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Archiv článků od 22.5.2021 do 23.8.2021

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3D tisk budov
23.8.2021
Ing. Josef Kamenický, Ing. Marek Štádler

3D printing technology has contribution in building automatization. Today, printed buildings for everyday usage already exist. 3D printers movements are controlled by G-code. These buildings are described geometrically and then it's transformed in G-code by postprocessor. That one for building printing must respect the properties of printing mixtures. This work designs new postprocessor for building printing. It must include mathematical model of material according to which G-code for specific building geometry will be generated. In the work are proposed experiments to find out parameters for mathematical material model.

22.8.2021
Ing. Petra Okřinová, Ing. Jiří Apeltauer, Ph.D., doc. Ing. Tomáš Apeltauer, Ph.D.

Fire safety assessment of a building is a process in which it is necessary to take into account a number of technical requirements and aspects prescribed by Czech legislation and technical standards. The requirements based on these documents are binding and form specific requirements for buildings and their solutions, which must be taken into account in the design phase of the project, both in its construction and in the technological part. As part of the fire safety assessment, the regulations allow for the possibility of using two basic design approaches, namely the standard approach and the engineering approach. The following work presents selected examples of the application of the engineering approach (specifically using the FEM and CFD methods) for fire safety solutions in comparison with the values obtained by the classical standard approach.

15.8.2021
Ing. Pavel Koudela, Ing. Juraj Chalmovský, Ph.D., doc. Ing. Lumír Míča, Ph.D.

Fibre reinforcing of the soils is one of the methods used for improving the properties of the soils. The many research papers were interested in the fibre reinforcing however, used fibres were straight with smooth surface usually. These properties may not ensure sufficient interaction between soil aggregates and fibres. This disadvantage could eliminate by modification of shape or surface of each fibre and achieve a higher strength of the soil-fibre composite. In this paper is present the soil reinforcing by fibres manufactured by 3D printer. The fibres with the various shapes were made and tested. In the case of the modified fibres, the higher peak strength of the composite occurred.

11.8.2021
Ing. Martin Nguyen, doc. Ing. Radomír Sokolář, Ph.D.

This article examines the process for the synthesis of forsterite–spinel refractory ceramics from different raw materials. Raw materials were milled, mixed in different ratios and sintered at 1500 °C for 2 h. Sintered samples were characterized by XRD and SEM. Porosity, water absorption, bulk density, refractoriness, refractoriness under load and thermal shock resistance were also investigated. The impact of different raw material mixtures was investigated in accordance with the resulting properties and microstructure of all fired samples. Presence of spinel in fired samples led to improved microstructural and mechanical properties and thermal shock resistance. In particular, mixtures with 10–20 % of spinel had the most promising results.

8.8.2021
Ing. Jan Vystrčil, Ing. arch. Tatiana Rebrova

The article describes the development of a prototype vegetation facade panel using parametric modelling. Parametric modelling was then most used for the design of individual parts of the panel, especially the visual part of the panel, which consists of a mathematically generated mesh, and also to create a supporting structure for vegetation. The production of individual prototypes of panels, their parts and components was performed with the help of FDM 3D printing. Individual prototypes were further subjected to testing in real conditions to verify the functionality of the proposed prototype and to identify the strengths and weaknesses of the panel, which will be used for further development.

5.8.2021
Ing. Simona Šarvaicová, Slovenská technická univerzita v Bratislave, Stavebná fakulta, Katedra betónových konštrukcií a mostov

This paper deals with experimental verification of punching shear resistance of a slab fragment. An experimental specimen with thickness of 0.2 m is supported by a rectangular column with cross-sectional dimensions of 0.15 × 0.9 m, as a result of which the shear stress is concentrated in the area of the support corners. As a result of this phenomenon, it is necessary to reduce the length of the control perimeter. Based on the results obtained from the experimental test and from the nonlinear analysis in the Atena program, the real necessity to reduce the length of the control perimeter was analyzed using the Eurocode 2 shear resistance evaluation formula. Subsequently, the reliability of selected design models was verified.

prosluněný interiér © Stock Adobe
2.8.2021
doc. Ing. Jan Kaňka, Ph.D., člen TNK 76 Osvětlení, ČKAIT Praha

To properly understand the meaning of standardization of daylight, it is necessary to think in general about the reason for the existence of standards and the means of their creation. Such a consideration may have its current significance at this time, when the European Commission for Standardization (CEN) unified standards for daylighting of buildings throughout Europe and when the Chamber of Deputies of the Parliament of the Czech Republic approved a new building law.

