Pub Date : 2022-01-01DOI: 10.32047/CWB.2022.27.1.1
M. Koniorczyk, Dalia Bednarsk, Iman Abbasi Nattaj Omrani, A. Masek, S. Cichosz
Alongside with all its difficulties and tragic consequences, the outbreak of the COVID-19 pandemic has also caused a drastic increase in the amount of the generated healthcare wastes. Healthcare wastes can accelerate the further spread of the virus and threaten the health of citizens and the environment. In order to deal with this lateral problem of the on-going pandemic, face-mask wastes were processed and recycled in concrete materials. The objective of this research was to investigate the influences of recycled facemask products on the performance of concrete. To do so, the compressive and splitting tensile strength tests were performed to assess the mechanical behaviour of concrete with and without of the recycled facemask products. Moreover, gas permeability test was conducted on the designed samples before and after exposure to fire temperature, to verify whether the proposed addition provides a similar effect like conventional polypropylene fibres, or not. The results were supplemented with the heat of cement hydration measurements.
{"title":"Performance of concrete containing recycled masks used for personal protection during SARS-CoV-2 coronavirus pandemic","authors":"M. Koniorczyk, Dalia Bednarsk, Iman Abbasi Nattaj Omrani, A. Masek, S. Cichosz","doi":"10.32047/CWB.2022.27.1.1","DOIUrl":"https://doi.org/10.32047/CWB.2022.27.1.1","url":null,"abstract":"Alongside with all its difficulties and tragic consequences, the outbreak of the COVID-19 pandemic has also caused a drastic increase in the amount of the generated healthcare wastes. Healthcare wastes can accelerate the further spread of the virus and threaten the health of citizens and the environment. In order to deal with this lateral problem of the on-going pandemic, face-mask wastes were processed and recycled in concrete materials. The objective of this research was to investigate the influences of recycled facemask products on the performance of concrete. To do so, the compressive and splitting tensile strength tests were performed to assess the mechanical behaviour of concrete with and without of the recycled facemask products. Moreover, gas permeability test was conducted on the designed samples before and after exposure to fire temperature, to verify whether the proposed addition provides a similar effect like conventional polypropylene fibres, or not. The results were supplemented with the heat of cement hydration measurements.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"15 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90877799","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.2022.27.2.4
Mostafa Hasan, L. Amleh, H. Othman
Nowadays transportation infrastructure is subjected to a high percentage of carbon dioxide emissions. CO 2 greatly affects the carbonation depth of concrete, which can affect the deck for reinforced concrete bridges causing corrosion to steel reinforcement. Cement content and water to cement ratio greatly influence the carbonation depth of concrete. This study aims to investigate the effect of climate change on carbonation depth by considering different Representative Concentration Pathways [RCPs]. In addition, the effect of different compressive strengths on the carbonation depth was investigated in this research. Additionally, the effect of different cement contents on the probability of carbonation-induced corrosion has been investigated. Two parameters are considered, namely, the cement content 400 kg/m3, 350 kg/m3, and 250 kg/m3 and, the water to cement ratio [0.45 and 0.55]. This study RCPs for CO2 concentrations. The RCP [2.6, 4.5, 6, and 8.5] trajectory was used by the Intergovernmental Panel on Climate Change [IPCC], which represents low emission pathways, intermediate emission pathways, and high emission pathways, respectively. Carbonation depth has been estimated using Yoon’s and Stewart’s equations. Furthermore, the probability of carbonation-induced corrosion has been investigated using Monte Carlo simulation and the first-order reliability method at different cement contents for RCP 8.5. The percentage increase in the carbonation depth using Yoon’s compared to Stewart’s equations for concrete mixes which consist of different water to cement ratios and cement content for the years 2025 and 2100 for both RCP 2.6 and RCP 8.5 were calculated. Finally, the probability of carbonation-induced corrosion conducted by FORM for cement content of 250 kg/m3 has been increased by 18% compared to the probability of carbonation including cement content equal to 400 kg/m 3 for the year 2100.
