Disclosed is a gypsum board comprising a set gypsum core disposed between two cover sheets. The set gypsum core is formed from a slurry comprising stucco, water, and at least one pregelatinized starch having a viscosity of from about 20 cP to about 300 cP as measured according to the VMA method described herein. The starch is present in an amount of greater than 10% by weight of the stucco. In preferred embodiments, the board has good strength properties even at lower densities, such as about 31 pcf or less. Also disclosed are a related method of making a gypsum wallboard and a slurry.

A method of cementing may include preparing a cement composition comprising: cementitious components comprising: a cement; a supplementary cementitious material; and nanoparticulate boehmite; and water; and introducing the cement composition into a subterranean formation.

A method of cementing may include preparing a cement composition comprising: cementitious components comprising: a cement; a supplementary cementitious material; and nanoparticulate boehmite; and water; and introducing the cement composition into a subterranean formation.

An activating composition, in particular for concrete or industrial mortars containing hydraulic binder and/or pozzolanic material, comprises at least 40% by weight, preferably at least 50% by weight of calcium carbonate and/or magnesium carbonate particles having a d80 less than or equal to 15 .Math.m, and a d50 less than or equal to 4 .Math.m, and at least 1.5% by weight and up to 60% by weight of at least one alkaline metal salt. A binder composition is also provided, the binder composition comprising the activating composition and a component C comprising at least one hydraulic binder. The binder composition and at least one aggregate are combined to form a dry concrete or industrial mortar composition. Also provided is a process for preparing wet concrete or mortar compositions and hardened concrete or industrial mortar compositions obtained therefrom.

The invention concerns a method for fluidifying wet concrete or industrial mortar compositions comprising: (a) at least one hydraulic binder, (b) at least one water reducing polymer, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials, the method comprising a step of adding at least one salt (ch) including at least one chaotropic ion to the concrete or industrial mortar composition.

The invention concerns a method for fluidifying wet concrete or industrial mortar compositions comprising: (a) at least one hydraulic binder, (b) at least one water reducing polymer, (c) at least one accelerator in the form of a salt containing at least one kosmotropic ion, (d) water, and (e) possibly one or more supplementary cementitious materials, and (f) possibly one or more filler materials, the method comprising a step of adding at least one salt (ch) including at least one chaotropic ion to the concrete or industrial mortar composition.

A method for the continuous production of a mineral foam of which the density in the dry state (d) is from 40 to 600 kg/m.sup.3, includes (i) mixing cement; a water reducing agent; 0.5 to 10%, % by weight with respect to the total weight of cement, of ultrafine particles having a liquid-solid contact angle comprised from 30° to 140°, and of which the D50 is from 10 to 600 nm; water, with a water/cement weight ratio from 0.3 to 2.5; (ii) adding to the mixture from 0.5 to 10% of a pore-forming agent, % by weight with respect to the weight of cement; (iii) applying the mixture obtained at step (ii) on a support; (iv) leaving the mixture to expand on the support.

A method for the continuous production of a mineral foam of which the density in the dry state (d) is from 40 to 600 kg/m.sup.3, includes (i) mixing cement; a water reducing agent; 0.5 to 10%, % by weight with respect to the total weight of cement, of ultrafine particles having a liquid-solid contact angle comprised from 30° to 140°, and of which the D50 is from 10 to 600 nm; water, with a water/cement weight ratio from 0.3 to 2.5; (ii) adding to the mixture from 0.5 to 10% of a pore-forming agent, % by weight with respect to the weight of cement; (iii) applying the mixture obtained at step (ii) on a support; (iv) leaving the mixture to expand on the support.

A geopolymer composite binder is provided herein, the composite binder including (i) at least one fly ash material having less than or equal to 15 wt % of calcium oxide; (ii) at least one gelation enhancer; and (iii) at least one hardening enhancer having a different composition from a composition of the at least one fly ash material.

A geopolymer composite binder is provided herein, the composite binder including (i) at least one fly ash material having less than or equal to 15 wt % of calcium oxide; (ii) at least one gelation enhancer; and (iii) at least one hardening enhancer having a different composition from a composition of the at least one fly ash material.