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Jorgen Skibsted - One of the best experts on this subject based on the ideXlab platform.
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role of calcium on chloride binding in hydrated Portland Cement metakaolin limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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Role of calcium on chloride binding in hydrated Portland Cement–metakaolin–limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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durability of Portland Cement blends including calcined clay and limestone interactions with sulfate chloride and carbonate ions
2015Co-Authors: Zhenguo Shi, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Josef Kaufmann, Wolfgang Kunther, Sergio Ferreiro, Duncan Herfort, Jorgen SkibstedAbstract:The durability has been investigated for mortars made from a Pure Portland Cement (CEM I) and five Portland Cement – SCM blends, using a Cement replaCement level of 35 wt% and the following SCM’s: (i) Pure limestone, (ii) Pure metakaolin, (iii) metakaolin and limestone (3:1 w/w), (iv) metakaolin and silica fume, and (v) metakaolin, silica fume and limestone. The blends with metakaolin and silica fume employ a fixed ratio for these components which mimics the alumina-silicate composition of a 2:1 clay (i.e., montmorillonite). All mortars were demoulded after hydration for one day and cured saturated in water at 20 °C for 90 days prior to exposure. Expansions induced by sulfate attack, chloride profiles, and carbonation depths were measured to investigate the durability performances of the mortars. Porosity and pore connectivity were analysed before exposure by mercury intrusion porosimetry. The results show that mortars incorporating metakaolin, independent of additional silica fume or limestone, all exhibit very high resistance towards sulfate attack and chloride ingress, but are vulnerable to carbonation. The binary Portland Cement – limestone blend is most susceptible to all types of studied chemical attacks, as expected. The Pure Portland Cement exhibits poor resistance to sulfate attack and chloride ingress, but high resistance to carbonation. The observed performances for the different blends can be explained based on their microstructure and phase assemblages. For example, the presence of metakaolin increases the chloride-ion binding capacity and enhances chloride resistance by the low pore connectivity present in the hydrated blends with metakaolin.
Zhenguo Shi - One of the best experts on this subject based on the ideXlab platform.
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role of calcium on chloride binding in hydrated Portland Cement metakaolin limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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Role of calcium on chloride binding in hydrated Portland Cement–metakaolin–limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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durability of Portland Cement blends including calcined clay and limestone interactions with sulfate chloride and carbonate ions
2015Co-Authors: Zhenguo Shi, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Josef Kaufmann, Wolfgang Kunther, Sergio Ferreiro, Duncan Herfort, Jorgen SkibstedAbstract:The durability has been investigated for mortars made from a Pure Portland Cement (CEM I) and five Portland Cement – SCM blends, using a Cement replaCement level of 35 wt% and the following SCM’s: (i) Pure limestone, (ii) Pure metakaolin, (iii) metakaolin and limestone (3:1 w/w), (iv) metakaolin and silica fume, and (v) metakaolin, silica fume and limestone. The blends with metakaolin and silica fume employ a fixed ratio for these components which mimics the alumina-silicate composition of a 2:1 clay (i.e., montmorillonite). All mortars were demoulded after hydration for one day and cured saturated in water at 20 °C for 90 days prior to exposure. Expansions induced by sulfate attack, chloride profiles, and carbonation depths were measured to investigate the durability performances of the mortars. Porosity and pore connectivity were analysed before exposure by mercury intrusion porosimetry. The results show that mortars incorporating metakaolin, independent of additional silica fume or limestone, all exhibit very high resistance towards sulfate attack and chloride ingress, but are vulnerable to carbonation. The binary Portland Cement – limestone blend is most susceptible to all types of studied chemical attacks, as expected. The Pure Portland Cement exhibits poor resistance to sulfate attack and chloride ingress, but high resistance to carbonation. The observed performances for the different blends can be explained based on their microstructure and phase assemblages. For example, the presence of metakaolin increases the chloride-ion binding capacity and enhances chloride resistance by the low pore connectivity present in the hydrated blends with metakaolin.
Mette Rica Geiker - One of the best experts on this subject based on the ideXlab platform.
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role of calcium on chloride binding in hydrated Portland Cement metakaolin limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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Role of calcium on chloride binding in hydrated Portland Cement–metakaolin–limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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durability of Portland Cement blends including calcined clay and limestone interactions with sulfate chloride and carbonate ions
2015Co-Authors: Zhenguo Shi, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Josef Kaufmann, Wolfgang Kunther, Sergio Ferreiro, Duncan Herfort, Jorgen SkibstedAbstract:The durability has been investigated for mortars made from a Pure Portland Cement (CEM I) and five Portland Cement – SCM blends, using a Cement replaCement level of 35 wt% and the following SCM’s: (i) Pure limestone, (ii) Pure metakaolin, (iii) metakaolin and limestone (3:1 w/w), (iv) metakaolin and silica fume, and (v) metakaolin, silica fume and limestone. The blends with metakaolin and silica fume employ a fixed ratio for these components which mimics the alumina-silicate composition of a 2:1 clay (i.e., montmorillonite). All mortars were demoulded after hydration for one day and cured saturated in water at 20 °C for 90 days prior to exposure. Expansions induced by sulfate attack, chloride profiles, and carbonation depths were measured to investigate the durability performances of the mortars. Porosity and pore connectivity were analysed before exposure by mercury intrusion porosimetry. The results show that mortars incorporating metakaolin, independent of additional silica fume or limestone, all exhibit very high resistance towards sulfate attack and chloride ingress, but are vulnerable to carbonation. The binary Portland Cement – limestone blend is most susceptible to all types of studied chemical attacks, as expected. The Pure Portland Cement exhibits poor resistance to sulfate attack and chloride ingress, but high resistance to carbonation. The observed performances for the different blends can be explained based on their microstructure and phase assemblages. For example, the presence of metakaolin increases the chloride-ion binding capacity and enhances chloride resistance by the low pore connectivity present in the hydrated blends with metakaolin.
