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Edgardo F Irassar - One of the best experts on this subject based on the ideXlab platform.
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blended cements with Limestone Filler and kaolinitic calcined clay Filler and pozzolanic effects
Journal of Materials in Civil Engineering, 2017Co-Authors: Alejandra Tironi, Alberto Nestor Scian, Edgardo F IrassarAbstract:AbstractIn this paper, binary and ternary blended cements (BC) based on calcined clay (CC, 0–30%) obtained from low-grade kaolinitic clay and Limestone Filler (LF, 0–10%) were developed and the int...
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ternary blended cement with Limestone Filler and kaolinitic calcined clay
2015Co-Authors: Alejandra Tironi, Alberto Nestor Scian, Edgardo F IrassarAbstract:The use of calcined clays providing from low grade kaolinitic clays combined with the Limestone Filler in ternary blended cement formulation has received considerable attention in recent years. This paper describes the results of a research project to study the behavior of kaolinitic calcined clays (CC) in combination with Limestone Filler (F). Blended cements were obtaining replacing CC (0–30 %) and F (0–10 %) by mass by Portland cement (PC). The pozzolanicity of blended cement was assessed by the Frattini tests at 2, 7 and 28 days. The response of the system was evaluated in terms of flow, and the compressive strength at 2, 7 and 28 days. The hydration progress was determined by the type and amount of hydration compounds at 2, 7 and 28 days using the Rietveld method. The change in pore size distribution was determined by mercury intrusion porosimetry (MIP). Hydrated phases obtained correspond to the pozzolanic reaction (contribution CC) and phase stabilization (contribution F) modifying the pore structure and all factors contribute to develop acceptable mechanical properties with a large reduction of energy consumption and CO2 emission.
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strength optimization of tailor made cement with Limestone Filler and blast furnace slag
Cement and Concrete Research, 2005Co-Authors: M. F. Carrasco, Viviana L Bonavetti, G Menendez, Edgardo F IrassarAbstract:The use of cements made with portland clinker and two or three additions has grown because they present several advantages over binary cements. Production of composite cements has produced a necessary shift in the manufacture process used in the cement industry. Now, it is known that the separate grinding and mixing technology is more convenient in order to produce these cements, called market-oriented or tailor-made cements. However, their optimum formulations require the help of methods of experimental design to obtain an appropriate performance for a given property with the least experimental effort. In this study, the interaction between Limestone Filler (LF) and blast-furnace slag (BFS) is analyzed in mortars in which portland cement (PC) was replaced by up to 22% LF and BFS. For this proposition, a two-level factorial design was used permitting to draw the isoresponse curves. Results show that compressive and flexural strength evaluated at 2, 7, 14, 28, 90 and 360 days are affected in different ways by the presence of mineral additions.
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strength development of ternary blended cement with Limestone Filler and blast furnace slag
Cement & Concrete Composites, 2003Co-Authors: G Menendez, Viviana L Bonavetti, Edgardo F IrassarAbstract:Abstract The benefits of Limestone Filler (LF) and granulated blast-furnace slag (BFS) as partial replacement of portland cement are well established. However, both supplementary materials have certain shortfalls. LF addition to portland cement causes an increase of hydration at early ages inducing a high early strength, but it can reduce the later strength due to the dilution effect. On the other hand, BFS contributes to hydration after seven days improving the strength at medium and later ages. Mortar prisms in which portland cement was replaced by up to 20% LF and 35% BFS were tested at 1, 3, 7, 28 and 90 days. Results show that the contribution of LF to hydration degree of portland cement at 1 and 3 days increases the early strength of blended cements containing about 5–15% LF and 0–20% BFS. The later hydration of BFS is very effective in producing ternary blended cements with similar or higher compressive strength than portland cement at 28 and 90 days. Additionally, a statistical analysis is presented for the optimal strength estimation considering different proportions of LF and BFS at a given age. The use of ternary blended cements (PC–LF–BFS) provides economic and environmental advantages by reducing portland cement production and CO2 emission, whilst also improving the early and the later compressive strength.
