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Karen Scrivener - One of the best experts on this subject based on the ideXlab platform.
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limestone Calcined Clay cement and concrete a state of the art review
Cement and Concrete Research, 2021Co-Authors: Meenakshi Sharma, Shashank Bishnoi, Fernando Martirena, Karen ScrivenerAbstract:Abstract This article reviews the rapidly developing state-of-the-art literature available on the subject of the recently developed limestone Calcined Clay cement (LC3). An introduction to the background leading to the development of LC3 is first discussed. The chemistry of LC3 hydration and its production are detailed. The influence of the properties of the raw materials and production conditions are discussed. The mixture design of concrete using LC3 and the mechanical and durability properties of LC3 cement and concrete are then compared with other cements. At the end the economic and environmental aspects of the production and use of LC3 are discussed. The paper ends with suggestions on subjects on which further research is required.
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strength promoting mechanism of alkanolamines on limestone Calcined Clay cement and the role of sulfate
Cement and Concrete Research, 2021Co-Authors: Hong Huang, François Avet, Wilasinee Hanpongpun, Karen ScrivenerAbstract:Abstract This paper reports the strength-promoting mechanism of alkanolamines on limestone-Calcined Clay cement (LC3). The hydration kinetics, phase formation and microstructure of LC3 with triethanolamine (TEA) or triisopropanolamine (TIPA) were investigated. TEA enhanced the strength of LC3, while TIPA was effective at 28 days, and a correct sulfate addition promoted their effects. Alkanolamines accelerated the aluminate reaction of LC3 during early hydration, increased sulfate slowed this reaction by producing more ettringite. TIPA favoured the hydration of ferrite in clinker, not only accelerated the silicate reaction of metakaolin, but also resulted in a rapid limestone reaction. Alkanolamines altered the morphology and chemical composition of the aluminate hydrates and C-A-S-H. Alkanolamines enabled the reduction of porosity of hardened pastes and the increased sulfate further refined them. It was the large pores being induced by TIPA at early ages that were considered to have an adverse impact on the early strength of LC3.
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improving the behaviour of Calcined Clay as supplementary cementitious materials by a combination of controlled grinding and particle selection
2020Co-Authors: Franco Zunino, Karen ScrivenerAbstract:This project explores the use of grinding aids to control the resulting particle-size distribution of Calcined Clay and limestone. It was observed that after grinding, Calcined Clays exhibit a strongly bimodal particle-size distribution, where the Clay minerals concentrate mainly in the finer particle population. A significant increase in compressive strength at early age was observed in systems incorporating alkanolamines. The effect appears to be restricted to the aluminate reaction, as the silicate peak remains virtually unmodified. Particle classification (air separation) techniques were applied to remove the impurities (mainly quartz and iron oxides) and, therefore, increase the amount of kaolinite in the resulting material. An increase in the kaolinite content from 29 to 45% by mass was achieved in one step and without pre-dispersion of the particles.
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density of c a s h in plain cement and limestone Calcined Clay cement lc 3
2020Co-Authors: François Avet, Karen ScrivenerAbstract:The density of C-A-S-H was investigated by 1H-nuclear magnetic resonance (NMR) on white plain cement and LC3. Despite the high variations in binder composition, the density of the C-A-S-H is found similar between all the systems, also being independent of the Calcined kaolinite content of Calcined Clay in LC3.
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the effect of calcite and gibbsite impurities in Calcined Clay on its reactivity
2020Co-Authors: Franco Zunino, Karen ScrivenerAbstract:This study explored the effect of calcite (calcium carbonate) and gibbsite (aluminum hydroxide) impurities on the reactivity of a model Calcined Clay. Pure metakaolin was combined with calcite and gibbsite to prepare model raw Clays, which were then Calcined in a furnace at 800 °C for 1 h. The R3 test was used to assess reactivity of the Calcined materials, and physical and mineralogical characterizations were performed. It was observed that calcite forms a layer of granular deposit over kaolinite particles, reducing its specific surface area. However, the impact on reactivity is relatively minor if the effect of dilution is accounted. In the case of gibbsite, it completely dehydrates upon calcination and transforms into inactive crystalline alumina. The effect of its presence was compared to quartz, and no significant differences were found. Thus, natural Clays with calcite and gibbsite impurities are suitable for LC3 applications.
Fernando Martirena - One of the best experts on this subject based on the ideXlab platform.
