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Artykuły w czasopismach na temat "Low carbon cement"
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McDonald, Lewis, Fredrik Glasser i Mohammed Imbabi. "A New, Carbon-Negative Precipitated Calcium Carbonate Admixture (PCC-A) for Low Carbon Portland Cements". Materials 12, nr 4 (13.02.2019): 554. http://dx.doi.org/10.3390/ma12040554.
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The production of Portland cement accounts for approximately 7% of global anthropogenic CO2 emissions. Carbon CAPture and CONversion (CAPCON) technology under development by the authors allows for new methods to be developed to offset these emissions. Carbon-negative Precipitated Calcium Carbonate (PCC), produced from CO2 emissions, can be used as a means of offsetting the carbon footprint of cement production while potentially providing benefits to cement hydration, workability, durability and strength. In this paper, we present preliminary test results obtained for the mechanical and chemical properties of a new class of PCC blended Portland cements. These initial findings have shown that these cements behave differently from commonly used Portland cement and Portland limestone cement, which have been well documented to improve workability and the rate of hydration. The strength of blended Portland cements incorporating carbon-negative PCC Admixture (PCC-A) has been found to exceed that of the reference baseline—Ordinary Portland Cement (OPC). The reduction of the cement clinker factor, when using carbon-negative PCC-A, and the observed increase in compressive strength and the associated reduction in member size can reduce the carbon footprint of blended Portland cements by more than 25%.
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Martirena-Hernández, J. F., L. M. Vizcaíno-Andrés, S. Sánchez-Berriel, S. Damas-Carrera, A. Pérez-Hernández i K. L. Scrivener. "Industrial trial to produce a low clinker, low carbon cement". Materiales de Construcción 65, nr 317 (29.01.2015): e045. http://dx.doi.org/10.3989/mc.2015.00614.
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Sanytsky, Myroslav, Tetiana Kropyvnytska, Stanislav Fic i Hanna Ivashchyshyn. "Sustainable low-carbon binders and concretes". E3S Web of Conferences 166 (2020): 06007. http://dx.doi.org/10.1051/e3sconf/202016606007.
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Sustainable development depends on a consistency of interests, social, ecological and economic, and that the interests are evaluated in a balanced manner. In order to reduce CO2 emissions, the conception of decreasing clinker factor and increasing the role of supplementary cementitious materials (SCMs) in the cementitious materials has high economical and environmental efficiency. The performance of clinkerefficient blended cements with supplementary cementitious materials were examined. The influence of superfine zeolite with increased surface energy on the physical and chemical properties of low-carbon blended cements is shown. Increasing the dispersion of cementitious materials contributes to the growth of their strength activity index due to compaction of cement matrix and pozzolanic reactions in unclincker part. In consequence of the early structure formation and the directed formation of the microstructure of the cement matrix is solving the problem of obtaining clinker-efficient concretes. Shown that low-carbon blended cements with high volume of SCMs are suitable, in principle, for producing structural concretes.
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Naqi, Ali, i Jeong Jang. "Recent Progress in Green Cement Technology Utilizing Low-Carbon Emission Fuels and Raw Materials: A Review". Sustainability 11, nr 2 (21.01.2019): 537. http://dx.doi.org/10.3390/su11020537.
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The cement industry is facing numerous challenges in the 21st century due to depleting natural fuel resources, shortage of raw materials, exponentially increasing cement demand and climate linked environmental concerns. Every tonne of ordinary Portland cement (OPC) produced releases an equivalent amount of carbon dioxide to the atmosphere. In this regard, cement manufactured from locally available minerals and industrial wastes that can be blended with OPC as substitute, or full replacement with novel clinkers to reduce the energy requirements is strongly desirable. Reduction in energy consumption and carbon emissions during cement manufacturing can be achieved by introducing alternative cements. The potential of alternative cements as a replacement of conventional OPC can only be fully realized through detailed investigation of binder properties with modern technologies. Seven prominent alternative cement types are considered in this study and their current position compared to OPC has been discussed. The study provides a comprehensive analysis of options for future cements, and an up-to-date summary of the different alternative fuels and binders that can be used in cement production to mitigate carbon dioxide emissions. In addition, the practicalities and benefits of producing the low-cost materials to meet the increasing cement demand are discussed.
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Bernard, Ellina, Hoang Nguyen, Shiho Kawashima, Barbara Lothenbach, Hegoi Manzano, John Provis, Allan Scott, Cise Unluer, Frank Winnefeld i Paivo Kinnunen. "MgO-based cements – Current status and opportunities". RILEM Technical Letters 8 (16.11.2023): 65–78. http://dx.doi.org/10.21809/rilemtechlett.2023.177.
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The cement industry is a major contributor to the anthropogenic CO2 emissions, with about 8% of all emissions coming from this sector. The global cement and concrete association has set a goal to achieve net-zero CO2 concrete by 2050, with 45% of the reduction coming from alternatives to Portland cement, substitution, and carbon capture and utilization/storage (CCU/S) approaches. Magnesia-based cements offer a conceivable solution to this problem due to their potential for low-to-negative CO2 emissions (CCU/S) but also being alternatives to Portland cement. The sources of magnesia can come from magnesium silicates or desalination brines which are carbon free for raw-material-related emissions (cf. carbonated rocks). This opens up possibilities for low or even net-negative carbon emissions. However, research on magnesia-based cements is still in its early stages.
In this paper, we summarize the current understanding of different MgO-based cements and their chemistries: magnesia oxysulfate cement, magnesia oxychloride cement, magnesia carbonate cement, and magnesia silicate cement. We also discuss relevant research needed for MgO-based cements and concretes including the issues relating to the low pH of these cements and suitability of steel reinforcement. Alternatives reinforcements, suitable admixtures, and durability studies are the most needed for the further development of MgO-based concretes to achieve a radical CO2 reduction in this industry. Additionally, techno-economic and life cycle assessments are also needed to assess the competition of raw materials and the produced binder or concrete with other solutions. Overall, magnesia-based cements are a promising emerging technology that requires further research and development to realize their potential in reducing CO2 emissions in the construction industry.
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Marin, Bogdan-Catalin, Georgeta Voicu i Stefania Stoleriu. "Synthesis of High-Performance CSA Cements as Low Carbon OPC Alternative". Materials 14, nr 22 (20.11.2021): 7057. http://dx.doi.org/10.3390/ma14227057.
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Starting from natural raw materials, cements based calcium sulphoaluminate (CSA) clinkers have been successfully obtained as an eco-friendly alternative to ordinary Portland cement. CSA-based cements with ye’elimite as the main phase have been produced over the years and are widely used today. In this regard, the present paper considers the study of hydration processes for CSA pastes prepared with a water/cement ratio of 0.5 according to the EN-197 standard and their characterization by thermal analysis (DTA-TG), X-ray diffraction analysis (XRD), and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). A mechanical strength of 60.9 MPa was the greatest achieved for mortars hardened for 28 days.
