Valorisation of rice husk ash as an activator in the preparation of alkali-activated cements based on electric arc furnace slag
Rice husk ash (RHA) was employed as a silica source to produce an alternative sodium silicate solution through the dissolution of varying quantities of RHA in an 8 M NaOH solution. The solution was employed in the production of alkali-activated cements based on electric arc furnace slag (EAFS). Solu...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/393658 |
| Acceso en línea: | http://hdl.handle.net/10261/393658 https://api.elsevier.com/content/abstract/scopus_id/105004193059 |
| Access Level: | acceso abierto |
| Palabra clave: | Rice husk ash Alkali-activated slag Alternative alkaline activators Compressive strength rice husks slags strength |
| Sumario: | Rice husk ash (RHA) was employed as a silica source to produce an alternative sodium silicate solution through the dissolution of varying quantities of RHA in an 8 M NaOH solution. The solution was employed in the production of alkali-activated cements based on electric arc furnace slag (EAFS). Solutions were prepared with varying activator modules (Ms, molar ratio SiO₂/Na₂O) of 0.60, 0.85, 1.00, and 1.15. As control samples, slags were activated with 8 M NaOH (Ms = 0.0) and with 8 M NaOH in conjunction with commercial sodium silicate (Ms = 1.0). Mechanical, physical, mineralogical (XRD, FTIR), and microstructural (SEM/EDS) tests were conducted to characterize the obtained pastes. The results of the FTIR and SEM analyses indicated that the SiO₂/Na₂O ratio exerts a significant influence on the reaction products formed. At Ms values higher than 0.85, the predominant reaction product was observed to be a more cross-linked hybrid gel (N,C)-A-S-H. Lower modules resulted in the predominant formation of C-A-S-H gel and a more porous structure with lower mechanical properties. Pastes activated with the alternative RHA solution and Ms = 1.0 exhibited a composition, microstructure, and strength that was similar to or superior to those prepared with conventional commercial activators. |
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