What is shown and described is a concrete element including a core concrete layer and a face concrete layer, the face concrete layer being obtained by compacting and hardening a mixture containing a latent hydraulic binder and/or a pozzolanic binder, water, a granular material and an alkaline hardener, with the granular material having, at a screen hole width of 2 mm, a through fraction from 35.5 wt. % to 99.5 wt. % and, at a screen hole width of 0.25 mm, a through fraction from 2.5 wt. % to 33.5 wt. %, each based on the total weight of the granular material.

The invention provides a carbon dioxide-resistant hydraulic cement composition. The inventive composition comprises a Portland cement, Class C fly ash and water. The Class C fly ash is present in the composition in an amount in the range of from about 5% to less than about 30% by weight based on the total weight of the cementitious components in the composition. In another aspect, the invention provides a method of cementing in a carbon dioxide environment. In yet another aspect, the invention provides a method of enhancing the recovery of a hydrocarbon fluid from a subterranean formation.

The invention provides a carbon dioxide-resistant hydraulic cement composition. The inventive composition comprises a Portland cement, Class C fly ash and water. The Class C fly ash is present in the composition in an amount in the range of from about 5% to less than about 30% by weight based on the total weight of the cementitious components in the composition. In another aspect, the invention provides a method of cementing in a carbon dioxide environment. In yet another aspect, the invention provides a method of enhancing the recovery of a hydrocarbon fluid from a subterranean formation.

A voltage source includes two electrically conductive terminals (101, 102) with an electrolyte (103) between them. Said electrolyte (103) is a mixture in which the main component is ash produced in a power plant or an incineration plant.

A voltage source includes two electrically conductive terminals (101, 102) with an electrolyte (103) between them. Said electrolyte (103) is a mixture in which the main component is ash produced in a power plant or an incineration plant.

A hydraulic binder includes at least 70% by weight of a solid mineral compound consisting of at least one mixture of silica, alumina and alkaline-earth metal oxides, the total sum of CaO and MgO representing at least 10% by weight of the solid mineral compound, and an activation system of which at least 30% by weight is a phosphoric acid-derived salt. Construction products can obtained from a mortar composition including such a binder.

A hydraulic binder includes at least 70% by weight of a solid mineral compound consisting of at least one mixture of silica, alumina and alkaline-earth metal oxides, the total sum of CaO and MgO representing at least 10% by weight of the solid mineral compound, and an activation system of which at least 30% by weight is a phosphoric acid-derived salt. Construction products can obtained from a mortar composition including such a binder.

A method of pumping a fluid and reactive solid into a mineral formation includes the fluid reacting with the mineral formation to produce a nucleation product. The method may be used in shale formations to seal fissures and prevent leakage. The fluid used in this method may comprise CO.sub.2 and the nucleation products may be the products of carbonation reactions. A cement formed by reacting CO.sub.2 with a reactive solid under deep geological formation conditions is also disclosed.

A method of cementing may include preparing a cement composition comprising: cementitious components comprising: a cement; a supplementary cementitious material; and nanoparticulate boehmite; and water; and introducing the cement composition into a subterranean formation.

A method of cementing may include preparing a cement composition comprising: cementitious components comprising: a cement; a supplementary cementitious material; and nanoparticulate boehmite; and water; and introducing the cement composition into a subterranean formation.