Production process of an eco-friendly one-part alkali-activated binder

One-part alkali-activated binder (AAB) is a product with lower environmental impact than Portland cement, and can be a feasible commercial alternative. The main objective of this study was to propose and test a method of obtaining one-part AAB with metakaolin and an alternative powder sodium silicate from rice husk ash (RHA). To evaluate the AAB properties, mortars were produced with different SiO₂/Al₂O₃ molar ratios (2.7, 3.1, and 3.3), and tests were conducted to characterize the binder. The results indicated that the process was efficient in generating a non-crystalline sodium silicate powdered material. With high SiO₂/Al₂O₃ molar ratio the mortars achieved high compressive strength and it increased with age, had low permeability, and capillary water absorption. Compressive strength results varied from 6 MPa to 12 MPa at 28 days, indicating the possibility of using the proposed method for one-part AAB production. AAB produced can be applied in different building materials. (author)