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Archiv článků od 2.9.2019 do 13.1.2020

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13.1.2020
doc. Ing. Vladimír Tichomirov, CSc., LL.M., Ing. Marek Kervitcer

In this paper, the authors consider the aspects of routine procedure compared to the expert approach in solving construction defects and failures. For better orientation in the issue the basic terminology of defects and failures sphere is given. Also, the authors describe in details the course of both solutions, contemplate their specific aspects and point out their consequences. An essential part of the article is presentation of the potential benefits of the expert approach, the advantages of the expert approach are emphasized in the conclusion.

6.1.2020
Ing. Dagmar Michoinová, Ph.D., Národní památkový ústav ČR, Technologická laboratoř,

The paper discusses the importance of water absorption of traditional building materials and the ability of traditional non-insulated buildings to withstand rising damp. It also draws attention to some of the risks involved in reducing the water absorption of building materials designed for remediation of moisture and salts problems of traditional buildings.

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30.12.2019
Ing. Eduard Schilhart, CSc., Sdružení výrobců pro ploché střechy

Any roof likely to fall from a height shall be fitted with a handrail or restraint system as appropriate for the intended operation. Protection of persons against falls from a height must be addressed already during construction. Therefore, Act No. 309/2006 Coll. in its current wording, it specifies the work of the contractor and sets out its obligations. In addition to this Act updated in 2016, it is of course necessary to take into account other legislative requirements in the construction process. This implies many responsibilities of individual construction participants, which will be discussed in this paper.

30.12.2019
doc. Ing. Petr Cikrle, Ph.D., Ing. Sabina Hüblová, Ing. Zuzana Oščatková, Mgr. Veronika Singrová

This article describes how to monitor panel house faults. Object movements are measured by a Hollan deformeter (used to measure changes in crack widths and joints) and by floor leveling.

23.12.2019
Ing. Jiří Kunecký, Ph.D., Ing. Martin Hataj, Ph.D., Ing. Hana Hasníková, Ph.D., Ing. Jaromír Milch, Ph.D., Ing. Monika Tyrová, Ing. Pavlína Suchomelová

Oak dowels find its use in carpentry joints, reconstructions of buildings and, also, dowel-joined CLT panels put together without adhesives. The article deals with influence of manufacturing techniques and shape of the cross-section on the bearing capacity of the dowels. Round shape (turning and perforation through steel hole) and hand hawing to the octagonal shape was tested. The results show negligible influence of manufacturing techniques on studied quantity.

16.12.2019
Ing. Lukáš Velebil, doc. Ing. Petr Kuklík, CSc.

The paper presents the results of experimental analysis and an analytical model describing the behavior of racking shear walls made of mechanically joined cross laminated timber. Tests of wall panels, tests for determination of stiffness of layers’ joints and material tests were carried out as part of experimental analysis. Outputs from the layer stiffness tests and material tests are used as input data for the analytical model. The analytical model is based on a component method that considers a wall panel as a system of interconnected elements. The action of the elements is described by springs with defined stiffness. The results of the experiments and the analytical procedure are then compared with each other.

4.12.2019
Josef Krupka, Zakládající člen České hydroizolační společnosti (ČHIS)

The flat roofs of warehouse and production halls show some typical defects. A very common cause of roof problems is incorrect implementation of anchoring detail of the attic. The causes and solutions to these typical defects are described below.

3.12.2019
Miroslava Ševčíková, Vědecko-výzkumný uhelný ústav (VVUÚ) Ostrava Radvanice

In this article, we focus on fundamental element of primary protection – detection devices for registering the rise of hazardous concentrations of gases and vapors. We have chosen and described for each type of device and kind of detected gas basic tests that are necessary for ensuring their correct and reliable function.

Ilustrační obrázek © Dmitry Vereshchagin - Fotolia.com
25.11.2019
Ing. Otto Dvořák, Ph.D., VŠB TUO FBI Ostrava, externí školitel

The article briefly introduces basic technical terminology, errors and computational algorithms for estimating uncertainty of type A, type B, combined and extended uncertainty of test results and that the test management performs the tasks specified in the standard ČSN EN ISO / IEC 17025.

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13.11.2019
Ing. Zuzana Vidholdová, PhD., Ing. Gabriela Slabejová, PhD.

Treatment of wood surfaces with various finish coating materials is recommended for long term protection of wood products exposed outdoor. However, in practice it can happen that wood in constructions has been attacked by wood decay fungi before to application of a finish. In this work, selected properties of sapwood and heartwood of pine (Pinus sylvestris, L.) surface such as surface roughness and adhesion of coating film were investigated on the surfaces attacked by wood decay fungi (Coniophora puteana and Trametes versicolor) and wood staining fungus (Aureobasidium pullulans). Two coating materials useable for wooden constructions in exterior conditions were used: dark brown long-oil alkyd-based system and light brown oil-based surface treatment. The result of the pull-off test for adhesion of both surface treatments was significantly greater on the heartwood surfaces than on the sapwood surfaces of the sound wood. With the increasing time of wood degradation by fungi, the adhesion of the alkyd surface treatment decreased on the sapwood. Adhesion of the oil surface treatment was comparable on the both sound and decayed wood. According to the disruption analysis following the pulling of the dolly, the weakest point was the surface layer of the wood impregnated with coatings. The adhesion of the both surface treatments is comparable to the sound and wood affected with the staining fungus.

