Patent ID: 8603238

Claim:
A dry binder premix comprising, in mass proportions: Portland clinker having a Blaine specific surface area comprised from 4500 to 9500 cm 2 /g, a minimum quantity of said clinker by mass percentage relative to the total mass of the premix being determined according to the following formula (I): [−6.10 −3 ×BSS k ]+75 Formula (I) in which BSS k is the Blaine specific surface area of the clinker given in cm 2 /g; fly ash, the quantity of clinker+the quantity of fly ash being greater than or equal to 75%, by mass percentage relative to the total mass of the premix; at least one alkali sulphate, the quantity of alkali sulphate being such that the quantity of equivalent Na 2 O in the premix is greater than or equal to 5% by mass percentage relative to the mass of fly ash; at least one source of SO 3 , in a quantity such that the quantity of SO 3 in the premix is greater than or equal to 2% by mass percentage relative to the mass of Portland clinker; complementary materials having a Dv90 less than or equal to 200 μm selected from the group consisting of limestone powders, calcined shale, metakaolins, siliceous fillers, silica powders, pozzolans, slags, fly ash and mixtures thereof; the total quantity of clinker in the premix being less than 60% by mass percentage relative to the total mass of the premix.