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Archiv článků od 19.2.2018 do 14.5.2018

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14.5.2018
doc. Ing. Milan Gaff, Ph.D., Ing. Kamil Trgala, Ph.D., Ing. Tereza Adamová

Wood and the materials on its basis fulfil the requirements of an ever-evolving and accelerating society. In addition to naturally grown wood, wood-based materials are frequently used as a basic material for production of furniture and for building constructions as well. Looking at changes in waste management, a significant shift from the waste to the circular economy can be observed. The valuable raw materials are kept in the production cycle instead of landfilling or burning. Wood and wooden products can be efficiently separated in waste management, reused and recycled. The so-called wood waste – old furniture, wooden pallets, window and door frames, demolition wood, used lumber, bark and other wood residues can be reused in particleboard production. Particle board manufacturers in the Czech Republic have adopted progressive waste management and currently use 60% of recycled wood into particle boards. A completed life cycle analysis (LCA) of OSB demonstrates that replacing of 50% of natural fibres with recycled wood has significant environmental benefits. The objective is to push furthermore on effective legislation to promote waste material utilization and thus lead to a more sophisticated waste wood collecting.

14.5.2018
Ing. Michal Venglár, prof. Ing. Milan Sokol, PhD., Ing. Katarína Lamperová

The article is devoted to extraction of some mode-shapes from measured data during the operational state. The measured bridge is in Bratislava and connects two city districts: The Old Town and the Petrzalka district. The structure is an asymmetric cable-stayed steel bridge with an orthotropic 2-box beam supported in one plane by cables from an inclined pylon. The bridge was measured twice, firstly in 2016 and secondly in 2017. Ambient vibration data were acquired during the measurements. The FEM model has been prepared before the measurements. Some mode-shapes were identified from the data and then compared to the calculated ones.

7.5.2018
doc. Ing. Milan Gaff, Ph.D., Ing. Kamil Trgala, Ph.D., Ing. Tereza Adamová

Wood and the materials on its basis fulfil the requirements of an ever-evolving and accelerating society. In addition to naturally grown wood, wood-based materials are frequently used as a basic material for production of furniture and for building constructions as well. Looking at changes in waste management, a significant shift from the waste to the circular economy can be observed. The valuable raw materials are kept in the production cycle instead of landfilling or burning. Wood and wooden products can be efficiently separated in waste management, reused and recycled. The so-called wood waste – old furniture, wooden pallets, window and door frames, demolition wood, used lumber, bark and other wood residues can be reused in particleboard production. Particle board manufacturers in the Czech Republic have adopted progressive waste management and currently use 60% of recycled wood into particle boards. A completed life cycle analysis (LCA) of OSB demonstrates that replacing of 50% of natural fibres with recycled wood has significant environmental benefits. The objective is to push furthermore on effective legislation to promote waste material utilization and thus lead to a more sophisticated waste wood collecting.

30.4.2018
Ing. Tomáš Hána, doc. Ing. Martina Eliášová, CSc., Ing. Klára Machalická, Ph.D., Ing. Miroslav Vokáč, Ph.D.

In contemporary architecture there are many various types of glass load bearing elements such as beams, slabs, floors or even columns. Most of these elements are made of laminated glass. Individual glass plies in the panel are bonded with polymeric interlayer providing shear forces transfer between the plies. This transfer primarily depends on the interlayer´s stiffness which is ambient temperature and static load duration dependent and is the subject of a current research. Considering the fact that shear stiffnesses of most interlayers have not been experimentally verified yet, civil engineers are compelled to design laminated glass structures on the safe side. This approach results in robust and uneconomic structures. This paper deals with the initial PVB (Trosifol BG-R-20, Trosifol Extra Strong) and EVA (Evasafe) initial shear modulus assessment depending on the temperature and loading ratio, these interlayers shear stiffness comparison and important results summary.

23.4.2018
Ing. Lukáš Velebil, Ing. Jan Včelák, Ph.D., Ing. Kristýna Čápová, Ing. Milan Dvořák

The paper deals with the experimental analysis aimed at function verification of fiber optic sensors (Fiber Bragg Gratings). The sensors are used for mechanical stress measurement in wooden load-bearing structures. Glued laminated timber beam with built-in fiber optic sensor system was mechanically loaded during two bending tests. The data obtained using the fiber optic sensors were compared with the results of reference measurement method and analytical calculation.

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23.4.2018
Ing. Karel Mrázek

Description of the heating system according to the European methodology. The theoretical part is complemented by a description of the current state of the heating systems in residential buildings that the professional public encounters. In the article, the recommended data for the correct application of the method and design procedures for assessing the energy performance of heating is given. The processed topic will thus help to understand the influence of individual variables on the economical operation of the heating system and its final evaluation.

26.3.2018
Ing. Jaromír Láník, Ph.D., Ing. Tereza Komárková

Diagnostics of building structures are used in non-destructive and destructive methods for evaluation of selected properties of building materials. Structural elements but also selected parts are assessed. Ultrasonic method, which is among the non-destructive testing methods, is being used for the diagnosis of concrete and steel structures for many years. The paper presents possibilities of carrying out inspections of selected elements of steel structures.

26.3.2018
doc. Ing. Radomír Sokolář, Ph.D., VUT FAST Brno, Ústav technologie stavebních hmot a dílců,

Sintering activity (dependence of porosity, flexural strength and firing shrinkage on the firing temperature) of feldspar dust (Casial) which is generated during the milling of potassium feldspar in Halamky quarry was determined. Potassium industrially milled feldspar Z75K13 as a reference material with similar granulometry and mineralogical composition with Casial was used for comparison. More intensive sintering activity showed dry pressed samples based on Casial in comparison with feldspar Z75K13 (about 30 °C lower sintering temperature – 1180 °C). Casial created red body after firing thanks to higher content of Fe2O3.

