalene formaldehyde plasticizer. Optimal dosages of input products were also revealed (basalt fiber, cement, plasticizer), which made it possible to create mixes of fine concrete and products based on it with class B25-B60 for compressive strength and Btb2,8-Btb6,0 for bending, frost resistance not less than F300.
Abstract: The energy intensity of production of the most common wall materials in Russia is significantly higher than their foreign counterparts. The urgent task is to reduce the energy intensity of the production of building materials, to develop and introduce energy-saving nature-like technologies for the production of building materials, which corresponds to modern trends in the development of "green" technologies. It is possible to reduce the energy intensity of the production of silicate materials due to the transition from traditional raw materials to the use of unconventional aluminosilicate raw materials of various genesis, in particular, clay rocks of the unfinished stage of mineral formation. In the course of the research, the possibility of the synthesis of the new growth in the system “aluminosilicate raw material – calcium hydroxide – water” under the conditions of hydrothermal treatment was shown. Due to the high reactivity of the raw materials used, under the conditions of hydrothermal processing, the synthesis of tumors occurs not only at high pressures and temperatures, but also at temperatures up to 100 °C. This will allow to obtain efficient hollow-walled wall building materials using energy-saving technology.
Abstract: One of the most important elements of the primary protection of concrete structures against chemical aggression is the correct choice of the type of cement. Specialists have done a lot of work to clarify the comparative stability of various types of cement systems in aggressive media containing various aggressive components [1-3]. Resistant cements for certain types of corrosion are known, but there is no complete concept of their choice. This causes difficulties in choosing the type of cement for specific types of corrosion in organic media, for complex types of corrosion, when the application of empirical approaches is unsuitable. This work is devoted to this issue.
Abstract: In the course of the work performance the following surveys were carried out: the analysis of the information assurance of the asphalt concrete mixtures production quality, the study of the relationship between the composition of asphalt concrete mixtures and the physical and mechanical characteristics of the coating. This paper presents the results of the analysis of the two types asphalt concrete mixtures qualitative composition and its effect on the physical, mechanical and technological characteristics of the coating. It is established that the deviation of asphalt concrete mixtures in composition from the required values ??leads to their under-compaction in the coating. It was also found that the increase in the number of inconsistencies in the composition of the asphalt concrete mixture leads to the increase in physical and mechanical characteristics that differ from the requirements of GOST 9128-2013 and GOST 31015-2002. The amount of bitumen on the asphalt concrete main characteristics, the data from the existing AP in the Belgorod Region were used as the information base in assessing the influence of granulometry of the asphalt concrete mineral part. Analysis of the particle size distribution was carried out using the laser analyzer for asphalt concrete AP 7 / 35B. The obtained data will be the basis for further study of the various parameters influence on the asphalt mixes properties, as well as improving the efficiency of the asphalt mix production control system.
Abstract: The article presents the results of the study of the bitumen-retaining ability of stabilizing additives developed on the basis of cellulose-paper waste and finely dispersed fillers of various genesis. Analysis of the test results of crushed stone-mastic asphalt mixtures of the same composition showed that all additives provide the value of the runoff index of the organic binder in the mixture, which meets the requirement of the State Educational Standard No. 31015-2002. The introduction of mineral fillers into the stabilizer contributes to a decrease in the studied parameter, which is due to the additional structuring effect. For a two-component additive (without mineral filler), the studied indicator has the greatest value, exceeding the recommended limit. It is important to note that the use of mineral powder in the composition of stabilizing additives has a positive effect on the flow of the binder. Mineral powder, due to the structuring effect on bitumen and the formation of a microporous structure, reduces the run-off rate of the binder. This is due to the fact that bitumen, being in thin interlayers and small pores, falls into the region of influence of the molecules of the surface layer of the mineral part, increasing the density of granules and facilitating the granulation process of the additive. The minimum runoff of the organic binder is observed in the preparation of crushed stone-mastic asphalt-concrete mix with additives based on mechanically activated wastes of wet magnetic separation of ferruginous quartzites and is 0.07.
Abstract: Due to the variety of the tasks solved by modern construction, the properties of Portland cement are far from optimal in all cases. One of the ways of deep modification is to obtain the composite binders on its basis, the properties of which largely depend on the mineral additive. The right choice is a kind of art, it is based on transdisciplinary principles. Another modern trend of concrete technology is the use of water-reducing additives. In this regard, the article considers the influence of the genetic type of the mineral additive in the composition of the composite binder, on the features of its interaction with a number of common superplasticizers. Criteria for the selection of rational combinations, taking into account the characteristics of the use of composite binders, are proposed.
Abstract: Many Russian and foreign scientists have been studying the processes of hydration of cement binders, but the processes of binders hydration with the use of mineral and organic additives have not been studied enough. The question of the superplasticizers influence on binder compositions consisting of cement and various mineral fillers requires a deep and detailed study in each case. In this regard, the aim of this work is to study the processes of portland cement hydration, modified by organomineral additive. Research was carried out on the study of changes occurring during the structure formation of modified binders by infrared spectroscopy (IR).