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Sirangi, Bhavani, i M. L. V. Prasad. "A low carbon cement (LC3) as a sustainable material in high strength concrete: green concrete". Materiales de Construcción 73, nr 352 (3.11.2023): e326. http://dx.doi.org/10.3989/mc.2023.355123.
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Limestone Calcined Clay Cement (LC3) Technology is a low carbon cement that combines limestone, calcined clay, and clinker, aiming to reduce CO2 emissions by 40%-50% during production. In this study, large-scale investigations were conducted to explore LC3 as a potential substitute for conventional cement (CC). Mechanical and durability tests were performed on LC3, comparing results with CC and Pozzolana Cement (PC) concretes. The findings revealed that LC3 concrete exhibited promising early-stage strength similar to CC concrete. However, at 90 days, LC3 showcased a 10% higher strength compared to CC concrete. Additionally, LC3 displayed a remarkable 45% increase in resistance to moisture ingress, indicating improved durability over CC concrete. These results highlight the efficacy of low carbon cement in developing ternary blended cements that offer early strength and enhanced durability, making it a viable eco-friendly alternative in the construction industry.
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Coffetti, Denny, Marina Cabrini, Elena Crotti, Gabriele Gazzaniga, Sergio Lorenzi, Tommaso Pastore i Luigi Coppola. "Durability of Mortars Manufactured with Low-Carbon Binders Exposed to Calcium Chloride-Based De-Icing Salts". Key Engineering Materials 919 (11.05.2022): 151–60. http://dx.doi.org/10.4028/p-f848r8.
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Calcium chloride is one of the main de-icing salts for removing snow and ice from roads, infrastructures and service areas. It is well known that reinforced concrete structures, if exposed to calcium chloride, can suffer from severe damages due to both corrosion of steel reinforcement and chemical attack of the cement paste. This paper aims at evaluating the resistance to chemical attack of mortars manufactured with different low-carbon binders (alkali activated slag cements, calcium sulphoaluminate cement-based blends, high volume ultrafine fly ashes cements) in presence of CaCl2-based de-icing salts in cold weather (temperature about 4°C). Results indicated that alkali activated slag-based mortars are quasi-immune to calcium chloride attack due to their mineralogical composition. On the contrary, calcium sulphoaluminate-based blends show the total loss of binding capacity, especially when calcium sulphoaluminate cement is used with gypsum and Portland cement. Finally, the partial substitution of Portland cement with ultrafine fly ash strongly reduces the mass change and the strength loss of mortars submerged in 30 wt.% CaCl2 solutions due to the strong reduction of calcium hydroxide responsible for the calcium oxychloride formation in the cement paste.
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Chopperla, Siva Teja, Rajeswari Jupalli, Deepak Kanraj, A. Bahurudeen, M. K. Haneefa i M. Santhanam. "Development of an Efficient Procedure for Sustainable Low Carbon Cement Manufacturing Process". Applied Mechanics and Materials 787 (sierpień 2015): 142–46. http://dx.doi.org/10.4028/www.scientific.net/amm.787.142.
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The consumption of Portland cement for the production of concrete is rapidly increasing because of the remarkable growth in the construction worldwide. Cement production is an energy intensive process. The energy consumption by the cement industry is estimated to be about 5% of the total global industrial energy consumption. Manufacturing process of cement consumes enormous quantities of raw materials from limited natural resources at a high rate and leads to their depletion. Due to the dominant use of carbon intensive fuels such as coal, the cement industry is a major emitter of carbon dioxide and other air pollutants. The cement industry contributes about 6 % of global carbon dioxide emissions which is the primary source of global warming. In addition to carbon dioxide emissions, significant amount of nitrogen oxides, sulphur dioxide, carbon monoxide, hydrocarbons and volatile organic compounds are emitted during cement manufacturing and causes severe environmental issues. In this regard, effective control techniques for reduction in carbon dioxide emissions from modern cement industry and an efficient procedure to achieve sustainable cement manufacturing process are discussed in this paper.
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Shen, Weiguo, Liu Cao, Qiu Li, Zhaijun Wen, Jing Wang, Yun Liu, Rui Dong, Yu Tan i Rufa Chen. "Is magnesia cement low carbon? Life cycle carbon footprint comparing with Portland cement". Journal of Cleaner Production 131 (wrzesień 2016): 20–27. http://dx.doi.org/10.1016/j.jclepro.2016.05.082.
Pełny tekst źródłaRozprawy doktorskie na temat "Low carbon cement"
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Slabbert, Michael Charles. "Utilising waste products from Kwinana industries to manufacture low specification geopolymer concrete". Thesis, Curtin University, 2008. http://hdl.handle.net/20.500.11937/606.
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One technology that makes concrete without cement and does not have the associated carbon footprint is geopolymer concrete. This technology utilizes waste fly ash from power stations and mixes it with activating chemicals to form a binder with similar or better properties than cement. Not only does this technology directly reduce carbon emissions by replacing cement it also utilizes the waste bi-product from power stations and prevents it from going to landfill. Concrete is composed of coarse aggregates, sand and cementitious paste. It seemed possible to make geopolymer concrete from 100% waste. The aggregates would come from recycled concrete and hard brittle bottom ash from power stations, the sand would come from foundries and the fly ash binder would also come from the same power station as the bottom ash. All of these materials are waste and would all be dumped in landfill. Where would one find all these waste materials in one place? The industrial suburb of Kwinana outside Perth is home to a large number of industries producing all these wastes. To find products that have a specification that these materials would suit was a material with a relatively low specification, one such specification is the concrete masonry units’ specification. For this to be adopted the mix design would then have to be altered to a drier type mix without any slump. As recycling facilities do not make a range of products it was decided to crush the aggregates in the laboratory specifically for this research and to blend all the waste materials. Numerous combinations were blended, analysed and assessed to establish which blends would best suit the aims and scope of this research. Eventually three blends were selected that encompassed all the waste products.To find the right mix design proved challenging as these masonry products generally require a mix to have zero slump. It was decided to test across all the known and analysed water to geopolymer solids ratios for each of the mixes and establish the best mix based on compressive strength, workability and slump A known mix design based on research into low calcium Class F geopolymer concrete, developed at Curtin University using natural aggregates, was applied to these selected recycled waste mix designs. The benefit was to be able to compare the results of this research to a known result. Flash setting, an unknown phenomenon in geopolymer concrete, did occur in the low water mixes, but in spite of this, geopolymer concrete was successfully manufactured. The compressive strengths were substantially lower than those of the design mix and more research is required in this regard, however an indirect relationship was observed between the amount of bottom ash and the compressive strength. The high degree of LOI (loss of ignition) in both ashes, porosity of recycled aggregates, angularity, degree of fineness of the fines and flash setting are all possible factors influencing the properties of the geopolymer concrete. More research is recommended in a number of these areas to be able to understand and develop this technology further in order to make this a practical and robust technology in the quest to find solutions to our warming planet and our changing climate.
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Slabbert, Michael Charles. "Utilising waste products from Kwinana industries to manufacture low specification geopolymer concrete". Curtin University of Technology, Department of Civil Engineering, 2008. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=117996.
