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Andrzej Szewczak
Faculty of Civil Engineering and Architecture, Lublin University of Technology, Nadbystrzycka 40, 20-618 Lublin, Poland

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Journal article
Published: 24 November 2020 in Materials
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Industrial waste from the production of metallic silicon and silicon–iron alloys, which includes silica fumes (microsilica), is subject to numerous applications aiming at its reuse in concrete and polymeric composites. Recycling solves the problem of their storage and adverse environmental impact. Six different formulas of epoxy resins were tested, differing in the type of polymer, the mixing process (sonication or not) and the presence of microsilica. The study showed that microsilica added to the epoxy resin changes its viscosity and free surface energy, and these are the parameters that determine the adhesion of the polymer to the concrete surface. Strength tests and SEM analysis have determined how microsilica molecules can penetrate the structure of polymer macromolecules by filling and forming temporary chemical bonds. Mixing the fillers with the adhesive was achieved by using a sonication process. The analysis of the obtained results showed that, depending on the initial composition of the polymer, the addition of microsilica can change the chemical, physical and mechanical properties of the hardened adhesive to varying degrees. In the case of adhesives used in the construction industry to strengthen and glue structural elements, these changes significantly affect the durability of the adhesive joints.

ACS Style

Andrzej Szewczak; Maciej Szeląg. Physico-Mechanical and Rheological Properties of Epoxy Adhesives Modified by Microsilica and Sonication Process. Materials 2020, 13, 5310 .

AMA Style

Andrzej Szewczak, Maciej Szeląg. Physico-Mechanical and Rheological Properties of Epoxy Adhesives Modified by Microsilica and Sonication Process. Materials. 2020; 13 (23):5310.

Chicago/Turabian Style

Andrzej Szewczak; Maciej Szeląg. 2020. "Physico-Mechanical and Rheological Properties of Epoxy Adhesives Modified by Microsilica and Sonication Process." Materials 13, no. 23: 5310.

Journal article
Published: 28 August 2020 in Materials
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In line with the current trend of seeking alternative methods for modification of the existing building composites, such as mineral–asphalt mixtures (MAMs), the materials from concrete and ceramics recycling are being used in increasingly wider applications. When added to MAMs as an aggregate, ceramic building material, which has different properties than the raw material (clay), may significantly influence the aggregate properties, including the wettability, porosity, asphalt adhesion, and consequently the mixture durability. The material’s microstructure was found using SEM. The wetting properties of mineral–asphalt mixtures were determined by measuring the contact angles (CA) of their surfaces, using water as the measuring liquid. The total surface free energy (SFE) values were determined using the Neumann method. When analyzing the research results, it can be noticed that the chemical composition of the ceramic aggregate has a significant influence on the adhesion of asphalt to its surface due to the chemical affinity. Waste ceramic aggregate, despite its acidic pH value being connected with its elevated silica content, exhibits good adhesive properties.

ACS Style

Wojciech Andrzejuk; Andrzej Szewczak; Stanisław Fic; Grzegorz Łagód. Wettability of Asphalt Concrete with Natural and Recycled Aggregates from Sanitary Ceramics. Materials 2020, 13, 3799 .

AMA Style

Wojciech Andrzejuk, Andrzej Szewczak, Stanisław Fic, Grzegorz Łagód. Wettability of Asphalt Concrete with Natural and Recycled Aggregates from Sanitary Ceramics. Materials. 2020; 13 (17):3799.

Chicago/Turabian Style

Wojciech Andrzejuk; Andrzej Szewczak; Stanisław Fic; Grzegorz Łagód. 2020. "Wettability of Asphalt Concrete with Natural and Recycled Aggregates from Sanitary Ceramics." Materials 13, no. 17: 3799.