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limestone Calcined Clay cement and concrete a state of the art review
Cement and Concrete Research, 2021Co-Authors: Meenakshi Sharma, Shashank Bishnoi, Fernando Martirena, Karen ScrivenerAbstract:Abstract This article reviews the rapidly developing state-of-the-art literature available on the subject of the recently developed limestone Calcined Clay cement (LC3). An introduction to the background leading to the development of LC3 is first discussed. The chemistry of LC3 hydration and its production are detailed. The influence of the properties of the raw materials and production conditions are discussed. The mixture design of concrete using LC3 and the mechanical and durability properties of LC3 cement and concrete are then compared with other cements. At the end the economic and environmental aspects of the production and use of LC3 are discussed. The paper ends with suggestions on subjects on which further research is required.
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influence grinding procedure limestone content and psd of components on properties of clinker Calcined Clay limestone cements produced by intergrinding
2nd International Conference on Calcined Clays for Sustainable Concrete, 2018Co-Authors: A Perez, Karen Scrivener, Aurelie Favier, Fernando MartirenaAbstract:This paper looks at the study of intergrinding for the production of ternary cement based on clinker, Calcined Clay, limestone and gypsum with 50% of clinker substitution (LC3). The impact of grinding time on clinker, limestone and Calcined Clay PSD, and how this parameter influences the overall performance of the ternary cement is assessed. Laboratory cement blends were produced by grinding all components in a batch laboratory mill. Industrial cements produced through intergrinding in a continuous ball mill were used for comparison. Three fractions were identified: d<7 µm, 7 µm < d < 40 µm and d< 40 µm, for each of the cements studied and the amount of each component were assessed. Fresh and hardened state properties of blends were tested. Results indicate that in intergrinding most of clinker remains at the medium fraction, and further grinding cannot improve clinker fineness due to fine Calcined Clay muffle clinker fineness gaining. PSD of limestone and Calcined Clay is wider than clinker PSD, with a high amount of each material on fine fraction, having a strong impact on rheology. A change in Calcined Clay/limestone ratio from 2:1 to 1:1 improves clinker grinding and rheology but has a negative impact on strengths due to the less proportion of Calcined Clay that impact negatively on the pozzolanic reaction.
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Calcined Clay limestone cements lc3
Cement and Concrete Research, 2017Co-Authors: Kare Scrivene, Fernando Martirena, Shashank Ishnoi, Soume MaityAbstract:Abstract The use of supplementary cementitious materials (SCMs) to replace part of the clinker in cement is the most successful strategy to reduce CO2 emissions in the global cement industry. However, limited supplies of conventional SCMs make it difficult to take this strategy further unless new types of SCMs become available. The only type of material available in the quantities needed to meet demand is Clay containing kaolinite, which can be Calcined to produce an effective SCM. Such Clays are widely available in countries where most growth in demand for cement is forecast. Calcined Clays have previously been used as pozzolans, but calcination makes the economics of substitution marginal in a conventional pozzolanic blend. The major innovation presented here is the possibility to make a coupled substitution of cement with Calcined Clay and limestone. This allows much higher levels of substitution. Blends where Calcined Clay is used as a pozzolan, typically have clinker contents around 65–70%. Combination of Calcined Clay with limestone allows higher levels of substitution down to clinker contents of around 50% with similar mechanical properties and improvement in some aspects of durability. The replacement of clinker with limestone in these blends lowers both the cost and the environmental impact.
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influence of the manufacturing process on the performance of low clinker Calcined Clay limestone portland cement
2015Co-Authors: A Perez, Fernando Martirena, Aurelie Favie, Kare ScriveneAbstract:This paper discusses influence of manufacture parameters of a new type of cement (low carbon cement, LC3) which can substitute up to 50 % of clinker by Calcined Clay and limestone. Limestone powder accelerates the early hydration and Calcined Clays and contributes to strength development at later ages due to its pozzolanic reaction. Further, it facilitates improving rheology of the fresh mix without compromising strength, possibly due to the synergetic interaction between Calcined Clays and limestone. Workability of this new system is strongly affected by the Particle Size Distribution (PSD) and PSD is affected by the grinding process, therefore, due to the different hardness and grindability between the materials forming this cement, new production parameters must be defined. This study compares the results obtain by separate grinding and intergrinding, especially the impact at rheology and early strength. The influence of clinker and limestone on both properties has been assessed, aided by microstructural studies using different techniques (XRD, TGA, IC, etc.) to determine the best fineness combination and analyze the effect of PSD of the new system in cement properties. Intergrinding seems to give reasonable good results in terms of rheology and early strength.