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effect of Limestone Filler on the sulfate resistance of low c3a portland cement
Cement and Concrete Research, 1998Co-Authors: M Gonzalez, Edgardo F IrassarAbstract:This paper presents an investigation of the sulfate resistance of Fillerized cements. Test was carried out on mortars containing one type II cement and two type V Portland cements with different C3S contents. Limestone Filler was used as 0%, 10%, and 20% of replacement by cement weight. The test method is based on the ASTM C 1012 procedure. Expansion, flexural and compressive strengths, solution consumption, and x-ray diffraction analysis were determined at different exposure times up to 1 year. After 360 days of sulfate immersion, the results indicate that the 10% of Limestone Filler replacement shows no significant effect on sulfate performance of these cements, whereas 20% of Limestone Filler (LF) causes detrimental effects on sulfate durability. This behavior can be explained by the changes in the hydration degree, capillary porosity, and type of hydration products produced by LF addition. Gypsum and ettringite were only detected in mortars exposed to sulfate solution.
Wu Yao - One of the best experts on this subject based on the ideXlab platform.
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eco efficient cementitious system consisting of belite ye elimite ferrite cement Limestone Filler and silica fume
ACS Sustainable Chemistry & Engineering, 2019Co-Authors: Chen Li, Mengxue Wu, Wu YaoAbstract:One of the main concerns in the modern cement industry is on reducing the CO2 emissions. As an alternative binder of Portland cement, belite-ye’elimite-ferrite (BYF) cement can reduce the CO2 emission by over 20% due to its benefits concerning the chemical composition and industrial processing. This paper proposed a ternary cementitious system consisting of BYF cement, Limestone Filler, and silica fume. The ternary system containing 10% Limestone and 5% silica fume showed higher compressive strength than the BYF cement, while the CO2 emission factor further reduced by ∼13%. The effect of Limestone and silica fume on the hydration was studied. It was found that the hydration reaction of Limestone induced the formation of hemicarbonate and stabilized ettringite. This reaction formed dissolution rims around the Limestone particles. At the early hydration ages, silica fume was bonded by aluminum hydroxide, forming aluminate silicate hydrate. During the hydration, the silicate dissolved and reacted with the hy...
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Eco-efficient Cementitious System Consisting of Belite-Ye’elimite-Ferrite Cement, Limestone Filler, and Silica Fume
2019Co-Authors: Wu YaoAbstract:One of the main concerns in the modern cement industry is on reducing the CO2 emissions. As an alternative binder of Portland cement, belite-ye’elimite-ferrite (BYF) cement can reduce the CO2 emission by over 20% due to its benefits concerning the chemical composition and industrial processing. This paper proposed a ternary cementitious system consisting of BYF cement, Limestone Filler, and silica fume. The ternary system containing 10% Limestone and 5% silica fume showed higher compressive strength than the BYF cement, while the CO2 emission factor further reduced by ∼13%. The effect of Limestone and silica fume on the hydration was studied. It was found that the hydration reaction of Limestone induced the formation of hemicarbonate and stabilized ettringite. This reaction formed dissolution rims around the Limestone particles. At the early hydration ages, silica fume was bonded by aluminum hydroxide, forming aluminate silicate hydrate. During the hydration, the silicate dissolved and reacted with the hydration products in the dissolution rims of Limestone. This reaction increased the Si content in the rims, and may potentially contribute to the compressive strength development of the ternary cementitious system
Ahmed Loukili - One of the best experts on this subject based on the ideXlab platform.
