A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement:SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement: SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement: SF:NP in the cementitious blend composition lies in the range of (24-63):(5-44):(32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water to the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

It has been unexpectedly discovered that the addition of a non-spec natural pozzolan to non-spec fly ash significantly improves the properties of the non-spec fly ash to the extent it can be certified under ASTM C618 and AASHTO 295, as either a Class F or Class C fly ash. Other pozzolans may also be used for this beneficiation process. Many pozzolans are experimentally tested and may be used to beneficiate non-spec fly ash into certifiable Class F fly ash. Additionally, this disclosure provides a method of converting a Class C fly ash to a more valuable Class F fly ash, by utilizing natural pozzolans. This discovery will extend diminishing Class F fly ash supplies and turn non-spec fly ash waste streams into valuable, certified fly ash pozzolan which will protect and enhance concrete, mortars and grouts.

It has been unexpectedly discovered that the addition of a non-spec natural pozzolan to non-spec fly ash significantly improves the properties of the non-spec fly ash to the extent it can be certified under ASTM C618 and AASHTO 295, as either a Class F or Class C fly ash. Other pozzolans may also be used for this beneficiation process. Many pozzolans are experimentally tested and may be used to beneficiate non-spec fly ash into certifiable Class F fly ash. Additionally, this disclosure provides a method of converting a Class C fly ash to a more valuable Class F fly ash, by utilizing natural pozzolans. This discovery will extend diminishing Class F fly ash supplies and turn non-spec fly ash waste streams into valuable, certified fly ash pozzolan which will protect and enhance concrete, mortars and grouts.

A method of cementing a subterranean formation includes forming a cement composition comprising cementitious material, an aqueous base fluid, a nano-reinforcement particle suspension comprising a surfactant; nano-reinforcement particle such as single-wall carbon nanotubes or multi-wall carbon nanotubes; and pozzolanic material; introducing the cement composition into a subterranean formation; and allowing the cement composition to set in the subterranean formation. A method of making a cement composition includes combining cementitious material, an aqueous base fluid, a nano-reinforcement particle suspension comprising a surfactant, nano-reinforcement articles such as single-wall carbon nanotubes or multi-wall carbon nanotubes, and a pozzolanic material, where the rate of hydration of the surfaces of the cementitious material is less retarded by the surfactant than an equivalent cement composition without pozzolanic material.

A method of cementing a subterranean formation includes forming a cement composition comprising cementitious material, an aqueous base fluid, a nano-reinforcement particle suspension comprising a surfactant; nano-reinforcement particle such as single-wall carbon nanotubes or multi-wall carbon nanotubes; and pozzolanic material; introducing the cement composition into a subterranean formation; and allowing the cement composition to set in the subterranean formation. A method of making a cement composition includes combining cementitious material, an aqueous base fluid, a nano-reinforcement particle suspension comprising a surfactant, nano-reinforcement articles such as single-wall carbon nanotubes or multi-wall carbon nanotubes, and a pozzolanic material, where the rate of hydration of the surfaces of the cementitious material is less retarded by the surfactant than an equivalent cement composition without pozzolanic material.

A variety of systems, methods and compositions are disclosed for cementing in subterranean formations. Embodiments may include the use of slag co-grind in well cementing operations.

A variety of systems, methods and compositions are disclosed for cementing in subterranean formations. Embodiments may include the use of slag co-grind in well cementing operations.