11.11.2019
prof. Ing. Martin Jiránek, CSc., ČVUT v Praze, Fakulta stavební

The article describes all significant changes in the field of designing and implementing radon protective and remedial measures introduced by the revised version of ČSN 73 0601, which came into force on 1.10.2019. A new way of selecting measures according to the building type and new concept of designing according to the design values of input parameters are introduced. A new methodology for designing radon-proof insulations is described in detail. According to this methodology, only insulation with a radon resistance greater than the prescribed minimum radon resistance can be used for building protection.

Parametrická štúdia tepelnej bilancie budovy, ilustrační snímek © Büros - Fotolia.com
22.10.2019
prof. Ing. Ivan Chmúrny, PhD., Stavebná fakulta STU Bratislava, Katedra konštrukcií pozemných stavieb

Increasing the thermal insulation properties of walls, roofs, floors and windows has a positive effect on reducing heat loss and energy need for heating. However, when assessing the energy need for cooling in buildings with conditioned indoor environment, this tendency to increase the thermal insulation capability may lead to an increase the energy need for cooling, when measures to reduce heat gains by transparent structures are not applied.

14.10.2019
Prof. Ing. Pavol Ďurica, CSc., Ing. Peter Barňák

In the contribution, we are focused on the quality of the heat-moisture microclimate and the aspects that affect it. We chose one office room in the building of the Research Center of the University of Žilina (UNIZA), oriented to the west. The subject of the measurements were all physical components of the indoor environment, the effect of solar radiation through window constructions and floor temperatures using low-temperature radiant floor heating. The contribution describes measuring methods, results of measurements and related partial conclusions for cold climatic conditions of the year.

7.10.2019
Ing. Dana Bellušová, Technický a skúšobný ústav stavebný, n.o.

The contribution deals with the experiment verifying the load bearing capacity of anchors for ETICS with thermal insulation of higher thicknesses. In connection with the increase of the requirements for the energy performance of buildings, the thermal insulation thicknesses are increased to meet the design conditions.

7.10.2019
doc. Ing. Pavel Schmid, Ph.D., Ing. Petr Daněk, Ph.D., Ing. Iva Rozsypalová, Ing. Petr Gabriel

The paper deals with a case study of building defects inspection of Lužánky Free Time Centre in Brno. It is described the history of the building and the building diagnostics. There were used the survey methods of visual-defectoscopic inspection, semidestructive diagnosis and diagnosis of foundations and foundation soil. The conclusions contain recommendations for immediate and long-term solution of the object's static problems.

2.10.2019
doc. Ing. Jiří Brožovský, CSc., VUT FAST Brno pracoviště AdMaS

Rebound hammers complying with the specifications of ČSN EN 12504-2 resp. ČSN 73 1373 is used primarily for the determination of compressive strength of concrete in the structure. The paper presents the knowledge of the use of mechanical rebound hammer with impact energy of 0.735 N.m (type L) for the determination of compressive strength and tensile bending of calcium silicate bricks 290 × 140 × 65 mm. Calibration relationships for compression and tensile strength bending from the rebound number are presented. In practice, the calibration relationship for compressive strength prediction is applicable, the relationship for tensile bending strength does not show sufficient tightness between the variables and can only be used provided that a refinement coefficient is defined in the sense of ČSN 73 1370.

9.9.2019
Ing. Gabriela Slabejová, PhD., Ing. Zuzana Vidholdová, PhD.

Treatment of wood surfaces with various finish coating materials is recommended for long term protection of wood products exposed outdoor. Due to natural weathering, the colour and the surface roughness of uncoated wood is changed. However, in practice it can happen that wood in constructions has been weathered before to application of a finish. In this work, selected properties of sapwood and heartwood of pine (Pinus sylvestris, L.) surface such as surface roughness and adhesion of coating film were investigated on the surfaces of previous naturally weathered wood Two coating materials useable for wooden constructions in exterior conditions were used: dark brown polyurethane-based system and light brown oil-based surface treatment. The results of pull-off test for adhesion showed that the polyurethane coating film showed the weakest point in the pre-weathered layer of wood substrate and also at the wood/coating interface. The oil-based surface treatment had the weakest place inside the coating film or in the coating penetration layer in the wood substrate. Pre-weathering did not significantly affect the adhesion the coating film on wood. The result of the pull-off test for adhesion of both surface treatments was significantly greater on the heartwood surfaces than on the sapwood surfaces of the sound wood.

7.9.2019
Ing. Lukáš Bříza, VUT Brno

An important part of the construction is the lifting mechanism. If it is used properly and efficiently, the schedule and the completion date of the construction can be better followed. Incorrect or inefficient use of lifting mechanisms leads to unwanted downtime, failure to meet the potential of the mechanism, or overflowing it with a number of ongoing work processes. With the help of data collection (lifting load time), we try to map the use of lifting mechanisms throughout the construction. The obtained and properly evaluated data will serve as a basis for the simulation model to assess the effective use of the lifting device on the site.

2.9.2019
prof. Ing. Leonard Hobst, CSc., doc. Ing. Petr Cikrle, Ph.D.

Steel structures are preferably used to build existing structures. However, when designing them, it is necessary to adhere to precise principles to avoid malfunctions during operation, such as condensation of water, in case of poorly chosen structure of the structure. Some nondestructive testing methods can be used to detect these potential defects.


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