Pełny tekst źródłaStreszczenie:
One technology that makes concrete without cement and does not have the associated carbon footprint is geopolymer concrete. This technology utilizes waste fly ash from power stations and mixes it with activating chemicals to form a binder with similar or better properties than cement. Not only does this technology directly reduce carbon emissions by replacing cement it also utilizes the waste bi-product from power stations and prevents it from going to landfill. Concrete is composed of coarse aggregates, sand and cementitious paste. It seemed possible to make geopolymer concrete from 100% waste. The aggregates would come from recycled concrete and hard brittle bottom ash from power stations, the sand would come from foundries and the fly ash binder would also come from the same power station as the bottom ash. All of these materials are waste and would all be dumped in landfill. Where would one find all these waste materials in one place? The industrial suburb of Kwinana outside Perth is home to a large number of industries producing all these wastes. To find products that have a specification that these materials would suit was a material with a relatively low specification, one such specification is the concrete masonry units’ specification. For this to be adopted the mix design would then have to be altered to a drier type mix without any slump. As recycling facilities do not make a range of products it was decided to crush the aggregates in the laboratory specifically for this research and to blend all the waste materials. Numerous combinations were blended, analysed and assessed to establish which blends would best suit the aims and scope of this research. Eventually three blends were selected that encompassed all the waste products.To find the right mix design proved challenging as these masonry products generally require a mix to have zero slump. It was decided to test across all the known and analysed water to geopolymer solids ratios for each of the mixes and establish the best mix based on compressive strength, workability and slump A known mix design based on research into low calcium Class F geopolymer concrete, developed at Curtin University using natural aggregates, was applied to these selected recycled waste mix designs. The benefit was to be able to compare the results of this research to a known result. Flash setting, an unknown phenomenon in geopolymer concrete, did occur in the low water mixes, but in spite of this, geopolymer concrete was successfully manufactured. The compressive strengths were substantially lower than those of the design mix and more research is required in this regard, however an indirect relationship was observed between the amount of bottom ash and the compressive strength. The high degree of LOI (loss of ignition) in both ashes, porosity of recycled aggregates, angularity, degree of fineness of the fines and flash setting are all possible factors influencing the properties of the geopolymer concrete. More research is recommended in a number of these areas to be able to understand and develop this technology further in order to make this a practical and robust technology in the quest to find solutions to our warming planet and our changing climate.
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Olivia, Monita. "Durability related properties of low calcium fly ash based geopolymer concrete". Thesis, Curtin University, 2011. http://hdl.handle.net/20.500.11937/506.
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Geopolymer material using by-products can lead to a significant reduction of the carbon footprint and have positive impact on the environment. Geopolymer is recognized as an alternative construction material for the Ordinary Portland Cement (OPC) concrete. The mechanical properties of geopolymer concrete are superior for normal exposure environments. In terms of durability in the seawater, a limited number of publications were available. The seawater environment contains chloride ions and microorganisms that are harmful for reinforced concrete structures. Hence, a study of the durability of fly ash geopolymer concrete is essential when this material is to be used in a real application. The present study aims to investigate the durability of fly ash geopolymer concrete mixture in a seawater environment such as seawater resistance and corrosion of steel reinforcement bars. The development of mixtures and their mechanical properties were also presented.The concrete mixtures were developed using the Taguchi optimization method. Three mixtures, labelled T4, T7, T10 and a control mix were investigated further. Mechanical properties such as compressive strength, tensile strength, flexural strength, Young’s Modulus of Elasticity were determined for each mix. In addition the water absorption/AVPV and drying shrinkage were also measured. The seawater resistance study comprises chloride ion penetration, change in strength, change in mass, change in Young’s Modulus of Elasticity, change in effective porosity and change in length. The corrosion performance of steel reinforcement bars in fly ash geopolymer concrete was determined by measuring the corrosion potential by half-cell potential, accelerated corrosion test by impressed voltage method and microbiologically influenced corrosion incorporating algae. The microstructure of the samples was also investigated using SEM and microscope.It can be summarized that the fly ash geopolymer concrete has an equivalent or higher strength than the OPC concrete. The seawater resistance revealed a high chloride ion penetration into the fly ash geopolymer concrete due to lack of a chloride binding ability and continuous hydration under aqueous medium. The geopolymer concrete had a higher strength and small expansion following exposure to wetting-drying cycles. There was a rapid depassivation of steel reinforcement bars in fly ash geopolymer concrete, although it has a smaller corrosion rate than the OPC concrete. This could delay the pressure in generating cracks in the concrete cover which is not favourable in the long term, due to a sudden loss of load carrying capacity. A novel study on the corrosion performance in algae medium demonstrated a risk of steel bar corrosion in fly ash geopolymer concrete due to the low alkalinity of this concrete. It can be concluded that the low calcium fly ash geopolymer offers some advantages in durability for reinforced concrete in seawater environments.
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Chang, Ee Hui. "Shear and bond behaviour of reinforced fly ash-based geopolymer concrete beams". Thesis, Curtin University, 2009. http://hdl.handle.net/20.500.11937/468.
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Concrete is by far the most widely used construction material worldwide in terms of volume, and so has a huge impact on the environment, with consequences for sustainable development. Portland cement is one of the most energy-intensive materials of construction, and is responsible for some emissions of carbon dioxide — the main greenhouse gas causing global warming. Efforts are being made in the construction industry to address these by utilising supplementary materials and developing alternative binders in concrete; the application of geopolymer technology is one such alternative. Indeed, geopolymers have emerged as novel engineering materials with considerable promise as binders in the manufacture of concrete. Apart from their known technical attributes, such as superior chemical and mechanical properties, geopolymers also have a smaller greenhouse footprint than Portland cement binders.Research on the development, manufacture, behaviour and applications of low calcium fly ash-based geopolymer concrete has been carried out at Curtin University of Technology since 2001. Past studies of the structural behaviour of reinforced fly ash-based geopolymer concrete members have covered the flexural behaviour of members. Further studies are needed to investigate other aspects of the structural behaviour of geopolymer concrete. Design for both shear and bond are important in reinforced concrete structures. Adequate shear resistance in reinforced concrete members is essential to prevent shear failures which are brittle in nature. The performance of reinforced concrete structures depends on sufficient bond between concrete and reinforcing steel. The present research therefore focuses on the shear and bond behaviour of reinforced low calcium fly ash-based geopolymer concrete beams.For the study of shear behaviour of geopolymer concrete beams, a total of nine beam specimens were cast. The beams were 200 mm x 300 mm in cross section with an effective length of 1680 mm. The longitudinal tensile reinforcement ratios were 1.74%, 2.32% and 3.14%. The behaviour of reinforced geopolymer concrete beams failing in shear, including the failure modes and crack patterns, were found to be similar to those observed in reinforced Portland cement concrete beams. Good correlation of test-to-prediction value was obtained using VecTor2 Program incorporating the Disturbed Stress Field Model proposed by Vecchio (2000). An average test-to-prediction ratio of 1.08 and a coefficient of variation of 8.3% were obtained using this model. It was also found that the methods of calculations, including code provisions, used in the case of reinforced Portland cement concrete beams are applicable for predicting the shear strength of reinforced geopolymer concrete beams.For the study of bond behaviour of geopolymer concrete beams, the experimental program included manufacturing and testing twelve tensile lap-spliced beam specimens. No transverse reinforcement was provided in the splice region. The beams were 200 mm wide, 300 mm deep and 2500 mm long. The effect of concrete cover, bar diameter, splice length and concrete compressive strength on bond strength were studied. The failure mode and crack patterns observed for reinforced geopolymer concrete beams were similar to those reported in the literature for reinforced Portland cement beams. The bond strength of geopolymer concrete was observed to be closely related to the tensile strength of geopolymer concrete. Good correlation of test bond strength with predictions from the analytical model proposed by Canbay and Frosch (2005) were obtained when using the actual tensile strength of geopolymer concrete. The average ratio of test bond strength to predicted bond strength was 1.0 with a coefficient of variation of 15.21%. It was found that the design provision and analytical models used for predicting bond strength of lapsplices in reinforced Portland cement concrete are applicable to reinforced geopolymer concrete beams.
