Anna Stepien - Academia.edu (original) (raw)
Papers by Anna Stepien
Thermal insulation of autoclaved materials
Journal of Physics: Conference Series, 2021
The construction industry relies on the production of building materials, which are created as a ... more The construction industry relies on the production of building materials, which are created as a result of particular actions of binding materials widely used in construction, and directly condition the quality of life of a society. Following these thesis, one should create possibilities of conscious choice and use of building materials not only among scientists and constructors, but among the whole society. Two types of additives are used in building materials: additives with a crystalline structure (SiO2) and additives with an amorphous structure (fly ash), which affects the properties and durability of materials. In the last decade industry is also moved on the fight against global warming and overproduction of materials. In May 2019, the level of CO2 concentration in the atmosphere exceeded 415ppm, which was the highest result in the last 50 years. Overproduction is, in turn, associated with the excessive use of natural resources (SiO2) and since 2010 there has been talk of the ...
The paper presents the key properties of calcium silicate products modified with basalt aggregate... more The paper presents the key properties of calcium silicate products modified with basalt aggregate. Silicates are organic products which are widely used in the construction industry. They are used to build partition, structural and even foundation walls. They are characterized by the low level of radioactivity compared to other building materials for walls. Interesting effect may also be seen in the microstructure of these products. Next to the C-S-H phase, other phases emerge in even more structured order Appropriate production technology and modification leads to the formation of tobermorite or xonotlite. It has been noticed that their presence is strictly related to the durability of silicates.
Crystals, 2021
This paper describes the use of glass sand in the production of autoclaved bricks. Traditional au... more This paper describes the use of glass sand in the production of autoclaved bricks. Traditional autoclaved materials consist of SiO2, CaO, and H2O. The purpose of the tests is to analyze the possibility of using glass sand in autoclaved materials and to determine their properties and durability. Depending on the structure, building materials can have porosities ranging from 0% (glass, metals) to over 90% (thermal insulation materials such as aerated concrete). Porosity of materials is directly related to the strength of materials and their density, and further to the thermal and acoustic insulation properties of products used especially for external wall construction, i.e., bricks, concrete, and aerated concrete. This type of silicate brick is formed at a temperature of 203 °C, therefore the dominant phase forming the microstructure is tobermorite, in contrast to the C-S-H phase, which dominates in concretes and which is characterized by a larger specific surface. The nature of pores...
The use of basalt powder in autoclaved brick as a method of production waste management
Journal of Cleaner Production, 2021
Microclimate and health properties of autoclaved building materials in the context of their modification
Bulletin of the Military University of Technology, 2018
The construction industry in a special way affects the condition of the state of the environment ... more The construction industry in a special way affects the condition of the state of the environment and human. It is necessary to search for materials with the lowest degree of risk to humans. The aim of the article is to focus attention on the materials which are composed of natural components such as: SiO2, CaO, H2O, and next on the thermal and moisture management of the material in the aspect of development of harmful microorganisms in construction materials (including the modified ones). The microstructure of the materials usually includes tobermorite with a ratio CaO/SiO2 = 0.83 and C-S-H phase, impregnability 16%, and compressive strength minimum 13 MPa. The article proposes the use of the ASR (Additive Ratio Assessment-ARAS) method to develop a model and analysis of the used building materials that affect the microclimate in the room. A case study can be defined as a decision problem. Keywords: architecture, sand, lime, silicate, environment, protection, recycling, ARAS.
Buildings, 2019
Far-reaching technological progress, manufacturing, and rapidly advancing globalization dictate n... more Far-reaching technological progress, manufacturing, and rapidly advancing globalization dictate new conditions for the development and changes in the construction industry. Valorization of by-products and the use of secondary materials in the production of building materials have attracted a lot of attention. Silicate materials were assessed on the basis of their compressive property. An orthogonal compositional plan type 3k (with k = 2), that is, a full two-factor experiment was applied in order to carry out the compressive strength and bulk density tests. Glass sand was added to the silicate mass as a modification. The results show that the compressive strength was higher than that of traditional bricks. Scanning electron microscopy coupled with energy dispersive spectrometry SEM/EDS was used to study the microstructure, whereas the XRD analysis was applied to examine the structures. Laboratory tests were performed on samples with dimensions of 50 × 50 × 50 mm. The results show th...
