David Bozsaky

57038981100

Publications - 16

Engineering Elegance at Altitude

David Bozsaky András Veöreös

Publication Name: Epites Epiteszettudomany

Publication Date: 2025-08-21

Volume: 53

Issue: 3-4

Page Range: 323-346

Description:

Water towers are a characteristic vertical visual element of today’s townscapes and rural landscapes. We encounter them in urban residential areas, industrial zones, but they are also decisive in the silhouette of villages. Their task is most often to ensure the supply of drinking water to the population, but we often encounter water towers belonging to industrial, railway or agricultural plants.In terms of their appearance, most water towers are simple engineering creations, but in some cases, the creators also placed emphasis on the aesthetic design of the structure.Historical water towers have survived from the 19thcentury, they were built using traditional construction techniques, usually with historicizing architecture. A significant part of the memorial material comes from the period between the two world wars, which is the time of the construction of early reinforced concrete structures; the appearance of the buildings is also determined by this structure. In the second half of the 20thcentury, the material of the towers continued to be reinforced concrete, but dynamic, architecturally sophisticated formal solutions were more common.Our study analyses the historical development of water towers, including their structural development, changes in form, and role in the settlement or landscape.

Open Access: Yes

DOI: 10.1556/096.2025.00145

Changes in properties of thermal insulations under certain environmental effects

David Bozsaky Mózes Norbert Bedo

Publication Name: Pollack Periodica

Publication Date: 2025-03-26

Volume: 20

Issue: 1

Page Range: 80-86

Description:

Saving energy and reducing greenhouse gas emissions is a priority for the construction sector. Heating of buildings requires the burning of fossil fuels, which can be significantly reduced by insulating the building envelope. Nowadays, the thermal insulation of buildings is essential. There are several important, well-known data about most thermal insulation materials, but there is only negligible information about the change of their properties under installation conditions or if they are already exposed to additional stresses due to structural failures and damages. This study aimed to examine the changes in properties of three common thermal insulation materials when installed in a flat roof or facade and exposed to excess moisture due to the damage of waterproofing or façade and/or when exposed to direct strong sunlight.

Open Access: Yes

DOI: 10.1556/606.2024.01039

Optimal Performance Assessment of Re-Recycled Concrete: Combining Water Absorption, Compressive Strength Using MOORA Technique

Tamás Horváth David Bozsaky M. Shmlls

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 1039-1044

Description:

This work presents water absorption and compressive strength testing of re-recycled aggregate concrete with fly ash and silica fumes. Two different types of fly ash and silica fume were used in place of ordinary Portland cement. According to test results, the selected ratios of fly ash and silica fume added to the used concrete mixtures enhanced its strength and balanced the loss in water absorption, at water-cement ratio of 0.4. The paper also thoroughly examines the full life cycle and evaluates the reuse of recycled concrete, considering seven various mixtures, using multi-criteria decision-making, namely MOORA technique. This framework is analysed by evaluating essential performance factors, namely water absorption, technical aspect (compressive strength for both short and long durations), environmental factors (effects on human health, quality of ecology, global changes in climate, and source utilization), and financial considerations (price-related). The results indicate that utilizing re-recycled concrete aggregate presents a significant environmental impact reduction (up to 39 %), and cost savings (5-10 %) compared to traditional concrete.

Open Access: Yes

DOI: 10.3303/CET24114174

Innovative Thermal Insulations from Cornstalk and Cereal Straw for Sustainable Architecture

David Bozsaky

Publication Name: Chemical Engineering Transactions

Publication Date: 2024-01-01

Volume: 114

Issue: Unknown

Page Range: 841-846

Description:

Nowadays, architects are increasingly prioritising sustainability, leading to the rise in the popularity of construction products made from renewable raw materials. Using thermal insulation materials has become crucial to ensure the energy-efficient operation of buildings. In the building materials market, especially in the field of thermal insulation products, there is a growing interest in products made from natural, renewable raw materials. This is because their use can reduce the energy consumption of buildings but also the CO2 emissions of the construction industry. There is an urgent need to utilise various industrial and agricultural by-products. In Hungary, a large amount of cereal straw and cornstalks are not used or are burned, which increases CO2 emissions. Using them as a construction product would be an excellent alternative solution for reducing the greenhouse gas emissions of the construction industry. In recent years, there have been two attempts to produce building insulation materials from cornstalks and cereal straws. As part of comprehensive research, a laboratory qualification test of both products was carried out. Based on the evaluation of the results, both thermal insulation products seem promising. Their material properties support their applicability in building construction, although some limitations should be considered. This paper aims to present the two experimental products mentioned above, analyse their material properties, and evaluate their applicability in the construction industry.