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Elkhaldi, Imane. "Effets de la composition des liants bas carbone sur l'hydratation et la durabilité des bétons : vers un indicateur de performance en lien avec l'empreinte carbone". Electronic Thesis or Diss., Ecole centrale de Nantes, 2023. http://www.theses.fr/2023ECDN0007.
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Utiliser des bétons bas carbone est devenu désormais une nécessité amenant les normes qui régissent les bétons (EN 206) et les ciments (EN 197) à évoluer. L’utilisation des ciments dits « bas carbone » est rendue par conséquent possible (CEM II/C-M et CEM VI). Le travail présenté se concentre sur l'évolution de la microstructure, des résistances mécaniques et de la durabilité des bétons à base de ciments bas carbone, notamment les mélanges ternaires Clinker-Laitier-Calcaire (K-S-LL). Un indicateur est proposé pour caractériser l'empreinte carbone du béton et sa durabilité en ce qui concerne la corrosion induite par la carbonatation..Les résultats de ce travail mettent en évidence le rôle important des additions réactives à réduire le coût carbone des liants tout en maintenant de bonnes propriétés mécaniques.Un modèle permettant la prévision de la durée de vie de l’enrobage en fonction des propriétés des matériaux cimentaires est adapté à notre problématique. Les bétons à base des ciments ternaires présentent des rapports CO2/ddv intéressants liés à une durée de propagation de corrosion élevée par rapport aux bétons à base de ciment portland. Cependant, la prise en compte de l’effet de carbonatation sur la résistivité électrique influence les tendances observéesThe use of low-carbon concrete has now become a necessity leading to changes inthe standards governing concrete (EN 206) and cement (EN 197). The use of so-called “lowcarbon” cements is therefore made possible(CEM II/C-M and CEM VI). The work presented focuses on the evolution of the microstructure,mechanical strength and durability of low-carboncement-based concretes, in particular clinkerslag-limestone ternary mixtures (K-S-LL). An indicator is proposed to characterize the carbon footprint of concrete and its durability with respect to corrosion induced by carbonation.The results of this work demonstrate the important role of the reactive additions inreducing the carbon cost of the binders while maintaining good mechanical properties. Amodel allowing the prediction of the service life of the coating as a function of the properties of the cement materials is adapted to our problem.Concretes based on ternary cements have advantageous CO2/ddv ratios associated with a high corrosion propagation time compared with concretes based on portland cement. However,consideration of the carbonation effect on electrical resistivity influences the observed trends
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Labruzzo, Pietro <1968>. "Influenza delle onde acustiche sulla crescita delle microalghe (sp. Scenedesmus obliquus)". Doctoral thesis, Università Ca' Foscari Venezia, 2014. http://hdl.handle.net/10579/4662.
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The aim of the PhD thesis was to study the effects of acoustic stimulation on the rate of growth of the microalgae Scenedesmus obliquus. This study required a long and complex work aimed to develop innovative means to detect and record algal growth, control and continuous monitoring of microalgal cultures in a serial photobioreactors (synchronous stirring system, automated serial and crops in the twelve fbr low acoustic impact) not to interfere with the delivered sound waves. The construction of photobioreactors of specific geometry and a material particularly efficient in the transmission of acoustic waves and electromagnetic radiation, together with innovative and quick measurement techniques to follow the time course of microalgae growth, has been a large part of the thesis work. In conclusion, the experimental setup and easily scalable fbr, could be an ideal form innovative, highly efficient (with the acoustic stimulation they increased the rate of growth of microalgae even of 320 %) and innovative system for Scenedesmus obliquus cultivation and energy conversion, for instance, in a cement plant.L’obiettivo della tesi di dottorato è stato quello di studiare gli effetti della stimolazione acustica sulla velocità di crescita della microalga Scenedesmus obliquus. Tale studio ha richiesto la messa a punto di metodi innovativi per favorire la crescita, il controllo e il monitoraggio continuo delle colture microalgali in fotobioreattori seriali (sistema di agitazione sincrono, seriale e automatizzato delle colture a basso impatto acustico; la costruzione di fbr di specifica geometria e materiale particolarmente efficiente nella trasmissione delle onde acustiche e della radiazione elettromagnetica; rapide tecniche di misura, continue e automatizzabili della crescita microalgale). In conclusione il banco sperimentale potrebbe rappresentare un ideale modulo di conversione energetica e rimozione della CO2 altamente efficiente (si sono avuti con le stimolazioni acustiche incrementi della velocità di crescita microalgale anche del 320%) di conversione energetica per una cementeria.
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Chang, Ee Hui. "Shear and bond behaviour of reinforced fly ash-based geopolymer concrete beams". Curtin University of Technology, Department of Civil Engineering, 2009. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=120482.
Pełny tekst źródłaStreszczenie:
Concrete is by far the most widely used construction material worldwide in terms of volume, and so has a huge impact on the environment, with consequences for sustainable development. Portland cement is one of the most energy-intensive materials of construction, and is responsible for some emissions of carbon dioxide — the main greenhouse gas causing global warming. Efforts are being made in the construction industry to address these by utilising supplementary materials and developing alternative binders in concrete; the application of geopolymer technology is one such alternative. Indeed, geopolymers have emerged as novel engineering materials with considerable promise as binders in the manufacture of concrete. Apart from their known technical attributes, such as superior chemical and mechanical properties, geopolymers also have a smaller greenhouse footprint than Portland cement binders.Research on the development, manufacture, behaviour and applications of low calcium fly ash-based geopolymer concrete has been carried out at Curtin University of Technology since 2001. Past studies of the structural behaviour of reinforced fly ash-based geopolymer concrete members have covered the flexural behaviour of members. Further studies are needed to investigate other aspects of the structural behaviour of geopolymer concrete. Design for both shear and bond are important in reinforced concrete structures. Adequate shear resistance in reinforced concrete members is essential to prevent shear failures which are brittle in nature. The performance of reinforced concrete structures depends on sufficient bond between concrete and reinforcing steel. The present research therefore focuses on the shear and bond behaviour of reinforced low calcium fly ash-based geopolymer concrete beams.