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hydration and durability of ternary binders based on metakaolin and Limestone Filler
2020Co-Authors: Emmanuel Roziere, Gildas Medjigbodo, Laurent Izoret, Ahmed LoukiliAbstract:The combination of Portland cement and mineral additions allows reducing the carbon footprint of cement-based materials and improving their resistance to several environmental actions. The development of binary binders is limited by the reactivity of pozzolanic materials at high substitution levels and the availability of industrial by-products such as slags and fly ash. Thus, it is necessary to develop new cements from natural raw materials such as clay and Limestone and to combine them to design ternary binders with higher hydraulic activity. The study is focused on mortar based on binary and ternary binders (Portland cement, metakaolin, Limestone Filler) with a maximum substitution level of 45%. Two sets of mortar mixtures with different water-to-cement ratios were designed. The experimental program includes the determination of strength, porosity, hydration heat, portlandite content, shrinkage and natural carbonation. The analysis of data aimed at correlating the evolution of mechanical properties with hydration degree and reactivity of calcined clays. The results actually showed that the performances of ternary binders closely depend on the properties of the three studied metakaolins, especially their production process and physical properties. For a given substitution level, the studied ternary binders clearly showed better performances than other mineral additions. The reduction of water-to-cement ratio resulted in an acceleration of pozzolanic reaction. This allowed an improvement of short-term strength as well as potential durability.
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hydration shrinkage and durability of ternary binders containing portland cement Limestone Filler and metakaolin
Construction and Building Materials, 2018Co-Authors: Gildas Medjigbodo, Kevin Charrier, Emmanuel Roziere, Laurent Izoret, Ahmed LoukiliAbstract:Abstract A partial replacement of the clinker by latent hydraulic or pozzolanic materials is encouraged due to environmental and specific technical requirements. Such substitution remains limited to a relatively low level (less than 30% by mass of cementitious materials). An experimental research work was carried out on mortars made with binary and ternary binders (Portland cement; metakaolin; Limestone Filler) to reach 45% total replacement. In order to investigate the activating effect of reduced water-to-cement ratio, two series of mixtures were designed with W/C0 of 0.42 and 0.5. Their heat of hydration, portlandite content, shrinkage, porosity, and carbonation were monitored. The tests were performed to understand the evolution of their relative strength (activity index) and durability parameters. The strength development of mortars with ternary binders was found to depend on metakaolin properties, including manufacturing process and particle size distribution. Reducing W/C0 ratio accelerated pozzolanic reaction and allowed improving early-age strength and durability parameters.
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performance based assessment of concrete resistance to leaching
Cement & Concrete Composites, 2011Co-Authors: Emmanuel Roziere, Ahmed LoukiliAbstract:Abstract Leaching of calcium and hydrates from concrete is likely to occur when concrete structures are immersed in pure or poorly mineralised water and acid environments. A performance-based test may be used to design concrete for such exposures, provided that it is representative, sensitive, and repeatable. In the experimental study a leaching test was performed on six vibrated concrete mixtures and five self-compacting concrete mixtures, varying aggregate type, water/binder ratio and mineral admixtures, such as fly ash, ground granulated blast-furnace slag and Limestone Filler. Two indicators have been used to assess damaged depth, taking Limestone aggregates into account. Fly ash (20–30% of binder) and slag (60%) significantly improved behaviour of concrete, whereas leaching rate increased with an increase in Limestone Filler content.
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Improvement of the early-age reactivity of fly ash and blast furnace slag cementitious systems using Limestone Filler
Materials and Structures, 2011Co-Authors: Pierre Mounanga, Muhammad Irfan Ahmad Khokhar, Rana El Hachem, Ahmed LoukiliAbstract:This article analyzes the effects of the addition of Limestone Filler on the hydration rate, setting times and early-age mechanical properties of binary and ternary-binder mortars containing Portland cement, blast furnace slag (BFS) and fly ash (FA), with various substitution rates of cement with mineral additions going up to 50%. Vicat needle penetration tests and measurements of heat flow of reaction, compressive strength and dynamic Young’s modulus were carried out on 14 mortars prepared with binary and ternary binders, at 20°C. The results obtained on the mortars containing binary binders, show that their loss of mechanical strength at early age is not caused by a deceleration of the reactions of cement in the presence of mineral additions, but is mainly explained by the dilution effect related to the reduction in cement content. A moderate addition of Limestone Filler (8–17%) makes it possible to obtain ternary binders with early-age reactivity equal or even higher than that of Portland cement, and with 28-days mechanical resistance close to those of the binary-binder mortars. This accelerating effect of Limestone Filler is particularly sensitive in the case of mortars containing FA.