Journal article
Published: 20 March 2020 in Budownictwo i Architektura
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Modifications of polymer composites are one of the fastest developing fields of technology. Research is focused on two directions: obtaining new composites or modifying existing materials. The first group of tests uses methods for preparing new chemical formulas of polymers containing, as the main structural element: carbon (organic polymers) or silicon (inorganic polymers). In the second group, the research consists in seeking methods to modify the properties of polymers. In building construction, among the others types, the glues (adhesive polymers) are used. They are exerted to connect materials with different physical andmechanical properties. Under the influence of the factor initiating the crosslinking reaction (hardener or temperature), the polymers obtain a solid form. The strength of the glued joint depends on the initial parameters of the glue resin and the target substrate of its application.The glued surface is usually the weakest element in this connection in terms of the possibility of damage due to the effects of loads, therefore methods to improve the strength parameters of adhesives are sought. The study presents the results of own research on methods of modification of a selected epoxy resin used in the technique as a glue. In order to ensure effective mixing of the adhesive with the fillers, ultrasound energy was used. After the resin had hardened, tests were carried out to determine the hardness and tensile strength of the obtained composites. Based on the results, SEM analysis and observation of the effect of ultrasound, the phenomena affecting the changes in the above mechanical properties were explained.

ACS Style

Andrzej Szewczak. Impact of epoxy resin modification on their strength parameters. Budownictwo i Architektura 2020, 18, 041 -050.

AMA Style

Andrzej Szewczak. Impact of epoxy resin modification on their strength parameters. Budownictwo i Architektura. 2020; 18 (4):041-050.

Chicago/Turabian Style

Andrzej Szewczak. 2020. "Impact of epoxy resin modification on their strength parameters." Budownictwo i Architektura 18, no. 4: 041-050.

Conference paper
Published: 23 February 2019 in IOP Conference Series: Materials Science and Engineering
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The material engineering of composites is currently one of the fastest growing fields of the technology. Research in this discipline currently focuses on two basic directions: a search for completely new materials and methods of modifying the properties of already known materials. Among the study belonging to the second group, research on the properties and modifications of polymers is a particularly dynamically developing field. Commonly, the most often used polymer types in construction engineering are: construction, coating, and adhesive polymers. The last group includes the so-called resins, e.g., epoxy, phenol, polyester, formaldehyde, and mixtures of these polymers. Their use is focused at combining construction materials, i.e. to strengthen structural elements. Their hardening process can be caused by two factors – the hardener (chemohardening polymers) or higher temperature (thermohardening polymers). These processes cause its cross-linking, i.e. the production of a crystallized resin structure to a permanent form. The conditions in which the resin was prepared have a big impact on its adhesion to the substrate during its application on the glued surfaces (early resin adhesion). This parameter largely depends on two important factors: the chemical composition of the resin and its viscosity. Changes of viscosity can have a measurable effect on the final effect of gluing. The following elaboration includes the results of modification tests of an epoxy resin with the addition of two inorganic fillers: microsilica (in the amount of 0.5% of resin weight) and carbon nanotubes (in the amount of 0.1% of resin mass). The epoxy resin commonly used in engineering for joining steel, concrete, carbon fiber, and glass elements was used. In addition, the ultrasound energy was used as a factor, which disintegrated the initial structure of the resin in liquid form and allowed the efficient mixingofthe resin with the filler. The influence of sonication and filler additives on the viscosity of the resin at temperature of 22 °C was determined. Based on the results obtained and observation of the ultrasound effect, the phenomena occurring at the interface of the liquid phase of the resin and the phase of individual fillers were explained. The increase of temperature of the resin under the influence of a dynamic action occurring during sonication was taken into account. The study conducted was the preliminary phase before investigating the influence of the modifications applied on the physical and mechanical parameters of the hardened resin.

ACS Style

Andrzej Szewczak; Maciej Szelag. Modifications of Epoxy Resins and their Influence on their Viscosity. IOP Conference Series: Materials Science and Engineering 2019, 471, 022038 .

AMA Style

Andrzej Szewczak, Maciej Szelag. Modifications of Epoxy Resins and their Influence on their Viscosity. IOP Conference Series: Materials Science and Engineering. 2019; 471 (2):022038.

