Abstract
This study investigates the influence of crushed waste glass (GL) and silica fume (SF) on the densification and microstructural characteristics of fired clay ceramics. Ceramic specimens were prepared by partially replacing clay with 10, 15, and 20 wt.% of GL and SF. They fired at 1050, 1100, and 1125 °C to evaluate the effect of temperature on bulk density and to determine the optimal firing regime. Based on density measurements and visual examination, the samples fired at 1125 °C were identified as the most effective and selected for further evaluation. Water absorption testing and microstructural characterization were conducted for specimens fired at 1125 °C. Increasing firing temperature enhanced densification for all compositions. Glass-modified ceramics exhibited the highest bulk density and lowest water absorption due to intensified liquid-phase sintering and pore filling. In contrast, silica fume additions resulted in comparatively higher porosity and water absorption under identical conditions. Microstructural analysis confirmed a denser and more homogeneous matrix in glass-containing specimens with uniformly distributed Si-, Al-, and Ca-rich phases. The results demonstrate that both additives can modify the properties of fired clay ceramics; however, crushed glass provides a more pronounced improvement in densification and water resistance at 1125 °C.