Detection of Changes in the Hydrological Balance in Seven River Basins Along the Western Carpathians in Slovakia

Due to a changing climate, likely changes to a hydrological regime are one of the primary sources of uncertainty to consider in managing water resources. In Slovakia, a decline in the country’s water resources, combined with a change in the seasonality of runoff and an increase in the extremeness of floods and droughts, represents a potential threat. The objective of the paper was to explore trends in the components of the long-term hydrological balance of various river basins to detect the impacts of changing climate conditions along the Western Carpathians. The proposed method is a comparative exploratory analysis of the hydrological balance of the selected river basins. Temporal changes in the catchments’ average air temperatures, precipitation, runoff, and their differences (considered as an index of the actual evapotranspiration), were estimated for 49 years of data; two non-overlapping sub-periods (25 and 24 years) in the seven river basins were also compared. This work also aims at evaluating the applicability of gridded inputs from the CarpatClim database for modelling the hydrological balance over an extended period. The results document the impact of the rising air temperature and, in part, local physiographic factors on the changes in runoff and actual catchment evapotranspiration.

Risk Assessment Model Based on Fuzzy Logic for Residential Buildings

Risk is involved in every construction project. Residential building construction projects comprise a variety of risks and are more likely to be affected due to their difficulty and many operations and threats. The study aims to identify the various risk elements and their effect on construction projects of residential buildings using a fuzzy approach with the help of MATLAB software. This study includes 60 risk factors recognised through an expert opinion and literature review. These factors are categorised into 7 major groups, i.e., construction, project manager, architect/consultant, contractor, owner, resources, and external environment-specific risk factors. A questionnaire was prepared and sent using emails based on the identified risk factors to be filled out by construction industry professionals in India and by conducting in-person interviews. Based on the risk severities obtained from the fuzzy model, the top 10 risk factors have been considered. As a result, for identified top severe risk factors, a significant risk response strategy was implemented.

Assessment of the Energy Demands for Heating in an Historic Building. Case Study: Renewal of a Functionalist Building of the Infectious Diseases Pavilion in Topoľčany, Slovakia

The case study seeks an optimal solution for preserving the cultural values of a functionalist building so that it fulfils the legislative essence of the protection of a historic building and, at the same time, contributes to the improvement of its thermophysical properties. The paper focuses on the degree of the application of energy performance requirements for the adaptive reuse of a historic building. The efforts to preserve cultural values (architectural, aesthetic, the value of the authenticity of an area and its building constructions, etc.) in legally protected buildings often do not permit the application of building construction processes such as those used in ordinary older buildings. The research responds to a situation where a building with historic values, built in a functionalist style (the 1940s), permits variants of the surface treatment of the facade so as to not disturb the essential stylistic values of that facade and, at the same time, reduce its energy demands to the required value. Heat demands for heating have a significant effect on the energy needs for heating and thus on the overall energy need of a building. The heat demands depend on the efficiency and quality of the thermal protection in buildings. In the case of cultural monuments, the calculation of the thermophysical properties of building structures forms the basis for determining the heating and cooling demands. Building structures and their elements that form the building envelope must meet current and demanding thermophysical requirements in accordance with the applicable standards, if technically and economically feasible. When restoring cultural monuments in the Slovak Republic, it is not required to meet requirements for energy efficiency. On the other hand, it is necessary to verify the thermophysical requirements in accordance with the applicable standards in each specific case. The paper responds to a continuing interdisciplinary discussion on this topic. The analysis is conducted within the scope of the KEGA 016STU-4/2017 project.

Analysis of the Effect of the Speed Factor on Highway Safety Using the Machine Learning Method

Speed is one of the most important factors that can significantly change the severity of accidents. Providing a model with predictive factors leads to designing traffic plans to promote safety. This study aims to create statistical models for accidents occurred on Firuzkuh highway, Iran. Moreover, the probability of each type of accident was determined using the logit model. Various modeling methods, such as backward, forward, and entering methods, were evaluated to find the best method. Finally, since the backward method had the best performance in terms of R2 and goodness of fit, the logit model of accidents was created. According to the model, the independent variables of the 12-24 hours, rainy weather, a speed of 81-95 and 96-110 km/h, the lack of attention ahead and the Pride brand of vehicle increased the severity of accidents, while the variables with negative coefficients of Tuesdays, the summer and spring seasons, sunny weather, a male driver, and daylight, reduced the severity of accidents.

Extensive Roof Greenery as a Response to Heat Islands: Some Problems

Extensive roof greenery is one of the ways to reduce the extent and impact of urban heat islands. A prerequisite is the correct design and operation of both the structural and vegetation part of a roof. If adequate maintenance, especially irrigation of the greenery, cannot be ensured, the use of extensive roof greenery can also be counterproductive. The case study to be presented deals with problems of a flat roof with extensive greenery above an underground garage under Central European climate conditions. Infrequent irrigation leads to extremely high temperatures of the substrate in the summer and makes the purpose of this roof pointless. The contribution analyzes the reason for the failure of the vegetation part of the roof, which was claimed to be maintenance-free, points out fire safety issues, and suggests improvements that might be considered in similar cases. At the present time, which is marked by the climate change crisis, there is great societal pressure to build green roofs. However, if it is not possible to ensure their perfect functionality, it is perhaps better to use classically proven types of roofs, but with greater reflectivity of the top layer surface.