Chicago/Turabian Style

Andrzej Szewczak; Maciej Szelag. 2019. "Modifications of Epoxy Resins and their Influence on their Viscosity." IOP Conference Series: Materials Science and Engineering 471, no. 2: 022038.

Conference paper
Published: 17 August 2018 in THE 3RD JOINT INTERNATIONAL CONFERENCE ON ENERGY ENGINEERING AND SMART MATERIALS (ICEESM-2018) AND INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY AND NANOMATERIALS IN ENERGY (ICNNE-2018)
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The internal structure of cement slurries and mortars constitutes the subject of numerous studies in material engineering. The physical and mechanical properties of this material on the macro level largely depend on its micro and nano levels. The internal system of clusters and nanoclusters, separated with scratches, cracks, capillaries, pores or intermediate phases on the aggregate-slurry interface, determines the character of damage of a given material subjected to loading. In order to predict the behavior of affected cement slurry/mortar, i.e. under static, dynamic or environmental load, it is important to investigate the internal structure and its characteristic properties. One of these properties involves microhardness, which directly corresponds to the mechanical properties, e.g. compression, flexural, and bending strength. The knowledge on the microhardness aids in determining the parameters connected with the cracking mechanics of this type of materials, including concrete.

ACS Style

S. Fic; A. Szewczak; Ł. Guz. Microhardness of the slurries and cement mortars. THE 3RD JOINT INTERNATIONAL CONFERENCE ON ENERGY ENGINEERING AND SMART MATERIALS (ICEESM-2018) AND INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY AND NANOMATERIALS IN ENERGY (ICNNE-2018) 2018, 2004, 030002 .

AMA Style

S. Fic, A. Szewczak, Ł. Guz. Microhardness of the slurries and cement mortars. THE 3RD JOINT INTERNATIONAL CONFERENCE ON ENERGY ENGINEERING AND SMART MATERIALS (ICEESM-2018) AND INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY AND NANOMATERIALS IN ENERGY (ICNNE-2018). 2018; 2004 (1):030002.

Chicago/Turabian Style

S. Fic; A. Szewczak; Ł. Guz. 2018. "Microhardness of the slurries and cement mortars." THE 3RD JOINT INTERNATIONAL CONFERENCE ON ENERGY ENGINEERING AND SMART MATERIALS (ICEESM-2018) AND INTERNATIONAL CONFERENCE ON NANOTECHNOLOGY AND NANOMATERIALS IN ENERGY (ICNNE-2018) 2004, no. 1: 030002.

Journal article
Published: 03 December 2017 in Budownictwo i Architektura
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Beton, jako uniwersalny, kompozytowy materiał, jest eksploatowany w konstrukcjach pod wpływem różnych, złożonych obciążeń statycznych, dynamicznych, wpływom środowiska zewnętrznego, np. nagłe uderzenia, temperatura, wilgotność. Zapewnienie konstrukcjom betonowym bezpiecznej eksploatacji i trwałości to zadania stawiane w okresie projektowania polegające na wykonaniu badań mieszanek i próbek betonowych. Badania służą jak najdokładniejszemu odwzorowaniu pracy betonu w warunkach naturalnych z uwzględnieniem obciążeń w czasie eksploatacji. Badania betonu w laboratorium dotyczą ustalenia wytrzymałości na ściskanie (fc), rozciąganie (fct); w obszarze trwałości: mrozoodporności, odporności na korozję, wpływu wysokiej temperatury, nasiąkliwości. W przypadku trwałości betonu ustala się zmianę dynamicznego modułu sprężystości Ed, współczynnik intensywności naprężeń (KIC), lub wpływ obciążeń dynamicznych na trwałość i wytrzymałość betonu – obecnie badania te stanowią prężnie rozwijającą się grupę testów, co ma także związek z pojawianiem się nowych rodzajów cementów, kruszyw a w konsekwencji betonów nowej generacji, tj. BWW, BUWW, BSZ. Poszukuje się również możliwości modyfikacji i zwiększenia trwałości tradycyjnych betonów. Niewątpliwie, na wszystkie w/w cechy betonu decydujący wpływ ma wskaźnik w/c, jako główny parametr strukturotwórczy definiujący układ matryca-kruszywo. W artykule przedstawiono analizę porównawczą kilku cech wytrzymałościowych betonu, w zależności od w/c (wartości 0,4-0,7). Przyjęto stałą ilość kruszywa grubego (żwiru). Analizowano wpływ wskaźnika w/c na: fc, fct, KIC, Ei betonu żwirowego.