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the origin of the pozzolanic activity of Calcined Clay minerals a comparison between kaolinite illite and montmorillonite
Cement and Concrete Research, 2011Co-Authors: Rodrigo Fernandez, Fernando Martirena, Karen ScrivenerAbstract:This paper investigates the decomposition of three Clayey structures (kaolinite, illite and montmorillonite) when thermally treated at 600 degrees C and 800 degrees C and the effect of this treatment on their pozzolanic activity in cementitious materials. Raw and Calcined Clay minerals were characterized by the XRF, XRD, Al-27 NMR, DTG and BET techniques. Cement pastes and mortars were produced with a 30% substitution by Calcined Clay minerals. The pozzolanic activity and the degree of hydration of the clinker component were monitored on pastes using DTG and BSE-IA, respectively. Compressive strength and sorptivity properties were assessed on standard mortars. It was shown that kaolinite, due to the amount and location of OH groups in its structure, has a different decomposition process than illite or montmorillonite, which results in an important loss of crystallinity. This explains its enhanced pozzolanic activity compared to other Calcined Clay cement blends. (C) 2010 Published by Elsevier Ltd.
Kare Scrivene - One of the best experts on this subject based on the ideXlab platform.
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Calcined Clay limestone cements lc3
Cement and Concrete Research, 2017Co-Authors: Kare Scrivene, Fernando Martirena, Shashank Ishnoi, Soume MaityAbstract:Abstract The use of supplementary cementitious materials (SCMs) to replace part of the clinker in cement is the most successful strategy to reduce CO2 emissions in the global cement industry. However, limited supplies of conventional SCMs make it difficult to take this strategy further unless new types of SCMs become available. The only type of material available in the quantities needed to meet demand is Clay containing kaolinite, which can be Calcined to produce an effective SCM. Such Clays are widely available in countries where most growth in demand for cement is forecast. Calcined Clays have previously been used as pozzolans, but calcination makes the economics of substitution marginal in a conventional pozzolanic blend. The major innovation presented here is the possibility to make a coupled substitution of cement with Calcined Clay and limestone. This allows much higher levels of substitution. Blends where Calcined Clay is used as a pozzolan, typically have clinker contents around 65–70%. Combination of Calcined Clay with limestone allows higher levels of substitution down to clinker contents of around 50% with similar mechanical properties and improvement in some aspects of durability. The replacement of clinker with limestone in these blends lowers both the cost and the environmental impact.
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effect of replacement of silica fume with Calcined Clay on the hydration and microstructural development of eco uhpfrc
Materials & Design, 2017Co-Authors: Kare Scrivene, Wei Huang, Hadi KazemikamyabAbstract:Abstract In this paper, the replacement of high cost silica fume with Calcined Clay was investigated in UHPFRC mixes. The impact of two grades of Calcined Clay on the hydration and microstructural development of UHPFRC matrices was investigated, where 54% of the cement by volume has already been replaced by a limestone with similar PSD. It was seen that comparable mixes were obtained when silica fume was replaced with Calcined Clay by volume. The experimental results revealed a competition for water between the cement hydration and pozzolanic reaction of kaolinite to form more AFt and AFm phases, which affected the compressive strength development of the UHPFRC matrices. This competition is more pronounced in mixes where the kaolinite content increases in the Calcined Clay.
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influence of the manufacturing process on the performance of low clinker Calcined Clay limestone portland cement
2015Co-Authors: A Perez, Fernando Martirena, Aurelie Favie, Kare ScriveneAbstract:This paper discusses influence of manufacture parameters of a new type of cement (low carbon cement, LC3) which can substitute up to 50 % of clinker by Calcined Clay and limestone. Limestone powder accelerates the early hydration and Calcined Clays and contributes to strength development at later ages due to its pozzolanic reaction. Further, it facilitates improving rheology of the fresh mix without compromising strength, possibly due to the synergetic interaction between Calcined Clays and limestone. Workability of this new system is strongly affected by the Particle Size Distribution (PSD) and PSD is affected by the grinding process, therefore, due to the different hardness and grindability between the materials forming this cement, new production parameters must be defined. This study compares the results obtain by separate grinding and intergrinding, especially the impact at rheology and early strength. The influence of clinker and limestone on both properties has been assessed, aided by microstructural studies using different techniques (XRD, TGA, IC, etc.) to determine the best fineness combination and analyze the effect of PSD of the new system in cement properties. Intergrinding seems to give reasonable good results in terms of rheology and early strength.
Arnaud Castel - One of the best experts on this subject based on the ideXlab platform.
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performance of limestone Calcined Clay blended cement based concrete against carbonation
Advances in Cement Research, 2020Co-Authors: M S H Khan, Quang Dieu Nguyen, Arnaud CastelAbstract:The aim of this work is to investigate the carbonation resistance of limestone and Calcined Clay blended cement-based concrete. Two limestone and Calcined Clay concretes with an average 28 d compre...
