The present invention discloses an optimized preparation method of a carbonization-based lightweight CO.sub.2 foamed cement-based material, and belongs to the field of geotechnical engineering materials. The preparation method includes: step S1: pre-screening existing common cement-based foaming agents and foam stabilizers; step S2: preparing a water-based carbon dioxide foam; step S3: preparing a cement slurry, and mixing the water-based carbon dioxide foam with the cement slurry to prepare a lightweight CO.sub.2 foamed cement-based material; step S4: selecting foaming agents of different types and different concentrations and foam stabilizers of different types and different concentrations to prepare slurries, subjecting the slurries to slurry performance tests, and selecting the optimal ones; step S5: optimizing initial water-to-cement ratio and foam-to-slurry ratio parameters; and step S6: optimizing a gas-filling volume parameter (water pump speed).

In general, the present invention is directed to the use of particular phosphorus containing compounds for making a gypsum board. The phosphorus containing compound may be a phosphite or a phosphate having a certain formula. In this regard, the present invention is directed to a slurry for making a gypsum board wherein the slurry includes such phosphorus containing compound. The present invention is also directed to a method of making a gypsum board from the slurry as well as a resulting gypsum board.

In general, the present invention is directed to the use of particular phosphorus containing compounds for making a gypsum board. The phosphorus containing compound may be a phosphite or a phosphate having a certain formula. In this regard, the present invention is directed to a slurry for making a gypsum board wherein the slurry includes such phosphorus containing compound. The present invention is also directed to a method of making a gypsum board from the slurry as well as a resulting gypsum board.

Gypsum panels and methods for their manufacture are provided herein. The gypsum panels include a gypsum core having a first surface and a second opposed surface and a first fiberglass mat associated with the first surface of the gypsum core, such that gypsum from the gypsum core penetrates at least a portion of the first fiberglass mat.

Gypsum panels and methods for their manufacture are provided herein. The gypsum panels include a gypsum core having a first surface and a second opposed surface and a first fiberglass mat associated with the first surface of the gypsum core, such that gypsum from the gypsum core penetrates at least a portion of the first fiberglass mat.

Disclosed herein is a liquid salt activator comprising a salt, a suspending aid, and water, wherein the salt is present in the liquid salt activator in an amount of from about 5 wt. % to about 95 wt. %, based on the total weight of the liquid salt activator. Also disclosed herein is an activated extended life slurry (ELS) composition comprising a hydraulic cement, a supplementary cementitious material, the liquid salt activator, and an aqueous fluid. The activated ELS composition can be used in a method of servicing a wellbore penetrating a subterranean formation.

A waterproofing system including a functional layer S1 including 10-80 wt.-% of at least one thermoplastic polymer P1 and 10-80 wt.-% of at least one solid particulate filler F, wherein the surface of the functional layer S1 has an Auto-correlation length of waviness W(Sal) of at least 50 μm. Further, a method for producing a waterproofing system and to the use of a mechanical surface treatment step to increase the waviness factor, determined as the ratio of the Root mean square roughness of waviness W(Sq) to the square of the Auto-correlation length of waviness W(Sal), of a surface of a functional layer S1.

A cement composition is disclosed that includes a cement slurry and an epoxy resin system that includes at least one epoxy resin and a curing agent. The cement slurry has a density in a range of from 65 pcf to 180 pcf and includes a cement precursor material, silica sand, silica flour, a weighting agent, and manganese tetraoxide. The epoxy resin system includes at least one of 2,3-epoxypropyl o-tolyl ether, alkyl glycidyl ethers having from 12 to 14 carbon atoms, bisphenol-A-epichlorohydrin epoxy resin, or a compound having formula (I): (OC.sub.2H.sub.3)—CH.sub.2—O—R.sup.1—O—CH.sub.2—(C.sub.2H.sub.3O) where R.sup.1 is a linear or branched hydrocarbyl having from 4 to 24 carbon atoms; and a curing agent.

A cement composition is disclosed that includes a cement slurry and an epoxy resin system that includes at least one epoxy resin and a curing agent. The cement slurry has a density in a range of from 65 pcf to 180 pcf and includes a cement precursor material, silica sand, silica flour, a weighting agent, and manganese tetraoxide. The epoxy resin system includes at least one of 2,3-epoxypropyl o-tolyl ether, alkyl glycidyl ethers having from 12 to 14 carbon atoms, bisphenol-A-epichlorohydrin epoxy resin, or a compound having formula (I): (OC.sub.2H.sub.3)—CH.sub.2—O—R.sup.1—O—CH.sub.2—(C.sub.2H.sub.3O) where R.sup.1 is a linear or branched hydrocarbyl having from 4 to 24 carbon atoms; and a curing agent.

A method of cementing a wellbore comprises combining a liquid additive with a cement slurry, the liquid additive comprising a metal gluconate, an alkali metal or an alkaline earth metal salt, an alkanolamine, a dispersant, and water to form a cementing composition; injecting the cementing composition into the wellbore; and allowing the cementing composition to set.