© Herby ( Herbert ) Me - Fotolia.com
1.8.2021
Ing. et Ing. Daniel Kliment, VUT v Brně, Ústav soudního inženýrství

The paper is elaborated in order to outline the understanding of architecture in relation to the environment and to reflect on a systemic conception of the issue of the role of architectural and urban factors in the valuation of buildings. The main task is to determine the progress of the solution method based on the initial research and analysis. A large part of the article is devoted to the explanation and definition of the system of important quantities. The results and findings will serve as a basis for further research.

29.7.2021
Ing. Ivana Kumpová, Ústav stavební mechaniky, Fakulta stavební, Vysoké učení technické v Brně

The method of X-ray micro-tomography is increasingly used in the research of material characteristics and fracture behavior of building materials. It brings promising results in the field of three-dimensional observation and quantification of microstructure elements, including fracture objects. However, with the standard approach to the tomographic data acquisition, the achievable resolution is severely limited by the size of the examined object resulting in a reduction or even complete loss of useful information regarding, for example, the shape and size of the fracture process zone. For this reason, the possibilities of tomographic targetting of the region of interest with a higher achievable resolution than the usual limit of the tomographic systems have been tested in this work.

26.7.2021
Ing. Gabriela Bariczová, Ing. Ján Erdélyi, PhD.

The paper briefly deals with building information modelling and creation of digital twins of buildings using modern techniques of spatial data collection (TLS). It describes an algorithm for automated verification of the building's structures. It presents algorithms for automated difference model creation between the BIM model and data obtained from TLS or photogrammetry. The results are used to verify the geometric parameters of structural elements (such as flatness of walls, straightness of pipes etc.), as well as to determine deviations in their location (position and orientation from the project itself). The information obtained is a basis for the qualification and quantification of deviations during construction management.

19.7.2021
Ing. Petr Figala, VUT FAST Brno, Ústav technologie stavebních hmot a dílců

This work deals with research and development of a new grouting mortar with increased chemical resistance based on portland cement. The aim of this work is to verify new mixtures with specific admixtures. Resistance to attack by external sulphates was monitored, while the test specimens were placed in a sulphate solution of 29.8 g / l (44 g / l Na2SO4) according to DIN 19753. The results of the work show that the addition of the optimal amount of crystalline waterproofing admixture can achieve a significant increase in resistance to sulfate corrosion. Based on the obtained results, new mixtures will be proposed, optimized by the addition of suitable secondary raw materials.

Membránová konstrukce stabilizující ocelový oblouk
19.7.2021
prof. Ing. Josef Macháček, DrSc., Ing. Ondřej Svoboda, Ph.D.

The article is a follow-up to the Part 1: Experiments and analysis [1], in which a numerical model dealing with membrane structures supported by steel arches in software SOFiSTiK using 3D GNIA and 3D GNA is introduced and validated. This part investigates parametrically stability and buckling of arches of a barrel type membrane structure using linear buckling analysis (3D LBA). The in-plane and out of plane buckling factors of the arches for a vast spectrum of practical geometrical parameters of the structure, membrane pretension and support conditions of the arches and membrane frontiers are presented and confronted with the ones belonging to the arches alone.

Detail ocelovo-membránové konstrukce
12.7.2021
prof. Ing. Josef Macháček, DrSc., Ing. Ondřej Svoboda, Ph.D.

The article describes and analyses testing of a shelter model with a textile membrane supported by a steel tube arch. The goal of the investigation is the spatial behaviour of the arch regarding its design. The difference in behaviour of the build-in arch alone and the one in the membrane structure is investigated. The entry data, prestressing and loading procedures are shown including test results. SOFiSTiK software was used for the elastic geometrically nonlinear analysis with imperfections (GNIA) respecting the orthotropic behaviour of the membrane (Précontraint FERRARI®). The successful validation of numerical results by tests warrants the extensive parametrical studies dealing with stability of arches in barrel type membrane structures in the second Part of the article.