Open Access: Yes

DOI: 10.3303/CET24114141

Sustainability framework of recycled aggregate concrete produced with supplementary cementitious materials

Tamás Horváth David Bozsaky Mohammed Abed M. Shmlls

Publication Name: Ain Shams Engineering Journal

Publication Date: 2023-08-01

Volume: 14

Issue: 8

Page Range: Unknown

Description:

Engineering products’ sustainability has changed from being a choice to a crucial requirement. In this study, the impact of employing 20 % fly ash (FA) and/or 12 % silica fume (SF) as cement substitutes in the production of recycled aggregate concrete is examined. The examination was conducted in two stages, evaluation stage and analysis stage. In the evaluation stage, the mechanical characteristics, environmental impact, and production costs of ten concrete mixtures were assessed with laboratory experiments and data collection. While in the analysis stage, three multi-criteria decision-making techniques (namely: EDAS, VIKOR, and TOPSIS) were utilized to optimize the most valuable and sustainable concrete mixture. The key results displayed that utilizing up to 70 % of recycled concrete aggregate with an optimal dosage of a combination of 20 % FA and 12 % SF provides high-quality, environmentally friendly, and costly effective concrete.

Open Access: Yes

DOI: 10.1016/j.asej.2022.102036

Towards closed-loop concrete recycling: Life cycle assessment and multi-criteria analysis

Tamás Horváth Jan Fořt David Bozsaky Mohammed Abed M. Shmlls

Publication Name: Journal of Cleaner Production

Publication Date: 2023-07-15

Volume: 410

Issue: Unknown

Page Range: Unknown

Description:

In this study, a wide-ranging life cycle assessment and multi-criteria analysis for close-loop cycling of concrete are conducted. Considering six performance keys in the technical (compressive strength at short and long ages), environmental (human health, ecosystem quality, climate change, resources), and economic (costs), a solid framework is created and analyzed by three multi-criteria decision-making techniques, namely, TOPSIS, VIKOR, and EDAS. The weight that must be taken into account for each of the applied criteria depends on the specific application and the demands of the user. Nevertheless, two different weighted methods, namely, the equal performance method and the entropy method, have been employed in this work to optimize for various construction-related applications, specifically sustainable residential buildings and residential housing. The findings demonstrate that the concrete mixtures produced with 20% FA+12% SF and MRCA incorporation are the best in terms of the criteria used for all applied techniques and the two weighted methods. This study demonstrates that multi-criteria decision-making techniques are simple to apply, requiring minimal time and effort and focusing on the finished result, allowing users to choose the best concrete mixtures. The proposed framework recommends the closed-loop recycling of concrete by introducing supplementary cementitious materials for sustainable, economical, and performance-based design applications.

Open Access: Yes

DOI: 10.1016/j.jclepro.2023.137179

Laboratory tests on properties of innovative natural thermal insulation material

David Bozsaky Rebeka Ábrahám-Horváth

Publication Name: Pollack Periodica

Publication Date: 2023-07-11

Volume: 18

Issue: 2

Page Range: 125-130

Description:

Nowadays, there is an increasing demand on environmentally friendly materials, so the environmentally conscious architecture and the use of environmentally friendly materials have also become preferred. It is becoming increasingly important to turn from artificial materials to products made from renewable raw materials. The straw quilt, which is considered to be a new, innovative product on the Hungarian construction market, can provide an alternative for this need. The aim of this research was to investigate the material properties and possible uses of straw quilt thermal insulation. Laboratory tests were performed before the product was placed on the market. The results have shown that it has several advantageous properties that can make it competitive in the market of thermal insulation materials.

Open Access: Yes

DOI: 10.1556/606.2022.00735

The Analysis of Lifecycle and Multi-Criteria Decision-Making for Three-Generation High-Strength Recycled Aggregate Concrete

Tamás Horváth David Bozsaky M. Shmlls

Publication Name: Chemical Engineering Transactions

Publication Date: 2023-01-01

Volume: 107

Issue: Unknown

Page Range: 229-234

Description:

The paper encompasses a comprehensive analysis of the life cycle of high-strength concrete (HSC), as well as a work on how HSC is made. Recycled concrete aggregate and multi-recycled concrete aggregate were utilized to partially replace natural aggregate (NA) in the production of the HSCs, while fly ash and silica fume were employed in place of cement. Firstly, the fresh state examination included a flow table test and compressive strength was tested at 28, 90, and 180 days. Moreover, the other aspects (cost and environmental life cycle) were considered to fulfill the sustainability of HSC, which might fit many applications in the building industry. The application of multi-criteria decision-making (MCDM) techniques can help in the development of sustainable concrete by identifying the best choice among multiple alternatives. Therefore, life cycle assessment (LCA) and MCDM technique, namely TOPSIS, were employed to select the best concrete mixture regardless of its generation. The output of the LCA is distributed as input for the TOPSIS technique. The results showed that the third generation of concrete, when compared to the first or second generation of recycled concrete, offers a more favorable alternative with acceptable technical performance, lower environmental impact, and less budget.

