Using high-volume cement in 3D printed concrete (3DPC) can lead to later crack formation. Accordingly, mineral admixtures can be used as cement replacements to mitigate this disadvantage. In this study, fly ash, slag, and a type of silica fume (with a high water consumption) are selected as supplementary materials in 3DPC under different substitution rates. A method for the printability evaluation of each test group in the orthogonal experiment is proposed based on a comprehensive analysis of the rheological behavior and mechanical performance of the test samples. The results indicate that a cement replacement ratio of 50% can be achieved in 3DPC while retaining its rheological behavior and mechanical performance. According to the actual printing test, the selected silica fume improves the buildability of 3DPC and can serve as an economical and effective cement substitute. The findings in this study also reveal the potential application of poor-quality mineral admixtures in 3DPC, which can increase economy and reduce CO2 emissions.
{"title":"Study of 3D printed concrete with low-carbon cementitious materials based on its rheological properties and mechanical performances","authors":"Weijiu Cui, Tianheng Wang, Xinfa Chen, Wenkai Shen, Xinyu Shi, Sheng Wang, P. Zhang","doi":"10.1080/21650373.2023.2189172","DOIUrl":"https://doi.org/10.1080/21650373.2023.2189172","url":null,"abstract":"Using high-volume cement in 3D printed concrete (3DPC) can lead to later crack formation. Accordingly, mineral admixtures can be used as cement replacements to mitigate this disadvantage. In this study, fly ash, slag, and a type of silica fume (with a high water consumption) are selected as supplementary materials in 3DPC under different substitution rates. A method for the printability evaluation of each test group in the orthogonal experiment is proposed based on a comprehensive analysis of the rheological behavior and mechanical performance of the test samples. The results indicate that a cement replacement ratio of 50% can be achieved in 3DPC while retaining its rheological behavior and mechanical performance. According to the actual printing test, the selected silica fume improves the buildability of 3DPC and can serve as an economical and effective cement substitute. The findings in this study also reveal the potential application of poor-quality mineral admixtures in 3DPC, which can increase economy and reduce CO2 emissions.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"832 - 841"},"PeriodicalIF":4.4,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44319025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-03-06DOI: 10.1080/21650373.2023.2184430
Dong Cui, Ying-chuan Wu, Xiaohui Xie, Guanfei Tian, Guantong Han, Yi Wan, K. Zheng, Wenting Li
The microstructure of a 3D-printed mortar was investigated in present study. To enhance the density contrast between sand and cementitious slurry, a novel leaching strategy was used as an auxiliary method, based on which the spatial dispersion of sands in 3D-printed mortar was rendered. Meanwhile, to alleviate the problem of CT’s limited resolution, X-ray attenuation method (XRAM) was introduced in this study to investigate the spatial distribution of local porosity in 3D-printed mortar. Besides, focusing on single filaments, the upper part of the filaments presented lower sand rate and higher porosity than the lower part, and the difference between the filaments located near the top of 3D-printed mortar was more significant. Finally, based on the sliding method, the interlayer width, average porosity and average sand ratio of 3D-printed mortar were estimated as 640 21.9% and 43.1%, respectively. The research results would deepen the understanding of 3D-printed concrete.
