Zoltán Major

55791244200

Publications - 28

Quantifying the Effect of Frame Stiffness – The Substitution Inertia of Meier's Calculation

Szabolcs Fischer Zoltán Major Attila Németh Vivien Jóvér

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2025-01-01

Volume: 1258 LNNS

Issue: Unknown

Page Range: 46-57

Description:

The internationally accepted method for assessing track stability is the calculation based on Meier's theory. A critical point is the inclusion of the equivalent track bending stiffness. Practical measurements have often given contradictory results in determining this, so the authors present a purely theoretical determination in this article. For this purpose, the Nemesdy theory, which is used in Hungarian practice, is invoked. By applying this theory, the paper introduces an auxiliary factor that allows us to calculate the value of the inertia of the two rails on the vertical axis. Stopping at this point in the theoretical derivation and recognizing the possibility, an iterative solution is proposed by which the magnitude of the substitute inertia can be considered in Meier's calculation without performing the necessary calculations using Nemesdy's theory.

Open Access: Yes

DOI: 10.1007/978-3-031-81799-1_5

Dynamic Modeling Possibilities of Embedded Rail Structures

Szabolcs Fischer Zoltán Major Attila Németh Vivien Jóvér Nándor Liegner

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2025-01-01

Volume: 22

Issue: 4

Page Range: 29-43

Description:

In Hungarian design practice, the Zimmermann-Eisenmann quasi-static design method is employed to dimension track structures with embedded rails. This method determines the mean values of deformations and stresses using an infinitely long elastically embedded beam as the static frame. After establishing these mean values, the effects of track condition and speed are considered through Eisenmann multiplication, enabling the definition of design values. Conversely, international practices include methods that calculate deformations and stresses based on dynamic models incorporating viscoelastic embedding, directly accounting for speed but not dynamic effects due to track characteristics. This paper presents a solution to the dynamic problem, extending it to studying rotating frames beyond the commonly considered uniaxial solution. Each factor's effect is separately analyzed for track structures with embedded rail tracks, leading to a recommendation for the value of the "load multiplication factor".

Open Access: Yes

DOI: 10.12700/APH.22.4.2025.4.3

Rolling Contact fatigue Defects and a New Approach to Rail Material Management

Éva Lublóy Zoltán Major Szigeti Cecília Róbert Horváth

Publication Name: Acta Polytechnica Hungarica

Publication Date: 2025-01-01

Volume: 22

Issue: 4

Page Range: 227-246

Description:

This article describes the current method of calculating the Hertzian contact stress and the corresponding shear stress occurring in the rail head at the rail-wheel contact and highlights the false sense of security that this approach creates among experts. The authors then present a method that is easy to implement in spreadsheet software and provides realistic results. In light of the results obtained, it is shown that it is not possible to prevent defects induced by the occurring stresses but only to keep them within limits by means of rail machining, which is a realistic objective, without significantly limiting the throughput capacity of the railway track. The combined effects of rail machining and natural wear cause the cross-sectional area and inertia and thus, the load-bearing capacity of the rails to decrease continuously. If the limit is exceeded, the rails may be installed again in less heavily used track sections and continue functioning. At the end of their service life, the track owner sells them as used rail scrap. If possible, recasting them as electro-steels, can significantly reduce the production costs and the amount of CO2 emitted during production.

Open Access: Yes

DOI: DOI not available

Investigation of CO2 Emission Concerning Levee Reinforcement Technologies

Edina Koch Zoltán Major Szigeti Cecília

Publication Name: Lecture Notes in Civil Engineering

Publication Date: 2025-01-01

Volume: 580 LNCE

Issue: Unknown

Page Range: 1-10

Description:

Flooding is one of the primary causes of losses from natural disasters in numerous regions worldwide, surpassing all other types of natural hazards in terms of damage. In recent decades, flood damage has been significantly severe due to the increase in the frequency and intensity of floods. Considering that levees are built for an established design life, it is essential to consider potential changes in loads due to atmospheric climate change. Climate variability may affect hydraulic loading and soil eroding with significant precipitation or during drought or high wind conditions. These atmospheric changes over time may affect the structural integrity of the levee. The dominating failure modes for typical ground conditions along rivers are slope stability, overtopping, through seepage, and underseepage. Several technologies can be applied to prevent levee failure, strengthen the levee, avoid overtopping or internal erosion, and ground subsidence due to changing groundwater. The most common ones are concrete columns, sheet piles, geosynthetics, and deep mixing using different binders. However, these technologies come out to be costly, in terms of materials. Moreover, the primary material of these interventions is cement. Nowadays, it is accepted that the cement industry is one of the two largest producers of carbon dioxide (CO2). The Sustainable Development Goals (SDGs) provide comprehensive guidelines for promoting sustainable development in terms of environmental, social, and economic dimensions in all sectors of the economy, including civil engineering. The study outlines the procedure to calculate the carbon dioxide emissions of different technologies for levee reinforcement. Considering a simple scenario, the technical suitability of the investigated technologies is analyzed, and the carbon dioxide emission is analyzed separately.