Open Access: Yes

DOI: 10.3303/CET23107039

Multicriteria based optimization of second generation recycled aggregate concrete

Tamás Horváth David Bozsaky Mohammed Abed M. Shmlls

Publication Name: Case Studies in Construction Materials

Publication Date: 2022-12-01

Volume: 17

Issue: Unknown

Page Range: Unknown

Description:

Through experiments with two generations of recycled aggregate concrete and the application of Multi-Criteria Decision-Making techniques, this research aims to establish a sustainable framework of second generation recycled aggregate concrete selection. The technical and environmental performances of seven concrete mixtures were evaluated experimentally and analytically. In addition to the control mixture, six mixtures were produced with two proportions of recycled concrete aggregate or multi-recycled concrete aggregate (30 % and 70 %). Four Multi-Criteria Decision-Making techniques, namely TOPSIS, EDAS, WSM, and WPM, were applied for optimizing the best concrete mixture in terms of technical and environmental based. The results of the four techniques agreed that reusing recycled aggregate concrete is possible as high quality and environmentally friendly concrete. Yet the highest CO2 emissions have belonged to the control mixture where no recycled or multi-recycled aggregate concrete was used.

Open Access: Yes

DOI: 10.1016/j.cscm.2022.e01447

Compressive, flexural and splitting strength of fly ash and silica fume concrete

Tamás Horváth David Bozsaky M. Shmlls

Publication Name: Pollack Periodica

Publication Date: 2022-04-30

Volume: 17

Issue: 1

Page Range: 50-55

Description:

Cement replacement materials are commonly used in concrete technology. Several researchers have examined high-performance concrete after adding mineral admixtures to it, but further studies are still needed to provide the optimum dosage of these materials for instance fly ash and silica fume. This study compares three types of concrete and the mechanical properties (compressive strength, flexural strength, and splitting tensile) of these types at the age of 28 and 90 days. The test results designate that adding the mineral admixtures commonly affects the mechanical properties of all the tested types. However, silica fume is more operative than fly ash. Furthermore, adding the fly ash and silica fume in the same concrete type slightly improves the mechanical properties.

Open Access: Yes

DOI: 10.1556/606.2021.00448

Literature review on steel fibre, silica fume and fly ash: improving methods for recycled and multiple recycled aggregate concretes

Tamás Horváth David Bozsaky M. Shmlls

Publication Name: Acta Technica Jaurinensis

Publication Date: 2021-02-14

Volume: 14

Issue: 1

Page Range: 60-79

Description:

If all concrete is to be recycled in a future scenario, recycled concrete will be needed. Usually concrete recycling causes loss of properties, but this does not have to be truth for all the mixtures. This paper shows a comprehensive knowledge about the improving methods used to keep the properties of the recycled aggregate concrete (RAC). In the reviewed literature several kinds of RAC were tested with various replacement ratios. The effect of adding steel fibres, silica fume or fly ash to the mixture were also examined both separately and together. Most of the experiments demonstrated excellent mechanical properties of the RAC compared with ordinary concretes. Based on these results the ideal RAC composition can be deduced and a future can be imagined when concrete can be recycled multiple times (MRAC).

Open Access: Yes

DOI: 10.14513/actatechjaur.00570

Thermodynamic Processes in Nanostructured Thermocoatings

David Bozsaky

Publication Name: Current Topics and Trends on Durability of Building Materials and Components Proceedings of the 15th International Conference on Durability of Building Materials and Components Dbmc 2020

Publication Date: 2020-01-01

Volume: Unknown

Issue: Unknown

Page Range: 1127-1134

Description:

In the 21st century, global climate change and the high level of fossil energy consumption have introduced changes affecting all sectors of the economy, including the building industry. This process has prompted EU members to create strict regulations in building energetics. It has become a serious task for architects to find more effective ways for thermal insulation. One of these options is the application of nanostructured materials. Among them nano-ceramic thermocoatings open a wide range of research fields, because complete agreement had not been already found about their insulating effect. In order to explore and describe the thermodynamic process inside nano-ceramic thermocoatings 6 series of heat transfer resistance experiments were performed in 2014-2018. Several building structure configurations with 12 different orders of layers were tested with a standard heat flow meter. On basis of these results it could be concluded that in case of nano-structured thermocoatings convective heat transfer coefficient might be taken account in different way than in case of traditional macro-structured thermal insulation materials. Based on research results, the limits of its applicability can also be concluded. It has also been found that the insulating effect of nanostructured thermocoatings depends on the material characteristics of the insulated surface.

