Effect of the Al content and the Ca/Si ratio on the structure and reactivity of calcium aluminosilicate glasses used as model SCMs

Since the reactivity of SCMs is affected by different specific properties, it is crucial to understand their impact. This study, therefore, focuses on how the Al content and Ca/Si ratio affect the structure and reactivity of calcium aluminosilicate glasses. The glasses were synthesized amorphous in 2 series with Al contents ranging from 5 to 40 wt% (Ca/Si mass ratio = 1:1) and Ca/Si ratios ranging from 0.21 to 1.00 (Al2O3 content = 15 wt%). Structural analysis by FTIR, 27Al and 29Si MAS NMR, and theoretical NBO/T calculations showed an increasing degree of polymerization with increasing Al content or decreasing Ca/Si ratio. The reactivity, examined by the R3 test and in cement pastes, was less affected by the degree of polymerization but more by the Al content. These findings provide insights into the dependence of structure and composition on the reactivity of model SCMs that may help in the search for new SCM sources in the future.     «

Since the reactivity of SCMs is affected by different specific properties, it is crucial to understand their impact. This study, therefore, focuses on how the Al content and Ca/Si ratio affect the structure and reactivity of calcium aluminosilicate glasses. The glasses were synthesized amorphous in 2 series with Al contents ranging from 5 to 40 wt% (Ca/Si mass ratio = 1:1) and Ca/Si ratios ranging from 0.21 to 1.00 (Al2O3 content = 15 wt%). Structural analysis by FTIR, 27Al and 29Si MAS NMR, and...     »