{"title":"Effect of different cement content and water cement ratio on carbonation depth and probability of carbonation induced corrosion for concrete","authors":"Mostafa Hasan, L. Amleh, H. Othman","doi":"10.32047/cwb.2022.27.2.4","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.2.4","url":null,"abstract":"Nowadays transportation infrastructure is subjected to a high percentage of carbon dioxide emissions. CO 2 greatly affects the carbonation depth of concrete, which can affect the deck for reinforced concrete bridges causing corrosion to steel reinforcement. Cement content and water to cement ratio greatly influence the carbonation depth of concrete. This study aims to investigate the effect of climate change on carbonation depth by considering different Representative Concentration Pathways [RCPs]. In addition, the effect of different compressive strengths on the carbonation depth was investigated in this research. Additionally, the effect of different cement contents on the probability of carbonation-induced corrosion has been investigated. Two parameters are considered, namely, the cement content 400 kg/m3, 350 kg/m3, and 250 kg/m3 and, the water to cement ratio [0.45 and 0.55]. This study RCPs for CO2 concentrations. The RCP [2.6, 4.5, 6, and 8.5] trajectory was used by the Intergovernmental Panel on Climate Change [IPCC], which represents low emission pathways, intermediate emission pathways, and high emission pathways, respectively. Carbonation depth has been estimated using Yoon’s and Stewart’s equations. Furthermore, the probability of carbonation-induced corrosion has been investigated using Monte Carlo simulation and the first-order reliability method at different cement contents for RCP 8.5. The percentage increase in the carbonation depth using Yoon’s compared to Stewart’s equations for concrete mixes which consist of different water to cement ratios and cement content for the years 2025 and 2100 for both RCP 2.6 and RCP 8.5 were calculated. Finally, the probability of carbonation-induced corrosion conducted by FORM for cement content of 250 kg/m3 has been increased by 18% compared to the probability of carbonation including cement content equal to 400 kg/m 3 for the year 2100.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"374 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84944500","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.2022.27.4.4
Eryk Goldmann, Aleksandra Kostrzanowska-Siedlarz, M. Górski, B. Klemczak
The addition of carbon nanomaterials influences the variety of properties, of cementitious composites. Despite the multiple researches in the topic of properties of the hardened cement materials the influence of the Mutiwall Carbon Nanotubes [MWCNT] on rheological parameters of the cement mortars is not sufficiently described. Research shows that rheological properties of cement mortars with the MWCNTs, determined with the use of Viscometer NT, proved to be strongly dependent on the sonication time and amount of MWCNT, added. Increase of sonication time of MWCNT suspension with surfactant and decrease of amount of MWCNT caused increment in fluidity while yield stress parameter and plastic viscosity parameter decreased.
{"title":"Effect of selected organic additives on the properties of magnesia-chromite refractories","authors":"Eryk Goldmann, Aleksandra Kostrzanowska-Siedlarz, M. Górski, B. Klemczak","doi":"10.32047/cwb.2022.27.4.4","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.4.4","url":null,"abstract":"The addition of carbon nanomaterials influences the variety of properties, of cementitious composites. Despite the multiple researches in the topic of properties of the hardened cement materials the influence of the Mutiwall Carbon Nanotubes [MWCNT] on rheological parameters of the cement mortars is not sufficiently described. Research shows that rheological properties of cement mortars with the MWCNTs, determined with the use of Viscometer NT, proved to be strongly dependent on the sonication time and amount of MWCNT, added. Increase of sonication time of MWCNT suspension with surfactant and decrease of amount of MWCNT caused increment in fluidity while yield stress parameter and plastic viscosity parameter decreased.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"4 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80692154","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.2022.27.3.4
W. Derkowski, Miłosz Jezierski
Precast floors are gaining more and more popularity in modern construction, mainly due to their fast realization. However, the provisions of standards regarding floor design are often ambiguous and sometimes questionable. The article discusses selected issues of HC slabs design, which often pose problems in practice, with references to relevant scientific research in this field. Particular attention was paid to the principles of distribution of the concentrated load on adjacent slabs in the floor field, openings in the floors, support conditions and taking into account the slab function as an element of a floor.