Open Access: Yes

DOI: 10.23967/dbmc.2020.139

Recent studies on thermodynamic processes in nano-ceramic thermal insulation coatings

David Bozsaky

Publication Name: Pollack Periodica

Publication Date: 2019-01-01

Volume: 14

Issue: 1

Page Range: 107-116

Description:

Among nanotechnology-based thermal insulation materials thermodynamic performance of nano-ceramic coatings generates intensive discussions. Complete agreement has not been found yet about the mechanism of their insulating effect. In the Laboratory of Building Materials and Building Physics at Széchenyi István University (Győr, Hungary) heat transfer resistance experiments have been performed in order to describe thermodynamic processes inside nano-ceramic coatings. Previous studies finding after new measurements conducted in 2016-2017 also supported the former assumption that in case of nano-ceramic coatings convective heat transfer coefficient might be taken into account in a different way. Results also showed that thermal insulating effect of nano-ceramic coatings could be caused by a relatively high surface heat transfer resistance.

Open Access: Yes

DOI: 10.1556/606.2019.14.1.11

Moisture behavior of thermal insulation coating consisted of vacuum-hollow nano-ceramic microspheres

David Bozsaky

Publication Name: Periodica Polytechnica Civil Engineering

Publication Date: 2018-01-01

Volume: 62

Issue: 4

Page Range: 980-985

Description:

Nanotechnology-based thermal insulation materials have appeared in building industry in the last two decades. Among them thermal insulating coatings consisted of vacuum-hollow nano-ceramic microspheres are the subjects of most professional discussion. Most studies about these coatings focus only on examination of thermodynamic properties, because there is still no consensus in academic circles about thermodynamic processes inside nano-ceramic coatings. These professional discussions distract attention from other unknown but also important material properties, like behavior by contact with moisture. This paper summarizes the results of moisture behavior tests with nano-ceramic thermal insulation coatings which were conducted to determine the time trend of water absorption, as well as volume, mass and thermal insulation quality changes caused by increasing moisture content. Analyzing the results mathematical connections were found to describe the relation between water content, dimensional and thermal conductivity changes.

Open Access: Yes

DOI: 10.3311/PPci.12178

Laboratory Tests with Liquid Nano-ceramic Thermal Insulation Coating

David Bozsaky

Publication Name: Procedia Engineering

Publication Date: 2015-01-01

Volume: 123

Issue: Unknown

Page Range: 68-75

Description:

Liquid nano-ceramic thermal insulation coatings appeared in the last decades on the market of thermal insulation materials. This paint-on insulation contains microscopic cellular ceramic microspheres. These vacuum-hollow balls were made of on high temperature melted ceramic. Its binding material is a mixture of synthetic rubber and other polymers. After mixing with the raw material with its binder, using brush or vacuum vaporizer can be taken on the surface to be insulated. The special literature of liquid nano-ceramic thermal insulation coatings gives different and contradictory thermodynamic details about this material. According to some sources its thermal conductivity is around 0,001-0,003 W/mK, but other papers publish much higher thermal conductivity values (from 0,01 W/mK to 0,14 W/mK). In the Laboratory of Building Materials and Building Physics at Szechenyi Istvan University (Gyor, Hungary) several thermodynamic test were made with liquid nano-ceramic thermal insulation coatings. On basis of European Standards (EN) the thermal conductivity and water absorption of this material was determined. The relationship between thermal conductivity and water content was analyzed. Experiments were performed with conventional thermal insulation materials with additional ceramic coating on one side, two sides and beside two plates. Results were analyzed in order to prove the low thermal conductivity and heat mirror effect of this material.

Open Access: Yes

DOI: 10.1016/j.proeng.2015.10.059

Thermodynamic tests with nano-ceramic thermal insulation coatings

David Bozsaky

Publication Name: Pollack Periodica

Publication Date: 2017-01-01

Volume: 12

Issue: 1

Page Range: 135-145

Description:

From nanotechnology-based thermal insulation materials nano-ceramic thermal insulation coatings are generally considered to be the most critical because of contradictory technical data that could be founded in special literature. Complete agreement had not been already found about the mechanism how does their insulating effect take. In the Laboratory of Building Materials and Building Physics at Széchenyi István University (Gyo′r, Hungary) several thermodynamic tests were made in order to find out thermodynamic process inside this material. Several building structures with different order of layers were tested with heat flow meter. Results showed that convective heat transfer coefficient cannot be taken account in usual way using this material as thermal insulation.

Open Access: Yes

DOI: 10.1556/606.2017.12.1.11