Moisture expansion (ME) is the term used to describe the expansion of ceramic materials due to the adsorption of water. ME usually occurs slowly and is relatively small, but, it can damage the ceramic tiles adhesion to the underlayment, craze the glaze and lead to the development of cracks on ceramics bricks. In this work kaolin and granite wastes were incorporated in ceramic compositions aiming study their influence on the ME of ceramic tiles. Raw materials were processed and submitted to characterization: physical and mineralogical by laser diffraction particle size analysis, chemical analysis, thermodifferential and thermogravimetric analysis and X-ray diffraction. Results showed that kaolin and granite wastes can be incorporated in ceramic composition because display characteristics similar to conventional not plastic ceramic materials, providing satisfactory ME results when compared to the ME limit value of 0.6 mm/m (0.06%) indicated by the ABNT for ceramic tiles. Compositions containing up to 20% of waste can be produced when firing above 1000 ºC
moisture expansion; waste; ceramic tiles
