Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.4.5
M. Wieczorek, P. Pichniarczyk
The paper presents a study to determine the applicability of blended cements with low Portland clinker content in construction mortars, including special mortars. The main additives used in the study, in the form of ground granulated blast furnace slag and silica fly ash, were characterised by a similar grain composition of less than 40 μm. They were introduced into mortars as a replacement for Portland cement in amounts of 50 and 70 % and their mixtures in amounts not exceeding 70 %. Tests were carried out to determine the influence of the proportion, as well as the SiO2 and CaO content of the individual main components, on the strength parameters of the designed cements. The results show that these cements can be used in self-compacting concrete technology and in sealing mixtures for geoengineering applications, which are designed to perform soil reinforcement and sealing. The proposed technology for the production of CEM V and CEM VI cements, in addition to the favourable changes in their properties, results in a significant reduction in the energy required to produce these cements.
{"title":"Properties of cement with the low Portland clinker and the different content of silica fly ash as well as granulated blast furnace slag","authors":"M. Wieczorek, P. Pichniarczyk","doi":"10.32047/cwb.2022.27.4.5","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.4.5","url":null,"abstract":"The paper presents a study to determine the applicability of blended cements with low Portland clinker content in construction mortars, including special mortars. The main additives used in the study, in the form of ground granulated blast furnace slag and silica fly ash, were characterised by a similar grain composition of less than 40 μm. They were introduced into mortars as a replacement for Portland cement in amounts of 50 and 70 % and their mixtures in amounts not exceeding 70 %. Tests were carried out to determine the influence of the proportion, as well as the SiO2 and CaO content of the individual main components, on the strength parameters of the designed cements. The results show that these cements can be used in self-compacting concrete technology and in sealing mixtures for geoengineering applications, which are designed to perform soil reinforcement and sealing. The proposed technology for the production of CEM V and CEM VI cements, in addition to the favourable changes in their properties, results in a significant reduction in the energy required to produce these cements.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"11 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84125553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.4.2
J. Wojsa, W. Zelik, Sebastian Sado, R. Świerszcz
An attempt was made to adjust the kind of organic additives to the components of the mass for the magnesia-chromite products. This was done using Sanderson’s concept of electronegativity and molar electronegativity. Four organic additives were selected and their influence on the properties of the refractories was studied by performing a total factorial experiment 24. The basic properties of the refractories are presented in the form of seven response functions, six of which are described by statistically verified equations. The most favourable options were selected on the basis of six criteria that characterise the materials. The introduction of organic additives as slip agents into the mass, resulted in an improvement in practically all properties of the magnesia-chromite materials after firing. The purposefulness of the additive composition was demonstrated.
{"title":"Effect of selected organic additives on the properties of magnesia-chromite refractories","authors":"J. Wojsa, W. Zelik, Sebastian Sado, R. Świerszcz","doi":"10.32047/cwb.2022.27.4.2","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.4.2","url":null,"abstract":"An attempt was made to adjust the kind of organic additives to the components of the mass for the magnesia-chromite products. This was done using Sanderson’s concept of electronegativity and molar electronegativity. Four organic additives were selected and their influence on the properties of the refractories was studied by performing a total factorial experiment 24. The basic properties of the refractories are presented in the form of seven response functions, six of which are described by statistically verified equations. The most favourable options were selected on the basis of six criteria that characterise the materials. The introduction of organic additives as slip agents into the mass, resulted in an improvement in practically all properties of the magnesia-chromite materials after firing. The purposefulness of the additive composition was demonstrated.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"56 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84513441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.3.1
Robert Turski, W. Rogala
The article presents the current situation of the industry manufacturing autoclaved aerated concrete and the possibilities for further development. It presents a roadmap for the industry to achieve net-zero-emission during production and life cycle till 2050, and discusses the sources of carbon dioxide emissions in the production of AAC and methods, which can be taken to reduce them. The article also discusses ways to increase the competitiveness of the AAC manufacturing industry as well as current and future ways of using digitisation and mechanisation on construction sites.