{"title":"Investigation on the microstructure of a 3D-printed mortar through a novel leaching-subsidiary tomography","authors":"Dong Cui, Ying-chuan Wu, Xiaohui Xie, Guanfei Tian, Guantong Han, Yi Wan, K. Zheng, Wenting Li","doi":"10.1080/21650373.2023.2184430","DOIUrl":"https://doi.org/10.1080/21650373.2023.2184430","url":null,"abstract":"The microstructure of a 3D-printed mortar was investigated in present study. To enhance the density contrast between sand and cementitious slurry, a novel leaching strategy was used as an auxiliary method, based on which the spatial dispersion of sands in 3D-printed mortar was rendered. Meanwhile, to alleviate the problem of CT’s limited resolution, X-ray attenuation method (XRAM) was introduced in this study to investigate the spatial distribution of local porosity in 3D-printed mortar. Besides, focusing on single filaments, the upper part of the filaments presented lower sand rate and higher porosity than the lower part, and the difference between the filaments located near the top of 3D-printed mortar was more significant. Finally, based on the sliding method, the interlayer width, average porosity and average sand ratio of 3D-printed mortar were estimated as 640 21.9% and 43.1%, respectively. The research results would deepen the understanding of 3D-printed concrete.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"818 - 831"},"PeriodicalIF":4.4,"publicationDate":"2023-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47389876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-02-22DOI: 10.1080/21650373.2023.2180103
Shaofeng Zhang, D. Niu, Yan Wang, Wenqiang Tian, Daming Luo, Lu Zhang
The impacts of steel slag (SS) and ground-granulated blast-furnace slag (GGBS) on the mechanical properties, hydration process, and microscopic characteristics of concrete were investigated in this study. The results show that substituting cement with SS has a negative impact on the strength; however, partial replacement of SS with GGBS could produce positive effect by facilitating the whole hydration of SS and cement. The improvement impact of GGBS on strength was small in early stages (3–28 days) and occurred mainly in the late stages (28–90 days). Meanwhile, the heat flow and cumulative hydration heat was decreased by the incorporation of SS and GGBS, in comparison to plain cement. The microscopic analysis results proved that replacing SS with GGBS could increase the whole hydration reaction degree, decrease the content of Ca(OH)2, enhance the compactness of the interfacial transition zone (ITZ), and refine the pore structure of concrete. Furthermore, a formula was established to estimate the splitting tensile strength according to compressive strength. The finding of this study provides valuable information on the practical application of the industrial wastes in concrete.
{"title":"Insight into mechanical properties and microstructure of concrete containing steel slag and ground-granulated blast-furnace slag","authors":"Shaofeng Zhang, D. Niu, Yan Wang, Wenqiang Tian, Daming Luo, Lu Zhang","doi":"10.1080/21650373.2023.2180103","DOIUrl":"https://doi.org/10.1080/21650373.2023.2180103","url":null,"abstract":"The impacts of steel slag (SS) and ground-granulated blast-furnace slag (GGBS) on the mechanical properties, hydration process, and microscopic characteristics of concrete were investigated in this study. The results show that substituting cement with SS has a negative impact on the strength; however, partial replacement of SS with GGBS could produce positive effect by facilitating the whole hydration of SS and cement. The improvement impact of GGBS on strength was small in early stages (3–28 days) and occurred mainly in the late stages (28–90 days). Meanwhile, the heat flow and cumulative hydration heat was decreased by the incorporation of SS and GGBS, in comparison to plain cement. The microscopic analysis results proved that replacing SS with GGBS could increase the whole hydration reaction degree, decrease the content of Ca(OH)2, enhance the compactness of the interfacial transition zone (ITZ), and refine the pore structure of concrete. Furthermore, a formula was established to estimate the splitting tensile strength according to compressive strength. The finding of this study provides valuable information on the practical application of the industrial wastes in concrete.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"1169 - 1180"},"PeriodicalIF":4.4,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49229687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-02-20DOI: 10.1080/21650373.2023.2178539
Xiaoniu Yu, Qiyong Zhang
Compared with the production of ordinary Portland cement (OPC) with large carbon emissions, biological carbon sequestration to prepare low-carbon cement can effectively decrease carbon dioxide (CO2) emissions, which can reduce the greenhouse effect, thereby reducing the frequency and intensity of climate disasters. Carbon-capturing bacteria (CCB) can capture atmospheric CO2 and convert it into bicarbonate ions, which can be combined with calcium ions to form CaCO3 cement that can partially replace OPC for dust control. This study compared the ability of two CCBs (Paenibacillus mucilaginosus and Streptomyces microflavus ) to capture CO2. The biomineralization efficiency of CaCO3 for P. mucilaginosus (39.34%) was much higher than that for S. microflavus (7.38%) in a Ca(NO3)2 solution in the concrete-curing room environment. The decomposition temperature of the CaCO3 crystals in DI was slightly higher than that of P. mucilaginosus and significantly higher than that of S. microflavus. When the spraying time was equal to three, 10% carbide sludge (CS) content was optimal according to the surface hardness (HD) of the consolidation layer of the sand samples. The CaCO3 mineralized by CCBs can be used to consolidate desert sand and dust in practical engineering applications.
