The underlying role of sodium tripolyphosphate on the cementitious mechanism of calcium carbonate binder

Calcium carbonate binder is well-known to reduce the carbon footprint and brings great economic environmental benefits. However, cementitious mechanism unclear due raw material diversity. We prepare calcium crystalline polymorphs-vaterite calcite in presence of sodium tripolyphosphate (STPP), revealed. Herein, optimal colloidal structure with vaterite as binding phase obtained at 5% STPP 1d compressive strength reaches 16.99 MPa. The property can be attributed crystallization transformation amorphous (ACC) electrostatic attraction particles. In process, effect on polymorph selection determined contents. At low contents (＜5%), more effective inhibiting nucleation growth than vaterite. high (＞5%), entirely inhibited while formation takes place surface bulk ACC through coupling dissolution-recrystallization solid-state growth. These results shed light function during biomineralization help for preparing low-carbon binder.