V and Cr substitution in dicalcium silicate under oxidizing and reducing conditions - Synthesis, reactivity, and leaching behavior studies.

Dicalcium silicate (CS) is known to incorporate potentially hazardous metals (Cr and V) in a belite-rich cementitious system. The effect of the electrovalence nature of V and Cr on CS polymorphs' (α´, β, γ) stability under oxidizing and reducing conditions as well as their reactivity are systematically investigated via analyzing oxidation states, phase composition, bonding system, and microstructure as well as oxide composition quantitively. It is shown that CS can incorporate Cr (VI) and V(V) consequently leading to stabilization of α´, β-CS.