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mitigation of alkali silica reaction by limestone Calcined Clay cement lc3
Cement and Concrete Research, 2020Co-Authors: Quang Dieu Nguyen, Taehwan Kim, Arnaud CastelAbstract:Abstract The study aims to investigate the influence of limestone Calcined Clay cement (LC3) on the alkali-silica reaction (ASR). Kinetics and sequence of ASR formation were monitored using the model reactant method. Accelerated mortar bar test (AMBT) was also conducted to evaluate the effect LC3 in the ASR expansion. 30 wt% replacement by flash Calcined Clay and limestone in binder reduced the mortar expansion lower than the limit of Australian Standard. From the model reactant method, the additional calcium rich phases in LC3 model reactant system seem to delay the ASR gel formation or produce high Ca/Si ASR products, relatively rigid C-S-H and C-A-S-H that has less expansive capability. The current results reveal the possibility to utilize model reactant experiments to monitor the formation sequence of ASR gels with the presence of Calcined Clay and limestone due to the consistent results observed between model reactant experiments and real LC3-based specimens.
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reinforcement corrosion in limestone flash Calcined Clay cement based concrete
Cement and Concrete Research, 2020Co-Authors: Quang Dieu Nguyen, Arnaud CastelAbstract:Abstract Limestone Calcined Clay cement (LC3) concrete has attracted world-wide attention as a newly promising low-carbon concrete. In this study, long-term reinforcement corrosion in LC3 concrete was investigated. Both chloride and carbonation-induced reinforcing bar corrosion were examined. Open circuit corrosion potential, polarization resistance, Tafel constants were monitored at regular intervals up to 500 days. Gravimetric mass loss was measured and compared to the loss of mass calculated using electrochemical methods. The performance of concrete with flash Calcined Clay and limestone was similar to that of traditional Portland cement concrete in long-term investigation. Traditional corrosion methods and classifications used widely to assess of steel in concrete can be applied to concrete containing LC3 providing a recalibration of polarization resistance range for passitivity condition.
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mitigation of alkali silica reaction in limestone Calcined Clay cement based mortar
2020Co-Authors: Quang Dieu Nguyen, M S H Khan, Arnaud Castel, Taehwan KimAbstract:This work aims to assess the potential of limestone Calcined Clay cement (LC3) in mitigating alkali–silica reaction (ASR). Two General Purpose (GP) cement substitution rates using Calcined Clay and limestone were tested: 20 and 30% with a ratio 2:1 by mass of Calcined Clay and limestone. Silica ions dissolution of rhyodacite rock used as reactive aggregate, expansion of mortar specimens using the accelerated mortar bar test (AMBT) and the initial chemical composition of the mortars pore solution were investigated. The combination of Calcined Clay and limestone significantly reduced the expansion of mortar bars compared to reference mortar using 100% GP cement. The reduction in mortar bar expansion correlates well with the reduction in alkalis ions concentration and pH of the pore solution of LC3 mortars compared to reference mortar. 30% OPC substituted by Calcined Clay and limestone seems to be able to mitigate the risk of ASR in concrete using alkali-reactive aggregate.
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carbonation of limestone Calcined Clay cement concrete
2018Co-Authors: M S H Khan, Quang Dieu Nguyen, Arnaud CastelAbstract:This study aims to investigate the carbonation resistance of limestone Calcined Clay (LC3) concrete. Ordinary Portland Cement (OPC) substitution rates considered were 15%, 30% and 45%. Low grade Calcined Clay was used with about 50% amorphous phase. Phenolphthalein indicator test was carried out in order to assess the carbonation depth of concrete exposed to natural and accelerated carbonation. Overall, results show that the carbonation front penetration is consistently increasing with the increase in OPC substitution rate Generally, LC3 concrete under performs compared to reference OPC concrete having similar 28 days compressive strength. At 30% OPC substitution rate, performance of LC3 concrete is close to that of OPC counterpart concrete, both having an average 28 days compressive strength of 36 MPa. Only a marginal increase in concrete cover would be enough to maintain the same service life. This is an important outcome showing that LC3 concrete with OPC substitution up to 30% is suitable for a large range of applications including outdoor exposure (assuming no other aggressive ions are involved). However, LC3 concrete with OPC substitution beyond 30% is not suitable in exposure condition where carbonation induced steel reinforcement corrosion can be an issue.
Shashank Bishnoi - One of the best experts on this subject based on the ideXlab platform.
