Briefing: Low-alkali cements as inhibitors of alkali–silica reaction

In this study, a compositional parameter, such as the maximum allowable total alkali content of cement (Matac) is proposed to identify the non-CEM I cements for their use as inhibitors of alkali–silica reaction in concrete. The Matac values for different types of Italian non-CEM I cements (cement type CEM III and CEM IV) were calculated using the authors' previously published experimental results. The Matac value is found to change significantly with the type of cement considered (blast furnace cement, pozzolanic cement made from coal fly ash or natural pozzolana). For cements of the same type (pozzolanic cements made with different natural pozzolanas), very similar Matac values are obtained. It is also demonstrated that the Matac value calculated for a CEM I cement is congruent with the limit of 0·6% as Na₂O_eq commonly specified for the total alkali content of low-alkali Portland cements.