The invention relates to a retarding mixture comprising sodium gluconate and alkali hydrogen carbonate, an alkali-activated binding agent containing sodium gluconate and alkali hydrogen carbonate and a method for adjusting the strength development, wherein sodium gluconate and alkali hydrogen carbonate are added to an alkali-activated binding agent.

The invention relates to an anti-filming surface adjuvant for hydraulic binders comprising at least one fat and at least one anti-caking agent, to its preparation method as well as to a method for preparing a hydraulic binder composition suitable for making screeds or self-compacting concretes (SCC) including the step consisting of adding to the hydraulic binder the adjuvant according to the invention at a dosage comprised between 50 and 1,500 g/m.sup.3 of screed or of concrete.

A cement product including a supplementary cementitious material (SCM) including natural aluminosilicate, and optionally metakaolin, and methods of producing the cement product, and methods of use thereof are provided. The natural aluminosilicate may have, for example, a d97 less than or equal to about 19 m; and may have a d10 less than or equal to about 2 m. The product may also have improved chloride permeability as compared to cement products including natural aluminosilicates having higher d97 and d10 values. Also, the product may also have improved compressive strength and RCPT values when a portion of the natural aluminosilicate in the SCM is replaced with metakaolin.

Fresh concrete is treated with carbon dioxide prior to delivery to a product mold for forming concrete products. Carbon dioxide gas is directed through a manifold, which may be coupled to a feedbox or a hopper, upstream from the product mold. Treating the fresh concrete with the carbon dioxide gas while it is in a loose state prior to placement in the product mold may generally promote uniform and enhanced carbon dioxide uptake.

It has been unexpectedly discovered that the addition of a natural or other 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. 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 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. 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 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.

It has been unexpectedly discovered that the addition of a natural or other 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. 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 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. 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 cement product including a supplementary cementitious material (SCM) including natural aluminosilicate, and optionally metakaolin, and methods of producing the cement product, and methods of use thereof are provided. The natural aluminosilicate may have, for example, a d97 less than or equal to about 19 m; and may have a d10 less than or equal to about 2 m. The product may also have improved chloride permeability as compared to cement products including natural aluminosilicates having higher d97 and d10 values. Also, the product may also have improved compressive strength and RCPT values when a portion of the natural aluminosilicate in the SCM is replaced with metakaolin.

The present invention relates to coloured fiber cement products as well as to methods for manufacturing such products. In particular, the present invention provides coloured fiber cement products, which fiber cement products are coloured in the mass, and at least comprise on at least part of their outer surface one or more cured layers of a coating composition, which composition at least comprises a binder and a pigment and/or a filler and is characterized by a pigment volume concentration (PVC) of between about 1% and about 20%. The present invention further provides processes for producing these coloured fiber cement products. Finally, the present invention provides uses of the coloured fiber cement products as building materials. In particular embodiments, the fiber cement products produced by the processes of the present invention can be used to provide an outer surface to walls, both internal as well as external, a building or construction, e.g. as fagade plate, siding, etc.

It has been unexpectedly discovered that the addition of a natural or other 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. 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 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. 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.