Research on a Trackside Concrete Reinforcement Scheme of a Small Radius Curve at a Junction Section of a Modern Tram

In order to ensure the normal use of a junction section of a modern tram, this paper mainly studied a trackside concrete reinforcement scheme. Firstly, the entire non-reinforcement system model with a small radius curve composed of rail, fastener, fastener cover, flexible material, asphalt layer and track slab was established using the ABAQUS finite element software, and the stress distribution and deformation state of the asphalt layers of the non-reinforcement system model under the social vehicle load were analyzed. Then, the whole system model of the concrete reinforcement scheme was founded, and the stress and deformation of the asphalt layers under the same load were investigated. Finally, the calculation results of the concrete reinforcement model were com-pared with those of the non-reinforcement model, and the reinforcement effect was studied. The results show that the concrete reinforcement scheme significantly reduces the stress and deformation of the asphalt layers and improves the stress distribution and deformation state of the asphalt layers.

Causes of Failures in Circular Concrete Silo Walls, Particularly Under Environmental Influences

The paper reports the results of a case study for achieving longer service life and increasing the environmental sustainability of concrete silos. Damage mechanisms in concrete silo walls, and respectively in cylindrical structures (e.g., chimneys, cooling towers, and tanks), are widely diverse. The common causes of failures include those due to poor design considerations, construction deficiencies, non-compliance with operational rules and regulations, lack of maintenance, and insufficient and/or corroded reinforcements, together with the environmental conditions affecting the walls. In addition to the ultimate limit state design, temperature-induced cracking may often be underestimated in the design of reinforced concrete silos, leading to premature deterioration and losses in serviceability. Cracks from environmental or service conditions facilitate the ingress of moisture and corrosive agents. Therefore, there is an increased interest in reducing the appearance of cracks and limiting their width. The aim of this paper is to highlight the synergistic effects in the design, construction, and operation of silo walls, particularly under varying environmental influences. The research undertaken indicates that systematic errors can be identified and corrected.

Modelling Pedestrian Crossing Behaviour at a Midblock Section

In general, pedestrians want to cross a road at a mid-block section instead of intersections because it is the shortest route. According to an Indian scenario, most of the crosswalks in urban areas are not signalised and controlled. In this study, the crossing behaviour of pedestrians in terms of speed at a midblock section was studied by considering several parameters. Statistical tests such as ANOVA and Pearson correlation tests were performed in order to know the effect of parameters on the crossing speed of a pedestrian. The pedestrian’s age and gender, crossing type, pattern, time, number of stops, number of two wheelers, three wheelers, light and heavy commercial vehicles, and groups significantly affect their crossing speed. A multiple linear regression model was developed by considering the most significant parameters. The mean absolute percentage error, root mean square error, and R2 values were calculated to validate the models.

A Simplified Matrix Analysis Approach to Multi Storey Buildings Involving a Friction Damper

Damping through friction tends to be one of the most efficient methods to suppress damage to structures from earthquakes. Realizing robust structures is therefore highly dependent on designing for the dynamic forces of friction- damped structures and exploring their reliability against natural disasters. This paper presents a simplified matrix analysis algorithm for multi-storey friction- damped buildings. We have analyzed the behavior of friction- damped systems more accurately by modeling the master-slave degree of freedom of the joints. First, the formulation of the problem is discussed, and a condensed general equation is derived. Then, an end- to- end solution is proposed to find the responses of structures. The displacement response of each storey has been carried out in both condensed and non-condensed general equations, and the results clearly show the accuracy of the proposed method. The numerical analysis and the results of the simulation of various friction- damped structures depicts the proposed approach consists with the commercial finite element method and is applicable for the analysis various types of structures. It is noted that the acceleration and displacement responses of the structures investigated under the proposed method and the traditional finite element method are so consistent that only a 1.5% difference is observed. Moreover, as a result of the proper allocation of degrees of freedom during the analysis, this method yields a reduction in computational costs especially in large buildings.

Evaluation of an Asphalt Mixture Containing a High Content of Reclaimed Asphalt and Different Crumb Rubber Modified Binders

Recently, environmental concerns have become a primary driving force in most countries and industries dealing with natural resources. As a part of this category, asphalt pavement industry is trying to implement more green and sustainable features in its products, while maintaining the mechanical and performance-based properties of the resulting asphalt mixtures. Among potential recycled materials, vehicle tires and aged asphalt pavement have been demonstrated to show economic, ecological, and behavioral improvements in the mixtures. However, mixtures with a high content of reclaimed asphalt (RA) and crumb rubber present some limitations. Therefore, using another group of additives, i.e., a warm mix asphalt (WMA) additive, has been considered. The presented paper investigates the use of an elevated content of RA with different crumb rubber modified binders and (in some mixtures) a warm mix additive in an asphalt concrete (AC) binder mix. Regular empirical tests have been conducted and more advanced performance or functional characteristics, i.e., stiffness, thermal induced cracking, resistance to permanent deformation, complex modulus have been determined and evaluated. Selected results are presented in the paper.