Reformulation of roofing tiles body with addition of granite waste from sawing operations

A ceramic body traditionally used to produce roofing tiles was reformulated by the addition of granite waste from sawing operations. The objective was to obtain a ceramic product with better technological properties. The main tool for the reformulation was the definition of the appropriate particle size of the raw materials as given by the Winkler diagram. The raw materials were characterized with respect to their mineralogical composition by X-ray diffraction, particle size distribution as well as chemical composition and plasticity. Specimens were made by extrusion and fired at temperatures from 850 to 1100 °C. The technological properties determined were: dry bulk density, linear shrinkage, water absorption and mechanical strength. Microstructural analysis of the fired samples was carried out by X-ray diffraction. The results showed that the granite waste contributes to reduce the plasticity and the linear shrinkage of the ceramic bodies. One reformulated ceramic body exhibited better values of water absorption and mechanical strength than the industrially used.