A process for the preparation of a wet concrete composition, including mixing Portland clinker in the form of grains having a Dv97 from 10 to 30 μm or having a Blaine specific surface greater than or equal to 5300 cm2/g; slag; calcium sulphate; complementary materials, having a Dv90 less than or equal to 200 μm; from 1500 to 2200 kg/m3 of aggregates; a plasticizer; optionally an accelerator and/or an air-entraining agent and/or a thickening agent and/or a retarder and/or a clay-inerting agent; with 140 to 220 l/m3 of effective water, the total quantity of clinker in the wet concrete being less than or equal to 200 kg/m3.