Open Access: Yes

DOI: 10.1007/978-981-96-1873-6_1

Laboratory and Numerical Investigation of Pre-Tensioned Reinforced Concrete Railway Sleepers Combined with Plastic Fiber Reinforcement

Szabolcs Fischer Mykola Sysyn Zoltán Major Sarah Khaleel Ibrahim Dmytro Kurhan Vivien Jóvér Szabolcs Szalai Hanna Csótár Klaudia Madarász András Pollák Dániel Harrach Bálint Molnár L. Gaspar Bence Hermán Szabolcs Kocsis Szurke Attila Németh I. Fekete Richárd Nagy Gusztáv Baranyai Miklós Kuczmann M. Movahedi Rad

Publication Name: Polymers

Publication Date: 2024-06-01

Volume: 16

Issue: 11

Page Range: Unknown

Description:

This research investigates the application of plastic fiber reinforcement in pre-tensioned reinforced concrete railway sleepers, conducting an in-depth examination in both experimental and computational aspects. Utilizing 3-point bending tests and the GOM ARAMIS system for Digital Image Correlation, this study meticulously evaluates the structural responses and crack development in conventional and plastic fiber-reinforced sleepers under varying bending moments. Complementing these tests, the investigation employs ABAQUS’ advanced finite element modeling to enhance the analysis, ensuring precise calibration and validation of the numerical models. This dual approach comprehensively explains the mechanical behavior differences and stresses within the examined structures. The incorporation of plastic fibers not only demonstrates a significant improvement in mechanical strength and crack resistance but paves the way for advancements in railway sleeper technology. By shedding light on the enhanced durability and performance of reinforced concrete structures, this study makes a significant contribution to civil engineering materials science, highlighting the potential for innovative material applications in the construction industry.

Open Access: Yes

DOI: 10.3390/polym16111498

Analysis of the Heating of Steel Structures During Fire Load

Dániel Balázs Merczel Éva Lublóy Zoltán Major J. Szép László Bodnár

Publication Name: Emerging Science Journal

Publication Date: 2024-02-01

Volume: 8

Issue: 1

Page Range: 1-16

Description:

During the preparation of our article, we present in detail the changes in the thermotechnical parameters of carbon steel and corrosion resistance during fire. After that, we present in detail the calculation of the heating of steel structures without fire protection. We feel this is important because it is not possible to provide stainless steel with fire protection for aesthetic reasons, and it is also not typical for thin-walled galvanized structures. We also present the calculation of structures with fire protection in detail and present the background for editing commonly used nomograms. Such a nomogram is also available in the literature, but it can be considered true with significant simplifications. During the practical planning, the applied fire protection regulations were highly standardized. Realizing that there is no design nomogram for these types of solutions, we created and published them in our article. The advantage of these is that the applicable design can also be found as the optimum of the designs considered to be potentially good. With this solution, we can save time during planning, and we can also get a more cost-effective solution for the fire protection cover. The advantage of the presented method is that, if required, the editing of the nomograms can be extended to other designs by knowing the material characteristics and the layer thickness. Another option of the presented method is that the solution can also be applied to special fire loads, and nomograms can be produced for them as well (e.g., hydrocarbon fires).

Open Access: Yes

DOI: 10.28991/ESJ-2024-08-01-01

Investigation of the Vertical Stability of Embedded Rail Structures

Szabolcs Fischer Zoltán Major Attila Németh Vivien Jóvér

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 37-43

Description:

In the case of embedded rail structures, the rails are fixed with a flexible embedding material that runs through a specially designed steel or reinforced concrete channel. The majority of the rail cross-section is embedded in these channels, eliminating the possibility of horizontal buckling as a failure mode. This paper investigates vertical stability, aiming to determine the stability resistance of a rail loaded with an initial failure in the vertical plane while considering elastic resistance. Vertical plane buckling is assumed to be a non-hazard for conventional rails because the wide rail footing can significantly inhibit vertical displacement, even without adhesion between the rail surface and the embedding material. However, the adhesion of the embedding material to the channel is adequate. Some rail sections lack adhesion between the rail and the embedding material due to the narrow width of the rail foot, making the phenomenon of "form-locking" uncertain, or the rail is partially embedded. In this article, the authors present a theoretical calculation method to investigate this problem, to transfer the results to everyday practice as simply as possible, and to present a solution suitable for manual calculation. Measuring the vertical spring constant in the method's input parameters under laboratory conditions is a difficult task, but by utilizing the possibilities provided by finite element modeling, the design can be significantly simplified. The introduced method has the significant advantage of quantifying the effect of vertical plane misalignments in the track compared to simpler solutions in the literature.

Open Access: Yes

DOI: 10.3233/ATDE240524

Change in Stiffness of Reinforced Concrete Tunnel Walls and Its Effect Under Fire Load

Edina Koch Éva Lublóy Zoltán Major

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 342-350

Description:

This article uses the knowledge gained from tunnel fires to address the structural analysis of tunnel walls during fire exposure. The designing at normal temperature and its theoretical background are discussed in the literature. As these books did not yet deal with the issue of fire protection designing, we tried to supplement the existing theoretical knowledge with the knowledge provided by the relevant standards for reinforced concrete tunnel walls. In addition, we have tried to add our own individual ideas to the theory where we felt that there were gaps. The theoretical summary has been compiled in such a way that it can be easily transferred and applied to everyday practice. In this article, we discuss in detail the calculation of the internal forces in tunnel walls during fire exposure. Due to space constraints, the issue of designing at normal temperatures is only touched upon in this article, limiting it to the knowledge available in the literature. Since finite element modelling has become a commonly used technique in tunnel design since the 1970s, we use its potential to investigate the effects of earth pressure and surface loads on the tunnel walls during fire and their changes, using specific software for geotechnical design. In accordance with the limitations of the scope, the determination of the equivalent thickness and the modulus of elasticity of the tunnel wall is also presented in order to determine the internal forces during the fire action.

