Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
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Comparative study of laterite and metakaolin/hematite-based geopolymers: Effect of iron source and alkalization
Abstract The objective of this study is to investigate and characterize geopolymers based on laterite or metakaolin-hematite mixture model. The model has been used to reproduce laterite in areas where laterite is not available. The geopolymers were synthetized using (i) calcined laterite and (ii) a mixture of metakaolin and hematite as solid precursors and two alkaline solutions of SiO2/Na2O and SiO2/K2O equal to 1.3. The obtained results reveal that both laterite and metakaolin/hematite-based geopolymers display efficient mechanical properties, regardless of the alkaline activating solution used. Thermal conductivity and compressive strength vary almost linearly, from 0.7 to 1 W/(m.K) and from 20 to 70 MPa, respectively: Na-activated laterite (NaLc) > Na-activated metakaolin + hematite (NaMF) > K-activated metakaolin + hematite (KMF) > K- activated laterite (KLc). This order can be explained by structural modifications after thermal treatment at 1175 °C. In the case of NaLc and NaMF, the samples display weak porosity due to higher crystallinity of the powder. In contrast, KMF and KLc are more heterogeneous with higher porosity.
Graphical abstract Display Omitted
Highlights It is possible to synthetize geopolymer based metakaolin-hematite model. Sodium-geopolymer has higher compressive strength and lower porosity than potassium-geopolymer. Sodium-geopolymer-laterite has higher properties than sodium-geopolymer-metakaolin-hematite.
Comparative study of laterite and metakaolin/hematite-based geopolymers: Effect of iron source and alkalization
Abstract The objective of this study is to investigate and characterize geopolymers based on laterite or metakaolin-hematite mixture model. The model has been used to reproduce laterite in areas where laterite is not available. The geopolymers were synthetized using (i) calcined laterite and (ii) a mixture of metakaolin and hematite as solid precursors and two alkaline solutions of SiO2/Na2O and SiO2/K2O equal to 1.3. The obtained results reveal that both laterite and metakaolin/hematite-based geopolymers display efficient mechanical properties, regardless of the alkaline activating solution used. Thermal conductivity and compressive strength vary almost linearly, from 0.7 to 1 W/(m.K) and from 20 to 70 MPa, respectively: Na-activated laterite (NaLc) > Na-activated metakaolin + hematite (NaMF) > K-activated metakaolin + hematite (KMF) > K- activated laterite (KLc). This order can be explained by structural modifications after thermal treatment at 1175 °C. In the case of NaLc and NaMF, the samples display weak porosity due to higher crystallinity of the powder. In contrast, KMF and KLc are more heterogeneous with higher porosity.
Graphical abstract Display Omitted
Highlights It is possible to synthetize geopolymer based metakaolin-hematite model. Sodium-geopolymer has higher compressive strength and lower porosity than potassium-geopolymer. Sodium-geopolymer-laterite has higher properties than sodium-geopolymer-metakaolin-hematite.
Comparative study of laterite and metakaolin/hematite-based geopolymers: Effect of iron source and alkalization
Nadia, Nouping Fekoua Joelle (Autor:in) / Gharzouni, Ameni (Autor:in) / Nait-Ali, B. (Autor:in) / Ouamara, Lila (Autor:in) / Ndassa, Ibrahim Mbouombouo (Autor:in) / Bebga, Gouet (Autor:in) / Elie, Kamseu (Autor:in) / Rossignol, Sylvie (Autor:in)
Applied Clay Science ; 233
12.01.2023
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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