MATEC Web of Conferences, 2018
The traditional way of producing sand-lime products is connected with the use of three basic raw ... more The traditional way of producing sand-lime products is connected with the use of three basic raw materials i.e. quartz sand of natural origin, water and quicklime ground lime. During hydrothermal treatment in an autoclave, chemical reactions take place between the calcium and silicon ions. As a result of these reactions, the products are created that provide advantageous appropriable traits. In order to improve the durability attributes of the discussed products, diabase and barite aggregate was introduced into the raw material mass. In addition, the change in the densification method of the silicate mixture was applied. Layering was replaced instead of traditional pressing. The article describes sand-lime products modified with diabase and barite aggregate in an amount up to 15% by weight. Two methods of thickening the sand-lime mixture were used: pressing and layering. The change of the applied technology significantly influences, among others for water absorption. The best result was obtained using 5% and 10% modifiers. Modification with 5% content of diabase aggregate and 5% content of barite aggregate increases the strength by over 60% in relation to the reference sample. The obtained properties are reflected in the image of the microstructure examined by means of the scanning electron microscope. In the sand-lime products, both traditional and modified with diabase and barite aggregates, the C-S-H phase and tobermorite is present. These phases are characteristic for autoclaved products, although depending on the method of thickening occur in varying degrees and intensities.
Buildings, 2019
The article focuses on brick products, the production of which is based on natural components, su... more The article focuses on brick products, the production of which is based on natural components, such as lime (CaO), quartz sand (SiO2) and water (H2O), and which are created during the process of the so-called hydrothermal treatment. In the production process of the modified brick, basalt components (basalt aggregate, with graining of 2–4 mm, basalt powder and basalt fibers) were used because of their natural origin, mineralogical composition, high volume density, and possibly minimal absorbability. In the article thermodynamic properties of minerals forming the construction of basalt components were determined, as well as the phases that arise during the autoclaving process. Compressive strength and density were investigated due to acoustic properties. The product modified with basalt aggregate shows decrease in water absorption as a result of capillary action and in absorbability up to 9% (in the reference sample up to 16%). The sample with basalt aggregate shows compressive resist...
The 9th International Conference "Environmental Engineering 2014", 2014
The aim of conducted research is to modify sand-lime blocks with organic compounds, which in turn... more The aim of conducted research is to modify sand-lime blocks with organic compounds, which in turn leads primarily to increase their strength characteristics and resistant to injury. The liquid admixture of organic compounds, which are rich in certain elements, chemical compounds and macro-, micro-and ultraelements (among others colloidal silica or phosphorus) beneficial effects on a number of chemical transformations in the manufacturing process of this products. The SEM (Scanning Electron Microscope) examination enabled the phase composition analysis of the modified products. Occurring transformations have an impact on the phase microstructure (C-S-H phase is remodeling, C-S-H is Calcium Silicate Hydrates CaO-SiO 2-H 2 O and and calcium silicate hydrates of arranged structure, i.e. tobermorite), the porosity and physical and mechanical properties of the final product, which is a sand-lime block. The research demonstrated that the application of organic compounds to silicate products led to the creation of the following phase known as tobermorite and sometimes xonotlite. Sand-lime products are a group of construction materials used to erect external and internal walls of buildings. Are called an environmentally friendly, because these products consist only of sand, lime and water. The aim of conducted modification, besides improving features of studied material, is to retain its naturalness and therefore used admixtures are also analyzed in order to estimate their influence on the environment and human.
