Abstract: A slag-based binder has at least one slag, optionally at least one CO3-containing mineral powder, optionally at least one co-binder different from the slag and mineral powder, at least one activator of the water/slag reaction, optionally at least one co-activator different from the one activator, at least one chelatant and/or at least one source of chelatant, said chelatant being preferably a scale inhibitor, and, optionally, at least one superplasticizer different from the chelatant. A kit is provided to make the binder. The binder is combined with an aggregate to make a dry concrete or mortar. A method for the preparation of a wet formulation (binder/water or concrete-mortar/water) is disclosed as is method of manufacturing buildings or civil engineering works or elements thereof, coatings, fillers, screeds, tiles, adhesives and/or internal or external insulation systems from the wet formulation. The binder is a substitute to OPC-based compositions and is environmentally friendly.