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Chemical shrinkage of cement pastes and mortars at very early age : Effect of Limestone Filler and granular inclusions
Cement and Concrete Composites, 2008Co-Authors: Marwen Bouasker, Ahmed Loukili, Pierre Mounanga, Ph Turcry, Abdelhafid KhelidjAbstract:This article presents a study on the influence of Limestone Filler and granular inclusions on the chemical shrinkage of cementitious matrices at very early age (⩽24 h). Measurements of chemical shrinkage and hydration degree are carried out on cement pastes and mortars. During this study, two cement types (CEM 1 and CEM 2), two water-to-cement ratios (W/C = 0.30 and 0.40) and three substitution rates of cement by Limestone Filler (LF/C = 0; 0.25 and 0.67) are used. The effects of aggregate shape (glass beads and natural sand), aggregate-to-cement mass ratio (A/C = 0.5 and 1) and particle size distribution (D = 1 and 2 mm) on the chemical shrinkage and the hydration rate are quantified. The results obtained show that Limestone Filler causes an acceleration of both Le Chatelier’s contraction and hydration process since the very first hours of hydration. In addition, the chemical shrinkage amplitude is not significantly influenced by the presence of aggregates. Finally, the presence of Limestone Filler and granular inclusions does not cause significant modification of the quasi-linear relation observed at early age between the chemical shrinkage and the hydration degree of the cementitious matrices.
Irassar, Egardo Fabián - One of the best experts on this subject based on the ideXlab platform.
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Performance of blended cements with Limestone Filler and illitic calcined clay immediately exposed to sulfate environment
'Springer Science and Business Media LLC', 2020Co-Authors: Rosetti Agustín, Ikumi Montserrat Tai, Segura Pérez Ignacio, Irassar, Egardo FabiánAbstract:The use of ternary blended cements with Limestone Filler and calcined clays can improve the durability of concrete structures exposed to aggressive environments and extend their service life. In sulfate-rich environments, the effects of supplementary cementitious materials depend on the replacement level and the progress of hydration. Low level of Limestone Filler contributes to the stabilization of AFt due to formation of monocarboaluminate. However, high replacement increases the effective w/c ratio and the capillary porosity, favoring the sulfate penetration. The use of active pozzolans improves sulfate resistance by reducing portlandite content and the permeability, which minimize ettringite and gypsum formation and sulfate penetration. It is generally assumed that curing prior to sulfate exposure should be extended to allow the pozzolanic reaction to progress. It is currently uncertain the effectiveness of calcined clay in combination with Limestone Filler when the cement is exposed immediately to aggressive environments. Typical structures affected by sulfate attack are commonly built in situ, thus being exposed to the aggressive environment since casting. This paper analyzes external sulfate attack of blended cements with 30% replacement by combinations of Limestone Filler and/or calcined clay exposed to Na2SO4 solution at two days after casting. For that, expansions, mass variation, visual appearance and compressive strength are monitored in mortars and pastes during 6 months. The evolution of microstructure was evaluated with XRD. Despite the lack of curing prior to sulfate exposure, cement with calcined clay showed an excellent resistance to external sulfate attack, while Limestone cements presented a worse performance.Postprint (published version
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Performance of blended cements with Limestone Filler and illitic calcined clay immediately exposed to sulfate environment
International Union of Laboratories and Experts in Construction Materials Systems and Structures (RILEM), 2020Co-Authors: Rosetti Agustín, Ikumi Montserrat Tai, Segura Pérez Ignacio, Irassar, Egardo FabiánAbstract:The use of ternary blended cements with Limestone Filler and calcined clays can improve the durability of concrete structures exposed to aggressive environments and extend their service life. In sulfate-rich environments, the effects of supplementary cementitious materials depend on the replacement level and the progress of hydration. Low level of Limestone Filler contributes to the stabilization of AFt due to formation of monocarboaluminate. However, high replacement increases the effective w/c ratio and the capillary porosity, favoring the sulfate penetration. The use of active pozzolans improves sulfate