A fire-proof material, in particular a fire-proof thermal insulation material containing water glass, which is composed of a compound which contains 34 to 49.9 wt % of inorganic non-flammable fibres, 50 to 65 wt % of an aqueous silicate solution, and 0.1 to 1 wt % of water glass stabiliser, while it further contains a water glass hardener and the aqueous silicate solution has a density in the range of 1370 to 1400 kg/m.sup.3 and a molar ratio of SiO.sub.2 to Na.sub.2O in the range of 3.2 to 3.4.

Disclosed is a novel cement and aggregate compositions, to uses thereof for protecting surfaces, in particular surfaces likely to be affected by biocorrosion.

Disclosed is a novel cement and aggregate compositions, to uses thereof for protecting surfaces, in particular surfaces likely to be affected by biocorrosion.

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 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.

Class C fly ash-based cementitious materials, concretes, and related techniques are disclosed. In accordance with some embodiments, an activated class C fly ash-based cementitious material may be produced by intergrinding class C fly ash (e.g., classified to remove quartz and/or other contaminants and, thus, increase the reactive materials present), an activator, sodium citrate, borax, and a polycarboxylate material. The class C fly ash may have an amorphous glass content of about 60 wt % or more, a calcium oxide (CaO.sub.2) content of about 20 wt % or more, and a quartz content of about 10 wt % or less. The activator may be a chemical which reacts with class C fly ash to form strätlingite structures therein when introduced with water. In some cases, the cementitious material may be provided as an all-in-one powder blend. In some case, techniques disclosed herein may be utilized in providing a fast-setting flowable fill material.

Class C fly ash-based cementitious materials, concretes, and related techniques are disclosed. In accordance with some embodiments, an activated class C fly ash-based cementitious material may be produced by intergrinding class C fly ash (e.g., classified to remove quartz and/or other contaminants and, thus, increase the reactive materials present), an activator, sodium citrate, borax, and a polycarboxylate material. The class C fly ash may have an amorphous glass content of about 60 wt % or more, a calcium oxide (CaO.sub.2) content of about 20 wt % or more, and a quartz content of about 10 wt % or less. The activator may be a chemical which reacts with class C fly ash to form strätlingite structures therein when introduced with water. In some cases, the cementitious material may be provided as an all-in-one powder blend. In some case, techniques disclosed herein may be utilized in providing a fast-setting flowable fill material.

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.