Influence of different particle sizes on reactivity of finely ground glass as supplementary cementitious material (SCM)

Finely ground glass can be pozzolanically reactive and serve as a supplementary cementitious material (SCM). In this study, the pozzolanic reactivity of three narrow size ranges of green glass cullet, 63–75 μm, 25–38 μm, and 0–25 μm was investigated in order to understand the effects of particle size on glassy SCM reactivity. Isothermal calorimetry, chemical shrinkage, thermogravimetric analysis, and leaching tests were used to measure cement and glass dissolution and reactions. Images taken by scanning electronic microscope (SEM) in backscattered (BS) mode were analyzed to measure glass degree of hydration. In addition, mortar compressive strength and water absorption of samples containing glass powder at different curing temperatures and ages were used to relate reaction degree to performance. Results showed that hydration degree of the glass particles could be directly accounted for through linear correlation with particles surface area.