{"title":"Microbially/CO2-derived CaCO3 cement and its microstructural and mechanical performance","authors":"Xiaoniu Yu, Qiyong Zhang","doi":"10.1080/21650373.2023.2178539","DOIUrl":"https://doi.org/10.1080/21650373.2023.2178539","url":null,"abstract":"Compared with the production of ordinary Portland cement (OPC) with large carbon emissions, biological carbon sequestration to prepare low-carbon cement can effectively decrease carbon dioxide (CO2) emissions, which can reduce the greenhouse effect, thereby reducing the frequency and intensity of climate disasters. Carbon-capturing bacteria (CCB) can capture atmospheric CO2 and convert it into bicarbonate ions, which can be combined with calcium ions to form CaCO3 cement that can partially replace OPC for dust control. This study compared the ability of two CCBs (Paenibacillus mucilaginosus and Streptomyces microflavus ) to capture CO2. The biomineralization efficiency of CaCO3 for P. mucilaginosus (39.34%) was much higher than that for S. microflavus (7.38%) in a Ca(NO3)2 solution in the concrete-curing room environment. The decomposition temperature of the CaCO3 crystals in DI was slightly higher than that of P. mucilaginosus and significantly higher than that of S. microflavus. When the spraying time was equal to three, 10% carbide sludge (CS) content was optimal according to the surface hardness (HD) of the consolidation layer of the sand samples. The CaCO3 mineralized by CCBs can be used to consolidate desert sand and dust in practical engineering applications.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"1156 - 1168"},"PeriodicalIF":4.4,"publicationDate":"2023-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45134806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-02-07DOI: 10.1080/21650373.2023.2169965
Yu Chen, Yu Zhang, Shanshan He, Minfei Liang, Yamei Zhang, E. Schlangen, O. Çopuroğlu
Limestone-calcined clay-cement (LC3), as one of the most promising sustainable cements, has been under development over the past decade. However, many uncertainties remain regarding its rheological behaviors, such as the metakaolin content of calcined clay. This study aims to investigate the effect of increasing the content of fine-grained metakaolin in calcined clay on the rheology of LC3 pastes. Rheological behaviors and early-age hydration of studied mixtures were characterized using flow curve, constant shear rate, small amplitude oscillatory shear and isothermal calorimetry tests. Results show that increasing the content of fine-grained metakaolin decreased flowability but promoted structural build-up and early-age hydration. These phenomena can be attributed to the decrease of mean interparticle distance caused by the increased amount of fine-grained metakaolin, which may enhance colloidal interactions, C-S-H nucleation and direct contact between particles. Overall, modifying the fine-grained metakaolin content is a feasible approach to control the rheology of LC3 pastes.
{"title":"Rheology control of limestone calcined clay cement pastes by modifying the content of fine-grained metakaolin","authors":"Yu Chen, Yu Zhang, Shanshan He, Minfei Liang, Yamei Zhang, E. Schlangen, O. Çopuroğlu","doi":"10.1080/21650373.2023.2169965","DOIUrl":"https://doi.org/10.1080/21650373.2023.2169965","url":null,"abstract":"Limestone-calcined clay-cement (LC3), as one of the most promising sustainable cements, has been under development over the past decade. However, many uncertainties remain regarding its rheological behaviors, such as the metakaolin content of calcined clay. This study aims to investigate the effect of increasing the content of fine-grained metakaolin in calcined clay on the rheology of LC3 pastes. Rheological behaviors and early-age hydration of studied mixtures were characterized using flow curve, constant shear rate, small amplitude oscillatory shear and isothermal calorimetry tests. Results show that increasing the content of fine-grained metakaolin decreased flowability but promoted structural build-up and early-age hydration. These phenomena can be attributed to the decrease of mean interparticle distance caused by the increased amount of fine-grained metakaolin, which may enhance colloidal interactions, C-S-H nucleation and direct contact between particles. Overall, modifying the fine-grained metakaolin content is a feasible approach to control the rheology of LC3 pastes.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"1126 - 1140"},"PeriodicalIF":4.4,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49453683","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-02-06DOI: 10.1080/21650373.2023.2175272
Yi Wang, Zhangli Hu, Hua Li, Wen Xu, Jiaping Liu
Applying plastic expansive agent to solve the debonding and non-compacting problem in sealed structures (e.g. concrete-filled steel tube) caused by the deformation of concrete has become an important method. In this study, the effect of azodicarbonamide expansive agent (ADC) on the deformation, mechanical properties, hydration process, and pore structure of cement pastes and concrete was investigated. The results show that the low static yield stress and viscosity promote the formation and growth of bubbles, which are disadvantageous for their stabilization. The ADC reaction rate increases with the elevated temperature, which benefits for shortening the time to mitigate shrinkage. ADC has a limited effect on cement hydration but remarkably alters the pore structure. The balance between deformation and strength is considered to be the important criteria for determining the optimal dosage of ADC.
