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Abstract

Most of the railway lines in Slovakia were built in the second half of the 19th century, or until 1918 (the establishment of Czechoslovakia). Except for the post-World War II period, when approximately 71 % of the Slovak lines had to be renewed, limited funds have been spent on repair and reconstruction works on the lines located in the Slovak territory. As some trans-European corridors cross the Slovak territory and the Slovak Republic assumed obligations arising from the AGC and AGTC agreements, the line modernization is more than desirable. The primary objective of the modernisation of railway lines in the territory of Slovakia is to ensure a high-quality and safe railway, which by its qualitative parameters corresponds to the standards of developed European countries. In this context, the paper deals with a section of the modernised corridor no. Va, specifically the section Považská Teplá - Žilina. During the period 2014-2017, quality diagnostics of the performed work was carried out on the sub-ballast layers of the above-mentioned line. Consequently, we carried out an analysis of the obtained values of the deformation resistance of the subgrade surface, as the weakest element in the construction of the sub-ballast layers.

Abstract

This paper depends on a test examination on basalt fibres which started from volcanic shakes and were dissolved at high temperatures. These stones were accessible from the world’s profound hull. M30 evaluation of concrete was structured according to is 10262:2009 with basalt fibres. The fibres alongside mineral admixtures were utilized in three distinct extents, that is 0 %, 1 %, 2 %, 3 % by heaviness of cement. The goal was to decide the characteristics of fibre reinforced concrete with various fibre extents. The strength properties, for example, compressive strength, split tensile strength, flexural strength, shear strength and the impact on strength of concrete when it was unprotected to sulphate attack after stipulated extended ages of curing were contemplated and thought about. From the examination, it was discovered that the basalt fibre expanded the strength of concrete notwithstanding when unprotected to sulphate attack bit by bit when compared with consistent concrete. The ideal strength of concrete was accomplished with an enlargement of 2 % basalt fibre.

Abstract

The distance a person is willing to commute has a direct influence on her/his employment opportunities and wage level. It raises a lot of interesting questions, especially whether intra-urban commuting (due to a well-developed transport infrastructure, geographical concentration of job opportunities, etc.) is connected with any wage returns, and how they differ in comparison with those of inter-urban commuting. This article uses three data-sets at national (N1 = 1,884; N2 = 933) and local (N3 = 3,193) levels from the Czech Republic, and different approximations of commuting in order to contribute to the discussion. It provides robust evidence on positive wage returns to both inter-urban and intra-urban commuting, comparable with Western countries. The differences between large national and limited urban labour markets are reflected in functional form: wage returns are linear for intra-urban and non-linear for inter-urban commuting. The article also explores the validity of different measures of commuting time and distance provided by the on-line application Mapy.cz, and suggests that it represents a suitable approximation in the case of missing or limited data.

Abstract

Considering that the unevenness of the road surface is the primary source of the kinematic excitation of the vehicle, it is necessary to map the unevenness, and then to describe it mathematically. The data sets thus obtained represent an important input for numerical simulations of the motion of vehicles on the road. This paper deals with the analysis and comparison of results from two methods of mapping the surface of the road - exact levelling and spatial scanning. The obtained results are evaluated qualitatively and quantitatively by methods of mathematical statistics and probability theory.

Abstract

This article is a dimensioning study of the landfill locker dike of the city of Casablanca, where the geotechnical parameters of waste have particular limitations, theses limitation are a common characteristic for most developing countries. Considering the very small available land area in general, the objective is to achieve an optimal dimensioning of the locker to maximize the volume to be buried, while respecting the requirements of stability of the structure; namely, the model whose safety factor will be greater than 1.5. The Factor of Safety (FoS) was calculated by the Finite Element Method (FEM) using “PLAXIS 2D” software. The results show that, for both cases (with and without final cover), FoS, as obtained from both the analysis, show a similar pattern, with the maximum FoS for low inclinations, especially those lower than 15.95°. The critical FoS (< 1), was obtained for slopes strictly greater than 21.80°. The study also demonstrated that the 3.5H 1V model could be considered as the optimal one that satisfies the structural stability requirements (FoS> 1.5) and maximizes the volume to be buried. Nevertheless, the validation of this model is conditioned by a geometric modification (weakening the lateral slope of the landfill, by moving the dikes by 3 m) and the improvement of the mechanical characteristics of the soil of the peripheral dike, through replacing the material with the compacted clay. This model was validated by PLAXIS, which showed that the FoS for the phase preceding the anchoring of the final cover is 1.577, which reaches 1.604 after anchoring.

Abstract

The paper deals with the determination of mechanical properties of fiber reinforced concrete in dependence on various dosages and recipe of concrete. The mechanical properties were determined for the default recipe of concrete, where the individual variants differ in the amount of fibers. The fibers dosing was 0, 25, 50 and 75 kg/m3. At the highest dosage of 75 kg/m3, the recipe is optimized with regard to the microstructure of the concrete. In the experimental program were determined compressive strength, modulus of elasticity, split tensile strength, flexural tensile strength and load-displacement diagram. The flexural tensile strength was determined based on a three-point and four-point bending test. Based on the evaluated data, the uniaxial tensile strength and the functional dependence for the resultant recipe of concrete with a dosage of 75 kg/m3 is with respect of the increasing importance and application of numerical modelling of building structures, the analysis is performed using non-linear calculation. The aim was to simulate the performed laboratory test and appropriately approximate the specific input parameters of the fiber reinforced concrete for nonlinear analysis.