Open Access: Yes

DOI: 10.3233/ATDE240565

Calculation of Heating of Reinforced Concrete Tunnel Wall During Fire

Éva Lublóy Zoltán Major J. Szép

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 366-374

Description:

In this article, we present the thermal parameters of reinforced concrete tunnel lining materials and their changes during fire exposure. After describing the material properties, we present a test method to investigate the heating of reinforced concrete tunnel linings. As the presented method can only be considered as partially standard, we validate it on the basis of the available literature and our Excel program based on the presented theory. During the validation, it has been demonstrated that the method is suitable for solving practical professional tasks and that it is able to provide sufficiently accurate results. Since the results presented can be used not only for design purposes but also as an initial step in fire diagnostics to determine the extent of damage in fire-loaded tunnel walls, we also construct novel curves for the analysis of reinforced concrete walls, which can be used effectively for fire curves with cooling phase, where the accumulated temperature inside the wall further heats the zones inside and further residual strength loss may occur due to chemical processes in the zones. Based on the results of the model presented in this paper, designers can take into account the changes in the temperature distribution of the reinforced concrete tunnel wall, which have a decisive influence on the evolution of the internal forces due to external influences, and can calculate the magnitude of the stresses due to inhibited thermal expansion by using approximate models.

Open Access: Yes

DOI: 10.3233/ATDE240568

Finite Element Analysis of Microtunneling Under a Railway Track

Edina Koch Zoltán Major Shaymaa Alsamia

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 351-357

Description:

Microtunneling is a trenchless construction method used to install pipelines beneath highways, railroads, runways, harbors, rivers, and environmentally sensitive areas. For railway lines, the primary objective of the method is to address the challenges posed by the installation of utilities without disrupting rail operations. The aim is to minimize the impact on railway services, ensuring the uninterrupted flow of transportation while facilitating essential infrastructure development. Traditional excavation methods often involve significant ground disturbance and pose risks to the stability of the railway track, leading to service interruptions and safety hazards. Microtunneling, on the other hand, offers a non-disruptive alternative by utilizing advanced tunneling equipment that minimizes ground settlement and vibration, reducing the risk of damage to the railway structure. The technique involves the use of remotely controlled boring machines to excavate tunnels with precision, allowing for the installation of pipelines or other utilities with minimal impact on the railway infrastructure above. The aim is to achieve a seamless integration of new underground utilities while maintaining the structural integrity and operational functionality of the railway line. Furthermore, microtunneling under a railway line contributes to sustainable development by minimizing the environmental footprint associated with construction activities. The reduced excavation and disturbance to the surrounding environment lead to lower levels of noise, dust, and disruption, aligning with modern principles of environmentally conscious infrastructure development. In this study, the installation of a sewage pipeline constructed by microtunneling under an existing railway track is investigated using geotechnical and structural FEM.

Open Access: Yes

DOI: 10.3233/ATDE240566

Calculation of Thermal Stresses of Cast Iron Tubbings Under Fire Effect

Éva Lublóy Zoltán Major J. Szép

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 431-437

Description:

This article builds on our existing knowledge of the heating of cast iron tunnel linings and deals with the structural analysis of tunnel linings under fire exposure. Due to space constraints, we do not address the issue of sizing for earth pressure and surface loads. Since the analysis of thermal stresses due to restrained deformations is insufficient in the available literature, we will try to complement the existing theoretical knowledge with the knowledge provided by the relevant standards for cast iron lining of tunnels. In addition, we will try to add our own individual reflections to the theory where we have identified gaps. The theoretical summary is compiled in such a way that it is easily transferable and applicable to everyday practice. Our finite element analysis shows that the value of the embedding factor has a small effect on the development of the axial constraint stresses in the tunnel direction, while in the ring direction has a significant effect. In all cases, stiffer embedding results in higher stress values. In all cases, the ring direction compressive stresses are lower than the longitudinal stresses due to the deformation of the tunnel ring. There is no literature data available on the value of the compressive stresses, so we have tried to provide some indicative data in tabular form for the profession. The solution adopted and the values proposed are based on the authors' individual ideas and are not the result of an accepted professional consensus. In all cases where more precise data are required, it is recommended that a more detailed study be carried out. Finite element modelling can provide the necessary support for designers and experts.