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limestone Calcined Clay cement and concrete a state of the art review
Cement and Concrete Research, 2021Co-Authors: Meenakshi Sharma, Shashank Bishnoi, Fernando Martirena, Karen ScrivenerAbstract:Abstract This article reviews the rapidly developing state-of-the-art literature available on the subject of the recently developed limestone Calcined Clay cement (LC3). An introduction to the background leading to the development of LC3 is first discussed. The chemistry of LC3 hydration and its production are detailed. The influence of the properties of the raw materials and production conditions are discussed. The mixture design of concrete using LC3 and the mechanical and durability properties of LC3 cement and concrete are then compared with other cements. At the end the economic and environmental aspects of the production and use of LC3 are discussed. The paper ends with suggestions on subjects on which further research is required.
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influence of cement replacement by limestone Calcined Clay pozzolan on the engineering properties of mortar and concrete
Advances in Cement Research, 2020Co-Authors: Vineet Shah, Sreejith Krishnan, Anuj Parashar, G Mishra, Satya Medepalli, Shashank BishnoiAbstract:This study investigates the effect of a new type of blended pozzolan on the hydration, mechanical and durability performance of cement. A blend of limestone Calcined Clay pozzolan (LCCP) was produc...
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influence of carbonation on mechanical and transport properties of limestone Calcined Clay blend mortar mix
2020Co-Authors: Tarun Gaur, Lav Singh, Shashank BishnoiAbstract:When calcium bearing phases of hydration products react with carbon dioxide, it results in formation of calcium carbonate. The consumption of alkaline compounds leads to reduction in the pH of concrete, thereby affecting the stability of hydration product and increasing the risk of steel corrosion in low alkaline environment. The reaction of pozzolans with calcium hydroxide reduces the reserve alkalinity in the hydrated cement paste which accelerates the rate of carbonation. The main objective is to determine the change in mechanical and transport properties of carbonated and non-carbonated samples. In this investigation, a cement blend mix has been prepared using OPC and limestone Calcined Clay. Mortar specimens were prepared for using blend to sand ratio as 1:3 to prepare samples for testing compressive strength, sorptivity and porosity using boiling water test. Paste samples were cast to measure reserve alkalinity and carry out thermogravimetric analysis. Some specimens were kept in carbonation chamber for 90 days at 3% CO2 concentration and 60% relative humidity for carbonation to occur at an accelerated rate while the other samples were sealed to avoid carbonation. The results show that after carbonation, there is slight decrease in the compressive strength and increase in sorptivity after carbonation of LC3.
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hydration and phase assemblage of ternary cements with Calcined Clay and limestone
Construction and Building Materials, 2019Co-Authors: Sreejith Krishnan, Arun C Emmanuel, Shashank BishnoiAbstract:Abstract This study aims to understand the impact of Calcined Clay, limestone and gypsum on the hydration mechanisms and phase development in limestone Calcined Clay cement (LC3). Crushed quartz was used as an inert filler to isolate the individual impact of Calcined Clay and limestone in LC3 systems. The hydration and the microstructure development in these systems were studied using X-ray diffraction (XRD), isothermal calorimetry, scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP) as well compressive strength experiments. The presence of Calcined Clay helped in achieving a well-refined microstructure in LC3 within 7 days of hydration. A reduction in the degree of hydration of clinker phases was observed due the presence of Calcined Clay. The AFt/AFm phase assemblage was seen to depend on the blend composition. Additional ettringite was seen to form when the amount of gypsum was increased in the LC3 system. However, the increased gypsum content also resulted in the reduction in reactivity of limestone.
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understanding the hydration of dolomite in cementitious systems with reactive aluminosilicates such as Calcined Clay
Cement and Concrete Research, 2018Co-Authors: Sreejith Krishnan, Shashank BishnoiAbstract:Abstract This study investigates the hydration of dolomite, CaMg(CO3)2, with Calcined Clay in presence of calcium hydroxide and ordinary Portland cement. The hydration products as well as the microstructure at various ages were characterized using X-ray diffraction (XRD), thermogravimetric analysis (TGA), and mercury intrusion porosimetry (MIP). Isothermal calorimetry was used to understand the reaction kinetics. The systems with dolomite were compared against control systems with limestone and quartz. It was seen that, the formation of carbonate – AFm phases takes place in the dolomite systems similar to limestone systems. No formation of brucite (Mg(OH)2) was observed till 90 days of hydration, with Mg2+ ions most likely being incorporated into hydrotalcite phase (Mg4Al2(OH)14). The synergetic effect observed in the Portland cement – Calcined Clay – dolomite system was found to result in a refined pore structure at early ages and improvement in the mechanical properties such as compressive strength.