{"title":"Specifi city of precast fl oor design, on the example of the hollow-care slabs","authors":"W. Derkowski, Miłosz Jezierski","doi":"10.32047/cwb.2022.27.3.4","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.3.4","url":null,"abstract":"Precast floors are gaining more and more popularity in modern construction, mainly due to their fast realization. However, the provisions of standards regarding floor design are often ambiguous and sometimes questionable. The article discusses selected issues of HC slabs design, which often pose problems in practice, with references to relevant scientific research in this field. Particular attention was paid to the principles of distribution of the concentrated load on adjacent slabs in the floor field, openings in the floors, support conditions and taking into account the slab function as an element of a floor.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"58 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84864549","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.2022.27.4.1
C. Stancu, Dawid Dębski, J. Michalak
The study analyzed the results of open time measurements of ceramic tile adhesives after not less than 30 minutes, obtained by 27 laboratories participating in the interlaboratory comparison program. The obtained results were statistically analyzed following the requirements of ISO 13528 and assessed under the z-score analysis criteria contained in the EN ISO/IEC 17043. 22 out of 24 laboratories that sent the results of the open time measurement confirmed their competencies, obtaining a “satisfactory” result following the evaluation criteria. The result obtained by one laboratory was classified as “questionable”, and another received the result as “unsatisfactory”. From the perspective of laboratories participating in interlaboratory comparisons, the obtained results should be assessed as satisfactory, and thus the laboratories confirm their competence. However, a wide scatter of the results of the open time measurement should be noted – 22 laboratories, the results of which were classified as “satisfactory”, obtained results from 0.1 N/mm2 to 1.0 N/mm2. Such a wide scatter of the results of open time measurements determined by the adhesion strength indicates that this method has too little accuracy, and it should not be used in the assessment and verification of constancy of performance of ceramic tile adhesives.
{"title":"Assessment of the possibility of using the measurement of open time to assess and verify the constancy of performance of cementitious ceramic tile adhesives","authors":"C. Stancu, Dawid Dębski, J. Michalak","doi":"10.32047/cwb.2022.27.4.1","DOIUrl":"https://doi.org/10.32047/cwb.2022.27.4.1","url":null,"abstract":"The study analyzed the results of open time measurements of ceramic tile adhesives after not less than 30 minutes, obtained by 27 laboratories participating in the interlaboratory comparison program. The obtained results were statistically analyzed following the requirements of ISO 13528 and assessed under the z-score analysis criteria contained in the EN ISO/IEC 17043. 22 out of 24 laboratories that sent the results of the open time measurement confirmed their competencies, obtaining a “satisfactory” result following the evaluation criteria. The result obtained by one laboratory was classified as “questionable”, and another received the result as “unsatisfactory”. From the perspective of laboratories participating in interlaboratory comparisons, the obtained results should be assessed as satisfactory, and thus the laboratories confirm their competence. However, a wide scatter of the results of the open time measurement should be noted – 22 laboratories, the results of which were classified as “satisfactory”, obtained results from 0.1 N/mm2 to 1.0 N/mm2. Such a wide scatter of the results of open time measurements determined by the adhesion strength indicates that this method has too little accuracy, and it should not be used in the assessment and verification of constancy of performance of ceramic tile adhesives.","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":"82307796","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 : 2021-01-01DOI: 10.32047/cwb.2021.26.6.2
W. Kurdowski
