The importance of proper evaluation of the geological conditions for the design of industrial floor subbase

Nowadays many problems concerning industrial floors or floors in shopping centres occurred when local geological characterization is not adequately considered by structural designers, material selection is not evaluated properly and in time for future stability, or consolidation of soft organic subsoil laid in active zone is not taken into account during design evaluation. Similar problems occur when flooding effects on subbase layers cause a new settlement of the upper floor structure. Generally speaking, majority of these symptoms of floor damage have their origin in underestimation of the geotechnical risk. At some locations, the selection of support structure and material type is not adequate due to lack of experience and in order to offer the lowest price as a contractor

The Effect of Exogenous Factors on Building Construction

AbstractThe foundation soil is influenced by many factors that have an impact on the realization of building structures. A large group consists of exogenous factors. Exogenous factors are acting on the earth surface at any moment. The dynamic and strength effects of each individual exogenous factor differs in each location. Understanding the basic exogenous factors and their effects on building construction is essential in the realization of any construction. Exogenous processes determine the process of weathering, which are applied as erosion and abrasion. In addition, landslides, whose destructive power is determined by the speed of movement and real extension. Furthermore, the process of karstification causes the creation of cavities. They also included the collapsibility of soils who, like the previous factors, have a negative impact on construction. They occur mostly in mutual interaction, although individual exogenous processes are presented separately.The publication presents problems of exogenous factors, their effects on building construction and changes in physico-mechanical parameters. Good knowledge of the fundamental problems occurring in connection with exogenous factors allows us to ensure measure and expect a number of complications early

Dynamic Analysis of Block Concrete Foundation

The paper is dedicated to the assessment of the dynamic response of a block concrete foundation to dynamic effect of an external force. The basic dynamic characteristic of the system is analysed. The state of resonance and introduction of the resonance curves are assessed. Description of the possibilities of numerical solution of the foundation response to dynamic loading and analysis of the behaviour of the foundation under different conditions are presented

Effective ecological and cheap heating of dwelling spaces

The sustainability of human civilization depends largely on green energy management. This work represents one way to achieve this goal. The work is devoted to converting microwave radiation to heat. The article analyses different ways of heating residential and utility areas. Materials suitable for converting microwave radiation to heat from ceramic composites, concretes, fire clays, and bauxite with water glass are enclosed. For all materials we have measured DTA/TG (Differential Thermal Analysis/Thermogravimetric Analysis) curves, XRD (X-Ray Diffraction) patterns, chemical composition of samples, the specific heat capacity c(p) [J/kg.K], thermal conductivity k [W/m.K] and diffusivity alpha [m(2)/s(-1)]. The cooling curves of these materials after microwave heating are characterized in detail. The paper also presents a description and construction of a microwave reactor together with the parameters of the living space heating.Web of Science121art. no. 5

Numerical modeling of batch formation in waste incineration plants

nefunkční DOIThe aim of this paper is a mathematical description of algorithm for controlled assembly of incinerated batch of waste. The basis for formation of batch is selected parameters of incinerated waste as its calorific value or content of pollutants or the combination of both. The numerical model will allow, based on selected criteria, to compile batch of wastes which continuously follows the previous batch, which is a prerequisite for optimized operation of incinerator. The model was prepared as for waste storage in containers, as well as for waste storage in continuously refilled boxes. The mathematical model was developed into the computer program and its functionality was verified either by practical measurements or by numerical simulations. The proposed model can be used in incinerators for hazardous and municipal waste.Web of Science1716

Experience with application of reagent to heat transfer surfaces of combustion device

The formation of deposits on heat exchange surfaces of combustion equipment causes a decrease in heat exchange, a decrease in power, and consequently deterioration in the economic balance of combustion equipment. The technology of French company A. I. T. DRIVEX has been developing and being applied in practice for many decades. Preventive technology is used as a mean reagent periodically injected during operation into the combustion chamber. Part of the application is always pre-prepared project resolving the location of the injection nozzles into the combustion chamber on the flue gas path. The article describes the experimental usage of reagent GEPERSUITE 2200 at the Sermaize refinery in France. The aim of the test is to evaluate the benefits and advantages of applied technology in the boiler refinery in full operation. The results clearly demonstrate that using the reagent GEPERSUITE 2200 is advantageous in terms of economic and technical propertiesWeb of Science1925

Effects of kaolin additives in fly ash on sintering and properties of mullite ceramics

