Isomorphic substitution and the hydration behavior of alinite cement

Zn and/or Fe substituted alinite cement was synthesized using reagent grade chemicals, and its formation and hydration behavior were investigated. Mg, which is known to be essential for alinite formation, was completely replaced by Zn. XRD, FT-IR, and ²⁹Si MAS NMR results indicated that a Zn substituted alinite was a nearly single phase and was easy to grind compared to Mg-alinite. In addition, partially or fully Zn substituted alinite had superior hydration characteristics, and NMR results showed that most of the alinite was hydrated after 100 days. Fe substitution of Al was not effective for alinite formation and its hydration properties were similar to Mg-alinite. Cl⁻ ions leached out during alinite hydration, but the exsolution of Zn and Fe was below the detection limit.