{"title":"Current situation and further development of AAC in Europe","authors":"Robert Turski, W. Rogala","doi":"10.32047/cwb.2022.27.3.1","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.3.1","url":null,"abstract":"The article presents the current situation of the industry manufacturing autoclaved aerated concrete and the possibilities for further development. It presents a roadmap for the industry to achieve net-zero-emission during production and life cycle till 2050, and discusses the sources of carbon dioxide emissions in the production of AAC and methods, which can be taken to reduce them. The article also discusses ways to increase the competitiveness of the AAC manufacturing industry as well as current and future ways of using digitisation and mechanisation on construction sites.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"9 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78501242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.2.5
Z. Owsiak
The studies carried out aimed to define the influence of the aggregate type on the simultaneous occurrence of the alkali-silica reaction and delayed ettringite formation. In their composition, sand or calcium aggregate and aggregates containing 6% opal with graining of 0.5 to 1.0 mm, were used. Mortars from each type of aggregate and Portland cement containing 1.2% Na2Oe and 4.5% SO 3 were prepared, and then cured in water at 90°C. Studies have shown a great influence of the type of aggregate on the expansion caused by the delayed ettringite formation. In this case, the calcium aggregate visibly reduces the expansion of a mortar caused by delayed ettringite formation, while it has a much smaller influence on the expansion of the bars, caused by the potassium reaction with opal. Microstructure observations have shown that sodium-potassium-calcium silicate gel and ettringite around the aggregate grains, are responsible for expansion in the case of sand with opal addition.
{"title":"Influence of the aggregate type on delayed ettringite formation","authors":"Z. Owsiak","doi":"10.32047/cwb.2022.27.2.5","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.2.5","url":null,"abstract":"The studies carried out aimed to define the influence of the aggregate type on the simultaneous occurrence of the alkali-silica reaction and delayed ettringite formation. In their composition, sand or calcium aggregate and aggregates containing 6% opal with graining of 0.5 to 1.0 mm, were used. Mortars from each type of aggregate and Portland cement containing 1.2% Na2Oe and 4.5% SO 3 were prepared, and then cured in water at 90°C. Studies have shown a great influence of the type of aggregate on the expansion caused by the delayed ettringite formation. In this case, the calcium aggregate visibly reduces the expansion of a mortar caused by delayed ettringite formation, while it has a much smaller influence on the expansion of the bars, caused by the potassium reaction with opal. Microstructure observations have shown that sodium-potassium-calcium silicate gel and ettringite around the aggregate grains, are responsible for expansion in the case of sand with opal addition.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"47 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84850724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.3.3
R. Jasiński, Ł. Drobiec, W. Mazur
The article describes the possibilities of non-destructive testing of existing structures, made of autoclaved aerated concrete [AAC] masonry units. Relationships that allow the determination of the normalized compressive strength of autoclaved aerated concrete, were developed with the MDT semi-non-destructive method. The general form of the Neville curve, known from the diagnosis of plain concrete was used, which was calibrated to AAC of nominal density classes 400, 500, 600 and 700. The tests were performed and additional empirical relationships were built, to allow for the influence of density and moisture. Moreover, an ultrasonic non-destructive NDT method calibrated on standard cubic 100 × 100 ×100 mm samples of various densities and moisture, is presented. In addition to the non-destructive ultrasound method, the sclerometric method, calibrated on the entire masonry elements, limited to one nominal density of 600 kg/m3 with varying moisture, was also used. A practical application of AAC strength assessment in the existing masonry structure, has been presented.
