Influence of Soda‐Lime Glass Powder on Magnesium Potassium Phosphate Cements

ABSTRACT This study investigated the effects of recycled waste soda‐lime glass powder on magnesium potassium phosphate (MKP) cements with Mg/PO 4 molar ratios of 4 and 8. Glass powder accelerated early hydration and modified K‐struvite crystallization. At Mg/PO 4 = 8, glass powder induced finer K‐struvite crystals than at Mg/PO 4 = 4, resulting in a more porous microstructure and lower air‐cured strength. After 90 days of water immersion, glass powder promoted K‐struvite crystallization and brucite formation. Consequently, water resistance decreased at Mg/PO 4 = 4, likely due to excessive K‐struvite formation within the initially dense matrix, whereas it improved at Mg/PO 4 = 8, possibly owing to gradual microstructural densification. Thermodynamic modeling predicted the formation of secondary phases (hazenite, M‐S‐H, and hydroxyapatite). Experimentally, these phases were observed in suspensions but not in pastes due to limited water availability. The use of glass powder as a mineral admixture in MKP cements requires optimized mix design to balance air‐cured strength and water resistance.