Aggregates useful in building materials such as concrete are described. The aggregates may include fly ash and an inorganic polymer binder, which may be present as an outer layer on a core of fly ash. Methods of preparing the aggregates and concrete mixtures comprising the aggregates are also described. For example, the aggregates may be prepared by contacting fly ash agglomerates with an alkaline solution. The concrete mixtures may comprise the aggregates and a hydraulic cement.

Aggregates useful in building materials such as concrete are described. The aggregates may include fly ash and an inorganic polymer binder, which may be present as an outer layer on a core of fly ash. Methods of preparing the aggregates and concrete mixtures comprising the aggregates are also described. For example, the aggregates may be prepared by contacting fly ash agglomerates with an alkaline solution. The concrete mixtures may comprise the aggregates and a hydraulic cement.

A method for the use of a clay including: less than 30% of kaolinite; and at least 20% of muscovite and/or illite; from 1% to 20% of smectite; the muscovite and/or illite/kaolinite weight ratio being greater than 1; for the preparation of a geopolymer precursor.

In the present disclosure, a cement board is disclosed. The cement board comprises a core having a first surface and a second surface opposite the first surface and a binder including a pozzolan material and a water-resistant additive, wherein the water-resistant additive is present in an amount of less than 5 wt. % based on the weight of the pozzolan material.

A downhole tool comprising a cylindrical housing, a sleeve disposed in the cylindrical housing, forming an annular space between the sleeve and the cylindrical housing, and a tool cement composition disposed in the annular space, wherein prior to setting the tool cement composition comprises a cement, sand, a silicon-containing material, a dispersant, and water, and wherein upon setting the tool cement composition provides an annular seal having a fluid leakage of less than 750 ml over 15 minutes at a pressure of 7500 psi and a temperature of 400° F.

A downhole tool comprising a cylindrical housing, a sleeve disposed in the cylindrical housing, forming an annular space between the sleeve and the cylindrical housing, and a tool cement composition disposed in the annular space, wherein prior to setting the tool cement composition comprises a cement, sand, a silicon-containing material, a dispersant, and water, and wherein upon setting the tool cement composition provides an annular seal having a fluid leakage of less than 750 ml over 15 minutes at a pressure of 7500 psi and a temperature of 400° F.

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

A downhole tool comprising a cylindrical housing, a sleeve disposed in the cylindrical housing, forming an annular space between the sleeve and the cylindrical housing, and a tool cement composition disposed in the annular space, wherein prior to setting the tool cement composition comprises a cement, sand, a silicon-containing material, a dispersant, and water, and wherein upon setting the tool cement composition provides an annular seal having a fluid leakage of less than 750 ml over 15 minutes at a pressure of 7500 psi and a temperature of 400° F.

A downhole tool comprising a cylindrical housing, a sleeve disposed in the cylindrical housing, forming an annular space between the sleeve and the cylindrical housing, and a tool cement composition disposed in the annular space, wherein prior to setting the tool cement composition comprises a cement, sand, a silicon-containing material, a dispersant, and water, and wherein upon setting the tool cement composition provides an annular seal having a fluid leakage of less than 750 ml over 15 minutes at a pressure of 7500 psi and a temperature of 400° F.

A novel engineered concrete binder composition providing overall reduced clinker factor and improved binding properties. The said concrete binder composition includes a primary binder in a ratio of 10-60 weight percent and a secondary binder in a ratio of 40-90 weight percent. The said primary binder is selected from a primary material group having spontaneous hydration property. The said secondary binder is selected from a secondary material group having induced hydration property.