{"title":"Features of non-destructive testing of existing masonry structures made of autoclaved aerated concrete units","authors":"R. Jasiński, Ł. Drobiec, W. Mazur","doi":"10.32047/cwb.2022.27.3.3","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.3.3","url":null,"abstract":"The article describes the possibilities of non-destructive testing of existing structures, made of autoclaved aerated concrete [AAC] masonry units. Relationships that allow the determination of the normalized compressive strength of autoclaved aerated concrete, were developed with the MDT semi-non-destructive method. The general form of the Neville curve, known from the diagnosis of plain concrete was used, which was calibrated to AAC of nominal density classes 400, 500, 600 and 700. The tests were performed and additional empirical relationships were built, to allow for the influence of density and moisture. Moreover, an ultrasonic non-destructive NDT method calibrated on standard cubic 100 × 100 ×100 mm samples of various densities and moisture, is presented. In addition to the non-destructive ultrasound method, the sclerometric method, calibrated on the entire masonry elements, limited to one nominal density of 600 kg/m3 with varying moisture, was also used. A practical application of AAC strength assessment in the existing masonry structure, has been presented.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"11 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83471871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.2.3
Szymon Sikora, Karol Skowera, Mariusz Hynowski, Z. Rusin
The construction sector is responsible for around 37% of global emissions of the carbon dioxide to the atmosphere. Therefore, reducing gas emissions, in this construction sector, is particularly important ,given the progressing climate change. For this reason, limiting its emissions and limiting the emission of other greenhouse gases in this sector, is of particular importance in view of the progress of climate change. It is important that new construction products have less impact on the environment during their entire life cycle, and their production has been decoupled from the use of primary energy. In this work, selected properties of geopolymeric materials were examined. Geopolymers are inorganic aluminosilicate polymers with an amorphous microstructure, which may be an alternative in certain applications, for products based on Portland cement. Here, the properties of geopolymer mortars, i.e. porosity, microstructure and mechanical strength, were compared. The influence of the composition of reaction mixture on these properties, defined by the appropriate SiO2/Al2O3 and SiO2/Na2O molar ratios, was also defined. The results show that increasing the content of SiO2 in relation to Al2O3 in the composition of the reaction mixture, reduces porosity. Thus, leading to a more compact microstructure and higher mechanical strength. A similar effect occurs when a higher NaOH solution concentration is used, in comparison to the sodium silicate [Na2SiO3] solution.
{"title":"Formation of geopolymeric materials properties depending on the molar modules of SiO2/Al2O3 and SiO2/Na2O","authors":"Szymon Sikora, Karol Skowera, Mariusz Hynowski, Z. Rusin","doi":"10.32047/cwb.2022.27.2.3","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.2.3","url":null,"abstract":"The construction sector is responsible for around 37% of global emissions of the carbon dioxide to the atmosphere. Therefore, reducing gas emissions, in this construction sector, is particularly important ,given the progressing climate change. For this reason, limiting its emissions and limiting the emission of other greenhouse gases in this sector, is of particular importance in view of the progress of climate change. It is important that new construction products have less impact on the environment during their entire life cycle, and their production has been decoupled from the use of primary energy. In this work, selected properties of geopolymeric materials were examined. Geopolymers are inorganic aluminosilicate polymers with an amorphous microstructure, which may be an alternative in certain applications, for products based on Portland cement. Here, the properties of geopolymer mortars, i.e. porosity, microstructure and mechanical strength, were compared. The influence of the composition of reaction mixture on these properties, defined by the appropriate SiO2/Al2O3 and SiO2/Na2O molar ratios, was also defined. The results show that increasing the content of SiO2 in relation to Al2O3 in the composition of the reaction mixture, reduces porosity. Thus, leading to a more compact microstructure and higher mechanical strength. A similar effect occurs when a higher NaOH solution concentration is used, in comparison to the sodium silicate [Na2SiO3] solution.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"16 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81314831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.1.5
R. Shanthi Vengadeshwari, H. J. Jagannatha Reddy, R. Prabhakara
Addition of fiber is a promising solution, to enhance the flexural behaviour of reinforced cement concrete [RCC] beams. It improves the peak load, ductility and energy absorption characteristics of RCC. Ineffective mono fibers in the concrete perform very effective, when combined through the hybridization and contribute towards the strength. Fiber hybridization offers appreciable improvement in fresh and hardened properties of concrete. To achieve optimum performance, synergetic effect of fibers is more important. Incorporation of two fibers in concrete matrix, bridges the cracks effectively. Hence to investigate the effect fiber hybridization in the flexural performance, RCC beams were cast, experimented and the results were compared with the control beams. In the present study, it is intended to evaluate and compare the impact of steel and basalt fibers in mono form and hybrid form, on the flexural parameters such as first crack load, load response behaviour, ductility, crack width and flexural strength of RCC beams. To evaluate the mechanical properties of M40 grade fiber reinforced concrete, volume fractions chosen were 0.25%, 0.5% and 0.75%. Comparatively addition of basalt fibers with steel fibers, improves synergetic response to a considerable extent. From overall assessment of the mechanical properties, it was established that the combination of basalt and steel fibers at 0.25% and 0.75% respectively, produced optimum results. Optimum volume fraction of fibers identified is used in the casting of RCC beams. Wherever possible, flexural parameters were cross checked, with Indian Standards.
