An ultrastable cementitious material with nano-molecular veneer makes a cementitious material by blending 29 wt % to 40 wt % of a magnesium oxide dry powder containing 80 wt % to 98 wt % of magnesium oxide based on a final total weight of the cementitious material, with 14 wt % to 18 wt % of a magnesium chloride dissolved in water and reacting to form a liquid suspension, mixing from 2 to 10 minutes, adding a phosphorus-containing material, and allowing the liquid suspension to react into an amorphous phase cementitious material, wherein a portion of the amorphous phase cementitious material grows a plurality of crystals. The plurality of crystals are encapsulated by the amorphous phase cementitious material forming a nano-molecular veneer. A process to make the ultrastable cementitious material. A tile backer board incorporating the ultrastable cementitious material and a process for making the tile backer board.

An additive for a cement slurry for a well that is capable of suppressing the generation of free water and preventing flotation/separation of low-specific-gravity aggregate while securing sufficient cement strength even at a high temperature and a method for producing this additive are disclosed. The additive contains an aqueous dispersion of silica and a layered silicate.

An additive for a cement slurry for a well that is capable of suppressing the generation of free water and preventing flotation/separation of low-specific-gravity aggregate while securing sufficient cement strength even at a high temperature and a method for producing this additive are disclosed. The additive contains an aqueous dispersion of silica and a layered silicate.

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.

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.

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.

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.

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.

An oil well cement composite permeation enhancement agent suitable for a hydrate layer and a preparation method thereof are disclosed. In parts by weight, the composition of raw materials of the composite permeation enhancement agent is 4.6 parts-5.0 parts of kerosene, 0.23 parts-0.25 parts of emulsifier, 0.8 parts-1.1 parts of modified polypropylene fiber, 10.0 parts-12.0 parts of porous and permeable microspheres, 1.0 part-1.2 parts of paraffin, and 57.5 parts-62.5 parts of water. The composite permeation enhancement agent can effectively improve the permeability of the cement stone which reshapes the formation framework and increase the mining rate of hydrate. The oil well cement composite permeation enhancement agent has the advantages of long-term performance, low cost, and green environmental protection. The composite permeation enhancement agent of the present invention does not need secondary treatment to increase permeation, the operation is convenient and fast, and the working time of holding pressure is reduced.

In the present disclosure, a cement board is disclosed. The cement board comprises a cement core having a first surface and a second surface opposite the first surface. The cement core comprises a binder, a lightweight aggregate, and a combustible additive, wherein the combustible additive is present in an amount of greater than 0 wt. % to less than 0.5 wt. % based on the weight of the cement core. The cement board passes CAN/ULC-S114:2018 and/or ASTM E136-19a.