For the study of shear behaviour of geopolymer concrete beams, a total of nine beam specimens were cast. The beams were 200 mm x 300 mm in cross section with an effective length of 1680 mm. The longitudinal tensile reinforcement ratios were 1.74%, 2.32% and 3.14%. The behaviour of reinforced geopolymer concrete beams failing in shear, including the failure modes and crack patterns, were found to be similar to those observed in reinforced Portland cement concrete beams. Good correlation of test-to-prediction value was obtained using VecTor2 Program incorporating the Disturbed Stress Field Model proposed by Vecchio (2000). An average test-to-prediction ratio of 1.08 and a coefficient of variation of 8.3% were obtained using this model. It was also found that the methods of calculations, including code provisions, used in the case of reinforced Portland cement concrete beams are applicable for predicting the shear strength of reinforced geopolymer concrete beams.
For the study of bond behaviour of geopolymer concrete beams, the experimental program included manufacturing and testing twelve tensile lap-spliced beam specimens. No transverse reinforcement was provided in the splice region. The beams were 200 mm wide, 300 mm deep and 2500 mm long. The effect of concrete cover, bar diameter, splice length and concrete compressive strength on bond strength were studied. The failure mode and crack patterns observed for reinforced geopolymer concrete beams were similar to those reported in the literature for reinforced Portland cement beams. The bond strength of geopolymer concrete was observed to be closely related to the tensile strength of geopolymer concrete. Good correlation of test bond strength with predictions from the analytical model proposed by Canbay and Frosch (2005) were obtained when using the actual tensile strength of geopolymer concrete. The average ratio of test bond strength to predicted bond strength was 1.0 with a coefficient of variation of 15.21%. It was found that the design provision and analytical models used for predicting bond strength of lapsplices in reinforced Portland cement concrete are applicable to reinforced geopolymer concrete beams.
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Jourdan, Julia. "Rôle de l’aluminium dans la réactivité pouzzolanique des métakaolins, replacé dans le contexte général de la pouzzolanicité pour des ciments à bas taux de CO2". Electronic Thesis or Diss., Sorbonne université, 2024. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2024SORUS116.pdf.
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La part de l'industrie cimentière représente aujourd'hui environ 8% des émissions mondiales de CO2 provenant principalement du processus de fabrication du clinker de ciment Portland. Une manière de réduire efficacement l'impact environnemental du ciment Portland est donc de diminuer le taux de clinker en utilisant des matériaux à hydraulicité potentielle (MHP) (matériaux pouzzolaniques ou à hydraulicité latente), portant une plus faible part de CO2 et qui, en présence d'eau et de chaux, sont capable de produire des hydrates aux propriétés liantes, tel que le clinker. Dans le cadre de cette thèse, nous nous intéresserons plus particulièrement aux kaolins qui, calcinés, puis combinés au carbonate de calcium, dans les ciments de type LC3, permettent de réduire le taux de clinker à 50% pour des performances similaires au ciment CEM I, grâce à la réactivité pouzzolanique du métakaolin et à l'effet synergique de ce dernier avec le calcaire.La forte réactivité des métakaolins (ou kaolins calcinés) est acquise lors de sa calcination entre 600 et 800°C, au cours de laquelle le kaolin subit d'importantes transformations structurelles avec le passage d'une structure cristallisée (kaolinite) à une structure fortement désordonnée, quasi-amorphe (métakaolinite). De nombreuses études ont mis en évidence les changements de l'environnement local de l'Al au cours de la calcination de la kaolinite, en observant les transitions de l'Al en sites octaédriques de la kaolinite vers des sites de coordinence 5 et 4 dans la métakaolinite. Ce changement de coordinence de l'Al, pourrait être à l'origine de la forte réactivité du métakaolin par rapport au kaolin, ou à d'autres types d'argiles calcinées (illite, montmorillonite, ...), dans lesquelles la présence d'[5]Al n'a pas été mise en évidence. Ainsi, la connaissance du rôle de l'aluminium dans la structure des métakaolins, qui intervient dans la formation des hydrates liants (C-A-S-H, carboaluminates) lors de l'hydratation des ciments LC3, est indispensable pour comprendre leur réactivité. L'objectif de cette thèse est d'une part, de mieux comprendre la structure des métakaolins, et l'influence du processus de calcination sur cette structure, à travers une approche multi-technique (DRX, ATG, FT-IR, …). On s'intéressera plus particulièrement à l'environnement local autour de l'Al en utilisant la RMN-MAS du solide de l'Al27 et la spectroscopie XANES au seuil K de l'Al. Et d'autre part, d'appréhender les relations structure-réactivité et d'identifier le rôle de l'Al dans la réactivité des métakaolins, à partir des essais de réactivité R3 par calorimétrie isotherme et de résistance mécanique sur des ciments de type LC3. Cette étude est menée à partir d'un échantillonnage de différents kaolins calcinés en four flash et en four à moufle à différentes températuresThe cement industry currently accounts for around 8% of global CO2 emissions, mainly from the Portland cement clinker manufacturing process. One way of effectively reducing the environmental impact of Portland cement is therefore to reduce the clinker content by using potentially hydraulic materials (PHM) (pozzolanic or latent hydraulic materials), which have a lower CO2 content and that can produce binding hydrates, as clinker, in the presence of water and lime. This thesis focuses specifically on kaolins. Through appropriate calcination and subsequent incorporation with calcium carbonate in LC3 cements, the clinker content can be reduced up to 50%. This reduction maintains performance levels comparable to CEM I cement, achieved through the pozzolanic reactivity of metakaolin and its synergistic impact with limestone.The high reactivity of metakaolins (or calcined kaolins) is acquired during calcination between 600 and 800°C, during which kaolin undergoes major structural transformations, moving from a crystallized structure (kaolinite) to a highly disordered, quasi-amorphous, structure (metakaolinite). Numerous studies have highlighted the changes in Al local environment during the calcination of kaolinite, observing Al transitions from octahedral sites in kaolinite to 5- and 4-coordination sites in metakaolinite. This change in Al coordination could be at the origin of the high reactivity of metakaolin compared to kaolin, or to other types of calcined clays (illite, montmorillonite, etc.), in which the presence of [5]Al has not been demonstrated. Thus, better knowledge of the role of aluminum in the structure of metakaolins, which is involved in the formation of binder hydrates (C-A-S-H, carboaluminates) during the hydration of LC3 cements, is essential for understanding their reactivity.The first aim of this thesis is to gain a better understanding of the structure of metakaolins, and the influence of the calcination process on this structure, using a multi-technique approach (XRD, TGA, FT-IR, etc.). Particular attention will be paid to the local environment around Al, using solid-state Al27 MAS-NMR and Al K-edge XANES spectroscopy. And secondly, to understand the structure-reactivity relationships and identify the role of Al in the reactivity of metakaolins, based on R3 reactivity tests by isothermal calorimetry and mechanical strength tests on LC3-type cements. The study is based on a sampling of different kaolins calcined at different temperatures using both a flash and a muffle furnace
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Závacký, Jakub. "Technologie úpravy nanočástic pro zlepšení jejich dispergovatelnosti pro využití v cemtových kompzitech". Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2021. http://www.nusl.cz/ntk/nusl-432484.
