Abstract: A method for preparing concrete or mortar using a fraction whose particle size d10 is greater than or equal to 150 ?m, the fraction having a loss on ignition varying from 3% to 30% and including: from 20% to 80% SiO2; from 5% to 40% CaO; from 1% to 15% Al2O3; and from 0.5% to 4% Fe2O3.

Abstract: An accelerated carbonatation method including the following steps: a) providing recycled concrete granulates with a grain size smaller than or equal to a value V1 being between 1 mm and 6 mm, in other words a 0/V1 sand; b) performing on the 0/V1 sand a separation step by defining a granulometric cut of a determined value V2 being between 0.1 mm and 0.2 mm so as to obtain: a 1st fraction whose grain size is less than V2, and a 2nd fraction whose grain size is between V2 and V1; c) subjecting the 2nd fraction to an accelerated carbonatation step in a dynamic carbonator so as to obtain carbonated recycled concrete granulates. Also, a method for valorizing concrete wastes and industrial gaseous discharges implementing the accelerated carbonatation method, in particular the gaseous discharges of a cement plant.