Study of SiO2/Al2O3 and CaO/SiO2 relationships in alkali-activated cements

Autor: Andreza Frare, Caroline Angulski da Luz, Marcelo Henrique Farias de Medeiros, José Ilo Pereira Filho
Jazyk: angličtina
Rok vydání: 2024
Předmět:
Zdroj: Revista IBRACON de Estruturas e Materiais, Vol 17, Iss 3 (2024)
Druh dokumentu: article
ISSN: 1983-4195
DOI: 10.1590/s1983-41952024000300013
Popis: Abstract This study investigates alkali-activated cements (AAC), comprising blast furnace slag (BFS) along with industrial by-products like rice husk ash (RHA) and metakaolin (MK), activated by sodium hydroxide (NaOH). The aim is to assess the impact of SiO2/Al2O3 and CaO/SiO2 ratios on AAC's mechanical strength and hydrated compounds. Mechanical and microstructural tests were carried out. Compositions with a CaO/SiO2 ratio near 1 exhibited superior mechanical strength, approximately 35–40 MPa at 28 days, while the SiO2/Al2O3 ratio did not significantly affect the outcomes. X-ray diffraction and thermal analysis revealed the formation of hydrated calcium silicate (CSH) and hydrotalcite as hydrated compounds. This suggests that BFS can enhance AAC results. In conclusion, CaO/SiO2 ratios play a crucial role in influencing the strength gains of AAC. Verifying the influence of these relationships can contribute to the study of dosage and understanding of hydration processes.
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