In the former years, the total amount of heat indispensable for clinker formation was obtained in the kiln burner, which determined the maximum of this heat, thus the kiln efficiency was simultaneously determined. The kiln has the double role: the hearth and the chemical reactor. The diminishing of the heat loading of the kiln can be obtained only by emitting the calcination heat of raw materials from the kiln. At the same time, it gives the possibility of significant increase of the kiln productivity, which was already no longer limited by the heat quantity, linked to the kiln burner. In this technology, the kiln burner was only applied to heat the material in the kiln from the temperature of 1100°C to 1450°C, which was fulfil about 15% of the heat, from the entire heat demand of clinker burning. It will be 3050 x 0.15 equal to about 480 kJ/kg of clinker. As is known in the clinker formation process, radical changes of the properties of the roasting material occur, which are started at the temperature of 1260°C and are linked with the liquid phase appearing. After the liquid phase appears, the process cannot be conducted in the fluid reactor, because the material can form the roasting formation on the reactor walls, which can cause its plugging. From these reasons, the best technological solution was the division of the process into two operations, applied in two different equipments: (a) heating and calcining conducting in the fluid heater, which was the preliminary calciner, and (b) sintering and clinker formation in the rotary kiln. This technological division caused the high kiln capacity, because the quantity of heat needed in the kiln was low and the heat charge of the zone of fuel burning in the kiln burner was also low
在过去的几年里，熟料形成所需的总热量是在窑炉中获得的，确定了该热量的最大值，从而同时确定了窑炉效率。窑炉具有双重作用:炉膛和化学反应器。窑炉热负荷的减小只能通过将原料的煅烧热从窑炉中放出来实现。与此同时，它提供了显着提高窑炉生产率的可能性，窑炉生产率已经不再受到与窑炉有关的热量的限制。在该技术中，窑炉只对窑内物料从1100℃加热到1450℃，满足了熟料燃烧全部热量需求的15%左右。它将是3050 x 0.15，相当于约480 kJ/kg的熟料。众所周知，在熟料形成过程中，焙烧物料的性质发生了根本性的变化，这种变化始于1260℃，并与液相的出现有关。液相出现后，该工艺不能在流体反应器中进行，因为物料会在反应器壁上形成焙烧形成，从而导致其堵塞。基于这些原因，最佳的技术解决方案是将该过程分为两个工序，分别在两个不同的设备上进行:(a)在流体加热器中进行加热和煅烧，这是初步的煅烧炉;(b)在回转窑中进行烧结和熟料形成。由于窑内所需热量低，窑内燃料燃烧区的热负荷也低，这种工艺划分造成了窑内容量高
{"title":"Preliminary calciner","authors":"W. Kurdowski","doi":"10.32047/cwb.2021.26.6.2","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.6.2","url":null,"abstract":"In the former years, the total amount of heat indispensable for clinker formation was obtained in the kiln burner, which determined the maximum of this heat, thus the kiln efficiency was simultaneously determined. The kiln has the double role: the hearth and the chemical reactor. The diminishing of the heat loading of the kiln can be obtained only by emitting the calcination heat of raw materials from the kiln. At the same time, it gives the possibility of significant increase of the kiln productivity, which was already no longer limited by the heat quantity, linked to the kiln burner. In this technology, the kiln burner was only applied to heat the material in the kiln from the temperature of 1100°C to 1450°C, which was fulfil about 15% of the heat, from the entire heat demand of clinker burning. It will be 3050 x 0.15 equal to about 480 kJ/kg of clinker. As is known in the clinker formation process, radical changes of the properties of the roasting material occur, which are started at the temperature of 1260°C and are linked with the liquid phase appearing. After the liquid phase appears, the process cannot be conducted in the fluid reactor, because the material can form the roasting formation on the reactor walls, which can cause its plugging. From these reasons, the best technological solution was the division of the process into two operations, applied in two different equipments: (a) heating and calcining conducting in the fluid heater, which was the preliminary calciner, and (b) sintering and clinker formation in the rotary kiln. This technological division caused the high kiln capacity, because the quantity of heat needed in the kiln was low and the heat charge of the zone of fuel burning in the kiln burner was also low","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"7 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74490091","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 : 2021-01-01DOI: 10.32047/cwb.2021.26.6.6
Adem Solak
It is inevitable to determine the earthquake performance of historical structures and to take the necessary precautions to protect historical masonry structures, located in an active earthquake zone. The first stage of evaluating the earthquake performance of historical masonry buildings is a detailed information about such buildings. Therefore, this study aims to investigate material properties of a historical building by means of acid loss, pH, electrical conductivity, X-ray fluorescence spectrometry [XRF], thermal analysis [TG/DTG], petrographic analysis, X-ray diffraction [XRD], density, mass water absorption, volume water absorption, specific mass, porosity and uniaxial loading tests. It has been determined that stones are quartzite, which is a metamorphic rock with high compressive strength, composed of quartz minerals. Examined masonry mortar does not show hydraulic properties, the aggregates are not pozzolanic aggregates and the binder material used in mortars is pure lime.
