Influence of the Colorless Waste Glass on the Mineralogical, Microstructural and Mechanical Properties of Clay Material from Wack (Adamawa, Cameroon)

This study reports the investigation of the influence of adding waste glass on the properties of fired clay specimen. Four different particle sizes (smaller than 100 μm, 300μm, 500μm, and 800 μm) of waste glass were mixed with a clay material at contents of 0%, 2%, 6% and 10% per weight. Specimen samples were fired at 750℃ in an electrical furnace for 6 hours, at a heating rate of 5℃/min. The physical and mechanical properties of terracotta are studied. The chemical analysis revealed that the clays were dominated by kaolinite and montmorillonite with small proportion of mixed layers clay. The fine grained texture (0.002 mm > 25%) and high plasticity (WP > 30%) of the clays were responsible for the moderate and high values of shrinkage upon oven drying and firing. The firing color variation from reddish brown shade was due to the amounts of iron and titanium oxides present in the obtained material. The water absorption was varied between 17.40% and 13.70%, while the linear shrinkage was estimated to be between 0.70% and 1.20% and the flexural strength from 5.30 to 8.10 MPa. These results showed that mixing clay with waste glass at 750℃ is an interesting approach to obtain reddish brown ceramics destined for bricks or roofing tiles.