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The diploma thesis deals with the possibility of using the addition of nanoparticles to improve the properties of cement composites. The theoretical part summarizes the findings of research in this area with a focus on methods of dispersion of nanoparticles and their treatment for use in cement composites. The experimental part focuses on the comparison of methods of dispersion and plasma treatment of reduced graphene oxide (rGO) nanoparticle solutions from the point of view of the agglomeration process. During this work, a method of systematic optical/visual monitoring of sedimentation/agglomeration was developed to complement sophisticated methods such as spectrophotometry (UV/Vis) and electron microscopy (SEM). Furthermore, the effect of the addition of rGO on the properties of cement mortar, in the form of aqueous solutions prepared by the dispersion methods determined in the previous section, was investigated.
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Zhang, Fei Hannah Doig. "Magnesium oxide based binders as low-carbon cements". Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/11000.
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Portland cement (PC) is a fundamental component of the construction industry. However, its manufacturing process is responsible for ~5 % of global anthropogenic CO2 emissions. Given current demand for PC which is expected to triple by 2050, there is an urgent need for the production of alternative binders with a lower carbon footprint. One type of such alternative binder are magnesium oxide (MgO) based cements. This research has investigated the properties of three novel magnesium oxide based cement systems as potential binders that could be used for some standard cement applications. Previous research at Imperial College London found that the addition of a hydrated magnesium carbonate to MgO prior to hydration resulted in the production of setting and strength gaining samples. One of the main objectives of this research was to understand how the addition of magnesium carbonate gave the system cement-like properties and to investigate the types of strength possible from a basic system as well as to identify the main parameters that affect strength, thus allowing for future optimisation. It was found that the presence of carbonate and its effect upon the system pH alters the type of Mg(OH)2 formed, giving a more stable microstructure that accounts for the strengths achieved. The type of MgO was found to be an important parameter, as was particle size. Due to water demand, a 10 % carbonate – 90 % MgO mix was chosen as the optimum mix. The second system studied was the silica (SiO2) – MgO system. This was investigated in order to assess the potential of the reaction between MgO and silica to form M-S-H gel and to study the mechanism of formation of reaction products. It was found that reactive MgO and amorphous silica can react together upon hydration to form a mixture of M-S-H gel and Mg(OH)2, dependent upon the SiO2/MgO ratio. These systems have considerable compressive strengths the extent of which depends upon the type of silica. An optimum mix of 30 % silica – 70 % MgO (by dry weight) was found Finally, a simple ternary system of magnesium carbonate - silica - MgO was investigated in order to assess if the presence of the combination of both ‘additives’ could create a better system than either of the two-component systems. Strength results suggested that there is no added benefit to the system in combining the two-component systems. For all three systems studied, the high w/s ratios required were found to be a significant limiting factor.
Książki na temat "Low carbon cement"
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Low-Carbon Transition in the Cement Industry. OECD, 2018. http://dx.doi.org/10.1787/9789264300248-en.
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Aie. Low-Carbon Transition in the Cement Industry. 2018.
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Low-Carbon Technology for the Indian Cement Industry. OECD, 2013. http://dx.doi.org/10.1787/9789264197008-en.
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Experimental study of carbon fiber reinforced cement composite using super low contractile admixture. Tōkyo, Japan: Kajima Technical Research Institute, Kajima Corporation, 1992.
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Budinski, Kenneth G., i Steven T. Budinski. Tribomaterials. ASM International, 2021. http://dx.doi.org/10.31399/asm.tb.tpsfwea.9781627083232.
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Tribomaterials: Properties and Selection for Friction, Wear, and Erosion Applications provides practical information on the tribological behaviors of engineering materials, how they are measured, and how to account for them in order to optimize product lifetime and performance. The first few chapters describe the mechanisms and manifestations of various types of friction, erosion, and wear and how to assess their impact on design and equipment operation using proven tribotesting methods. The chapters that follow cover the tribological properties and characteristics of important engineering materials, including carbon and low-alloy steels, tool steels, stainless steels, nickel- and cobalt-base alloys, copper alloys, and cast iron as well as ceramics, cermets, cemented carbides, polymers, and polymer composites. The book also includes chapters on treatments and coatings, lubrication, and the selection and screening of materials for tribosystems, including medical applications. Each chapter ends with a review of terms, takeaway concepts, essential questions, and related reading. For information on the print version, ISBN: 978-1-62708-321-8, follow this link.
Części książek na temat "Low carbon cement"
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Makul, Natt. "Principles of Low-Carbon Cement". W Structural Integrity, 43–77. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69602-3_3.
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Iffat, S., F. Matta, J. Gaillard, M. Elvington, M. Sikder, M. Baalousha, S. Tinkey i J. Meany. "Partially-Unzipped Carbon Nanotubes as Low-Concentration Amendment for Cement Paste". W Lecture Notes in Civil Engineering, 187–95. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_20.
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AbstractPartially-unzipped multiwalled carbon nanotubes (PUCNTs) combine the chemical structure and basic mechanical properties of multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) with exceptionally high graphene-edge content. As a result, PUCNTs can be effectively oxidized for dispersion in aqueous solutions and have a specific surface area that is larger than that of MWCNTs with a comparable aspect ratio. Thus, the incorporation of relatively small concentrations of PUCNTs in cement composites may result in significant physicomechanical enhancements. In the proof-of-concept study presented here, cement paste specimens were manufactured with oxidized PUCNT concentrations of 0, 0.001, and 0.005% in weight of cement (wt%), that is, one order of magnitude smaller than lower-bound concentrations for MWCNTs reported in the literature. Stable dispersion in water was verified through dynamic light scattering analysis. Physicomechanical changes and PUCNT dispersion in the cement matrix were investigated through uniaxial compression tests on 25 × 25 × 76 mm prism specimens, and visual inspection of scanning electron microscopy (SEM) micrographs, respectively. The incorporation of 0.001 wt% and 0.005 wt% of PUCNTs resulted in an average increase in compressive strength of 10% and 29%, respectively, compared with plain cement paste. In both instances, representative SEM micrographs show the preferential formation of cement hydrates in cement paste that accorded with well-dispersed PUCNTs.
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Dutta, Bhaskar, i Soumen Maity. "CO2 Abatement During Production of Low Carbon Cement". W RILEM Bookseries, 583. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9939-3_79.
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Sahu, Sadananda. "Technological Forecasting for Commercializing Novel Low-Carbon Cement and Concrete Formulations". W Intelligent and Sustainable Cement Production, 405–54. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003106791-12.
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Nagrath, Kriti, i Soumen Maity. "Sustainable Benefits of a Low Carbon Cement Based Building". W RILEM Bookseries, 581. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9939-3_78.
