Abstract: Information is provided on the composition of polysilicate solutions obtained by mixing liquid glass and silica sol. It was found that the introduction of the sol leads to an increase in the silicate module and contributes to an increase in the fraction of high-polymer fractions of the silicon-oxygen anions. The results of the kinetics of the variation of α-SiO2 and β-SiO2. It is shown, that coatings based on the polysilicate solutions are characterized by faster curing. The was found correlation between the content of high-polymer fractions of silicic anions in a polysilicate solution and the tensile strength of films. Increase in the g-SiO2 content promote increase in the tensile strength of films. The composition of sol silicate paint is developed. Coatings based on paint have a high performance property.
Abstract: The paper presents methods for testing the composite materials using two types of fiber-optic sensors as well as a method for using radiation of the vertical-cavity emitting laser radiation (VCSEL) for checking the material deformation and its performances. The deformation checking sensor is a fiber Bragg grating (FBG) with a spectrum width of 50 pm, which is interrogated by the VCSEL. A new algorithm for modulating the laser diode current is proposed for the FBG interrogation providing a dynamic range of at least 3 nm. A new interrogation method of impulse Fabry-Perot interferometer was proposed. The interrogation method was applied for a fiber-optic acoustic emission sensor manufacturing. The sensor was experimentally investigated by the impact of a 6 mm diameter steel ball and compared to a reference piezoelectric acoustic emission transducer.
Abstract: We have investigated a possibility of photon propagation into the human tissue model (skin, fat, and skeletal muscle) by Monte Carlo method using Matlab program. There were some parameters of each tissue layer effecting on the light packet, for instance the absorption coefficient, scattering coefficient, anisotropy factor and thickness. It was found that the photon distribution on the surface of the human tissue and photon penetration into the human tissue under the propagation of 100,000 photons were - 0.8580 cm to + 0.7030 cm (served as two detection points) and 0.7220 cm respectively. Therefore, the simulation result gave the photon penetration depth of 0.2220 cm at the skeletal muscle. These numbers could be primarily used as a standard for design and construction of the tissue diagnostic instrument.
Abstract: This paper investigates both fresh and hardened properties of concrete produced with different particle sizes of coarse aggregate (CA). The CAs with the maximum sizes (Dmax) of 25 mm, 19 mm, 15 mm, 12.5 mm, and 9.5 mm were used to produce concrete samples with a water-to-binder ratio of 0.4. The workability, fresh unit weight, compressive strength, and ultrasonic pulse velocity (UPV) of the concrete were tested. Additionally, some concrete samples were fully immersed in 5% sodium sulfate solution in order to assess the performance of the concrete under sulfate attack condition. The experimental results show that the workability of fresh concrete increased with increasing the particle size of CA used, while the particle size of CA insignificantly affected to the unit weight of fresh concrete mixtures. The concrete mixture produced with Dmax of 12.5 mm obtained the highest compressive strength and UPV values in comparison with those of other mixtures. This study also found that the compressive strength values of concrete samples that fully immersed in sulfate solution reduced about 15% as compared with those of the concrete samples cured in lime-saturated water. All of the concrete samples prepared for this investigation exhibited good durability performance with ultrasonic pulse velocity values of above 4300 m/s. Test results also indicated that the concrete properties can be enhanced if the CA sizes were appropriately selected.
Abstract: This paper presents the possible deviations between “realistic” (performance-based) calculations of fire resistance of steel structures and corresponding calculations made by one of the often used simplified (prescriptive) procedures of EN 1993-1-2 i.e. the method of critical temperature (MCT). The comparison is done for a case of an assembly consisting of a steel beam and a steel girder connected to each other by a bolted fin-plate connection. For such structure the MCT method suggests that the structural fire resistance is 50 minutes. However, the realistic fire resistance calculated by an advanced performance-based procedure is evaluated to 44 minutes. Although the discrepancy between the results of both methods is not significant in the presented case, this finding implies that MCT can be on the unsafe side for some cases. More future debates and clarifications are therefore encouraged regarding the actual limits of the applicability of the simplified procedures.
Abstract: This paper presents possible deviations between advanced (performance-based or ‘realistic’) and simplified calculations of initiation and spread of a fire in a factory for the production of insulation panels made of extruded polystyrene (XPS). Simplified procedures, discussed in the paper, are founded on several assumptions regarding the evolution of the fire. They are normally based on a great deal of practical experience of the fire designer and/or reports of eyewitnesses of similar fires. Provided that the latter are easily accessible, such procedures are fast and can provide a reasonably good first impression regarding the expected fire as the paper shows. However, they also almost inevitably lead to temperatures which are somewhat underestimated in the most intense fire phase but are overestimated in the decaying phase. Hence, for a more reliable calculation, advanced procedures are recommended.
Abstract: The possibility of modification of mineral extenders with a specific surface of 350 m2/kg with ultraviolet irradiation is considered. Infrared spectroscopy confirmed that under the influence of ultraviolet irradiation, the bonds of OH-groups with SiO2 tetrahedra are weakened, that contributes to the formation of extenders of the acid centers of Lewis and Bronsted on the surface. The optimum time of ultraviolet exposure is determined, at which the concentration of active Lewis and Bronsted acid sites on the extenders surface increases by more than 100%. It was found that replacing 10% of cement mass with a modified extenders makes it possible to produce concretes with strength values 20-30% higher than for composites without extenders. Obtaining equal strength concrete is possible with replacing 20% of cement with modified extenders.
Abstract: A Continuum (filled polymer) is inhomogeneous and anisotropic. The Continuum is used in an injection moulding simulation at first (generally unnewton type of fluid). Then the continuum is solid (after cooling) and it is possible to carry out ordinary structural analysis with it both static and dynamic. The solid continuum has different mechanical properties for each of discrete element. The consequent values of mechanical characteristics (after simulation of load) will generally have different values when influence of injection moulding is taken into account for analyses.
Abstract: The article shows results of the influence of "DORLUK" impregnation on physical and mechanical characteristics of asphalt concrete pavement. "DORLUK" impregnation is produced by "Scientific-Production Enterprise" Plant Innovation Industrial Equipment" ("SPE "PIIE"). The impregnation was tested on the section of road «1P-193 from Voronezh to Tambov». The research of the additive’s effectiveness was carried out according to the following characteristics of asphalt-concrete samples: density, water saturation, water resistance, water permeability, fatigue strength. According to the findings the application of the "DORLUK" impregnation results in a significant decrease in the water saturation of asphalt concrete samples by 36%, and also in water permeability decrease under the pressure by 3-4 min. Reducing the water saturation and water permeability of asphalt concrete with impregnation will reduce the negative impact of water on the strength characteristics of asphalt concrete. It is important to note that the impregnation has no negative effect on the fatigue strength of asphalt concrete samples, since the amount of cycles of samples with impregnation and without it is the same.