Study of a binder based on alkaline activated limestone

Binders based on the alkaline activation of raw materials is a subject of increasing importance for construction. This study focuses on a new non-hydraulic binder based on the alkali-activation of limestone by an aqueous solution of sodium hydroxide. An optimized mortar of about 20 MPa compressive strength, made with siliceous sand, was studied by XRD, FTIR and SEM-EDX analyses showing that crystalline pirssonite and portlandite are the reaction products responsible of the cohesive capacity of the binder. A methodology based on thermal gravimetric analysis was applied to quantify the products formed and the consumption of reagents with high reliability.