{"title":"Experimental investigation on influence of hybrid fibers in flexural behavior of reinforced concrete beams","authors":"R. Shanthi Vengadeshwari, H. J. Jagannatha Reddy, R. Prabhakara","doi":"10.32047/cwb.2022.27.1.5","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.1.5","url":null,"abstract":"Addition of fiber is a promising solution, to enhance the flexural behaviour of reinforced cement concrete [RCC] beams. It improves the peak load, ductility and energy absorption characteristics of RCC. Ineffective mono fibers in the concrete perform very effective, when combined through the hybridization and contribute towards the strength. Fiber hybridization offers appreciable improvement in fresh and hardened properties of concrete. To achieve optimum performance, synergetic effect of fibers is more important. Incorporation of two fibers in concrete matrix, bridges the cracks effectively. Hence to investigate the effect fiber hybridization in the flexural performance, RCC beams were cast, experimented and the results were compared with the control beams. In the present study, it is intended to evaluate and compare the impact of steel and basalt fibers in mono form and hybrid form, on the flexural parameters such as first crack load, load response behaviour, ductility, crack width and flexural strength of RCC beams. To evaluate the mechanical properties of M40 grade fiber reinforced concrete, volume fractions chosen were 0.25%, 0.5% and 0.75%. Comparatively addition of basalt fibers with steel fibers, improves synergetic response to a considerable extent. From overall assessment of the mechanical properties, it was established that the combination of basalt and steel fibers at 0.25% and 0.75% respectively, produced optimum results. Optimum volume fraction of fibers identified is used in the casting of RCC beams. Wherever possible, flexural parameters were cross checked, with Indian Standards.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"36 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83809412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.1.2
Sebastian Czernik, Bartosz Michałowski, J. Tomaszewska, J. Michalak
The construction sector is one of the branches of the economy with a significant impact on the environment. It uses a vast amount of different raw materials. Also, it produces substantial amounts of waste and emits high amounts of greenhouse gases into the atmosphere. Reducing the energy consumption and emissivity of buildings, decarbonizing existing energy sources, optimizing the use of renewable energy, and minimizing the carbon footprint of materials and construction works are imperative to counteract climate change. It is also a minimum plan for ensuring sustainable social development. The current environmental policy in the construction sector is insufficient and it results from the legal regulations currently in force. Assessment of construction products for the seventh basic requirement, sustainable use of natural resources, is voluntary and almost always neglected. Assessment tools, such as Type III Environmental Product Declarations [EPDs] for construction products, are not widely used. Moreover, these documents are poorly recognizable among consumers, proving that there is still insufficient environmental awareness. In addition, the emerging differences in environmental impact indicators values specified in environmental declarations, resulting from using differentiated approaches in setting system boundaries or the quality of available generic data, do not support the proper development of knowledge about the impact of construction products on the environment. In this work, an analysis of the environmental impact of cement, which is a component of adhesives used in the External Thermal Insulation Composite System [ETICS], was carried out. The study on four indicators, i.e., global warming potential [GWP], soil and water acidification potential [AP], eutrophication potential [EP], and tropospheric ozone formation potential [POCP], was performed.
