The increasing generation of glass waste and the need for sustainable materials represent major challenges for the construction and ceramics industries. At the same time, highly plastic clays such as those from Campos dos Goytacazes (RJ, Brazil) present limitations for additive manufacturing due to their low solid content. This study investigates the incorporation of recycled glass powder into kaolinitic clay for ceramic additive manufacturing using Direct Ink Writing (DIW). Clay-based mixtures containing 0%, 10%, 20%, and 30 wt% glass powder were used to produce perforated rectangular bricks, which were sintered at 800 °C, 900 °C, and 1000 °C. The results show that the addition of glass significantly improves densification and mechanical performance. The formulation containing 30 wt% glass sintered at 1000 °C exhibited the highest density (3.13 g/cm 3 ) and compressive strength (∼7.66 MPa). Glass addition also reduced porosity and water absorption due to enhanced liquid-phase sintering. Weibull statistical analysis further indicated improved mechanical reliability of the glass-containing samples. Overall, these findings demonstrate that recycled glass powder is a promising sustainable additive for improving the performance and reliability of clay-based ceramics produced by DIW.
H et al. (2026) studied this question.