IOP Conference Series: Materials Science and Engineering, 2019
The basis of construction is made of materials such as: wood, stone (including artificial stone, ... more The basis of construction is made of materials such as: wood, stone (including artificial stone, i.e. concrete and brick), steel and glass. Currently, the glass is a product that enjoys increased interest, also due to the phenomenon of recycling. At the moment, construction industry is a field in which good solutions are sought for the proper management of waste. One of the recycled waste is glass cullet coming from bottles mainly of wine. Not every country produces wines because there are no suitable conditions, but wine is drunk in every country. Powdered glass is already applied in the form of glass powder in concretes (research conducted in India, China and America), and the results of the research are the basis for exploring this topic in the context of other materials. The paper presents the results of research on modifications of sand-lime materials using cullet (glass sand). Non-destructive testing of samples was carried out: lime hydration control in a mixture containing powdered recycled glass, /humidity that affects the water absorption of the product, and further on density and strength (water migration in the pores) and microstructural investigations. The conducted tests showed increased humidity of the modified product with recycling glass (approximately 2% compared to the reference sample of 0.5%) and the presence of hydrated calcium silicates in the form of gyrolite as a phase resulting from high pressure.
Buildings
This study describes the relationship between the physio-mechanical and chemical properties of sa... more This study describes the relationship between the physio-mechanical and chemical properties of sand-lime materials which have undergone hydrothermal treatment, and which were modified through the introduction of glass components (90% glass sand, GS). Process parameters such as temperature, pressure and saturation vapor pressure were found to have a significant impact on the series of chemical reactions as well as on the formation and transformation of solid hydrates. During the stirring process of sand-lime mass, the temperature of the reaction between lime and water in the presence of quartz sand (QS) was determined to be 83 °C. In the presence of glass sand, measured temperature was only 42 °C. Thermodynamic equilibrium-based modelling was applied to predict stable phase assemblages in the studied systems. It was found that compositional modification along with the application of the autoclaving process resulted in the formation of two crystalline phases: natrolite and gyrolite. C...
Thermal insulation of autoclaved materials
Journal of Physics: Conference Series, 2021
The construction industry relies on the production of building materials, which are created as a ... more The construction industry relies on the production of building materials, which are created as a result of particular actions of binding materials widely used in construction, and directly condition the quality of life of a society. Following these thesis, one should create possibilities of conscious choice and use of building materials not only among scientists and constructors, but among the whole society. Two types of additives are used in building materials: additives with a crystalline structure (SiO2) and additives with an amorphous structure (fly ash), which affects the properties and durability of materials. In the last decade industry is also moved on the fight against global warming and overproduction of materials. In May 2019, the level of CO2 concentration in the atmosphere exceeded 415ppm, which was the highest result in the last 50 years. Overproduction is, in turn, associated with the excessive use of natural resources (SiO2) and since 2010 there has been talk of the ...
The paper presents the key properties of calcium silicate products modified with basalt aggregate... more The paper presents the key properties of calcium silicate products modified with basalt aggregate. Silicates are organic products which are widely used in the construction industry. They are used to build partition, structural and even foundation walls. They are characterized by the low level of radioactivity compared to other building materials for walls. Interesting effect may also be seen in the microstructure of these products. Next to the C-S-H phase, other phases emerge in even more structured order Appropriate production technology and modification leads to the formation of tobermorite or xonotlite. It has been noticed that their presence is strictly related to the durability of silicates.
Crystals, 2021
This paper describes the use of glass sand in the production of autoclaved bricks. Traditional au... more This paper describes the use of glass sand in the production of autoclaved bricks. Traditional autoclaved materials consist of SiO2, CaO, and H2O. The purpose of the tests is to analyze the possibility of using glass sand in autoclaved materials and to determine their properties and durability. Depending on the structure, building materials can have porosities ranging from 0% (glass, metals) to over 90% (thermal insulation materials such as aerated concrete). Porosity of materials is directly related to the strength of materials and their density, and further to the thermal and acoustic insulation properties of products used especially for external wall construction, i.e., bricks, concrete, and aerated concrete. This type of silicate brick is formed at a temperature of 203 °C, therefore the dominant phase forming the microstructure is tobermorite, in contrast to the C-S-H phase, which dominates in concretes and which is characterized by a larger specific surface. The nature of pores...