{"title":"Properties of the bearing construction materials used in a historical masonry structure of Haci Hasan Feyzi mosque","authors":"Adem Solak","doi":"10.32047/cwb.2021.26.6.6","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.6.6","url":null,"abstract":"It is inevitable to determine the earthquake performance of historical structures and to take the necessary precautions to protect historical masonry structures, located in an active earthquake zone. The first stage of evaluating the earthquake performance of historical masonry buildings is a detailed information about such buildings. Therefore, this study aims to investigate material properties of a historical building by means of acid loss, pH, electrical conductivity, X-ray fluorescence spectrometry [XRF], thermal analysis [TG/DTG], petrographic analysis, X-ray diffraction [XRD], density, mass water absorption, volume water absorption, specific mass, porosity and uniaxial loading tests. It has been determined that stones are quartzite, which is a metamorphic rock with high compressive strength, composed of quartz minerals. Examined masonry mortar does not show hydraulic properties, the aggregates are not pozzolanic aggregates and the binder material used in mortars is pure lime.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"6 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87169123","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 : 2021-01-01DOI: 10.32047/cwb.2021.26.1.7
Mehdi Saliani, A. Honarbakhsh, R. Zhiani, S. M. Movahedifar, A. Motavalizadehkakhky
Recent research in the construction industry justifi es the partial replacement of cement by nanomaterials. Graphene oxide na-nocomposite is a material that has been recently proposed as a suitable alternative for part of cement in concrete. However, there is no research on the addition of these synthetic compounds to concrete, and little is known about the effect of these materials on the mechanical and durability properties of concrete. Therefore, in this laboratory study, the synthesis of Fe3O4/SiO2/GO and GO nanoparticles was performed and confi rmed with FT-IR, SEM, TEM analyses. These nanoparticles partially replaced cement by 1, 2, 3, and 4 % by mass of the cement, and their effect on mechanical and durability properties of concrete at the ages of 7, 28, and 90-day, were investigated. The results suggest that mixtures in which 2% Fe3O4/ SiO2/GO and 3% GO substituted cement yielded the best results in the mechanical properties tests. Concrete containing Fe3O4/SiO2/GO nanoparticles enhanced compressive strength by 14% and splitting tensile strength by 12% after 28-days of curing. Also, concrete containing 2% Fe3O4/SiO2/GO, had the highest re-sistance to an acidic environment, the lowest permeability, and the highest transient pulse velocity in the ultrasonic test, compared to the specimen containing GO nanoparticles and the control sample.
建筑行业最近的研究证明，纳米材料可以部分替代水泥。氧化石墨烯纳米复合材料是最近被提出的一种适合替代混凝土中部分水泥的材料。然而，目前还没有研究将这些合成化合物添加到混凝土中，对这些材料对混凝土力学性能和耐久性的影响也知之甚少。因此，在本实验室研究中，我们进行了Fe3O4/SiO2/GO和GO纳米颗粒的合成，并通过FT-IR, SEM, TEM分析进行了验证。研究了这些纳米颗粒分别以1、2、3和4%的水泥质量部分替代水泥，并研究了它们对混凝土在7、28和90天龄期的力学和耐久性性能的影响。结果表明，2% Fe3O4/ SiO2/GO和3% GO取代水泥的混合料在力学性能测试中取得了最好的效果。掺Fe3O4/SiO2/GO纳米颗粒的混凝土在养护28天后抗压强度提高14%，劈裂抗拉强度提高12%。此外，在超声波测试中，与含有氧化石墨烯纳米粒子的试样和对照试样相比，含2% Fe3O4/SiO2/GO的混凝土具有最高的抗酸性环境能力，最低的渗透率和最高的瞬态脉冲速度。
{"title":"Investigating the mechanical properties and durability indices of concrete containing Fe3O4/SiO2/GO and GO nanoparticles","authors":"Mehdi Saliani, A. Honarbakhsh, R. Zhiani, S. M. Movahedifar, A. Motavalizadehkakhky","doi":"10.32047/cwb.2021.26.1.7","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.1.7","url":null,"abstract":"Recent research in the construction industry justifi es the partial replacement of cement by nanomaterials. Graphene oxide na-nocomposite is a material that has been recently proposed as a suitable alternative for part of cement in concrete. However, there is no research on the addition of these synthetic compounds to concrete, and little is known about the effect of these materials on the mechanical and durability properties of concrete. Therefore, in