A method of making a cement composite can include contacting an aqueous solution comprising calcium ions with a carbon dioxide source producing a carbonated aqueous solution. Fine particles can be submerged in the carbonated aqueous solution to produce microaggregate particles comprising the fine particles coated with calcium carbonate. The microaggregate particles can be combined with cement particles to produce the cement composite. The cement composite can be used in cementing applications for hydrocarbon wells including for casing liners and well plugs.

A method of making a cement composite can include contacting an aqueous solution comprising calcium ions with a carbon dioxide source producing a carbonated aqueous solution. Fine particles can be submerged in the carbonated aqueous solution to produce microaggregate particles comprising the fine particles coated with calcium carbonate. The microaggregate particles can be combined with cement particles to produce the cement composite. The cement composite can be used in cementing applications for hydrocarbon wells including for casing liners and well plugs.

A method for processing material that contains cement rock may involve comminuting the material in a first comminuting device, feeding the material to a reactor in which the material is mixed with an aqueous liquid and CO.sub.2 and in which a mixing movement of the material is generated, and removing the material from the reactor and subdividing the material into at least two fractions by way of a classifying device. The temperature and the pressure in the reactor are maintained such that the pressure exceeds atmospheric pressure and such that the temperature is greater than 100° C. The method may further involve removing a withdrawal stream of the aqueous liquid from the reactor and separating and discharging suspended particles of the material from the withdrawal stream.

A method for processing material that contains cement rock may involve comminuting the material in a first comminuting device, feeding the material to a reactor in which the material is mixed with an aqueous liquid and CO.sub.2 and in which a mixing movement of the material is generated, and removing the material from the reactor and subdividing the material into at least two fractions by way of a classifying device. The temperature and the pressure in the reactor are maintained such that the pressure exceeds atmospheric pressure and such that the temperature is greater than 100° C. The method may further involve removing a withdrawal stream of the aqueous liquid from the reactor and separating and discharging suspended particles of the material from the withdrawal stream.

An aqueous dispersion of graphene oxide is prepared in an additive process by subjecting graphitic carbon, such as biochar, in water or an aqueous solution to a high-shear environment in the presence of a dispersing agent to exfoliate graphene oxide. An intercalating agent may be added to facilitate exfoliation, and optionally neutralized. The graphitic carbon may be pre-processed by wet milling prior to exfoliation. The aqueous dispersion of graphene oxide may be used as a concrete admixture in a concrete composition.

An aqueous dispersion of graphene oxide is prepared in an additive process by subjecting graphitic carbon, such as biochar, in water or an aqueous solution to a high-shear environment in the presence of a dispersing agent to exfoliate graphene oxide. An intercalating agent may be added to facilitate exfoliation, and optionally neutralized. The graphitic carbon may be pre-processed by wet milling prior to exfoliation. The aqueous dispersion of graphene oxide may be used as a concrete admixture in a concrete 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.

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.

Bentonite-based grout fluids and methods of using the grout fluids are provided. A method of using a grout fluid includes placing a geothermal conduit in at least one hole in the earth, providing a grout fluid consisting essentially of water and a bentonite-based grout, wherein the bentonite-based grout consists essentially of calcium carbonate, a bentonite, one or more grout-setting modifiers, and one or more thermally conductive materials, introducing the grout fluid into a space between the geothermal conduit and sidewalls of the at least one hole so that the grout fluid is in contact with the geothermal conduit, and after introducing the grout fluid, allowing the grout fluid to set to fix the geothermal conduit to the at least one hole, wherein after setting, the grout fluid has a hydraulic conductivity of between about 1×10.sup.−7 cm/s and about 1×10.sup.−9 cm/s.

The present application relates to a mixture comprising at least one compound A selected from glyoxylic acid, salts thereof, and condensation or addition products of glyoxylic acid or salts thereof; and at least one polyhydroxy compound B. Furthermore, the present application relates to a construction material composition comprising said mixture, and to the use of said mixture for modifying the hardening of inorganic binder containing building material formulations, and/or for producing building products.