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 method for continuously forming gypsum-based panels of high fixing strength comprises the steps of: •forming a mixture comprising stucco, non-pregelatinized migratory starch, glass fibre, fluidizer and water; •casting the mixture in a continuous band; •maintaining the band under conditions sufficient for the stucco to form an interlocking matrix of set gypsum; •cutting the band to form one or more wet panel precursors; and •drying the wet panel precursor to form one or more gypsum-based panels. •The weight ratio of water to stucco in the mixture is less than 0.7; •the stucco is present in the mixture in an amount of over 60 wt % relative to the total solids content of the mixture; •the starch is present in the mixture in an amount of over 3 wt % relative to the stucco; •the glass fibre is present in the mixture in an amount of over 1 wt % relative to the stucco; •the fluidizer is present in the mixture in an amount of at least 0.1 wt % relative to the stucco; and the density of the gypsum-based panel is greater than 700 kg/m.

A method for continuously forming gypsum-based panels of high fixing strength comprises the steps of: •forming a mixture comprising stucco, non-pregelatinized migratory starch, glass fibre, fluidizer and water; •casting the mixture in a continuous band; •maintaining the band under conditions sufficient for the stucco to form an interlocking matrix of set gypsum; •cutting the band to form one or more wet panel precursors; and •drying the wet panel precursor to form one or more gypsum-based panels. •The weight ratio of water to stucco in the mixture is less than 0.7; •the stucco is present in the mixture in an amount of over 60 wt % relative to the total solids content of the mixture; •the starch is present in the mixture in an amount of over 3 wt % relative to the stucco; •the glass fibre is present in the mixture in an amount of over 1 wt % relative to the stucco; •the fluidizer is present in the mixture in an amount of at least 0.1 wt % relative to the stucco; and the density of the gypsum-based panel is greater than 700 kg/m.

A multi-component mortar system including a component A and a component B wherein, component A includes aluminous cement, at least one set inhibitor, at least one mineral filler and water, and component B includes an initiator system for the set-inhibited aluminous cement, at least one mineral filler and water. The multi-component mortar system is easy to use and suitable for repair and refurbishment and particularly for printing 3D structures.

A multi-component mortar system including a component A and a component B wherein, component A includes aluminous cement, at least one set inhibitor, at least one mineral filler and water, and component B includes an initiator system for the set-inhibited aluminous cement, at least one mineral filler and water. The multi-component mortar system is easy to use and suitable for repair and refurbishment and particularly for printing 3D structures.

Described herein are plugging materials with polysaccharides that can be used in wellbore operations. A plugging material can include hydraulic cement, amorphous silica, polysaccharides, a retarder, clay, and an aqueous base, where the material is injectable into a wellbore. The polysaccharides can be cross-linked with borate. The retarder can be at least one of an organo phosphoric acid, a modified sulfonated styrene-maleic anhydride polymer, lignosulfonate, or a polyacrylic acid.

Described herein are plugging materials with polysaccharides that can be used in wellbore operations. A plugging material can include hydraulic cement, amorphous silica, polysaccharides, a retarder, clay, and an aqueous base, where the material is injectable into a wellbore. The polysaccharides can be cross-linked with borate. The retarder can be at least one of an organo phosphoric acid, a modified sulfonated styrene-maleic anhydride polymer, lignosulfonate, or a polyacrylic acid.

A set control composition for cementitious systems comprises (a) an amine-glyoxylic acid condensate, and (b) at least one of (i) a borate source and (ii) a carbonate source. The carbonate source is selected from inorganic carbonates having an aqueous solubility of 0.1 gL.sup.−1 or more, and organic carbonates. The set control composition improves workability of cementitious systems for prolonged periods of time without compromising early compressive strength. Due to the retarding action of the set control composition, the dosage of dispersant(s) necessary to obtain a desired flowability of the cementitious system can be reduced.

A two-component mortar system, which includes a component A; and a component B, which is in aqueous-phase for initiating a curing process. Component A comprises water, aluminous cement, at least one plasticizer, and at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid, and a phosphoric acid. Component B includes an initiator, at least one retarder, at least one mineral filler, and water.

A two-component mortar system, which includes a component A; and a component B, which is in aqueous-phase for initiating a curing process. Component A comprises water, aluminous cement, at least one plasticizer, and at least one blocking agent selected from the group consisting of phosphoric acid, metaphosphoric acid, phosphorous acid, and a phosphoric acid. Component B includes an initiator, at least one retarder, at least one mineral filler, and water.