The effective utilization of fly ash (FA) as a raw material for ceramics production is performed on the FA-kaolin mixtures containing kaolins 10% by mass. The mixtures in comparison with FA and three raw kaolins were annealed to mullite ceramics at temperatures of 1000, 1100, 1200 and 1300 degrees C. The main aims were to contribute to the discussion on the effect of impurity of Na,K-feldspars in kaolins and Fe2O3 in FA on sintering procedure, porous ceramics properties and mullite structural properties. The phases were characterized using X-ray diffraction and thermogravimetry DTA/TGA methods. Mercury intrusion porosimetry was used for characterization of porosity of ceramic samples. Results evidenced the influence of feldspars in kaolins and Fe2O3 in FA on the sintering temperatures and properties of mullite ceramics. The fully FA-based ceramic sintered at 1100 degrees C exhibited post-sintering properties of bulk density 2.1 g/cm(3); compressive strength 77.5 MPa; and porosity, 2% in comparison with the FA/kaolin-based ceramics properties of bulk density 2.2 g/cm(3); compressive strength, 60-65 MPa; and porosity from 9.3 to 16.4% influenced by Na,K-feldspars. The best structural and mechanical characteristics were found for the FAK3 sample, supported by the high content of kaolinite and orthoclase in the kaolin K3 additive. The FAK3 annealed at 1100 degrees C exhibited good compressive strength of 87.6 MPa at a porosity of 10.6% and density of 2.24 g/cm(3) and annealed at 1300 degrees C the compressive strength of 41.3 MPa at a porosity of 19.2% and density of 1.93 g/cm(3).Web of Science118art. no. 88

Measurement the thermal profile of steelmaking ladle with subsequent evaluation the reasons of lining damage

Based on the operational measurement, of which content was to determine ladle thermal profile, there were analysed causes of possible damage of lining in steel ladles by steel breakout through the ladle shell. There exists connection between thermal state of ladle lining during the operation and its lifetime. There were reached to the conclusion that the cause of failure in the lining of ladle is except for high temperature of bath, also wide interval of temperature change during the tap operation, in consequence with possible insufficient pre-heating of ladle, discontinuous operation of aggregate and damage of insulating lining layer, respectively deformation of ladles shell.Web of Science61128227

The effect of temperature and milling process on steel scale utilized as a pigment for ceramic glaze

This study is focused on the evaluation of the re-utilizability of scale originated during the steel casting and steel rolling processes as a pigment for glazes. Non-oiled scale with Fe3O4 as the major phase were used as a coloring component of transparent glaze matrix in: (i) as received state, (ii) thermally pre-treated at 700 and 900 degrees C, (iii) mechanically treated in planetary ball mill (60, 120 and 240 min) and (iv) mechanically treated in vibratory disc mill (60 and 120 min). Prepared glazes were applied on the surface of ceramic tiles prepared from a commercially available white ceramic slurry. The resulting tiles with given glaze were thermally treated at 800, 900 and 1060 degrees C. The pigments were characterized by X-ray powder diffraction method (XRD), X-ray fluorescence spectroscopy (XRF), granulometry (PSD), thermogravimetric analysis (TG) and differential thermal analysis (DTA), scanning electron microscopy (SEM/EDAX). The color of the samples was described by the coordinates L*a*b* from CIELAB color space. The results showed that the non-oiled scale is suitable as the pigment for ceramic glazes. Careful control of the scale treatment process (mechanical as well as thermal) together with the temperature of final glaze firing is necessary to obtain the glaze of desired color and quality.Web of Science138art. no. 181

Identification of phase composition of binders from alkali-activated mixtures of granulated blast furnace slag and fly ash

The prepared alkali-activated binders (AAB) and composites using suitable latent hydraulic raw materials represent an alternative to materials based on Portland cements. This paper deals with ways how to influence the functional parameters of AAB by setting up mixtures of granulated blast furnace slag (GBFS) and fly ash with selected chemical compositions. In this way the course of hydration process is modified and the phase composition of products of alkali activation is changed as well as their final properties. The amorphous character of the hydration products makes evaluation of the phase composition of hardened AAB difficult and significantly limits the number of experimental techniques suitable to characterise their phase composition. It was observed that measuring the pH of water extracts obtained from the alkali-activated mixtures can give supplementary information about the process of hardening of alkali-activated mixtures of GBFS and fly ash.Web of Science581887