Abstract
The Spanish industry is the world leader in the ceramic sanitary-ware market. This industry produces large amounts of waste during the manufacturing process, which is simply dumped. This study investigated the potential of forming geopolymers by the alkali activation of ceramic sanitaryware.
Ceramic material was alkali-activated with NaOH/sodium silicate solutions, and Ca(OH)2 was used as a source of calcium. The starting material was physico-chemically characterised (chemical composition, X-ray diffraction, granulometric analysis, thermogravimetry and scanning electron microscopy). The developed alkali-activated pastes were characterised by SEM and TGA, and mortars were used to assess compressive strength evolution. Compressive strength values ranging from 14 to 36 MPa were obtained in the mortars cured for 7 days at 65ºC, depending on the activator concentration and Ca(OH)2 addition. This provides added value for significant waste material and contributes to the development of a new low CO2-emission binder.
