A method of designing a cement slurry may include: (a) selecting at least a cement and concentration thereof, a water and concentration thereof, and one or more chemical additives and a concentration thereof such that a cement slurry formed from the cement, water, and the one or more chemical additives meet a density requirement; (b) calculating a thickening time of the cement slurry using a thickening time model; (c) comparing the thickening time of the cement slurry to a thickening time requirement, wherein steps (a)-(c) are repeated if the thickening time of the cement slurry does not meet or exceed the thickening time requirement, wherein the step of selecting comprises selecting concentrations and/or different chemical identities for the one or more chemical additives, cement, or water, or step (d) is performed if the thickening time of the cement slurry meets or exceeds the thickening time requirement; and (d) preparing the cement slurry.

A cement grout material is provided, which does not freeze even in an environment where the ambient temperature can be −5° C. or below, and which does not require fuel or large-scaled equipment for maintaining curing temperature. Lithium nitrite is added to a cement grout material that contains cement, water and an admixture. By setting the weight ratio of the lithium nitrite to the cement to a value from 3 to 10% by weight, freezing of the grout material is able to be prevented even in an installation environment where the ambient temperature can be −5° C. during the initial stage of installation. By setting the weight ratio of the lithium nitrite to the cement to a value from 4.5 to 8% by weight, freezing of the grout material is able to be prevented even in an installation environment where the ambient temperature can be −10° C. during the initial stage of installation.

A cement grout material is provided, which does not freeze even in an environment where the ambient temperature can be −5° C. or below, and which does not require fuel or large-scaled equipment for maintaining curing temperature. Lithium nitrite is added to a cement grout material that contains cement, water and an admixture. By setting the weight ratio of the lithium nitrite to the cement to a value from 3 to 10% by weight, freezing of the grout material is able to be prevented even in an installation environment where the ambient temperature can be −5° C. during the initial stage of installation. By setting the weight ratio of the lithium nitrite to the cement to a value from 4.5 to 8% by weight, freezing of the grout material is able to be prevented even in an installation environment where the ambient temperature can be −10° C. during the initial stage of installation.

The present invention relates in part to an alkali-silica reaction mitigation admixture comprising an organic or inorganic salt that provides an aluminum, calcium, magnesium, or iron cation. The present invention also relates to a method of mitigating the alkali-silica reaction in a concrete product. The invention is further related to kits comprising the alkali-silica mitigation admixture and an instruction booklet.

The present invention relates in part to an alkali-silica reaction mitigation admixture comprising an organic or inorganic salt that provides an aluminum, calcium, magnesium, or iron cation. The present invention also relates to a method of mitigating the alkali-silica reaction in a concrete product. The invention is further related to kits comprising the alkali-silica mitigation admixture and an instruction booklet.

The present invention primarily relates to the use of a mixture capable of biocementation as a means of preventing or reducing plant growth, preferably weed growth. The invention also relates to a method for preventing or reducing plant growth, preferably weed growth, on/in a substrate.

The present invention primarily relates to the use of a mixture capable of biocementation as a means of preventing or reducing plant growth, preferably weed growth. The invention also relates to a method for preventing or reducing plant growth, preferably weed growth, on/in a substrate.

Methods, compositions, and tools for use in creating rapidly forming plugs in situ in subterranean formations. In one instance, the disclosure provides a method that includes: placing a first pill comprising a calcium-aluminate-based cement composition at a plug location within the wellbore with the tubing; and placing a second pill comprising an alkaline fluid composition into the wellbore adjacent to the first pill with the tubing. In some cases there is a spacer fluid or spacer device between the first pill and the second pill. In some cases tubing having a mixing device is located at the bottom of the tubing in the wellbore to aid I mixing the first pill and the second pill to facilitate a chemical in situ reaction of the first pill and the second pill. The reaction between the first pill and the second pill forms a set plug at the plug location.

Methods, compositions, and tools for use in creating rapidly forming plugs in situ in subterranean formations. In one instance, the disclosure provides a method that includes: placing a first pill comprising a calcium-aluminate-based cement composition at a plug location within the wellbore with the tubing; and placing a second pill comprising an alkaline fluid composition into the wellbore adjacent to the first pill with the tubing. In some cases there is a spacer fluid or spacer device between the first pill and the second pill. In some cases tubing having a mixing device is located at the bottom of the tubing in the wellbore to aid I mixing the first pill and the second pill to facilitate a chemical in situ reaction of the first pill and the second pill. The reaction between the first pill and the second pill forms a set plug at the plug location.

An accelerator powder for cement and also rapid-setting binder compositions which contain the accelerator powder and the use in mortar or concrete. The accelerator powder includes from 10 to 99.7% by weight of a water-insoluble mineral powder P and from 0.3 to 90% by weight of at least one compound V selected from the group consisting of alkali metal halides and alkaline earth metal halides, alkali metal nitrates and alkaline earth metal nitrates, alkali metal nitrites and alkaline earth metal nitrites, alkali metal thiocyanates and alkaline earth metal thiocyanates and hydroxyalkylamines or salts thereof, and mixtures thereof.