this laboratory study, the synthesis of Fe3O4/SiO2/GO and GO nanoparticles was performed and confi rmed with FT-IR, SEM, TEM analyses. These nanoparticles partially replaced cement by 1, 2, 3, and 4 % by mass of the cement, and their effect on mechanical and durability properties of concrete at the ages of 7, 28, and 90-day, were investigated. The results suggest that mixtures in which 2% Fe3O4/ SiO2/GO and 3% GO substituted cement yielded the best results in the mechanical properties tests. Concrete containing Fe3O4/SiO2/GO nanoparticles enhanced compressive strength by 14% and splitting tensile strength by 12% after 28-days of curing. Also, concrete containing 2% Fe3O4/SiO2/GO, had the highest re-sistance to an acidic environment, the lowest permeability, and the highest transient pulse velocity in the ultrasonic test, compared to the specimen containing GO nanoparticles and the control sample.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"115 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89120771","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 : 2021-01-01DOI: 10.32047/cwb.2021.26.4.5
F. Khan, S. W. Khan, Imad Said, S. Hussain
The production of conventional engineered cementitious composites – ECC consumes low-volume and expensive ultrafine silica sand [UFSS] – maximum size 250 μm, which negatively affecting dry shrinkage, cost and practical application of ECC. This study develops an economical ECC featuring ordinary quarry sand [QS] with a lower fineness modulus – FM = 2.2 and a maximum particle size of 2350 μm. The quarry sand particle size was ten times greater, and the price was 30 times lower than UFSS. The experimental finding was shown that ECC prepared with QS exhibited the strain hardening phenomenon, with multiple cracks produced, before failure. The performance of QS was also checked under different temperature regimes, and a minor decrease in the mass density and compressive strength was observed, up to 200°C. After 200°C, a significant decrease in compressive strength was found, due to the melting of the PVA fibers.
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Pub Date : 2021-01-01DOI: 10.32047/cwb.2021.26.2.1
A. Nazari, Shadi Riahi
By the decision of the Editor-in-Chief, article (1) has been withdrawn from Issue 3 Volume 16 (2011) of the Cement Wapno Beton journal. The withdrawn article contains content borrowed without citation, e.g. from Jo et al. (2). The presented cement composition is identical to the cement composition presented in the work of Givi et al. (3). We would like to apologize to the Readers of Cement Wapno Beton for this situation. We assure You that the Editorial Board makes every effort to avoid such situations. The authors did not respond to messages regarding the withdrawal of the article sent to them by the Editorial Of ce.
根据总编辑的决定，文章(1)已从Cement Wapno Beton杂志第16卷(2011)第3期撤回。被撤回的文章包含未引用的内容，例如Jo et al.(2)。所提供的水泥成分与Givi et al.(3)所提供的水泥成分相同。对于这种情况，我们向cement Wapno Beton的读者道歉。我们向您保证，编委会将尽一切努力避免此类情况的发生。作者没有回复ce编辑部发给他们的关于撤回文章的消息。
{"title":"Retraction Notice to: Effect of TiO2 nanoparticles on the properties of self compacting concrete","authors":"A. Nazari, Shadi Riahi","doi":"10.32047/cwb.2021.26.2.1","DOIUrl":"https://doi.org/10.32047/cwb.2021.26.2.1","url":null,"abstract":"By the decision of the Editor-in-Chief, article (1) has been withdrawn from Issue 3 Volume 16 (2011) of the Cement Wapno Beton journal. The withdrawn article contains content borrowed without citation, e.g. from Jo et al. (2). The presented cement composition is identical to the cement composition presented in the work of Givi et al. (3). We would like to apologize to the Readers of Cement Wapno Beton for this situation. We assure You that the Editorial Board makes every effort to avoid such situations. The authors did not respond to messages regarding the withdrawal of the article sent to them by the Editorial Of ce.","PeriodicalId":55632,"journal":{"name":"Cement Wapno Beton","volume":"29 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86228375","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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