Open Access: Yes

DOI: 10.3233/ATDE240576

Calculation Possibilities of the Local Fire Effect for the Examination of Bridge Superstructures

Éva Lublóy Zoltán Major J. Szép

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 382-388

Description:

For the examination of bridge superstructures, there is no single standard method in the literature for the design of structures, and possibility for their diagnosis after fire damage. Designers often overcome this problem by examining the fire curves used for tunnel fires, as the materials feeding the combustion are considered to be very similar. In contrast, in some articles, the use of localised fires in design and control is suggested by the authors. This is a standard method used in Eurocode. To solve the problem, two methods must be applied. Heskestad's method describes the case where the flame does not reach the superstructure of the bridge, while Hasemi's method describes the case where the flame does. Heskestad's method is presented in the standard in a way that can be used by practising engineers. The great advantage of Hasemi's method is that it can quantify the effects of several localised fires, each one separate from the other. This feature is very useful for the fire design of, for example, covered car parks and bridge structures. In such a test, the total heat flow on the lower plane of the slab or superstructure can be interpreted as the sum of the heat flows from each local fire. The standard, on the other hand, it does not provide additional assistance to designers in solving the problem. That is way, he should be able to determine the temperature of the structural element, a method which is not provided for in the standard. This problem leads to a fourth degree equation, which again leaves the designer on his own to solve. There is no formula for solving the fourth degree equation. In this case, it becomes more useful to find a sufficiently accurate approximate solution (Newton's method) rather than an exact solution. In this article, we present in detail the possibilities of solving the local fire effect in order to enable practising engineers to use it.

Open Access: Yes

DOI: 10.3233/ATDE240570

Providing Decent, Affordable, and Sustainable Housing: Analysing Environmental Impacts of Family Houses Built with Conventional and Unconventional Building Materials

Zoltán Major Herta Mária Czédli Szigeti Cecília Áron Szennay Róbert Horváth

Publication Name: Environmental Footprints and Eco Design of Products and Processes

Publication Date: 2024-01-01

Volume: Part F3205

Issue: Unknown

Page Range: 105-126

Description:

The construction industry is considered an activity responsible for both significant CO2 emissions and material flows. Providing affordable, decent, and sustainable habitats is, however, a fundamental human need. Therefore, the chapter aims to analyse the environmental impacts of construction and energy upgrades of detached family dwellings typical in Hungary. For the analysis of environmental impact, the concept of ecological footprint (EF) was used. The main advantages of this method are that (1) results can be compared to the upper limits of sustainability, (2) figures are rather easy to understand for each stakeholder, and (3) the concept may take into consideration all impacts of human activities. The chapter, however, analyses only the EF of material use of constructions. The sample consists of data on five detached family houses, representing the housing in Hungary: (1) a new two-storey family house with a gable roof, (2) a new family house made of timber, and (3) an energy upgrade of a typical family dwelling built between 1950 and 1990, called “Hungarian cube”. The results show that the construction of new detached family dwellings has a significantly higher ecological footprint than renovating an existing one. Using non-conventional construction materials (e.g. timber), however, can decrease the ecological footprint of construction, but useful lifetime should be considered more deeply in this case. Volatile energy prices have highlighted the importance of the energy efficiency of the housing stock. Newly built dwellings have outstanding insulation and, therefore, have nearly zero emission during operation, but they are not the means of affordable housing due to their construction costs, and the construction itself has a significant environmental impact which is not outweighed by the energy savings during the useful lifetime. Therefore, retrofitting and even extension of dwellings can better contribute to the Sustainable Development Goals (SDGs).

Open Access: Yes

DOI: 10.1007/978-3-031-63057-6_6

The Ecological Footprint of Embedded Rail Structures

Zoltán Major Szigeti Cecília Tomasz Witko Áron Szennay Róbert Horváth

Publication Name: Lecture Notes in Networks and Systems

Publication Date: 2024-01-01

Volume: 877 LNNS

Issue: Unknown

Page Range: 42-52

Description:

Since the 1990s, tramway transport in East-Central Europe has been experiencing a renaissance. In urban planning practice, there has been a growing trend towards the displacement of individual motorized transportation, thereby reducing traffic congestion and air pollution, creating the foundations of a healthier, more liveable urban environment. In the major cities, large-scale investments have recently been carried out or are being planned. Most of the investments focused the modernization and renovation of existing line sections, but there are also examples of new lines being built. Due to the increasing demands placed on rail transport (reduction of noise and vibration loads, as well as of life cycle costs), the use of embedded superstructures is gaining ground in Poland as well. These superstructures are excellent from a technical point of view and have a lower environmental impact in terms of noise and vibration, but the cost savings and ecological footprint reductions vary between designs. Our research proposes a standardized approach to measure environmental impacts of urban railway projects using ecological footprint (EF) calculation. As a result of our previous studies, we found that the ecological footprint of a design built with B3 rails is significantly smaller than that of a design built with 59Ri2 rails. In our current study, we have investigated how the ecological footprint of the design with the more favourable ecological footprint changes when it is modified to meet the environmental considerations. We examined the additional environmental impact of reducing noise and vibration. In our research we present an example from Krakow to illustrate the practical application.