ACS Style

Stanisław Fic; Andrzej Szewczak. Porównanie charakterystyk różnych wytrzymałości betonu żwirowego o zmiennym wskaźniku w/c. Budownictwo i Architektura 2017, 16, 155 -166.

AMA Style

Stanisław Fic, Andrzej Szewczak. Porównanie charakterystyk różnych wytrzymałości betonu żwirowego o zmiennym wskaźniku w/c. Budownictwo i Architektura. 2017; 16 (3):155-166.

Chicago/Turabian Style

Stanisław Fic; Andrzej Szewczak. 2017. "Porównanie charakterystyk różnych wytrzymałości betonu żwirowego o zmiennym wskaźniku w/c." Budownictwo i Architektura 16, no. 3: 155-166.

Journal article
Published: 06 January 2017 in Materials
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The article presents a proposal of a model of fatigue destruction of hydrophobised ceramic brick, i.e., a basic masonry material. The brick surface was hydrophobised with two inorganic polymers: a nanopolymer preparation based on dialkyl siloxanes (series 1–5) and an aqueous silicon solution (series 6–10). Nanosilica was added to the polymers to enhance the stability of the film formed on the brick surface. To achieve an appropriate blend of the polymer liquid phase and the nano silica solid phase, the mixture was disintegrated by sonication. The effect of the addition of nano silica and sonication on changes in the rheological parameters, i.e., viscosity and surface tension, was determined. Material fatigue was induced by cyclic immersion of the samples in water and drying at a temperature of 100 °C, which caused rapid and relatively dynamic movement of water. The moisture and temperature effect was determined by measurement of changes in surface hardness performed with the Vickers method and assessment of sample absorbability. The results provided an approximate picture of fatigue destruction of brick and hydrophobic coatings in relation to changes in their temporal stability. Additionally, SEM images of hydrophobic coatings in are shown.

ACS Style

Stanisław Fic; Andrzej Szewczak; Danuta Barnat-Hunek; Grzegorz Łagód. Processes of Fatigue Destruction in Nanopolymer-Hydrophobised Ceramic Bricks. Materials 2017, 10, 44 .

AMA Style

Stanisław Fic, Andrzej Szewczak, Danuta Barnat-Hunek, Grzegorz Łagód. Processes of Fatigue Destruction in Nanopolymer-Hydrophobised Ceramic Bricks. Materials. 2017; 10 (1):44.

Chicago/Turabian Style

Stanisław Fic; Andrzej Szewczak; Danuta Barnat-Hunek; Grzegorz Łagód. 2017. "Processes of Fatigue Destruction in Nanopolymer-Hydrophobised Ceramic Bricks." Materials 10, no. 1: 44.

Journal article
Published: 08 December 2015 in Budownictwo i Architektura
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The article describes the studies of efficacy of ceramic brick surface hydrophobisation by preparations based on silicones (micropolymer). The different series of specimens were subjected to a process of surface hydrophobisation by immersion for 15 s using the hydrophobizing formulations, whose structure was further sonificated by power of 400 W. In order to determine the average absorption of polymer by specimens in respective series, before the hydrophobisation samples were dried to a constant weight and weighed. Then, after 14 days of their immersion in the formulation, specimens were weighed again in order to determine the percent change in the sample weight to the weight of the dried sample. The impact of ultrasonic energy on the viscosity of the polymer (measured by Ostwald viscometer) and on the surface tension (measured by stalagmometer) was determined. The hydrophobic properties of the resulting nanofilm created on the surface of the ceramic brick were determined on the basis of the measurement of surface free energy γs (SFE) by using Owens – Wendt method measuring the sample surface contact angles with distilled water (highly polar liquid) and diiodomethane (a polar liquid) to determine the dispersive γsd and polar γsp components (expressed in mJ/m2). Based on the results, the effect of sonification on some adhesive and physico. – mechanical properties of the tested material surface was determined.

