Delgado-Plana, P.Rodriguez-Exposito, A.Bueno-Rodriguez, S.Perez-Villarejo, L.Tobaldi, D. M.Labrincha, J. A.Eliche-Quesada, D.2023-02-122023-02-122021-07-01http://hdl.handle.net/10668/19330The valorization of spent oil bleaching earths (SOBE) is crucial for the protection of the environment and the reuse of resources. In this research, alkali-activated binders were manufactured at room temperature using SOBE as a precursor by varying the mass ratio between the activating solutions of sodium silicate (Na2SiO3) and 6 M sodium hydroxide (NaOH) (activating solution modulus) (Na2SiO3/NaOH ratio = 1/1; 1/2; 1/3; 1/4) to investigate the influence on the technological properties of the materials. This process intends to evaluate the potential of SOBE, heat-treated at 550 degrees C (1 h), as a precursor of the reaction (source of aluminosilicates). Samples produced with higher amounts of sodium silicate developed a denser structure, with lower porosity and a higher amount of geopolymer gel. Maximum flexural (8.35 MPa) and compressive (28.4 MPa) strengths of samples cured at room temperature for 28 days were obtained with a Na2SiO3/NaOH mass ratio of 1/1. The study demonstrates that SOBE waste can be used as a precursor in the manufacture of geopolymer binders that show a good compromise between physical, mechanical and thermally insulating characteristics.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/spent bleaching earthgeopolymersactivating solutionactivator moduluscompressive strengthmicrostructureAsh-based-geopolymersFly-ashWaste glassInorganic geopolymersMechanical-propertiesPart iCementSodiumFabricationResistanceresearch articleopen access10.3390/su131375012071-1050https://www.mdpi.com/2071-1050/13/13/7501/pdf?version=1625539574671318600001