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Denisa Valachova, Nada Zdrazilova, Vladan Panovec and Iveta Skotnicova

Abstract

For the best possible thermal-technical properties of building structures it is necessary to use materials with very low thermal conductivity. Due to the increasing thermal-technical requirements for building structures, the insulating materials are developed. One of the modern thermal insulating materials is so-called aerogel. Unfortunately, this material is not used in the field of external thermal insulation composite systems because of its price and its properties. The aim of this paper is to present possibilities of using this insulating material in the civil engineering - specifically a usage of aerogel in the production of windows.

Open access

Maciej Major, Izabela Major, Daniela Kuchárová and Krzysztof Kuliński

Abstract

The paper presents numerical analysis of block made of three layers: concrete with I-shape rubber pads, space filled with air and concrete with embedded cross rubber pads, respectively. The block is subjected to the dynamic load. To the analysis as rubber the hyperelastic incompressible Zahorski material model was assumed. This material well describes the real material properties in the range of large elastic deformations. Embedded rubber pads provide an additional protection against the transversal dynamic load. ADINA software was utilized to perform numerical analysis of determining the percentage damping factor of rubber-concrete composite in comparison with block made of concrete.

Open access

Leonid Diachenko, Andrey Benin, Vladimir Smirnov and Anastasia Diachenko

Abstract

The aim of the work is to improve the methodology for the dynamic computation of simple beam spans during the impact of high-speed trains.

Mathematical simulation utilizing numerical and analytical methods of structural mechanics is used in the research.

The article analyses parameters of the effect of high-speed trains on simple beam spanning bridge structures and suggests a technique of determining of the dynamic index to the live load. Reliability of the proposed methodology is confirmed by results of numerical simulation of high-speed train passage over spans with different speeds. The proposed algorithm of dynamic computation is based on a connection between maximum acceleration of the span in the resonance mode of vibrations and the main factors of stress-strain state. The methodology allows determining maximum and also minimum values of the main efforts in the construction that makes possible to perform endurance tests. It is noted that dynamic additions for the components of the stress-strain state (bending moments, transverse force and vertical deflections) are different. This condition determines the necessity for differentiated approach to evaluation of dynamic coefficients performing design verification of I and II groups of limiting state. The practical importance: the methodology of determining the dynamic coefficients allows making dynamic calculation and determining the main efforts in split beam spans without numerical simulation and direct dynamic analysis that significantly reduces the labour costs for design.

Open access

Jozef Prokop and Josef Vičan

Abstract

Verification of beam-column resistance can be accomplished according to design approaches given in EN 1993-1-1 [1]. These approaches are derived from verification of single span beam with pinned end conditions subjected to compression and bending moments. In the case of different end conditions, the application of those approaches is not so accurate and more difficult. Therefore, the comparison of verification according to above standard EN 1993-1-1 [1] as well as EN 1999-1-1 [2] to results of experimental analyses of beam-columns having pinned-fixed end conditions subjected to an eccentric compressive force simulating the behaviour of columns integrated into frames is presented in this paper.

Open access

Martin Decký, Matúš Kováč, Juraj Mužík, Lenka Mičechová and Lukáš Ďuriš

Abstract

The article deals with the road pavement surface morphology objectification in term of the surface unevenness degradation during the life cycle of bus stop pavements. The article presents the results of long-term rut depth measurements performed during 25 years on selected bus stops which were intended to determine correlation dependences of pavement rut depth on a number of design axles. The article also presents different methods for rut depth measurements including the straightedge test, Profilograph GE, TRIMBLE CX, and dynamic Road Scanner.

Open access

Martina Margorínová, Mária Trojanová, Martin Decký and Eva Remišová

Abstract

Building and improving road infrastructure in Slovakia is currently influenced by the amount of state funding. Therefore, it is necessary to determine the effectiveness of each proposed solution of road project, which is based on life-cycle costs. Besides capital costs, social costs are also important, which valued the negative impacts due to road construction and operation on road users, the environment, and the population living in the affected area. Some components of social costs have shortcomings in quantifying and valuating, which need to be resolved. The one of important components which affects human health and the value of an area, and have some shortcomings are noise costs. Improvement of this component will lead to more accurate valuation of economic efficiency of roads.

Open access

Ali Vatanshenas, Mohammad Sadegh Rohanimanesh and Ehsan Mohammadiha

Abstract

One of the most important factors that make structures vulnerable to earthquakes is the short distance between structures and epicenter. Near-field earthquakes have special properties, such as increasing acceleration applied to the structure, which distinguishes them from far-field earthquakes. Therefore, the absorption of input energy for structures located near the faults is very important. Hence, by rotating the earthquake acceleration time history and comparing the resulting spectral acceleration response, the angle which applies the greatest force to the structure on the earthquake directivity side is obtained, and then the performance of a steel structure with viscoelastic dampers (VED) under near-field earthquakes with directivity feature is investigated. After analyzing the structure using nonlinear time history analysis, it was observed that the directivity phenomenon leads to significant increase in the force applied to the structure, but the viscoelastic dampers showed an acceptable performance in both states of with and without directivity.

Open access

Zuzana Grúňová

Abstract

Gothic architecture is one of the oldest surviving architecture in Slovakia. The Church of St Catherine of Alexandria in Handlová was built in the High Gothic period of 1360 - 1370; its main stone portal belongs to the later phase of 1502. The paper focuses on architectural features and geometry of this late gothic portal. The portal has a geometrical construction clearly based on the square of 2670 × 2670 mm. The division into thirds is applied in the details of the intersecting stone mouldings. Conclusions of the geometrical analysis suggest that the ratio of width to height of the entire portal could be close to 2 : 3 or 5 : 8 to suggest some consideration, but it was not a primary goal to attain precise ratios. The stone cutter just followed many times repeated geometrical procedure - square and the pointed arch, based on it.

Open access

Glib Vatulia, Maryna Rezunenko, Dmytro Petrenko and Sergii Rezunenko

Abstract

Experimental studies of rectangular steel-concrete columns under centric compression with random eccentricity were conducted. The stress-strain state and the carrying capacity exhaustion have been assessed. The regression dependence is proposed to determine the maximum carrying capacity of such columns. The mathematical model takes into account the combined influence of the physical and geometric characteristics of the columns, such as their length, crosssectional area, casing thickness, prism strength of concrete, yield strength of steel, modulus of elasticity of both steel and concrete. The correspondence of the obtained model to the experimental data, as well as the significance of the regression parameters are confirmed by the Fisher and Student criteria.

Open access

Oto Makýš, Peter Krušinský, Renáta Korenková and Dominika Šrobárová

Abstract

The paper deals with the lifetime of wooden poles, situated in the archaeological open-air museum Liptovská Mara - Havránok, which were erected outdoors about 12 years ago. It is aimed at diagnosing their condition using sonic tomography. The poles differ from each other in the location, anchorage, and positioning in terms of the terrain slope. Investigation was focused on the free-standing poles (quasi sacrifice poles) and the poles that are part of the fortification (gates and walls). Measurements were carried out using the device Fakopp ArborSonic 3D Sonic Tomograph that has 18 sensors. It measures the sonic response (sound velocity) in a tree stem. Sound wave velocity within sound wood depends on its species, moisture content, and the direction of measurement. Measurements brought remarkable results.