ACS Style

Stanisław Fic; Andrzej Szewczak. Hydrophobisation effectiveness of building ceramics, polymeric inorganic ultrasound integrated with the addition of fillers. Budownictwo i Architektura 2015, 14, 019 -027.

AMA Style

Stanisław Fic, Andrzej Szewczak. Hydrophobisation effectiveness of building ceramics, polymeric inorganic ultrasound integrated with the addition of fillers. Budownictwo i Architektura. 2015; 14 (4):019-027.

Chicago/Turabian Style

Stanisław Fic; Andrzej Szewczak. 2015. "Hydrophobisation effectiveness of building ceramics, polymeric inorganic ultrasound integrated with the addition of fillers." Budownictwo i Architektura 14, no. 4: 019-027.

Journal article
Published: 10 March 2015 in Budownictwo i Architektura
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The article presents the literature review about the application of stereology and image analysis for quantitative evaluation of the building materials structure. At the outset, the development of stereological methods and computer image analysis techniques in the study of building materials was provided. Then quantitative structure parameters were defined and their methods of determining were showed. In the paper, the application of image analysis for the determination of properties of the cement composites was reported, including: an assessment of the porosity of the hardened concrete, determination of the aggregate distribution in the cementitious matrix, the crack analysis. It was found that the leading problem of image analysis is the process of sample preparation in order to obtain the correct extraction of examinated phase, and measurement automation process.

ACS Style

Maciej Szeląg; Andrzej Szewczak. Application of stereology in engineering of building materials. Budownictwo i Architektura 2015, 14, 115 -125.

AMA Style

Maciej Szeląg, Andrzej Szewczak. Application of stereology in engineering of building materials. Budownictwo i Architektura. 2015; 14 (1):115-125.

Chicago/Turabian Style

Maciej Szeląg; Andrzej Szewczak. 2015. "Application of stereology in engineering of building materials." Budownictwo i Architektura 14, no. 1: 115-125.

Journal article
Published: 11 September 2014 in Budownictwo i Architektura
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Developed in Poland systems of prefabricated residential buildings provide an opportunity for an effective solution to the basic problem of the period of industrial development which was the lack of an adequate number of apartments. Unfortunately, the degree of realization of objectives due to numerous errors caused problems in the usage of made objects. The paper provides an overview of the basic causes of failures and defects in the prefabricated residential buildings, starting from the design stage, the conditions of transport, assembly of components and ending with negligence resulting from their improper use. The effects of neglect are shown in the examples of buildings from Lublin and the surrounding area as one of the most common technical problems. An analysis of the causes of the faults and their effects in the form of failure and damage of structural elements was shown.

ACS Style

Stanisław Fic; Maciej Szeląg; Andrzej Szewczak. Operational phase problems of prefabricated residential buildings on the example of the objects in the Lublin region. Budownictwo i Architektura 2014, 13, 007 -014.

AMA Style

Stanisław Fic, Maciej Szeląg, Andrzej Szewczak. Operational phase problems of prefabricated residential buildings on the example of the objects in the Lublin region. Budownictwo i Architektura. 2014; 13 (3):007-014.

Chicago/Turabian Style

Stanisław Fic; Maciej Szeląg; Andrzej Szewczak. 2014. "Operational phase problems of prefabricated residential buildings on the example of the objects in the Lublin region." Budownictwo i Architektura 13, no. 3: 007-014.