Open Access: Yes

DOI: 10.1007/978-3-031-51449-4_4

Investigation of the Geometrical Deterioration of Paved Superstructure Tramway Tracks in Budapest (Hungary)

Szabolcs Fischer Zoltán Major Mykola Sysyn Attila Németh Dmytro Kurhan Vivien Jóvér

Publication Name: Infrastructures

Publication Date: 2023-08-01

Volume: 8

Issue: 8

Page Range: Unknown

Description:

In the 21st century, one of the key requirements is to develop and maintain our infrastructure facilities most efficiently using the available resources. Tramways are of significant national economic importance and represent an important national asset. There are currently seven different types of superstructure systems in Hungary, based on the national regulations and the related requirements currently in force. This paper compares the paved tramway superstructure systems in the context of track geometry, through-rolled axle tons of track, and the age of track sections. Paved tracks have many benefits, but the main ones are easier maintenance and road traffic use. Elastically supported continuous rail bedding (ESCRB; in Hungary, this is known as “RAFS”) and “large” slab superstructure systems are used to create paved superstructure systems. Road crossings use the latter systems, while heavily loaded lines use several ESCRB systems. This article examines the geometrical changes in several ESCRB superstructure systems. A TrackScan 4.01 instrument was used to take measurements in June and September 2021 and in April 2022, September 2022, and May 2023. Track gauge, alignment, and longitudinal level are examined. Regardless of the ESCRB superstructure system or age, a medium-loaded line’s track gauge trendline increases, which means that the track gauge is widening and, regardless of traffic load or age, the average longitudinal level is constantly increasing from year to year. When it is a medium-loaded line, the average value of alignment increases slightly, and the trendline is almost straight, but it decreases when it is an extremely heavily loaded line. The authors will analyze how the reference track section will change in the future. Based on the results, it is important to assess how subsequent measurements affect the trend lines. Because the data evaluations show similar results, comparing open tramway tracks to paved ones is crucial.

Open Access: Yes

DOI: 10.3390/infrastructures8080126

INVESTIGATION OF TRAFFIC INDUCED DYNAMIC RESPONSE OF A BRIDGE

Zoltán Major P. Szalai Péter Horváth F. Hajdu Rajmund Kuti M. Brinissat Antal Apagyi Cs Papp

Publication Name: Strojnicky Casopis

Publication Date: 2023-05-01

Volume: 73

Issue: 1

Page Range: 85-102

Description:

Bridges are special structures that provide a transport connection between areas divided by a physical barrier. Vehicles passing over bridges cause vibrations in the structural elements of the bridge, which can damage these structural elements over time. The aim of our research was to investigate the vibrations generated by vehicles on Hungary's first steel girder welded bridge, which was subjected to the maximum allowable load. In this paper, we describe the measurements we have carried out, analyse the results, present the vehicle-bridge interaction model we have constructed and the computer simulation we have carried out by using it. Our research results are intended to contribute to accident prevention and the safe operation of bridges.

Open Access: Yes

DOI: 10.2478/scjme-2023-0007

Numerical Investigation of Pre-Stressed Reinforced Concrete Railway Sleeper for High-Speed Application

Szabolcs Fischer Zoltán Major Szabolcs Szalai Mykola Sysyn Attila Németh Dmytro Kurhan Dóra Harangozó M. Movahedi Rad Sarah Khaleel Ibrahim Dániel Harrach Szabolcs Kocsis Szurke Gusztáv Baranyai Géza Herczeg L. Gaspar

Publication Name: Infrastructures

Publication Date: 2023-03-01

Volume: 8

Issue: 3

Page Range: Unknown

Description:

The current paper deals with the numerical investigation of a unique designed pre-stressed reinforced concrete railway sleeper for the design speed of 300 km/h, as well as an axle load of 180 kN. The authors applied different methodologies in their research: traditional hand-made calculations and two types of finite element software. The latter were AxisVM and ABAQUS, respectively. During the calculations, the prestressing loss was not considered. The results from the three methods were compared with each other. The hand-made calculations and the finite element modeling executed by AxisVM software are adequate for determining the mechanical inner forces of the sleeper; however, ABAQUS is appropriate for consideration of enhanced and sophisticated material models, as well as the stress-state of the elements, i.e., concrete, pre-stressed tendons, etc. The authors certified the applicability of these methodologies for performing the dimensioning and design of reinforced concrete railway sleepers with pre-stressing technology. The research team would like to continue their research in an improved manner, taking into consideration real laboratory tests and validating the results from FE modeling, special material models that allow calculation of crackings and their effects in the concrete, and so that the real pattern of the crackings can be measured by GOM Digital Image Correlation (DIC) technology, etc.

Open Access: Yes

DOI: 10.3390/infrastructures8030041

Investigation of “Open” Superstructure Tramway Tracks in Budapest

Szabolcs Fischer Zoltán Major Mykola Sysyn Attila Németh Dmytro Kurhan Vivien Jóvér

Publication Name: Infrastructures

Publication Date: 2023-02-01

Volume: 8

Issue: 2

Page Range: Unknown

Description:

The most important thing nowadays is to use available resources to develop infrastructure as efficiently as possible. In this regard, evaluating the deterioration of tramway tracks is critical from both a technical and an economic viewpoint. In Hungary, seven types of superstructure systems are currently differentiated in the case of tramway transport, but the geometrical deterioration, lifecycle, and lifecycle cost of the tramway tracks are not accurately known. The current study aimed to evaluate and compare the results of track geometry measurements of two different “open” tramway superstructure systems depending on their traffic load and age. The geometry measurements we re executed by TrackScan 4.01 instrument, developed and maintained by a Hungarian developer company called Metalelektro Méréstechnika Ltd. The evaluation of the measurements showed a clear relationship between the traffic load, age, and track deterioration. Based on the results, it can be generally stated, concerning “open” superstructure systems, that regardless of the “open” superstructure system or the level of traffic load, the average value of alignment is decreasing; however, the average value of the longitudinal level is increasing. Furthermore, the deterioration of an older ballasted track with lower traffic is similar to that of a younger ballasted track that has a higher traffic load. Another significant result was that the deterioration of the track gauge parameter in the case of concrete slab tracks is clearly described as the broadening of the track gauge.

Open Access: Yes

DOI: 10.3390/infrastructures8020033

Head Checks and the Useful Life of Rails

Zoltán Major Ferenc Horvat Róbert Horváth

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 295-300

Description:

Transport systems, including railways, are an important part of everyday life in modern societies. Whether it is passenger or freight transport, railways are an environmentally friendly solution with their robust throughput capacity and modern electrified lines. The significant changes in transport needs over the last fifty years have partly modified its role, increasing both track speed and axle load. Head Checks (HC) appeared on the MÁV (Hungarian Railway Corporation) network in the early 2010s. This phenomenon had been an unknown problem in Hungary before. Several cases abroad (e.g., a train derailment at Hatfield station in 2000 with four fatalities) have highlighted the extreme danger of this phenomenon. Materials and railway track experts at Széchenyi University have been working on the subject of HC defects in rail heads for several years. The results of research work carried out for MÁV Zrt. form the base of this article. The novelty of this article is the complexity consideration. Not only the structural changes of the rail material were investigated, but also the time/traffic load-dependent crack evolution was mathematically described. Based on the strategy outlined in the report of the research work, MÁV has taken up the fight against HC cracks, which were initially proliferating. The modern laboratory test in this article is based on the tests of Csizmazia and Horvát (2014). The stresses causing damage were investigated previously by Horváth and Major (2023). The economic analysis is based on Róbert Horváth's own calculation results.

Open Access: Yes

DOI: 10.3303/CET23107050

Investigating the Ecological Footprint of Deep Mixing

Edina Koch Zoltán Major Szigeti Cecília

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 349-354

Description:

In railway construction practice, we are increasingly faced with the problem of having to pass our new lines through areas with unfavorable subsoil conditions or with the need to reinforce the substructure of our existing lines due to increasing traffic demands (speed, axle load). The low strength, high compressibility, and low permeability of unfavorable subsoil will result in stability problems and prolonged consolidation with extremely high settlements, respectively. One of the effective technologies to counter the geotechnical problems is the deep mixing. The technology requires the addition of a binder (cement, lime) to the local soils. These materials have a high installed CO2 emission, thus significantly increasing the ecological footprint of infrastructure development. Due to the increasing demands on reducing CO2 emissions, secondary raw materials, e.g., fly ash or slag, have been increasingly prioritized. The study reports the methodology for calculating the ecological footprint of deep-mixing as an embankment foundation. Based on a simple case, the effect of different cement content (5 and 8%), and the application of slag and fly ash as a secondary raw material is analyzed, and the ecological footprint is calculated separately. The results show that the ecological footprint of deep mixing can be drastically reduced; under the conditions of the study, the reduction compared to clean cement is 40% for slag stabilization and 50% for fly ash.

Open Access: Yes

DOI: 10.3303/CET23107059

The Ecological Footprint of Construction Materials—A Standardized Approach from Hungary

Zoltán Major Szigeti Cecília Daniel Robert Szabo Áron Szennay

Publication Name: Resources

Publication Date: 2023-01-01

Volume: 12

Issue: 1

Page Range: Unknown

Description:

Due to the large volume and mass of materials used, the construction industry is one of the sectors with the highest environmental impact. However, to provide good quality, affordable, and low-energy housing, the business case must be maintained. Accordingly, we aimed to develop and test a calculator to measure the ecological footprint of the embodied carbon in materials used in construction projects in a standardized way, without the need for environmental or even civil engineering expertise, and thus in a way that is accessible to SMEs. The novelty of our research is that although there are calculators for measuring the environmental impact (e.g., carbon footprint) of the construction industry, and there is a methodology for calculating the ecological footprint of construction, there is no free, easy-to-use, online calculator for calculating the ecological footprint of embodied carbon in materials available to all enterprises. In other words, this approach extends our previously developed corporate ecological footprint calculator with the environmental impacts of material usage. The study summarises the baseline research for an ecological footprint calculator, tested on two new condominium buildings and the energy renovation of five condominium buildings, built with a prefabricated technology typical in Hungary and other post-socialist countries. Based on our results and in accordance with former literature sources, most of the ecological footprint of new construction projects is determined by materials with high mass and volume, in particular, concrete, steel, and masonry; so it is not necessary to take into account all construction materials in a calculator in a detailed way. We also conclude that renovation and ongoing maintenance, as well as preservation, are recommended for structurally sound buildings, as embodied carbon in materials in the case of an energy upgrade of an existing condominium building has an environmental impact of 0.3–0.8 global hectares per dwelling, depending on the technical content, while in the construction of a new building, this value is between 10.49–14.22 global hectares. Our results can help investors and clients in their decisions, and policymakers in determining urban development directions.