{"title":"Expansive deformation and mechanical properties of cementitious materials with azodicarbonamide expansive agent: influencing factors and mechanisms","authors":"Yi Wang, Zhangli Hu, Hua Li, Wen Xu, Jiaping Liu","doi":"10.1080/21650373.2023.2175272","DOIUrl":"https://doi.org/10.1080/21650373.2023.2175272","url":null,"abstract":"Applying plastic expansive agent to solve the debonding and non-compacting problem in sealed structures (e.g. concrete-filled steel tube) caused by the deformation of concrete has become an important method. In this study, the effect of azodicarbonamide expansive agent (ADC) on the deformation, mechanical properties, hydration process, and pore structure of cement pastes and concrete was investigated. The results show that the low static yield stress and viscosity promote the formation and growth of bubbles, which are disadvantageous for their stabilization. The ADC reaction rate increases with the elevated temperature, which benefits for shortening the time to mitigate shrinkage. ADC has a limited effect on cement hydration but remarkably alters the pore structure. The balance between deformation and strength is considered to be the important criteria for determining the optimal dosage of ADC.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"1141 - 1155"},"PeriodicalIF":4.4,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45982497","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-01-17DOI: 10.1080/21650373.2022.2163432
M. Zając, H. Hilbig, F. Bullerjahn, Mohsen Ben Haha
CO2 curing of fresh concrete is one of the solutions allowing direct carbon sequestration within the construction industry. Additionally, it enhances the early mechanical performance when comparing to traditional hydration curing. Temperature of carbonation curing has pronounced impact on both reactions involved in hardening of Portland cement: carbonation and hydration. Both reactions are accelerated with rising temperature, while the formed products and resulting microstructure are altered. Higher curing temperature promotes the precipitation of silica gel and C-S-H phase with reduced Ca/Si ratio. Furthermore, alumina and sulfate distributions among the reaction products are different. Temperature of carbonation curing has a distinct impact on the cement paste hydration after carbonation curing. The high curing temperature results in a densification of the matrix which limits further reaction progress, compared to the samples cured at lower temperatures. During the post hydration, calcium deficient system changes into C-S-H phase with higher Ca/Si and eventually portlandite.