The use of basalt powder in autoclaved brick as a method of production waste management
Journal of Cleaner Production, 2021
Microclimate and health properties of autoclaved building materials in the context of their modification
Bulletin of the Military University of Technology, 2018
The construction industry in a special way affects the condition of the state of the environment ... more The construction industry in a special way affects the condition of the state of the environment and human. It is necessary to search for materials with the lowest degree of risk to humans. The aim of the article is to focus attention on the materials which are composed of natural components such as: SiO2, CaO, H2O, and next on the thermal and moisture management of the material in the aspect of development of harmful microorganisms in construction materials (including the modified ones). The microstructure of the materials usually includes tobermorite with a ratio CaO/SiO2 = 0.83 and C-S-H phase, impregnability 16%, and compressive strength minimum 13 MPa. The article proposes the use of the ASR (Additive Ratio Assessment-ARAS) method to develop a model and analysis of the used building materials that affect the microclimate in the room. A case study can be defined as a decision problem. Keywords: architecture, sand, lime, silicate, environment, protection, recycling, ARAS.
Buildings, 2019
Far-reaching technological progress, manufacturing, and rapidly advancing globalization dictate n... more Far-reaching technological progress, manufacturing, and rapidly advancing globalization dictate new conditions for the development and changes in the construction industry. Valorization of by-products and the use of secondary materials in the production of building materials have attracted a lot of attention. Silicate materials were assessed on the basis of their compressive property. An orthogonal compositional plan type 3k (with k = 2), that is, a full two-factor experiment was applied in order to carry out the compressive strength and bulk density tests. Glass sand was added to the silicate mass as a modification. The results show that the compressive strength was higher than that of traditional bricks. Scanning electron microscopy coupled with energy dispersive spectrometry SEM/EDS was used to study the microstructure, whereas the XRD analysis was applied to examine the structures. Laboratory tests were performed on samples with dimensions of 50 × 50 × 50 mm. The results show th...
MATEC Web of Conferences, 2018
The traditional way of producing sand-lime products is connected with the use of three basic raw ... more The traditional way of producing sand-lime products is connected with the use of three basic raw materials i.e. quartz sand of natural origin, water and quicklime ground lime. During hydrothermal treatment in an autoclave, chemical reactions take place between the calcium and silicon ions. As a result of these reactions, the products are created that provide advantageous appropriable traits. In order to improve the durability attributes of the discussed products, diabase and barite aggregate was introduced into the raw material mass. In addition, the change in the densification method of the silicate mixture was applied. Layering was replaced instead of traditional pressing. The article describes sand-lime products modified with diabase and barite aggregate in an amount up to 15% by weight. Two methods of thickening the sand-lime mixture were used: pressing and layering. The change of the applied technology significantly influences, among others for water absorption. The best result was obtained using 5% and 10% modifiers. Modification with 5% content of diabase aggregate and 5% content of barite aggregate increases the strength by over 60% in relation to the reference sample. The obtained properties are reflected in the image of the microstructure examined by means of the scanning electron microscope. In the sand-lime products, both traditional and modified with diabase and barite aggregates, the C-S-H phase and tobermorite is present. These phases are characteristic for autoclaved products, although depending on the method of thickening occur in varying degrees and intensities.
