Key Engineering Materials Vol. 864

Abstract: The properties of coatings largely depend on the nature of the interaction of the film material with the substrate – the type of bonds between them. The degree of this interaction, associated with the nature of the paint and varnish material, mineral fillers and the nature of the surface to be protected, may be a criterion for evaluating the protective and operational properties. Therefore, an urgent scientific and practical task is to study the silicate fillers effect on the nature of adhesive interactions at the interface of water-based coatings with a steel substrate and to establish the relationship of adhesion strength properties with the thermodynamic adhesion work. It is shown that the adhesion strength in the paint systems for steel is significantly affected by the thermodynamic adhesion work, in which the dispersed component of the surface free energy makes the greatest contribution when the degree of filler content changes.

Abstract: The aim of the researches is to identify indicators of longevity of the mineral wool products in the course of their use as an insulation layer of building envelope of construction projects with the working life up to 100 years. The objectives of the research consisted in evaluating changes of the operational characteristics of material – thermal conductivity, air permeability, compression strength at 10% linear deformation, specimen appearance and geometric parameters under cyclic climate effects that simulate environment effect on the state of the thermal insulating materials of building envelopes in the course of operation of construction projects.

Abstract: The article considers the influence of the structure of polymer-cement plaster coating on the nature of its destruction during the operation of the wall structure. It was shown that the use of purposefully selected components of the mixture (RPP, polymer fiber, cellulose ethers, fine aggregate with a low modulus of elasticity, etc.) made it possible to increase the uniformity of its structure and contact area with masonry, reduce the number of cracks during hardening, and slow down their development during operation, increase the durability of it and the wall structure. The durability of the wall structure largely depends on the number of defects in the plaster coating and the contact area between it and the masonry.

Abstract: Improving the reliability and durability of sidewalks, footways, car parks and areas for various purposes, made of concrete paving blocks (CPBs), is an important task of construction. In order to improve the quality characteristics, new pavements consisting of concrete paving blocks with a ribbed underside surface are proposed. Hypotheses about the advantages of the developed structural solutions of pavements relative to traditional pavements of blocks with a flat underside surface were formulated. To confirm the hypotheses, studies of one of the developed pavement variants of in laboratory conditions were performed. The article describes the plan and methodology for implementation two series of experiments. In the first series of the experiment, a section of a traditional pavement of concrete blocks with a flat underside surface was investigated, in the second, a section from a pavement of concrete paving blocks with a ribbed underside surface consisting of three prismatic elements. Qualitative characteristics of the pavement are determined by various indexes. As a result of laboratory tests, the dynamics of settlement of experimental CPBs under the influence of vertically applied load was studied, and density index of a sand structural layer located under the tested CPBs was also obtained. The settlement indexes of the tested CPBs were investigated for three days. A comparative analysis of the experimental results confirmed the hypothesis about the advantages of pavements of concrete paving blocks with a ribbed underside surface. For the further implementation of the developed pavement variant in the construction industry, additional research is required. Further research directions of pavements of concrete paving blocks with a modified geometric shape of the underside surface are determined.

Abstract: In recent years, solid waste of the production of mineral fertilizers, phosphogypsum, has been of great scientific and practical interest in construction. The results of scientific research and practical experience in many countries have convincingly proved the technical feasibility and feasibility of using phosphogypsum. The problems of reducing impurities of phosphorus and fluorine in the manufacture of building materials from phosphogypsum are considered. Comparative experimental studies of the presence of phosphorus impurities for the initial phosphogypsum of the Dnieper Mineral Fertilizer Plant, calcined phosphogypsum and mixtures of phosphogypsum were carried out. Comparative indicators of the presence of radioactive elements in phosphogypsum are given. It is shown that there are methods for reducing heavy metals in phosphogypsum.

Abstract: In the article the effect of fillers of various chemical nature on the corrosion resistance of polyester powder coatings in terms of flaking widths and corrosion expansion widths in accordance with DSTU ISO 4628-8: 2012 was reviewed. According to the results of studies, the effectiveness of the use of fillers to increase the corrosion resistance of the powder coating varies depending on the average particle size and crystalline form of the filler was found. As a rule, in order to receive a powder coating based decorative coating you should apply only one layer of paint, while liquid coatings require applying several layers; this increases the time of coating production. The powder coating can be easily utilized and recycled, thus the economic feasibility of production increases.

Abstract: The article describes the first exploratory studies on the reinforcement of heat-insulating autoclaved aerated concrete with a basalt microfiber. The aim of the work is to obtain autoclaved aerated concrete of reduced density with improved tensile and bending characteristics. The first results obtained using basalt microfiber for reinforcing cellular concrete with a density of 150 kg/m³ are analyzed.

Abstract: The problems of energysaving are considered in building in number of different manners warming of facades of buildings and structures. The possibilities of the using are offered for new thermalinsulating material “PERVOLIN”.

Abstract: The article presents the results of the evaluation of the strength of fine-grained concrete of ordinary grades on mixed cement binders with ash and slag waste of thermal power plants. To ensure the required strength, the preliminary activation of the mixed binder was envisaged, which is one of the main techniques for reducing cement consumption. Experimental-statistical models of the strength properties of fine-grained concrete was obtained, which make it possible to predict the required strength with a minimum consumption of cement and the optimal concentration of ash in the binder.

Abstract: Fireproof coatings at the time of operation of the building structure is a separate and complex task, covering both the stages of the process protection from moisture, and subsequent fire protection formed during the swelling of the coating. They have been proven to create a layer of material on the surface that prevents moisture from penetrating the wood when the destruction of the coating begins. This makes it possible to determine the effect of flame retardants and the properties of the protective compositions on the process of slowing down the rate of water absorption. The process of moisture transfer by flame retardant coating in the presence of a polymeric shell is simulated, the diffusion and mass transfer dependences are obtained, and the diffusion coefficient is determined, which is 7.08·10^-12 m²/s, which allow to obtain a change in the dynamics of moisture upon washing out of the flame retardant. The results of determining the weight loss of the coating sample during exposure to water indicate the ambiguous effect of the nature of the leaching agent. In particular, this implies the availability of data sufficient for qualitatively conducting the process of inhibition of moisture diffusion and detection on its basis of the moment from which the fall of the coating efficiency begins. Features of slowing down the process of moving the moisture to the material that is treated with flame retardant, are in several aspects. Namely, the use of water-insoluble flame retardants and other components, as well as polymer binder, which are characterized by the formation of polymer shell on the surface of the wood.