{"title":"Reactions involved in carbonation hardening of Portland cement: effect of curing temperature","authors":"M. Zając, H. Hilbig, F. Bullerjahn, Mohsen Ben Haha","doi":"10.1080/21650373.2022.2163432","DOIUrl":"https://doi.org/10.1080/21650373.2022.2163432","url":null,"abstract":"CO2 curing of fresh concrete is one of the solutions allowing direct carbon sequestration within the construction industry. Additionally, it enhances the early mechanical performance when comparing to traditional hydration curing. Temperature of carbonation curing has pronounced impact on both reactions involved in hardening of Portland cement: carbonation and hydration. Both reactions are accelerated with rising temperature, while the formed products and resulting microstructure are altered. Higher curing temperature promotes the precipitation of silica gel and C-S-H phase with reduced Ca/Si ratio. Furthermore, alumina and sulfate distributions among the reaction products are different. Temperature of carbonation curing has a distinct impact on the cement paste hydration after carbonation curing. The high curing temperature results in a densification of the matrix which limits further reaction progress, compared to the samples cured at lower temperatures. During the post hydration, calcium deficient system changes into C-S-H phase with higher Ca/Si and eventually portlandite.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"1107 - 1125"},"PeriodicalIF":4.4,"publicationDate":"2023-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45847746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-01-02DOI: 10.1080/21650373.2022.2161661
Jiangtao Xu, Jiaqi Pei, D. Lu, Zhongzi Xu
For clarifying the effect of dolomite on the volume stability of Portland dolomite cement (PDC) at high reaction degree, the length change of PDC pastes with the replacement levels of 10–30 wt% dolomite and cured in different conditions was examined, in contrast with Portland limestone cement (PLC). The hydration products and microstructure were investigated using XRD, TGA, and SEM. Results indicate that at 40 and 60 °C the PDC and PLC show similar deformation patterns, with a small expansion. At 80 °C, however, the PDC are characterized by a higher expansion than the PLC, especially at high replacement levels. The reaction process of dolomite in PDC is dependent on the availability of aluminate phases. In the presence of free alumina, dolomite would react preferentially to form carboaluminates, hydrotalcite, and calcite. When the alumina is exhausted, dedolomitization reaction takes place producing brucite and calcite. The high expansion in PDC is mainly associated with the dedolomitization, which may result in the reinforcing frame volume and crystallization pressure due to the formation of brucite and calcite in confined space. However, the expansion of PDC is too small to cause damage to hardened pastes. Therefore, the incorporation of dolomite in PDC has no adverse effect on the volume stability of cement-based materials.
{"title":"Volume stability of Portland-dolomite cement pastes cured in different conditions","authors":"Jiangtao Xu, Jiaqi Pei, D. Lu, Zhongzi Xu","doi":"10.1080/21650373.2022.2161661","DOIUrl":"https://doi.org/10.1080/21650373.2022.2161661","url":null,"abstract":"For clarifying the effect of dolomite on the volume stability of Portland dolomite cement (PDC) at high reaction degree, the length change of PDC pastes with the replacement levels of 10–30 wt% dolomite and cured in different conditions was examined, in contrast with Portland limestone cement (PLC). The hydration products and microstructure were investigated using XRD, TGA, and SEM. Results indicate that at 40 and 60 °C the PDC and PLC show similar deformation patterns, with a small expansion. At 80 °C, however, the PDC are characterized by a higher expansion than the PLC, especially at high replacement levels. The reaction process of dolomite in PDC is dependent on the availability of aluminate phases. In the presence of free alumina, dolomite would react preferentially to form carboaluminates, hydrotalcite, and calcite. When the alumina is exhausted, dedolomitization reaction takes place producing brucite and calcite. The high expansion in PDC is mainly associated with the dedolomitization, which may result in the reinforcing frame volume and crystallization pressure due to the formation of brucite and calcite in confined space. However, the expansion of PDC is too small to cause damage to hardened pastes. Therefore, the incorporation of dolomite in PDC has no adverse effect on the volume stability of cement-based materials.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"1094 - 1106"},"PeriodicalIF":4.4,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45665112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-12-28DOI: 10.1080/21650373.2022.2161660
N. Cristelo, J. Coelho, J. Rivera, I. García-Lodeiro, T. Miranda, A. Fernández-Jiménez
In steel manufacturing, electric arc furnaces are increasingly common, as they use mostly scrap metal as ore source. Thus, blast furnace slag (BFS) is decreasing, while electric arc slag (EAFS) is proportionally increasing. This study focuses on the potential of EAFS in alkaline cements, as precursor or aggregate. Different EAFS/BFS mixtures, some including fly ash (FA), were activated with a NaOH solution, and characterized from a mechanical and microstructural perspective. Selected pastes were used to prepare mortars, using EAFS as aggregate. Results showed that EAFS alone doesn’t deliver an adequate strength. However, when combined with BFS and FA, it formed compact matrices with significant mechanical strength and lower hydration heat. The use of EAFS as aggregate produced higher strength than obtained with silica sand. EAFS showed the potential to be applied as a precursor in alkaline cements, and the combination of BFS/EAFS yielded higher compressive strengths than obtained with BFS alone.