Abstract

Degradation and disintegration of concrete depend on the formation of cracks and micro cracks intensively. With increase loading, micro cracks are linked together and form cracks. To solve the problem and to provide the homogenous condition, a series of thin fibers having been spread through the volume of concrete are used in the several last decades and they are called as fibers. In the study, the steel fibers integrated in the different percentages of weight have been investigated. The performance of fibers has been studied how to increase compressive strength, tensile strength, and bending strength. To survey compressive strength, tensile strength, and bending strength in the produced concrete, three plans of mixtures including the different percentages of the steel fibers have been examined. The results show that compressive strength in the concrete reinforced with steel fibers relies mainly on the quality of mortar. The added steel fibers cause the inconsiderable changes in the compressive strength of concrete. The results demonstrate that the concrete reinforced with steel fibers increase tensile strength considerably. The more the volume of steel fibers is, the more tensile strength is. Pozzolanic materials used in the specimens reinforced in steel fibers improve tensile strength. To investigate bending strength of the specimens reinforced with steel fibers, the study has used 4-point loading system. Generally, steel fibers used in the concrete increase bending strength of the concrete. The results indicate the increased steel fibers enhance bending strength in three plans of mixtures. Among the specimen reinforced with steel fibres, the most mechanical properties are related to the plans including 1, 1.5, and 2 percentages of dramix hooked steel fibers in the study. To examine crack pattern of the matrix tensile specimen reinforced with the different percentages of fibers, parameters such as the number of cracks, width of cracks, and distance between them are investigated.

Abstract

The paper presents the influence of Key Performance Indicators (KPI) on decision making during the architectural design process. In the beginning, the researcher selected a functional complex of industrial nature for the test and defined five criteria for evaluating the architectural design and then created two categories of result and process indicators to explore the decision making during the design process through Verbal Protocol Analysis (VPA). Two groups of subjects attended the VPA, while one group received the indicators; the other one did not receive the indicators. The protocols were transcribed and encoded to make the comparison more efficient. At the same time, the jury evaluated the sketches separately to check the previous results. The study indicates that the indicators were affecting the decision making and design process and design product simultaneously. First of all, framing decisions were made more organized and mature and at the same time increased in numbers, the key decisions were evaluated easier and in some cases divided into smaller decisions related to one or more criteria and then merged into a final concept, the enabler decision making was done more efficiently and faster because of better thought key decisions and the use of indicators for control. The design process, although still has iterative nature. However, iteration was done in smaller cycles due to the use of result indicators for evaluation and process indicators to lead the process. Indicators facilitate idea generation, and the whole process is without difficulties. The design quality assessment by the jury shows the improvement in the final quality of design outcome in specific aspects related to indicators.

Abstract

Long-term changes in the development of service establishments in the vicinity of the border crossing points on the Polish-Czech border are discussed in this paper. These changes are the result of the border being opened and subsequent economic integration. A series of panel studies, which took place in 1995, 2000 and 2016, analysed of the locations and types of service establishments located within a half kilometre of 18 Polish-Czech border crossings. Given the increasing ease of crossing the border and the maintenance of passport and customs controls, the number of service and retail establishments increased until 2000. After the abolition of passport control in 2007, this number has decreased at many border crossings, with the most significant decreases in financial, insurance-related and commercial facilities (small shops). Most crossings have become little more than transport corridors that offer no important service functions. The total number of cultural, recreational and tourism-related establishments, however, has increased, mainly at border crossings located in towns and villages. The most important changes in service developments at the Polish-Czech border are discussed, as well as the probable reasons for these changes. The results may prove useful for spatial planning in municipalities that are located on the borders of countries undergoing political and economic integration.

Abstract

The patterns of scientific cooperation between the 28 European Union (EU) member countries, Switzerland and Norway, from 1993 and 2017, are evaluated in this article. We consider co-authorship patterns to be proxies for international transfers of tacit knowledge. The theoretical part of the paper contains propositions by researchers in evolutionary economic geography on path-dependence, selection and variation, and the role of networks in knowledge transfer. The principal argument is that the geographical configurations of knowledge transfers over distance are shaped via a set of connectivities – specific communication channels for the exchange of people, goods and knowledge between two or more countries. Some connectivities are more conducive for the transfer of explicit knowledge (e.g. merchandise trade, trade in patents), while human exchange flows (students, migrants, travellers) favour the transfer of tacit knowledge. The research project found that a considerable increase in human exchanges has helped to increase the total number of co-authored papers, but did not amend the geography of the European co-authorship network over last two decades. Rather, the layout of the network stems from a relatively stable set of historical, cultural and political legacies in Europe.