Open Access: Yes

DOI: 10.3390/resources12010015

The Impact of Cement Aggregates on the Fire Resistance Properties of Concrete and its Ecological Footprint

Éva Lublóy Zoltán Major J. Szép Szigeti Cecília

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 337-342

Description:

The strength properties of concrete are significantly influenced by the type of binder used. In the case of cement, the use of cement-containing admixtures (CEM II) is becoming increasingly popular from a durability and environmental point of view. The first question was how cements containing different admixtures behave and how their compressive strength changes under high temperatures (fire). First, the experiments were carried out with the cement tests, and then the concrete specimens were checked for the extent to which the addition of admixtures modifies the favourable effect measured for cement. Under thermal loading, the value of the residual compressive strength of the cement paste increased with the addition of the admixture content. The results of the compressive strength test and the developed crack patterns were consistent with each other. The most severe cracking was observed in the Portland cement specimens, and the decrease in strength was also the most significant. Based on the results of the cement tests, several types of cement were used for the concrete tests. The second research question was: Which concrete recipe has the lowest specific ecological footprint? Therefore, for each formulation, the specific ecological footprint is crucially influenced by the type and amount of substitute used, as their specific CO2 emissions are typically lower than those of Portland cement. Based on our previous studies, a reduction in the specific ecological footprint of up to 10 % can be achieved by using substitutes. The novelty of our research lies in the combined use of fire resistance and ecological aspects, which helps to select a formulation with better technical properties and, at the same time, more sustainable.

Open Access: Yes

DOI: 10.3303/CET23107057

"Green" Tram Tracks for the Sustainability of the Urban Environment

Zoltán Major Herta Mária Czédli Szigeti Cecília

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 289-294

Description:

Greening tram tracks has ecological, urban planning and economic impacts. Greening of the tracks supports the development of sustainable stormwater management as well as improving the visual appearance of the city. The restoration of the natural water cycle is achieved through water-sensitive design: the innovative solution used achieves both the retention of water, the reduction of run-off and the increase of the surface area available for evaporation. The literature data (Grüngleis Netzwerk, 2011) show that 50-70 % of the annual precipitation projected onto the green runway is absorbed and re-evaporated. The urban climate impact of the vegetation systems to be developed is most pronounced in the summer months. The microclimate of green track environments has a positive impact on the health of the population. Our work will investigate the effects of green vegetated areas. In this study, we analysed the ecological impact and the capacity to sequester of carbon dioxide from the atmosphere by photosynthesis of grass- and crowfoot-lined tracks. The Sedum green roofs quantified carbon storage is approximately 160 gC/m2 during a two-year period (Collazo-Ortega et al., 2017). The concept of a vegetated track leads to an improvement of green space indicators in a complex system of urban environments through the correct choice of vegetation plants. Prioritising and encouraging the construction of green tracks is one of the possibilities to make the urban environment more livable. It is also necessary to encourage this at the regulatory level in cities.

Open Access: Yes

DOI: 10.3303/CET23107049

Ecological Footprint Analysis of Tramway Track Structures

Zoltán Major Szigeti Cecília Áron Szennay Róbert Horváth

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 283-288

Description:

The European urban landscape has been constantly evolving in the last 70 years since the Second World War. Thus, European cities are developing their own public transport networks. Urban rail transportation, namely trams, can be considered a mobility option with (1) high capacity, (2) relatively low life-cycle cost, and (3) low Greenhouse Gas (GHG) emission. Developing green urban transport systems requires, however, using a more comprehensive and complex approach. To do this, infrastructure operators should consider the environmental aspects of construction projects in the decision-making process. This article analyses the construction and maintenance issues of a very common and widespread tramway superstructure from the environmental point of view, using the methodology of ecological footprint calculations. Considering environmental impacts is highly recommended as early as the design stage by selecting the most suitable construction materials and technologies. Therefore, structural and vibration-damping solutions are compared that are equivalent in terms of technical suitability to highlight CO2 emissions and ecological footprint during the production and life cycle of each building material. The results suggest that a multi-directional assessment can help to develop a more sustainable, liveable and environmentally friendly urban transport without major trade-offs. The article also shows how the ecological footprint of the designed track structure changes when it is optimised to minimise the environmental impact. Such a change could result in a reduction of up to 20 % in the ecological footprint.