Buildings, 2019
The article focuses on brick products, the production of which is based on natural components, su... more The article focuses on brick products, the production of which is based on natural components, such as lime (CaO), quartz sand (SiO2) and water (H2O), and which are created during the process of the so-called hydrothermal treatment. In the production process of the modified brick, basalt components (basalt aggregate, with graining of 2–4 mm, basalt powder and basalt fibers) were used because of their natural origin, mineralogical composition, high volume density, and possibly minimal absorbability. In the article thermodynamic properties of minerals forming the construction of basalt components were determined, as well as the phases that arise during the autoclaving process. Compressive strength and density were investigated due to acoustic properties. The product modified with basalt aggregate shows decrease in water absorption as a result of capillary action and in absorbability up to 9% (in the reference sample up to 16%). The sample with basalt aggregate shows compressive resist...
The 9th International Conference "Environmental Engineering 2014", 2014
The aim of conducted research is to modify sand-lime blocks with organic compounds, which in turn... more The aim of conducted research is to modify sand-lime blocks with organic compounds, which in turn leads primarily to increase their strength characteristics and resistant to injury. The liquid admixture of organic compounds, which are rich in certain elements, chemical compounds and macro-, micro-and ultraelements (among others colloidal silica or phosphorus) beneficial effects on a number of chemical transformations in the manufacturing process of this products. The SEM (Scanning Electron Microscope) examination enabled the phase composition analysis of the modified products. Occurring transformations have an impact on the phase microstructure (C-S-H phase is remodeling, C-S-H is Calcium Silicate Hydrates CaO-SiO 2-H 2 O and and calcium silicate hydrates of arranged structure, i.e. tobermorite), the porosity and physical and mechanical properties of the final product, which is a sand-lime block. The research demonstrated that the application of organic compounds to silicate products led to the creation of the following phase known as tobermorite and sometimes xonotlite. Sand-lime products are a group of construction materials used to erect external and internal walls of buildings. Are called an environmentally friendly, because these products consist only of sand, lime and water. The aim of conducted modification, besides improving features of studied material, is to retain its naturalness and therefore used admixtures are also analyzed in order to estimate their influence on the environment and human.
IOP Conference Series: Materials Science and Engineering, 2019
The basis of construction is made of materials such as: wood, stone (including artificial stone, ... more The basis of construction is made of materials such as: wood, stone (including artificial stone, i.e. concrete and brick), steel and glass. Currently, the glass is a product that enjoys increased interest, also due to the phenomenon of recycling. At the moment, construction industry is a field in which good solutions are sought for the proper management of waste. One of the recycled waste is glass cullet coming from bottles mainly of wine. Not every country produces wines because there are no suitable conditions, but wine is drunk in every country. Powdered glass is already applied in the form of glass powder in concretes (research conducted in India, China and America), and the results of the research are the basis for exploring this topic in the context of other materials. The paper presents the results of research on modifications of sand-lime materials using cullet (glass sand). Non-destructive testing of samples was carried out: lime hydration control in a mixture containing powdered recycled glass, /humidity that affects the water absorption of the product, and further on density and strength (water migration in the pores) and microstructural investigations. The conducted tests showed increased humidity of the modified product with recycling glass (approximately 2% compared to the reference sample of 0.5%) and the presence of hydrated calcium silicates in the form of gyrolite as a phase resulting from high pressure.
Buildings
This study describes the relationship between the physio-mechanical and chemical properties of sa... more This study describes the relationship between the physio-mechanical and chemical properties of sand-lime materials which have undergone hydrothermal treatment, and which were modified through the introduction of glass components (90% glass sand, GS). Process parameters such as temperature, pressure and saturation vapor pressure were found to have a significant impact on the series of chemical reactions as well as on the formation and transformation of solid hydrates. During the stirring process of sand-lime mass, the temperature of the reaction between lime and water in the presence of quartz sand (QS) was determined to be 83 °C. In the presence of glass sand, measured temperature was only 42 °C. Thermodynamic equilibrium-based modelling was applied to predict stable phase assemblages in the studied systems. It was found that compositional modification along with the application of the autoclaving process resulted in the formation of two crystalline phases: natrolite and gyrolite. C...