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Libor Ižvolt, Peter Dobeš and Juraj Pieš

Abstract

The initial part of the paper briefly characterizes the present state of the track substructure dimensioning for the non-traffic load and the necessity of updating the design map of frost indexes IFd as a basis for dimensioning. A substantial part of the paper is dedicated to the method of evaluating the data provided by the Slovak Hydrometeorological Institute (SHMI), and determining the dependency of design air frost indexes IFd on altitude for the coldest winter period in the past 50 years. The paper conclusion presents the updated design map of frost indexes and the assessment of the importance of its updating in terms of the track substructure dimensioning methodology for the non-traffic load.

Open access

Rositsa Petkova-Slipets and Penka Zlateva

Abstract

The paper presents the results from a study of the thermo-physical properties of a new synthetic acrylic polymer used as material in road construction and as concrete on its basis. For the purposes of the study, the Modified Transient Plane Source Method (MTPS) was used. Data on the following thermal characteristics were obtained: thermal conductivity coefficient, thermal effusion, thermal diffusion and specific thermal capacity. A comparative analysis was made with the analogous indicators of conventional petroleum bitumen and asphalt concrete. The results of the study can be used for a more precise calculation and prognosis of temperature deformations and thermal stresses, as well as the crack propensity at low temperatures in asphalt concretes.

Open access

Zeynab Mohammadian and Majid Shahbazi

Abstract

Housing is a widespread and complex issue with a variety of dimensions. First, housing was considered as a physical location and as a shelter and basic necessity of the households, but today the concept of dwelling as the place that provides all the services and facilities necessary for a better life of the family has been created. One of the issues discussed at many conferences and in general in the scientific community is the definition of sustainability in the psychological point of view, along with the ways to introduce this concept into the architecture and human habitat environments. This research first begins with the main question about how the concept of sustainability can be found within the scope of housing. Then existing resources search is done and accessible projects are analyzed and the weaknesses and strengths of traditional architecture and contemporary architecture are compared. Finally, the relationship between the definitions of three concepts: dwelling, sustainable design and traditional Iranian architecture was discussed. At the end, the sustainable design that is also appropriate to the Iranian culture was presented.

Open access

Veronika Valašková and Jozef Vlček

Abstract

This article illustrates the applicability of the Finite Element Method (FEM) in the analysis of multi-layer concrete pavement systems subjected to tire loading of a heavy vehicle. For the purpose of simplifying the interaction of the interaction system, it is appropriate to divide the system into two separate independent subsystems, the vehicle and the pavement. For this reason, 2-dimensional interaction model of the contact vehicle-obstacle and 3-dimensional FEM model of the concrete pavement were created. A several constitutive material models, such as linear elastic model, are applied in the analysis to describe the behaviour of the pavement structure. The numerical results from the first computational model can be used as the input for the second calculation phase. The concrete pavement represents a standard pavement, which is used for the regular road structures in road engineering. FEM modelling of the pavement can be used for the direct estimation of the pavement response without performing time and cost expensive field experiments. Calculations were performed in software ADINA using FEM method.

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Mária Kúdelčíková and Eva Merčiaková

Abstract

In structural dynamics models of mechanical oscillator and vibration analysis are of great importance. In this article motion of mechanical oscillator is modelled using second order linear autonomous differential systems. Stability of such 1 DOF models is investigated with respect to the coefficients of systems. Phase portraits for various cases are displayed and the character of fixed points is described.

Open access

Andrey Benin and Ekaterina Bogdanova

Abstract

A trend of applying composite reinforcement in construction industry has been growing in Russia recently: hence, new manufacturing plants have appeared and the volume of sales has increased. However there were not enough experimental studies of the polymer reinforcement chemical stability and the influence of various factors (climate, corrosive environments, nonstationary loading, etc.) on the strength of structures reinforced with polymer rebars. The objective of this investigation was to identify the influence of long-term storage conditions and exposure to corrosive environment (i.e. 5 % NaCl solution) produced on the mechanical properties of GFRP rebars.

Open access

Soňa Medvecká, Oľga Ivánková, Marek Macák and Vladimíra Michalcová

Abstract

In this article, the results of pressure coefficient on the atypical object obtained by experimental measurements in a boundary layer wind tunnel (BLWT) of Slovak University of Technology in Bratislava (STU) and computational fluid dynamics simulation (CFD) are presented. The pressure coefficient is one of the most important parameters expressing the wind pressure distribution on the structure. The loading by wind can only be acquired by execution of detailed tests and numerical analyses [1].

Open access

Zuzana Grúňová and Michaela Holešová

Abstract

Entasis, upward curvature, columnar inclination and several other manipulations or deviations from the strict geometrical rules were known in Ancient Greece and Rome and some of them - entasis could be taken as example - were used up to the beginning of the 20th century in eclectic and historicizing architecture. The article mentions historical texts about entasis from Vitruvius up to Renaissance works. Mainly Vignola’s description of proper and elegant way of how to construct columnar entasis curve of the Tuscan and Doric order columns is discussed in detail and expressed mathematically.

Open access

Daniela Jurasova

Abstract

The climate change assumes nowadays on significance. Weather data may be available on various time scales – long-term, minutes, hours, days, periods, years. Measurements of air temperature are realized for a long time. Data in Slovakia are available from few weather stations of Slovak Hydrometeorological Institute (SHMI). For long-term and wide-ranging measurement of various parameters this can be complicated and expensive. This paper is focused on temperature measurement near the experimental laboratory. Estimation of daily, monthly and yearly mean temperatures is done in different ways. Results from experimental temperature measurement, in a way of selection of unusual extremes are presented. Shorter recording intervals describe the temperature courses in a more pertinent way.

Open access

Vladimir Andreevich Usoltsev, Seyed Omid Reza Shobairi and Viktor Petrovich Chasovskikh

Abstract

In recent years, as the ecological role of forests has grown to a global level, the need to analyze their biological productivity in terms of biogeography has increased. Such studies are carried out mainly on a regional scale at the levels of both single-trees and forest stands. Thanks to formed by the authors the database on the biomass of 1076 sample trees of the genus Betula sp. growing on the territory of Eurasia, the trans-Eurasian model of tree biomass is proposed for the first time. The model takes into account regional differences in the biomass structure of equal-sized trees, harmonized on the principle of additivity.