Open Access: Yes

DOI: 10.3303/CET23107048

Comparative Life Cycle Analyses of Regular and Irregular Maintenance of Bridges with Different Support Systems and Construction Technologies

O. Kegyes-Brassai Zoltán Major Attila Németh Boglárka Eisingerné Balassa

Publication Name: Chemical Engineering Transactions

Publication Date: 2022-01-01

Volume: 94

Issue: Unknown

Page Range: 571-576

Description:

The maintenance cost of bridges is huge in every country e. g. in the USA it is (approx.) 41.8 G$. This causes a 6.2 % GHG emission rise annually. Reducing and minimizing cost, GHG level and CO2 pollution is a key factor and a major goal for sustainability. This study presents a comparative life cycle assessment (LCA) of bridges with different support systems and construction technologies but with the same span and location. LCA considers regular and irregular bridge maintenance as well having a great influence on the need and timing for major maintenance or restoration in every 25 to 30 y. Regular maintenance means every 1 - 5 and 10 - y minor maintenance works take place. The analysis is based on primary data collected in Hungary examining fully constructed bridges. For the LCA, the cost of maintenance over a 100 y timespan is based on NIF regulations, the total rate of CO2 pollution and the EF (Ecological Footprint, Gha) level is used (Long et al., 2020;). In practice the maintenance of the bridges take place occasionally when the damage on the bridges are already visible and cannot be postponed based on the in - depth interviews with experts. It is assumed that the cost, EF and CO2 pollution of the regular maintenance over the examined timespan is less compared to results of the irregular life cycle model. Based on the case study presented, it can be concluded that the cost of LCA for regular bridge maintenance is 637,348.32 (k€) and for irregular bridge maintenance it is 994,415.12 (k€). The CO2 pollution for regular bridge maintenance is 12,948.24 (kt) and for irregular bridge maintenance is 13,876.86 (kt). The EF pollution for regular bridge maintenance is 3,237.06 (kGha) and for irregular bridge maintenance it is 3,469.22 (kGha). Considering the long - term sustainability aspects, it is recommended that the maintenance should be a regular and a controlled activity. It is vital to draw the attention of the decision makers, the legislators of the businesses, the maintenance operators, and the inspectors to these sustainability aspects.

Open Access: Yes

DOI: 10.3303/CET2294095

Special problems of interaction between railway track and bridge

Zoltán Major

Publication Name: Pollack Periodica

Publication Date: 2013-08-01

Volume: 8

Issue: 2

Page Range: 97-106

Description:

This paper deals with the phenomenon of track-bridge interaction in railway bridges. Due to the continuity of the rails on the structural expansion joints, the deformations of the deck might induce stresses in the rails that need to be checked. The main design criteria are now specified in Eurocode 1-2.

Open Access: Yes

DOI: 10.1556/Pollack.8.2013.2.11

Conservative Method for the Calculation of Thermal Forces in Reinforced Concrete Tunnel Wall During Fire

Éva Lublóy Zoltán Major J. Szép

Publication Name: Advances in Transdisciplinary Engineering

Publication Date: 2024-01-01

Volume: 59

Issue: Unknown

Page Range: 455-463

Description:

This article builds on the author's existing knowledge of the heating of reinforced concrete tunnel linings and deals with the structural analysis of tunnel linings under fire exposure. Due to space constraints, the issue of designing for earth pressure and surface loads is not address. Since the analysis of thermal stresses due to restrained deformations is insufficient in the available literature, we complement the existing theoretical knowledge with the knowledge provided by the relevant standards for reinforced concrete tunnel linings. In addition, we add our own individual reflections to the theory where we have identified gaps. In determining the additional stresses due to inhibited thermal expansion, we use a numerical model based on our own ideas. The reason for this is that the heating of reinforced concrete tunnel lining during fire is extremely uneven and it is almost impossible to take this into account in the finite element programs commonly used. The other important reason is that this uneven temperature change that causes the colder zones of the wall to inhibit deformation. Thus, a solution implemented in MS Excel environment is presented, which allows an approximate accurate determination of the force effects due to inhibited deformation. The solution used and the values proposed are based on the authors' individual ideas and are not the result of an accepted professional consensus. In all cases where more precise data are required, it is recommended that a more accurate test be carried out. Advanced finite element modelling can provide the necessary support for designers and experts.

Open Access: Yes

DOI: 10.3233/ATDE240579

The Ecological Footprint and Fire Resistance of Concrete Mixtures

Éva Lublóy Zoltán Major J. Szép Szigeti Cecília

Publication Name: Journal of Sustainable Development of Energy Water and Environment Systems

Publication Date: 2025-09-01

Volume: 13

Issue: 3

Page Range: 1-13

Description:

Different types of binders can significantly affect the strength properties of concrete. The use of cement-containing admixtures is becoming more widespread in the building industry when considering durability and environmental impact. This paper examines how different types of cement containing different admixtures behave. How the compressive strength of concrete changes under elevated temperature, and which concrete mixture has the lowest CO2 emission. To determine the strength parameters, test specimens of 150x150x150 mm and 70x70x250 mm were prepared from the concrete mixtures. After heating and cooling, they were broken, thereby determining the compressive and flexural-tensile strength values. The ecological footprint was calculated for each mixture, which is substantially influenced by specific parameters for example the type and amount of substitute materials. These materials typically have lower CO2 emissions than Portland cement. The novelty of this research lies in the combined investigation of the changing compressive strength of concrete at elevated temperatures and its sustainability. The change in the formulation resulted in a saving of the emission of ~10% (43.22 kgCO2e emissions) compared to the reference value. The importance of reducing the ecological footprint is demonstrated by the authors using a case study of the Gotthard tunnel.

Open Access: Yes

DOI: 10.13044/j.sdewes.d13.0597