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Rocha, D., R. Almenares, S. Sanchez, A. Alujas i F. Martirena. "Standardization Strategy of Low Carbon Cement in Cuba. Case Study for “Siguaney” Cement Factory". W RILEM Bookseries, 391–97. Dordrecht: Springer Netherlands, 2017. http://dx.doi.org/10.1007/978-94-024-1207-9_63.
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Yu, Z., H. Jing, Y. Gao, X. Wei i A. Wang. "Effect of Carbon Nanotubes on the Acoustic Emission Characteristics of Cemented Rockfill". W Lecture Notes in Civil Engineering, 513–19. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-3330-3_54.
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AbstractThe use of carbon nanotubes (CNTs) to reinforce cemented rockfill is attracting considerable interest due to the remarkable improvement in performance and the extremely low dose of the added nanomaterial. To reveal the enhancement mechanism of the CNTs on cemented rockfill, the acoustic emission (AE) characteristics of cemented rockfill specimens during the Brazilian split test were investigated. The results demonstrated that CNTs improved tensile strength by 17.2% and decreased the AE count. The nucleation and micropore-filling effects of the CNTs promoted the cement hydration reaction and formation of a denser structure, thereby improving resistance to loads. Meanwhile, finer pores avoid stress concentration, resulting in AE activity becoming more sparse. Finally, the AE b-value increased by 14.8%, which further indicated that the overall failure process was at a lower intensity.
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Berriel, Sofía Sánchez, Yudiesky Cancio Díaz, José Fernando Martirena Hernández i Guillaume Habert. "Assessment of Sustainability of Low Carbon Cement in Cuba. Cement Pilot Production and Prospective Case". W RILEM Bookseries, 189–94. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9939-3_23.
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Hernandez, Jose Fernando Martirena, i Karen Scrivener. "Development and Introduction of a Low Clinker, Low Carbon, Ternary Blend Cement in Cuba". W RILEM Bookseries, 323–29. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-9939-3_40.
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Srivastava, Abhishek, Rajesh Kumar i Rajni Lakhani. "Low Energy/Low Carbon Eco-cementitious Binders as an Alternative to Ordinary Portland Cement". W Handbook of Smart Materials, Technologies, and Devices, 2619–40. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-84205-5_143.
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Okeke, Ikenna J., Sachin U. Nimbalkar, Kiran Thirumaran i Joe Cresko. "Role of Hydrogen as Fuel in Decarbonizing US Clinker Manufacturing for Cement Production: Costs and CO2 Emissions Reduction Potentials". W Foundations of Computer-Aided Process Design, 533–40. Hamilton, Canada: PSE Press, 2024. http://dx.doi.org/10.69997/sct.155078.
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As a low-carbon fuel, feedstock, and energy source, hydrogen is expected to play a vital role in the decarbonization of high-temperature process heat during the pyroprocessing steps of clinker production in cement manufacturing. However, to accurately assess its potential for reducing CO2 emissions and the associated costs in clinker production applications, a techno-economic analysis and a study of facility-level CO2 emissions are necessary. Assuming that up to 20% hydrogen can be blended in clinker fuel mix without significant changes in equipment configuration, this study evaluates the potential reduction in CO2 emissions (scopes 1 and 2) and cost implications when replacing current carbon-intensive fuels with hydrogen. Using the direct energy substitution method, we developed an Excel-based model of clinker production, considering different hydrogen�blend scenarios. Hydrogen from steam methane reformer (gray) and renewable-based electrolysis (green) are considered as sources of hydrogen fuel for blend scenarios of 5%�20%. Metrics such as the cost of cement production, facility-level CO2 emissions, and cost of CO2 avoided were computed. Results show that for hydrogen blends (gray or green) between 5% and 20%, the cost of cement increases by 0.6% to 16%, with only a 0.4% to 6% reduction in CO2 emissions. When the cost of CO2 avoided was computed, the extra cost required to reduce CO2 emissions is $229 to $358/ metric ton CO2. In summary, although green hydrogen shows promise as a low-carbon fuel, its adoption for decarbonizing clinker production is currently impeded by costs.
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Costa, C., i P. Marques. "Low-carbon cement with waste oil-cracking catalyst incorporation". W 2012 IEEE-IAS/PCA Cement Industry Technical Conference. IEEE, 2012. http://dx.doi.org/10.1109/citcon.2012.6215691.
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Cheng, Ta-Wui, Yung-Chin Ding i Cing-Wun Jhong. "Production of Low Carbon Dioxide Emission Geopolymer Green Cement". W 2014 International Conference on Materials Science and Energy Engineering (CMSEE 2014). WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814678971_0095.
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Abdelaal, Ahmed Elsayed, i Salaheldin Mahmoud Elkatatny. "High Density Geopolymers: A Step Forward Towards Low Carbon Footprint Cementing Operations". W Offshore Technology Conference. OTC, 2023. http://dx.doi.org/10.4043/32341-ms.
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Abstract The utilization of ordinary Portland cement (OPC) in well cementing is accompanied by technical and environmental problems, leading researchers to explore alternative materials that address these issues and promote eco-friendliness. Geopolymer technology, widely used in construction and other industries, has not yet been fully implemented in oil and gas well cementing. Industrial waste materials, such as Class F fly ash (FFA), can be utilized to improve cement properties or create new cement binders. Hematite is used as a weighting agent to increase cement slurry density. However, heavy particle sedimentation in cement and geopolymer slurries is a significant issue that leads to heterogenous properties along the cemented section. This study introduces a new class of geopolymers that use both hematite and Micromax as weighting materials for high-density well cementing applications. One system only used hematite, while the other used both hematite and Micromax in an effort to eliminate sedimentation issues associated with hematite in geopolymers. The effects of adding Micromax on different FFA geopolymer properties were also evaluated. The study evaluated mixability, rheology, and pumpability to determine the mix design, which was then used to examine other properties such as strength, and density variation. The results showed that adding Micromax to hematite reduced the average density variation from 12.5% to 3.9%. Micromax addition also decreased plastic viscosity by 44.5% and fluid loss by 10.5%. Both systems performed closely in terms of strength.
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Niu, Quanlin, i Rui Zhang. "Experimental study on some properties of a low-carbon cement". W 2015 3rd International Conference on Advances in Energy and Environmental Science. Paris, France: Atlantis Press, 2015. http://dx.doi.org/10.2991/icaees-15.2015.268.
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Lee, Norman M. H., i Yassine Bennani Braouli. "Application of Low Carbon Concrete on Reinforced Earth Wall". W The HKIE Geotechnical Division 42nd Annual Seminar. AIJR Publisher, 2022. http://dx.doi.org/10.21467/proceedings.133.25.
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Global warming is one of the big issues all over the world. Continued global warming could bring a series of damaging effects. Many countries are now pursuing a broad range of strategies to reduce emissions of greenhouse gases, such as reducing the vehicle use, development of renewable energy etc. Minimize the use of cement is one the method to reduce the emission of carbon dioxide. Comparing the concrete volume used between Reinforced Earth Wall and traditional R.C. wall, Reinforced Earth Wall is an environmental friendly and more economical solution with less concrete consumption. Apart from this, the carbon dioxide emission can be reduced by minimizing the cement ratio in concrete.