resistance by reducing portlandite content and the permeability, which minimize ettringite and gypsum formation and sulfate penetration. It is generally assumed that curing prior to sulfate exposure should be extended to allow the pozzolanic reaction to progress. It is currently uncertain the effectiveness of calcined clay in combination with Limestone Filler when the cement is exposed immediately to aggressive environments. Typical structures affected by sulfate attack are commonly built in situ, thus being exposed to the aggressive environment since casting. This paper analyzes external sulfate attack of blended cements with 30% replacement by combinations of Limestone Filler and/or calcined clay exposed to Na2SO4 solution at two days after casting. For that, expansions, mass variation, visual appearance and compressive strength are monitored in mortars and pastes during 6 months. The evolution of microstructure was evaluated with XRD. Despite the lack of curing prior to sulfate exposure, cement with calcined clay showed an excellent resistance to external sulfate attack, while Limestone cements presented a worse performance
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Sulfate resistance of blended cements (Limestone illite calcined clay) exposed without previous curing
'Scipedia S.L.', 2020Co-Authors: Rosetti Agustín, Ikumi Montserrat Tai, Segura Pérez Ignacio, Irassar, Egardo FabiánAbstract:Durability in aggressive environments is an important factor to extend the service life of concrete and the use ternary blended cements (Limestone Filler + calcined clays) can contribute to this purpose. In sulfate environments, the effects of supplementary cementing materials depend on the concentration, Portland cement and the progress of hydration reactions. Low level of Limestone Filler replacement influences the stabilization of AFt due to formation of monocarboaluminate, but high replacement increases the effective w/c and the capillary porosity promoting sulfate penetration. The use of active pozzolans suppresses the sulfate attack by minimizing both ettringite and gypsum formation. It is generally assumed that curing prior to sulfate exposure should be extended to allow the development of the pozzolanic reaction and subsequent reduction of portlandite content, pore size structure refinement and permeability reduction. However, in most field applications, concretes exposed to sulfate attack are cast in situ and thus, these are exposed to sulfate since early ages. This paper evaluatesthe sulfate resistance of an illitic-calcined clay and Limestone Filler when the cement is exposed immediately to aggressive environments. In this paper, the external sulfate resistance of blended cements containing 30% replacement of Limestone Filler and/or calcined clay (C30F, C30CC and C15F15CC) are analysed. Two different calcined clays from Buenos Aires, Argentina were selected. Mortar prisms and cement paste cubes were fabricated and exposed to a sodium sulfate solution after 2 days. Comparison ofsulfate resistance was based on the expansion, mass variation, visual appearance and compressive strength . Furthermore, the evolution of microstructure of blended cements exposed to sodium sulfate solution was characterized by XRD tests on the external surface and the core of cementblended pastes.Postprint (published version
Chen Li - One of the best experts on this subject based on the ideXlab platform.
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eco efficient cementitious system consisting of belite ye elimite ferrite cement Limestone Filler and silica fume
ACS Sustainable Chemistry & Engineering, 2019Co-Authors: Chen Li, Mengxue Wu, Wu YaoAbstract:One of the main concerns in the modern cement industry is on reducing the CO2 emissions. As an alternative binder of Portland cement, belite-ye’elimite-ferrite (BYF) cement can reduce the CO2 emission by over 20% due to its benefits concerning the chemical composition and industrial processing. This paper proposed a ternary cementitious system consisting of BYF cement, Limestone Filler, and silica fume. The ternary system containing 10% Limestone and 5% silica fume showed higher compressive strength than the BYF cement, while the CO2 emission factor further reduced by ∼13%. The effect of Limestone and silica fume on the hydration was studied. It was found that the hydration reaction of Limestone induced the formation of hemicarbonate and stabilized ettringite. This reaction formed dissolution rims around the Limestone particles. At the early hydration ages, silica fume was bonded by aluminum hydroxide, forming aluminate silicate hydrate. During the hydration, the silicate dissolved and reacted with the hy...