Átriový rodinný dům - bungalov © habrda - Fotolia.com
14.6.2021
Ing. Tereza Jandásková, VUT v Brně, Ústav soudního inženýrství

The paper deals with the development of parameters of the offer for sale (already realized price) real estate. In the conducted research, bid prices are monitored for the duration of their bid until the transaction is realized as indicators of the efficiency of the real estate market. Within the framework of microeconomic research, a database has been created, namely of family houses in the district of Brno - venkov. In the database, the bid price, the selling price and the duration of the bid, including individual changes in the bid price during the bid period, are known for a particular immovable item. The article includes a foreign search of articles dealing with the liquidity of real estate, as well as the development of liquidity memory parameters for family houses in the Brno-venkov district from 2017 to the present.

Hotel Evropa v Praze
14.6.2021
doc. Ing. Jan Masopust, CSc., ČVUT Praha, Fakulta stavební, katedra geotechniky

The paper deals with the monitoring of deformations during the completion and reconstruction of the Hotel Evropa in Prague. Part of the implementation design documentation was the detailed design of geotechnical monitoring of deformations of the foundation pit. This article presents the main features of the measurement outputs in the form of the vertical and horizontal deformations. Monitoring is one of the most extensive and detailed of all that has ever been implemented in our republic, both in terms of its scope and its duration.

7.6.2021
prof. Ing. Jiří Barták, DrSc., ČVUT v Praze, Fakulta stavební, katedra geotechniky

After the demolition of the brutalist Transgas building on Vinohradská street in Prague, whose buildings were situated above the historic Vinohrady tunnels II and III, the Vinohradská Administrative Center and the completion of building no. 345 “Above the Museum” will be built. Both buildings have a foundation joint immediately above the lining of the existing tunnels. The paper describes the main phases of construction, the character and size of the deformation affecting the stone block lining of tunnels.

© imfotograf - Fotolia.com
1.6.2021
Ing. Petra Schůtová, Ing. Kamil Staněk, Ph.D., Ing. Jan Richter

In simplified engineering calculations, the thermal-technical properties of wood are considered to be constant, but in real conditions they are moisture-dependent. This paper deals with the long-term measurement of absorbency at different initial and boundary conditions for the formulation of the coefficient of liquid water transport in wood for advanced computer modelling. A measurement procedure was designed to eliminate the effect of moisture transport in the measurement of water capillary uptake during partial immersion.

© Fotolia.com
31.5.2021
doc. Ing. Michal Stehlík, Ph.D., Mgr. Jana Knapová, Ing. Vojtěch Kostka

The paper deals with the possibilities for use of glass recyclate from photovoltaic panels for concrete masonry units. It compares partivular recipes and its physical and mechanical properties with the main focus on the compressive strength. It then compares the values of these recipes with the values of commonly used composite materials for masonry units without recyclates.

24.5.2021
Ing. Pavel Černý, Ing. Věra Heřmánková, Ph.D.

The present time in the Czech Republic brings a number of diagnostic problems and therefore the diagnostics is currently a widely used field for structural assessment. Otherwise, this is not the case with wooden structures. The paper presents groups of diagnostic methods used for diagnostics of wooden elements built into the structure, which are divided according to invasiveness (non-destructive, semi-destructive and destructive). For each group, the methods that are appropriate to the appropriate group and their brief description are named.

© Christian Delbert - Fotolia.com
22.5.2021
Ing. Tomáš Hrdlička, VUT v Brně, Ústav soudního inženýrství

It was finished 18 390 houses in the Czech Republic. Houses are the most frequent finished type of buildings. The share of construction of brick houses is 83.1% and for wood-base houses its 14.9%. Database of 1520 bids for houses was completed and how what is typical Czech house. It is single floor brick house with sloped roof. The heating system is compiled by electric heater and radiators. Also house market analysis was made. 631 sold houses was examined in the period 2017-2020 in Brno-venkov district, Czech Republic. Only 1.3% wood-based houses was detected.


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