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Tongbo, Sui, i Cai Yuliang. "Progressing towards a Green and Low Carbon Cement Industry – China’s Experience". W Fourth International Conference on Sustainable Construction Materials and Technologies. Coventry University, 2016. http://dx.doi.org/10.18552/2016/scmt4s269.
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Dalton, J., J. Winegarden, T. Thomas, D. Townsend i C. Enos. "Success Using Low Emissions API Class L Cement in Cementing Marcellus Production Strings". W SPE Eastern Regional Meeting. SPE, 2023. http://dx.doi.org/10.2118/215928-ms.
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Abstract The manufacture of Portland cement accounts for approximately 8% of the world’s total carbon dioxide emissions. Cement manufacturers and their end users are under immense pressure to find ways to reduce the amount of Portland cement in their processes. While the well-construction industry accounts for a very small portion of the cement produced worldwide, it is still our responsibility to be good stewards of the environment and do what is in our power to reduce greenhouse gas emissions. This paper describes the use of a novel API Class L cement with significantly reduced clinker content as a replacement for Class A in cementing Marcellus production casing strings in Monongalia County, West Virginia. The testing team compared the cementing processes from two pads. The team cemented first pad using a single slurry consisting of 50:50 Poz:Class A cement, and they cemented the second pad using a new slurry consisting of 50:50 Poz:Class L cement. The study presents cement slurry lab results for comparison, as well as results of all jobs using a radial cement bond logging tool. The lab results show that Class L is an adequate replacement for Class A cement, exhibiting similar properties in standard oilwell cement testing. Slurry stability, thickening time, rheology, fluid loss and compressive strength can be tuned to similar ranges by making simple adjustments with commonly used cement additives. The radial cement bond log results show that the zonal isolation provided by the Class L cement is equivalent to that provided by Class A cement.
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Kasuga, Akio. "Low carbon technologies to be challenged in the supply chain of concrete structures". W IABSE Symposium, Manchester 2024: Construction’s Role for a World in Emergency. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2024. http://dx.doi.org/10.2749/manchester.2024.0046.
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<p>Cement used in structural concrete accounts for 60% of all cement. Thus, the amount of CO2 emission by cement in structural concrete in a year is about 5% of the amount emitted by mankind. LCA of structural concrete should consider not only the materials at the product stage but also the maintenance phase at the use stage after construction. A rough indicator is presented to grasp the CO2 emissions of structural concrete. And low-carbon technologies currently in use is introduced. Then the need for multi-cycle structural concrete with a circular economy is presented. Moreover, it is estimated that CO2 emissions due to disasters in the use stage could be enormous. The carbon neutrality of structural concrete is not a risk but an opportunity for us.</p>
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Rahman, Farzana, i Raissa Douglas Ferron. "Thermodynamic Modeling of Carbonation of Blended Cements for Wellbore Integrity". W 58th U.S. Rock Mechanics/Geomechanics Symposium. ARMA, 2024. http://dx.doi.org/10.56952/arma-2024-1110.
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ABSTRACT: Carbon capture and storage (CCS) holds promise for mitigating global greenhouse gas emissions by capturing carbon dioxide (CO2) from industrial sources and storing it in deep geological formations. However, the potential impacts of CCS on oil well cements, critical components for wellbore integrity, demand careful evaluation. These cements are employed in primary, remedial cementing and plugging and abandonment operations of oil and gas wells. Alteration of cement hydration products via carbonation poses threat to wellbore integrity since it leads to leaching of cement matrix. Although carbonation of Portland cement is an inevitable process due to its favorable thermodynamic conditions, its negative impacts can be mitigated by optimizing the chemical composition of blended cements, tailored to specific thermodynamic environments. These blended cements incorporate supplementary cementitious materials (SCMS), such as silica, calcined clay, limestone, fly ash etc, to promote pozzolanic reactions. These pozzolanic reactions in blended systems produce chemically resistant hydration products. These hydration products differ from those of neat Portland cement due to the blend's initial lower calcium-to-silica (C/S) ratio. Blending cements with a low C/S ratio have been shown to produce hydration products that are less susceptible to CO2 attack. This study investigates the carbonation behavior of blended cements using thermodynamic modeling. Predicted carbonated phase assemblages indicate blended cements with SCMs are expected to provide wellbore integrity in the long run under static conditions. Thermodynamic modeling of neat and blended cements will provide us with insight to understand the progress of carbonation and the effectiveness of SCMs in blended cements for improving carbonation resistance. 1. INTRODUCTION Recent years have seen a spike in global interest to reduce carbon footprint in hopes of mitigating climate change. More actions are being taken by global society towards a low carbon future. Keeping that in mind, the energy industry is adapting to the emerging needs of the 21st century by means of effective sustainable practices and development. Oil and gas wells require high temperature and pressure (HTHP) resistant cement sheath that provides structural integrity and zonal isolation to these wells. At the end of their service life, these geothermal wells require plugging and abandonment (P&A) in the form of cement sealant to prevent hydrocarbon leakage. It is estimated that over 2 million of unplugged abandoned wells in U.S. are leaking pollutants such as methane into groundwater reservoir, sea, and ocean, causing severe environmental pollution (Marcacci, 2020). Thus, advanced cement performance is required for geothermal cementing to mitigate issues related to leaky wellbore (both active and abandoned). Additionally, cement production itself is a carbon intensive process, which accounts for at least 8% of global CO2 emission. The cement industry needs to cut down its emission by at least 16% by 2030 to comply with the Paris Agreement (Tigue, 2022). Although concrete construction is considered as an avenue for such a reduction, one area that is overlooked is the cement used in the wellbores.
Raporty organizacyjne na temat "Low carbon cement"
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Bailey, Jed, Livia Minoja, Alexandra Alvear i Christiaan Gischler. Building a More Resilient and Low-Carbon Caribbean: Report 5: Decarbonization Pathways for the Caribbean Construction Industry. Inter-American Development Bank, listopad 2023. http://dx.doi.org/10.18235/0005284.
Pełny tekst źródłaStreszczenie:
The Caribbean islands are among the 25 most-vulnerable nations in terms of disasters per-capita or land area, and climate change is only expected to intensify these vulnerabilities. Within this context, the series “Building a more resilient and low-carbon Caribbean”, focuses on improving the resiliency, sustainability and decarbonization of the construction industry in the Caribbean. The first three reports of the series analyze the economic losses caused by climate related events, the benefits of improving building resiliency to reduce those economic losses and the benefits of subsidized financing for resilient buildings in the Caribbean, showing that increasing building resiliency is economically viable for the high-risk islands of the Caribbean, generating long term savings and increasing the infrastructure preparedness to the impacts of CC. The fourth report focused on the potential role for nature-based solutions (NBSs) in the region. This report extends the previous analysis to examine potential options to reduce embodied carbon in traditional resilient building materials such as cement and steel in the region.