Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Influence of Calcium Sulphate on Hydration of Cements Containing Calcined Clay
https://orcid.org/http://orcid.org/0000-0001-5671-2822
https://orcid.org/http://orcid.org/0000-0002-9088-0384
https://orcid.org/http://orcid.org/0000-0002-2183-2530
The present study tries to understand the effect of sulphates on the hydration of Portland cement—calcined clay systems. Calcined clay was obtained by calcining a clay having 95% kaolinite at temperatures ranging from 700 to 800 °C. The calcined clay was used to replace 30% of clinker. A clinker with low aluminate and low alkali content was used. Laboratory grade gypsum was used as the source of sulphates. In this study, the sulphate content in the cement system was varied as 2.5 and 5.0%. Mainly, the effect of sulphates on the hydration of cement was studied by conducting isothermal calorimetry on cement pastes for 48 h. In addition, the phase assemblage studies were done at 1 day and 3 days by performing X-ray diffraction on the paste samples. It was observed from calorimetry that the blends with higher sulphate content show a significant delay in aluminate hydration. It was again noticed that the main hydration peak was also affected with increase in sulphates. In calcined clay blend, the amount of ettringite formed was lesser than the normal OPC blend at similar sulphate content. In the other case where the dosage of sulphate was high, the ettringite continues to form till 3 days.
Influence of Calcium Sulphate on Hydration of Cements Containing Calcined Clay
https://orcid.org/http://orcid.org/0000-0001-5671-2822
https://orcid.org/http://orcid.org/0000-0002-9088-0384
https://orcid.org/http://orcid.org/0000-0002-2183-2530
The present study tries to understand the effect of sulphates on the hydration of Portland cement—calcined clay systems. Calcined clay was obtained by calcining a clay having 95% kaolinite at temperatures ranging from 700 to 800 °C. The calcined clay was used to replace 30% of clinker. A clinker with low aluminate and low alkali content was used. Laboratory grade gypsum was used as the source of sulphates. In this study, the sulphate content in the cement system was varied as 2.5 and 5.0%. Mainly, the effect of sulphates on the hydration of cement was studied by conducting isothermal calorimetry on cement pastes for 48 h. In addition, the phase assemblage studies were done at 1 day and 3 days by performing X-ray diffraction on the paste samples. It was observed from calorimetry that the blends with higher sulphate content show a significant delay in aluminate hydration. It was again noticed that the main hydration peak was also affected with increase in sulphates. In calcined clay blend, the amount of ettringite formed was lesser than the normal OPC blend at similar sulphate content. In the other case where the dosage of sulphate was high, the ettringite continues to form till 3 days.
Influence of Calcium Sulphate on Hydration of Cements Containing Calcined Clay
https://orcid.org/http://orcid.org/0000-0001-5671-2822
https://orcid.org/http://orcid.org/0000-0002-9088-0384
https://orcid.org/http://orcid.org/0000-0002-2183-2530
The present study tries to understand the effect of sulphates on the hydration of Portland cement—calcined clay systems. Calcined clay was obtained by calcining a clay having 95% kaolinite at temperatures ranging from 700 to 800 °C. The calcined clay was used to replace 30% of clinker. A clinker with low aluminate and low alkali content was used. Laboratory grade gypsum was used as the source of sulphates. In this study, the sulphate content in the cement system was varied as 2.5 and 5.0%. Mainly, the effect of sulphates on the hydration of cement was studied by conducting isothermal calorimetry on cement pastes for 48 h. In addition, the phase assemblage studies were done at 1 day and 3 days by performing X-ray diffraction on the paste samples. It was observed from calorimetry that the blends with higher sulphate content show a significant delay in aluminate hydration. It was again noticed that the main hydration peak was also affected with increase in sulphates. In calcined clay blend, the amount of ettringite formed was lesser than the normal OPC blend at similar sulphate content. In the other case where the dosage of sulphate was high, the ettringite continues to form till 3 days.
Influence of Calcium Sulphate on Hydration of Cements Containing Calcined Clay
RILEM Bookseries
Bishnoi, Shashank (Herausgeber:in) / Dhoopadahalli, Gopala Rao (Autor:in) / Krishnan, Sreejith (Autor:in) / Bishnoi, Shashank (Autor:in)
Calcined Clays for Sustainable Concrete ; Kapitel: 37 ; 315-322
RILEM Bookseries ; 25
14.04.2020
8 pages
Aufsatz/Kapitel (Buch)
Elektronische Ressource
Englisch
Blended Cements with Calcined Illitic Clay: Workability and Hydration
| Springer Verlag | 2017
Calcined Clay—Limestone Cements: Hydration and Mechanical Properties of Ternary Blends
| Springer Verlag | 2020
Sulphate and ASR Resistance of Concrete Made with Calcined Clay Blended Cements
| Springer Verlag | 2015