An accelerated carbonatation method including the following steps: a) providing recycled concrete granulates with a grain size smaller than or equal to a value V.sub.1 being between 1 mm and 6 mm, in other words a 0/V.sub.1 sand; b) performing on the 0/V.sub.1 sand a separation step by defining a granulometric cut of a determined value V.sub.2 being between 0.1 mm and 0.2 mm so as to obtain: a 1st fraction whose grain size is less than V.sub.2, and a 2nd fraction whose grain size is between V.sub.2 and V.sub.1; 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.

A method of preparing a concrete composition for downhole injection includes utilizing a controller to control a process including circulating process water in a process water supply loop for a predetermined period while monitoring and controlling the temperature and flow rate of the process water, circulating aqueous-based air entrainment solution in an aqueous-based air entrainment solution supply loop for the predetermined period and controlling the flow rate of the aqueous-based air entrainment solution and after the predetermined period of time in which the flow of process water and aqueous-based air entrainment solution have stabilized, simultaneously actuating valves to divert and mix the process water, the aqueous-based air entrainment solution and compressed air to produce an air-entrained foam and mixing the foam with a concrete composition to be deployed downhole.

A method of preparing a concrete composition for downhole injection includes utilizing a controller to control a process including circulating process water in a process water supply loop for a predetermined period while monitoring and controlling the temperature and flow rate of the process water, circulating aqueous-based air entrainment solution in an aqueous-based air entrainment solution supply loop for the predetermined period and controlling the flow rate of the aqueous-based air entrainment solution and after the predetermined period of time in which the flow of process water and aqueous-based air entrainment solution have stabilized, simultaneously actuating valves to divert and mix the process water, the aqueous-based air entrainment solution and compressed air to produce an air-entrained foam and mixing the foam with a concrete composition to be deployed downhole.

A method of preparing a concrete composition for downhole injection includes utilizing a controller to control a process including circulating process water in a process water supply loop for a predetermined period while monitoring and controlling the temperature and flow rate of the process water, circulating aqueous-based air entrainment solution in an aqueous-based air entrainment solution supply loop for the predetermined period and controlling the flow rate of the aqueous-based air entrainment solution and after the predetermined period of time in which the flow of process water and aqueous-based air entrainment solution have stabilized, simultaneously actuating valves to divert and mix the process water, the aqueous-based air entrainment solution and compressed air to produce an air-entrained foam and mixing the foam with a concrete composition to be deployed downhole.

A method for manufacturing hydraulically hardening building materials, includes the steps of: providing concrete demolition waste with a maximum particle size of up to 150 mm as a starting material, mixing the starting material with water to form a feedstock slurry, introducing carbon dioxide or a precursor thereof into the feedstock slurry to form carbonated concrete fines in an amount from 1 to 100 wt.-% of the hardened binder contained in the starting material and to detach the concrete fines from the aggregate contained in the starting material to form a product slurry, and mixing the product slurry with a cement forming the building material,
and use of the obtainable building material for manufacturing building structures as well as method for manufacturing a supplementary cementitious material slurry.

Provided herein are methods and compositions for carbonation of recycled concrete aggregates (RCA) to produce carbonated RCA. In addition, uses of the carbonated RCA, such as in building materials, and building materials containing RCA, are included. Carbonation of RCA may be used alone or may be used in combination with other carbonation processes associated with concrete manufacture, such as carbonation of wet concrete mixes and/or carbonation of concrete wash water.

Apparatus, systems, and methods for preparing foam cement compositions in a laboratory are disclosed. The apparatus includes a blender body, a base connector, an inlet port, a test port, an outlet port, a blender blade apparatus, and a blender cap. Systems to prepare foam cement compositions in a laboratory, include the apparatus, a first tubing assembly threaded to the inlet port configured to receive a pressurized gas and provide the pressurized gas to the apparatus, a second tubing assembly threaded to the test port, and a motorized base. Methods for preparing a foam cement composition using the apparatus for preparing foam cement compositions in a laboratory include adding a cement composition to the apparatus, fitting a blender cap on the apparatus, mixing the cement composition, and providing a pressurized gas and surfactant to the cement composition to produce a foam cement composition.

Provided herein are methods and compositions for carbonation of recycled concrete aggregates (RCA) to produce carbonated RCA. In addition, uses of the carbonated RCA, such as in building materials, and building materials containing RCA, are included. Carbonation of RCA may be used alone or may be used in combination with other carbonation processes associated with concrete manufacture, such as carbonation of wet concrete mixes and/or carbonation of concrete wash water.

An apparatus (100) for the production of a plaster slurry is described, the apparatus (100) comprising a mixer (102) for mixing at least plaster and water to form a plaster slurry, the mixer (102) comprising an outlet conduit (122), a foam generator (106) for mixing at least air, a foaming agent and water to produce a foam, the foam generator (106) in fluid communication with the mixer (102) via a fluid pathway (116) comprising a foam conduit (117); and a mass flow meter (124), wherein the mass flow meter (124) is configured to measure the density and mass flow rate of the foam within the foam conduit (117) or the plaster slurry within the outlet conduit (122). Additionally, a method of manufacturing a plaster slurry is described.

According to the present invention, there is provided an apparatus (100) for manufacturing a cementitious slurry comprising foam, the apparatus (100) comprising a mixing chamber (101) for mixing a cementitious material and water to form a cementitious slurry, a channel (103) fluidly connected to the mixing chamber (101) at a first end (111), the channel (103) for receiving a cementitious slurry from the mixing chamber (101). In the apparatus, the channel (103) extends from the first end (111) and terminates at at least one second end (112). The channel (103) comprises a first foam inlet (106) for introducing foam into the channel (103), wherein the apparatus (100) is configured, in use, to introduce foam through the first foam inlet (106) at a velocity 5.4 times or less the velocity of the cementitious slurry in the channel (103). A method using the apparatus is also described.