{"title":"Application of electric arc furnace slag as an alternative precursor to blast furnace slag in alkaline cements","authors":"N. Cristelo, J. Coelho, J. Rivera, I. García-Lodeiro, T. Miranda, A. Fernández-Jiménez","doi":"10.1080/21650373.2022.2161660","DOIUrl":"https://doi.org/10.1080/21650373.2022.2161660","url":null,"abstract":"In steel manufacturing, electric arc furnaces are increasingly common, as they use mostly scrap metal as ore source. Thus, blast furnace slag (BFS) is decreasing, while electric arc slag (EAFS) is proportionally increasing. This study focuses on the potential of EAFS in alkaline cements, as precursor or aggregate. Different EAFS/BFS mixtures, some including fly ash (FA), were activated with a NaOH solution, and characterized from a mechanical and microstructural perspective. Selected pastes were used to prepare mortars, using EAFS as aggregate. Results showed that EAFS alone doesn’t deliver an adequate strength. However, when combined with BFS and FA, it formed compact matrices with significant mechanical strength and lower hydration heat. The use of EAFS as aggregate produced higher strength than obtained with silica sand. EAFS showed the potential to be applied as a precursor in alkaline cements, and the combination of BFS/EAFS yielded higher compressive strengths than obtained with BFS alone.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"1081 - 1093"},"PeriodicalIF":4.4,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47706916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2022-12-27DOI: 10.1080/21650373.2022.2154287
Yue Wang, Jianhui Liu, Xiang Hu, Jun Chang, Tingting Zhang, Caijun Shi
Accelerated carbonation can promote the application of steel slag in construction materials. This method can not only resolve the fatal volume expansion of steel slag, but also sequestrate CO2. The carbonation thermodynamics, carbonation degree, carbonation methods and influencing factors of steel slag were reviewed. The theoretical CO2 uptake of steel slag is between 25% to 50%. However, the actual CO2 uptake distribution curve obeys normal distribution with a median value of 15%, which affected by carbonation methods, different influencing factors such as curing temperature, CO2 concentration and pressure, particle size of steel slag, liquid to solid ratio, and extraction agents. The improvement mechanism of accelerated carbonation on mechanical properties and stability of steel slag-based building materials was analyzed. Besides, different accelerated carbonated steel slag-based products with enhanced properties were summarized. Finally, some valuable suggestions concerning accelerated carbonation of steel slag were presented for further research and industrial application.
{"title":"Utilization of accelerated carbonation to enhance the application of steel slag: a review","authors":"Yue Wang, Jianhui Liu, Xiang Hu, Jun Chang, Tingting Zhang, Caijun Shi","doi":"10.1080/21650373.2022.2154287","DOIUrl":"https://doi.org/10.1080/21650373.2022.2154287","url":null,"abstract":"Accelerated carbonation can promote the application of steel slag in construction materials. This method can not only resolve the fatal volume expansion of steel slag, but also sequestrate CO2. The carbonation thermodynamics, carbonation degree, carbonation methods and influencing factors of steel slag were reviewed. The theoretical CO2 uptake of steel slag is between 25% to 50%. However, the actual CO2 uptake distribution curve obeys normal distribution with a median value of 15%, which affected by carbonation methods, different influencing factors such as curing temperature, CO2 concentration and pressure, particle size of steel slag, liquid to solid ratio, and extraction agents. The improvement mechanism of accelerated carbonation on mechanical properties and stability of steel slag-based building materials was analyzed. Besides, different accelerated carbonated steel slag-based products with enhanced properties were summarized. Finally, some valuable suggestions concerning accelerated carbonation of steel slag were presented for further research and industrial application.","PeriodicalId":48521,"journal":{"name":"Journal of Sustainable Cement-Based Materials","volume":"12 1","pages":"471 - 486"},"PeriodicalIF":4.4,"publicationDate":"2022-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46116249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：