Disclosed are a mixed shrinkage reducing agent for concrete and a preparation method thereof. The mixed shrinkage reducing agent for concrete includes the following components in parts by weight: 35-45 of alkali modified diatomite, 15-22 of magnesium oxide, 13-20 of vermiculite, 8-11 of borax, 3-9 of sodium hexametaphosphate, and 7-13 of citric acid modified starch. The mixed shrinkage reducing agent for concrete according to the present application is used as an admixture to be mixed into cement for preparing concrete.

Disclosed are a mixed shrinkage reducing agent for concrete and a preparation method thereof. The mixed shrinkage reducing agent for concrete includes the following components in parts by weight: 35-45 of alkali modified diatomite, 15-22 of magnesium oxide, 13-20 of vermiculite, 8-11 of borax, 3-9 of sodium hexametaphosphate, and 7-13 of citric acid modified starch. The mixed shrinkage reducing agent for concrete according to the present application is used as an admixture to be mixed into cement for preparing concrete.

The invention relates to processes for making improved ultra-high performance concrete with plasma-treated inclusions and articles made from the same. The invention includes a process for producing silicon carbide and multiwalled carbon nanotubes by heating agricultural waste husks in an inert atmosphere to a temperature higher than 1300 degrees C. to obtain a mixture containing silicon carbide and MWCNTs, and treating the mixture to extract the silicon carbide and MWCNTs for use as microinclusions in ultra high performance concrete.

The invention relates to processes for making improved ultra-high performance concrete with plasma-treated inclusions and articles made from the same. The invention includes a process for producing silicon carbide and multiwalled carbon nanotubes by heating agricultural waste husks in an inert atmosphere to a temperature higher than 1300 degrees C. to obtain a mixture containing silicon carbide and MWCNTs, and treating the mixture to extract the silicon carbide and MWCNTs for use as microinclusions in ultra high performance concrete.

A fiber cement material formulation comprising a cementitious binder, a siliceous material, fiber, alumina trihydrate and a bifunctional low density additive wherein the bifunctional low density additive comprises any one or more of diatomaceous earth, recycled autoclave fiber cement dust or cellulose dust. The fiber cement material formulation optionally further comprises a secondary low density additive which may be perlite. In some embodiments, a fiber cement article manufactured from the fiber cement material formulation comprises a density of approximately 1.1 g/cm.sup.3 or below.

A fiber cement material formulation comprising a cementitious binder, a siliceous material, fiber, alumina trihydrate and a bifunctional low density additive wherein the bifunctional low density additive comprises any one or more of diatomaceous earth, recycled autoclave fiber cement dust or cellulose dust. The fiber cement material formulation optionally further comprises a secondary low density additive which may be perlite. In some embodiments, a fiber cement article manufactured from the fiber cement material formulation comprises a density of approximately 1.1 g/cm.sup.3 or below.

A fiber cement material formulation comprising a cementitious binder, a siliceous material, fiber, alumina trihydrate and a bifunctional low density additive wherein the bifunctional low density additive comprises any one or more of diatomaceous earth, recycled autoclave fiber cement dust or cellulose dust. The fiber cement material formulation optionally further comprises a secondary low density additive which may be perlite. In some embodiments, a fiber cement article manufactured from the fiber cement material formulation comprises a density of approximately 1.1 g/cm.sup.3 or below.

A 3D printable clay-based mortar cementitious ink includes a blend of commercially available Type I/II Portland cement, and a fine and coarse silica sand. The ratio of Portland cement to fine sand or fine clay, may be approximately 1.02. The ratio of water-to-binder (Portland cement and SCM) may be approximately 0.55, and the ratio of water-to-powder (binder plus fine clay smaller than 75 microns) can be approximately 0.416. Included with the water and binder/powder mix is an admixture. According to one embodiment, the admixture can include a water reducing admixture, or plasticizer. The fine clay within the aggregate material is unprocessed, and the binder material is approximately 84 to 90 percent cement and 10 to 16 percent SCM. The unprocessed clay, or fine sand, does not undergo any heating, any chemical modification or sifting before being added to the aggregate material.

A 3D printable clay-based mortar cementitious ink includes a blend of commercially available Type I/II Portland cement, and a fine and coarse silica sand. The ratio of Portland cement to fine sand or fine clay, may be approximately 1.02. The ratio of water-to-binder (Portland cement and SCM) may be approximately 0.55, and the ratio of water-to-powder (binder plus fine clay smaller than 75 microns) can be approximately 0.416. Included with the water and binder/powder mix is an admixture. According to one embodiment, the admixture can include a water reducing admixture, or plasticizer. The fine clay within the aggregate material is unprocessed, and the binder material is approximately 84 to 90 percent cement and 10 to 16 percent SCM. The unprocessed clay, or fine sand, does not undergo any heating, any chemical modification or sifting before being added to the aggregate material.

Cement compositions and associated methods for cementing. An example method includes introducing a cement composition into a wellbore penetrating a subterranean formation, the cement composition comprising a composite material, a cement, and an aqueous fluid. The composite material comprises a monophase amorphous hydraulic binder material and a particulate core. The monophase amorphous hydraulic binder material coats the particulate core. The method further comprises allowing the cement composition to set in the wellbore.