A method may include comprising: defining engineering parameters of a proposed cement slurry, the engineering parameters comprising at least a compressive strength requirement, a density requirement, a storage time requirement, and a thickening time requirement; selecting, based at least in part on a model of compressive strength, a model of storage time, and the density requirement, at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a set cement formed from the cement, the at least one supplementary cementitious material, and the water meets or exceeds the compressive strength requirement and the density requirement; selecting, based at least in part on a model of thickening time, an accelerator and mass fraction thereof; and preparing a cement slurry comprising the cement and mass fraction thereof, the at least one supplementary cementitious material and mass fraction thereof, the water and mass fraction thereof, and the cement retarder and mass fraction thereof.

A method may include comprising: defining engineering parameters of a proposed cement slurry, the engineering parameters comprising at least a compressive strength requirement, a density requirement, a storage time requirement, and a thickening time requirement; selecting, based at least in part on a model of compressive strength, a model of storage time, and the density requirement, at least a cement and mass fraction thereof, at least one supplementary cementitious material and mass fraction thereof, and a water and mass fraction thereof, such that a set cement formed from the cement, the at least one supplementary cementitious material, and the water meets or exceeds the compressive strength requirement and the density requirement; selecting, based at least in part on a model of thickening time, an accelerator and mass fraction thereof; and preparing a cement slurry comprising the cement and mass fraction thereof, the at least one supplementary cementitious material and mass fraction thereof, the water and mass fraction thereof, and the cement retarder and mass fraction thereof.

A method of cementing may include: measuring a feeding rate of water and a feeding rate of cement blend into a cement blender; calculating a cement retarder feeding rate and/or an accelerator feeding rate using a thickening time model, wherein the thickening time model uses at least a thickening time requirement, the feeding rate of water, and the feeding rate of cement blend, to calculate the cement retarder feeding rate and/or the accelerator feeding rate; introducing a cement retarder at the cement retarder feeding rate and/or an accelerator at the accelerator feeding rate into the cement blender; mixing at least the water, cement blend, and at least one of the cement retarder and/or the accelerator in the cement blender to provide a cement slurry; and placing the cement slurry in a wellbore.

This invention is test equipment for determining a concrete's compressive strength class and characteristic equivalent cube compressive strength value while the concrete is in its fresh concrete period.

Disclosed is a composite gypsum board comprising a set gypsum core disposed between face (e.g., Manila) and back (e.g., Newsline) cover sheets. The set gypsum core is formed from a core slurry comprising stucco, water, and optional additives, such as foaming agent, migrating starch, accelerator, retarder, dispersant, etc. A dense layer formed from a dense layer slurry comprising stucco, water, fiber (e.g., paper fiber), and optionally, strength-enhancing starch, is disposed between the core and the face paper. The dense layer slurry contains a greater concentration of fiber, and optionally, strength-enhancing starch, than the core slurry, but the concentration of one or more other additives (e.g., accelerator, retarder, dispersant, or combinations thereof) is lower or the same in the dense slurry as compared with the core slurry. Also disclosed is a method of making board using one board mixer. In embodiments, paper fiber is added to water to form a suspension. The suspension is introduced, while in a non-laminar state, into the dense slurry. Further disclosed is apparatus, such as an extractor and an additive injection system, which can be a part of a cementitious slurry mixing and dispensing assembly.

A concrete and asphalt repair coating formulation includes a cement component and an aggregate component. The cement component includes a calcium sulfoaluminate cement and a Portland cement. The aggregate component includes coarse aggregates between 125-500 microns in diameter and fine aggregates between 5-62.5 microns in diameter.

The present invention allows for better control over strength in concrete mixes and mix designs, while minimizing the over-use of cement and promoting sustainability within the industry. Disclosed are novel method and system which employ a diagnostic delta data (DDD) curve, or, in other words, data that displays a curvilinear relationship when plotted on a visual graph, as obtained by considering the differences (e.g., subtractive differences or ratios) as between (i) target slump and target (or maximum) water content, and (ii) slump and water content values as determined using an automated slump monitoring system which measures slump and water content in the concrete mix during delivery. This DDD curve can then be compared to monitored delta slump and delta water content for later or other deliveries, such that adjustments can be made to the concrete mix or mix design, in a manner that encourages avoidance of cement over-dosing or over-prescription.

A method of designing a cement composition may include: minimizing an objective function subject to a plurality of constraints to produce a cement composition including at least one cement component and water; and preparing the cement composition.

A method of designing a cement composition may include: minimizing an objective function subject to a plurality of constraints to produce a cement composition including at least one cement component and water; and preparing the cement composition.

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.