Barbara Lothenbach - One of the best experts on this subject based on the ideXlab platform.
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role of calcium on chloride binding in hydrated Portland Cement metakaolin limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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Role of calcium on chloride binding in hydrated Portland Cement–metakaolin–limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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durability of Portland Cement blends including calcined clay and limestone interactions with sulfate chloride and carbonate ions
2015Co-Authors: Zhenguo Shi, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Josef Kaufmann, Wolfgang Kunther, Sergio Ferreiro, Duncan Herfort, Jorgen SkibstedAbstract:The durability has been investigated for mortars made from a Pure Portland Cement (CEM I) and five Portland Cement – SCM blends, using a Cement replaCement level of 35 wt% and the following SCM’s: (i) Pure limestone, (ii) Pure metakaolin, (iii) metakaolin and limestone (3:1 w/w), (iv) metakaolin and silica fume, and (v) metakaolin, silica fume and limestone. The blends with metakaolin and silica fume employ a fixed ratio for these components which mimics the alumina-silicate composition of a 2:1 clay (i.e., montmorillonite). All mortars were demoulded after hydration for one day and cured saturated in water at 20 °C for 90 days prior to exposure. Expansions induced by sulfate attack, chloride profiles, and carbonation depths were measured to investigate the durability performances of the mortars. Porosity and pore connectivity were analysed before exposure by mercury intrusion porosimetry. The results show that mortars incorporating metakaolin, independent of additional silica fume or limestone, all exhibit very high resistance towards sulfate attack and chloride ingress, but are vulnerable to carbonation. The binary Portland Cement – limestone blend is most susceptible to all types of studied chemical attacks, as expected. The Pure Portland Cement exhibits poor resistance to sulfate attack and chloride ingress, but high resistance to carbonation. The observed performances for the different blends can be explained based on their microstructure and phase assemblages. For example, the presence of metakaolin increases the chloride-ion binding capacity and enhances chloride resistance by the low pore connectivity present in the hydrated blends with metakaolin.
Klaartje De Weerdt - One of the best experts on this subject based on the ideXlab platform.
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role of calcium on chloride binding in hydrated Portland Cement metakaolin limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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Role of calcium on chloride binding in hydrated Portland Cement–metakaolin–limestone blends
Cement and Concrete Research, 2017Co-Authors: Zhenguo Shi, Tone Anita Ostnor, Frank Winnefeld, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Jorgen SkibstedAbstract:Abstract Chloride binding is investigated for Portland Cement–metakaolin–limestone pastes exposed to CaCl 2 and NaCl solutions. The phase assemblages and the amount of Friedel's salt are evaluated using TGA, XRD and thermodynamic modeling. A larger amount of Friedel's salt is observed in the metakaolin blends compared to the Pure Portland Cement. A higher total chloride binding is observed for the pastes exposed to the CaCl 2 solution relative to those in the NaCl solution. This is reflected by the fact that calcium increases the quantity of Friedel's salt in the metakaolin blends by promoting the transformation of stratlingite and/or monocarbonate to Friedel's salt. Calcium increases also the amount of chloride in the diffuse layer of the C-S-H for the Pure Cement. A linear correlation between the total bound chloride and the uptake of calcium from the CaCl 2 solution is obtained and found to be independent on the type of Cement blend.
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durability of Portland Cement blends including calcined clay and limestone interactions with sulfate chloride and carbonate ions
2015Co-Authors: Zhenguo Shi, Klaartje De Weerdt, Barbara Lothenbach, Mette Rica Geiker, Josef Kaufmann, Wolfgang Kunther, Sergio Ferreiro, Duncan Herfort, Jorgen SkibstedAbstract:The durability has been investigated for mortars made from a Pure Portland Cement (CEM I) and five Portland Cement – SCM blends, using a Cement replaCement level of 35 wt% and the following SCM’s: (i) Pure limestone, (ii) Pure metakaolin, (iii) metakaolin and limestone (3:1 w/w), (iv) metakaolin and silica fume, and (v) metakaolin, silica fume and limestone. The blends with metakaolin and silica fume employ a fixed ratio for these components which mimics the alumina-silicate composition of a 2:1 clay (i.e., montmorillonite). All mortars were demoulded after hydration for one day and cured saturated in water at 20 °C for 90 days prior to exposure. Expansions induced by sulfate attack, chloride profiles, and carbonation depths were measured to investigate the durability performances of the mortars. Porosity and pore connectivity were analysed before exposure by mercury intrusion porosimetry. The results show that mortars incorporating metakaolin, independent of additional silica fume or limestone, all exhibit very high resistance towards sulfate attack and chloride ingress, but are vulnerable to carbonation. The binary Portland Cement – limestone blend is most susceptible to all types of studied chemical attacks, as expected. The Pure Portland Cement exhibits poor resistance to sulfate attack and chloride ingress, but high resistance to carbonation. The observed performances for the different blends can be explained based on their microstructure and phase assemblages. For example, the presence of metakaolin increases the chloride-ion binding capacity and enhances chloride resistance by the low pore connectivity present in the hydrated blends with metakaolin.