{"title":"The infl uence of cement on the environmental performance of construction products on the example of cementitious adhesives – External Thermal Insulation Composite Systems [ETICS] components","authors":"Sebastian Czernik, Bartosz Michałowski, J. Tomaszewska, J. Michalak","doi":"10.32047/cwb.2022.27.1.2","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.1.2","url":null,"abstract":"The construction sector is one of the branches of the economy with a significant impact on the environment. It uses a vast amount of different raw materials. Also, it produces substantial amounts of waste and emits high amounts of greenhouse gases into the atmosphere. Reducing the energy consumption and emissivity of buildings, decarbonizing existing energy sources, optimizing the use of renewable energy, and minimizing the carbon footprint of materials and construction works are imperative to counteract climate change. It is also a minimum plan for ensuring sustainable social development. The current environmental policy in the construction sector is insufficient and it results from the legal regulations currently in force. Assessment of construction products for the seventh basic requirement, sustainable use of natural resources, is voluntary and almost always neglected. Assessment tools, such as Type III Environmental Product Declarations [EPDs] for construction products, are not widely used. Moreover, these documents are poorly recognizable among consumers, proving that there is still insufficient environmental awareness. In addition, the emerging differences in environmental impact indicators values specified in environmental declarations, resulting from using differentiated approaches in setting system boundaries or the quality of available generic data, do not support the proper development of knowledge about the impact of construction products on the environment. In this work, an analysis of the environmental impact of cement, which is a component of adhesives used in the External Thermal Insulation Composite System [ETICS], was carried out. The study on four indicators, i.e., global warming potential [GWP], soil and water acidification potential [AP], eutrophication potential [EP], and tropospheric ozone formation potential [POCP], was performed.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"8 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80836719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.3.2
W. Pichór
Autoclaved aerated concrete is an environmentally friendly material. However, the demands of the modern world and, above all, care for the future, necessitate the search for new solutions to minimise negative environmental effects. This paper presents selected solutions for the use of waste materials and by-products from other techniques in autoclaved aerated concrete production, taking into account potential risks and limitations. Attention was also drawn to the use of aerated concrete waste in other methods, primarily as a cement substitute, or concrete additive. The paper is selective in nature due to its volume, but the main purpose is to present trends and directions in the search for new material solutions in this technology.
{"title":"Environmentally friendly material solutions in the technology of autoclaved aerated concrete","authors":"W. Pichór","doi":"10.32047/cwb.2022.27.3.2","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.3.2","url":null,"abstract":"Autoclaved aerated concrete is an environmentally friendly material. However, the demands of the modern world and, above all, care for the future, necessitate the search for new solutions to minimise negative environmental effects. This paper presents selected solutions for the use of waste materials and by-products from other techniques in autoclaved aerated concrete production, taking into account potential risks and limitations. Attention was also drawn to the use of aerated concrete waste in other methods, primarily as a cement substitute, or concrete additive. The paper is selective in nature due to its volume, but the main purpose is to present trends and directions in the search for new material solutions in this technology.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"26 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80208793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-01-01DOI: 10.32047/cwb.2022.27.1.4
W. Kurdowski, Paweł Zajd
In laboratory experiments, we found the unexpected influence of zinc addition, which was the acceleration of the Portland cement setting. This untypical cement behaviour was caused by the addition of anhydrite II as the setting time regulator, by its producer. Anhydrite II dissolves very slowly and the sulphate ions concentration in the paste of the hydrating cement, was very low. However, zinc was soluted very quickly and its hydroxide precipitated on the surface of C 3 A crystals, limiting the formation of the continuous ettringite layer. Thus, ettringite is formed in the free areas in the solution, linking the cement grains, with the formation of the quick “ettringite” setting. Ettringite precipitated in the free areas within the solution, binds to the cement grains and causes the ‘quick’ setting of ettringite. However, the alite crystals remain continuously covered by the amorphous layer of Zn(OH) 2 , and under this condition the induction period with water reaction of this phase remains hang-up. The elongation of this period is increasing with the increase in the addition of zinc
{"title":"Importance of zinc in Portland cement production","authors":"W. Kurdowski, Paweł Zajd","doi":"10.32047/cwb.2022.27.1.4","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.1.4","url":null,"abstract":"In laboratory experiments, we found the unexpected influence of zinc addition, which was the acceleration of the Portland cement setting. This untypical cement behaviour was caused by the addition of anhydrite II as the setting time regulator, by its producer. Anhydrite II dissolves very slowly and the sulphate ions concentration in the paste of the hydrating cement, was very low. However, zinc was soluted very quickly and its hydroxide precipitated on the surface of C 3 A crystals, limiting the formation of the continuous ettringite layer. Thus, ettringite is formed in the free areas in the solution, linking the cement grains, with the formation of the quick “ettringite” setting. Ettringite precipitated in the free areas within the solution, binds to the cement grains and causes the ‘quick’ setting of ettringite. However, the alite crystals remain continuously covered by the amorphous layer of Zn(OH) 2 , and under this condition the induction period with water reaction of this phase remains hang-up. The elongation of this period is increasing with the increase in the addition of zinc","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"10 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74448442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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