19.3.2018
Ing. Luděk Vejvara, Ph.D., Západočeská univerzita v Plzni, Katedra mechaniky

The magnitude of the load on the walls of tall wooden constructions can be assembled according to the existing standards according to the valid combination equations in several ways. There are differences between the results. Determining the appropriate procedure for determining vertical strength from construction in different parts of building preparation and comparing it with other options is the subject of this paper.

19.3.2018
Ing. Jakub Hodul, Ing. Jana Hodná, prof. Ing. Rostislav Drochytka, CSc.,

Within this work possibility of using four kinds of waste glass as a replacement for the commonly used filler, silica sand DORSILIT, to epoxy based polymer concrete (PC) is experimentally verified. Determination of compressive and flexural strength, chemical resistance and thermal resistance is examined in order to find out if PC containing waste glass as filler can be used for rehabilitation of concrete structures. Even based on the results of the tests it will be assessed whether it is possible replace DORSILIT by waste glass.

12.3.2018
Ing. Daniel Mátl, Ing. Lenka Nevřivová, Ph.D.

There are applications of refractory concretes for places where these are exposed to corrosive environments. This text deals with both description the corrosive effects and methodology of their testing. One of the most important properties of materials, affecting the chemical corrosion resistance, is their density. The second part of this text is focused on testing the refractory concretes which are currently used for applications. The aggregates were tested for the resistance to sulfuric acid.

5.3.2018
doc. Ing. Šárka Kročová, Ph.D., VŠB TU Ostrava, Fakulta bezpečnostního inženýrství

The paper deals with the ways and means of eliminating primary and secondary water scarcity threats to an acceptable level and at the same time reducing the risk of contamination of surface water by water used in fire interventions.

5.3.2018
doc. Ing. Michal Stehlík, Ph.D., Ústav stavebního zkušebnictví, Fakulta stavební, Vysoké učení technické v Brně

Adding structural fibres into concrete has an impact, both positive and negative, on the long-term durability of concrete. Polymer fibres do not resist shrinkage of the concrete, steel fibres, on the other hand, create a tough skeleton preventing deformation. Porous structure of fibre concretes exposed for a long time in the environment of CO2 is estimated using the method of determining the coefficient of diffusion resistence and the method of determining the capillary hight. Comparison of measured capillary hight and diffusion coefficient of fibreconcrete samples bring the knowledge, that close correlation between both quantities does not exist, due to the physical difference between determination of both quantities.

26.2.2018
Ing. Otto Dvořák, Ph.D., VŠB TUO FBI Ostrava, externí školitel

The article informs briefly about the international standardization of ISO, IEC, CEN and CENELEC in the field of fire safety, as well as the competence of the Czech Office for Standards, Metrology and Testing. It emphasizes their importance, including the significance of fire tests and the need to present the uncertainties of their quantitative and qualitative results.

26.2.2018
Ing. Martin Križma, PhD., doc. Ing. Ľubomír Bolha, PhD., doc. Ing. Martin Moravčík, PhD., Mgr. Matúš Holúbek, PhD.

With strengthening of damaged concrete linear elements have been engaged since 2003. It is a co – ÚSTARCH SAS Bratislava, FCE University of Zilina, STU Bratislava. Repaired the damaged components – new the coupling plate with reinforced contact, the coupling plate without reinforcement – replacing the geometrical condition of contact. The use of GFRP panels. The effect of the time factor on both the MS.

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26.2.2018
Ing. Karel Mrázek

When rebuilding the HVAC systems, it is necessary to respect the implementing regulations which define the framework of the certified technical procedures. In a number of examples of practice, it shows the absence of these facts. The article deals with the implementing standards and recommendations for the assembly and acceptance process of heating systems. It is designed not only for assembly companies, but also for investors and administrators who take over the work and then use it.

26.2.2018
Ing. Zuzana Lacová, doc. Ing. Juraj Olbřímek, PhD.

The detail of the chimney system passage is one of the possible details, from a fire point of view, that occurred due to the installation of new chimney systems in to the construction of the building. The chimney system passing through the combustible structure is one of the most dangerous details in the building, from a fire safety point of view, and as practice shows, is often very underestimated. An appropriate solution for the chimney passage requires the knowledge and correct design, as well as the realization and consequently correct use of the thermal appliance and the chimney system. The article deals with passage according to the requirements of the national standards for fire segments and design according to STN EN for chimneys.

19.2.2018
Ing. Milan Dermek, doc. Ing. Mikuláš Monoši, PhD.

The article deals with the issue of water transport by hose lines to fire. It describes pump connections when transporting water according to required parameters at the intervention site. Compares how the hose line is connected and determines the suitability of its use.

Brilon a.s.
19.2.2018
Ing. Karel Mrázek

In the area of existing thermal energy supply systems, the processes of disconnection of existing heat consumers have been ongoing for a long time. The key point is correctness of the Energy Certificates. The article provides an example of a specific assessment of disconnection from central source heat supplier.

19.2.2018
Ing. Ondrej Bajza, doc. Ing. Alena Rohanová

The text describes why and under what conditions the use of beech wood in building structures. Given the legislative and experimental requirements for verification of properties of beech sorting into classes of forts "D". Evaluation of the quality beech wood over the strength of the reliable design, production technology class predictive level as well as the durability of wooden building elements.


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