A method for the production of a cavity filled with a low-density mineral foam includes (i) preparing a cement slurry including Portland cement; ultrafine particles of which the D50 is from 10 to 600 nm; a water reducing agent; a manganese salt; and water; wherein the mass ratio of manganese salts/Portland cement is below 0.014; (ii) adding to the cement slurry obtained after (i) a gas-forming liquid including a gas-forming agent; and a viscosity-modifying agent which is a polymer chosen among anionic bio-based polymer, amphiphilic bio-based polymer, alkali swellable acrylic polymer and mixture thereof; to obtain a foaming slurry; (iii) filling the cavity with the foaming slurry obtained at (ii); (iv) leaving the foaming slurry to expand within the cavity.

A cementitious mixture for a 3D printer, with improved performance, is described, and its relative use, more specifically for the production of finished products having a complex geometry using a 3D printing apparatus.

A cementitious mixture for a 3D printer, with improved performance, is described, and its relative use, more specifically for the production of finished products having a complex geometry using a 3D printing apparatus.

Water-based paint is used as a sacrificial agent to reduce the detrimental effect of carbon-containing fly ash on the entrainment of air in concrete. The invention provides a composition for reducing the effect of carbon contained in fly ash on air entrainment in cementitious mixtures comprising water, cement, fly ash and entrained air. The composition comprises water-based paint and one or more of pulverized or un-pulverized pozzolan, pulverized or un-pulverized cementitious solids, a superplasticizer, a defoamer, an air-entraining admixture, a water-reducing admixture, a retarding admixture, an accelerating admixture, a hydration control admixture and a rheology modifying admixture. The invention also provides a method of reducing the effect of carbon on air entrainment in carbon-containing fly ash, comprising mixing the fly ash with water-based paint.

Water-based paint is used as a sacrificial agent to reduce the detrimental effect of carbon-containing fly ash on the entrainment of air in concrete. The invention provides a composition for reducing the effect of carbon contained in fly ash on air entrainment in cementitious mixtures comprising water, cement, fly ash and entrained air. The composition comprises water-based paint and one or more of pulverized or un-pulverized pozzolan, pulverized or un-pulverized cementitious solids, a superplasticizer, a defoamer, an air-entraining admixture, a water-reducing admixture, a retarding admixture, an accelerating admixture, a hydration control admixture and a rheology modifying admixture. The invention also provides a method of reducing the effect of carbon on air entrainment in carbon-containing fly ash, comprising mixing the fly ash with water-based paint.

A rheology modifying agent that develops a rheology modifying effect over a wide temperature region is provided. A rheology modifying agent comprising two or more types of compounds represented by the following general formula (1):

##STR00001##

wherein X is a group represented by R.sup.1a or R.sup.1b—[CONH—CH.sub.2CH.sub.2CH.sub.2].sub.n—; R.sup.1a is an alkyl group with 14 or more and 22 or less carbons or an alkenyl group with 14 or more and 22 or less carbons; R.sup.1b is an alkyl group with 13 or more and 21 or less carbons or an alkenyl group with 13 or more and 21 or less carbons; n is an integer of 1 or more and 3 or less; each of R.sup.2 and R.sup.3 is independently an alkyl group with 1 or more and 4 or less carbons or a group represented by —(C.sub.2H.sub.4O).sub.pH; and p is an average number of added moles and a total for R.sup.2 and R.sup.3 is a number of 0 or more and 5 or less,

wherein the two or more types of compounds differ in X in the general formula (1) and

at least one of the two or more types of compounds is a compound in which R.sup.1 of X in the general formula (1) is an alkenyl group.

A cementitious composition with accelerated curing at low temperatures particularly at temperatures <5° C., especially at temperatures <0° C. The cementitious composition consists of 2 components with a first component A including at least one ordinary Portland cement, at least one cement selected from calcium aluminate cement and/or calcium sulfoaluminate cement, a powder P, selected from the group consisting of carbonates or hydrogen carbonates of alkali and/or alkaline earth metals, optionally aggregates, optionally other additives and a second component B comprising at least one accelerator, an anti-freeze agent, water, and optionally other additives. The composition shows increased development of compressive strength, maintain good workability, and have particularly low shrinkage, also when cured at temperatures <5° C., especially <0° C., and as low as −10° C.

A cementitious composition with accelerated curing at low temperatures particularly at temperatures <5° C., especially at temperatures <0° C. The cementitious composition consists of 2 components with a first component A including at least one ordinary Portland cement, at least one cement selected from calcium aluminate cement and/or calcium sulfoaluminate cement, a powder P, selected from the group consisting of carbonates or hydrogen carbonates of alkali and/or alkaline earth metals, optionally aggregates, optionally other additives and a second component B comprising at least one accelerator, an anti-freeze agent, water, and optionally other additives. The composition shows increased development of compressive strength, maintain good workability, and have particularly low shrinkage, also when cured at temperatures <5° C., especially <0° C., and as low as −10° C.

The object of the present invention is a novel admixture comprising a hardening accelerator for hydraulic compositions based on Portland cement and other supplementary cementitious materials.

PCE-type copolymers in powder form can be obtained by spry-drying and are easily re-dispersed in water. The fineness and the anti-caking properties of said PCE-type copolymers in powder form, as well as their water reduction potential and influence on slump life are improved. A production process of said PCE-type copolymers in powder form is by a spray-drying method, and PCE-type copolymers can be used for the improvement of mineral binder compositions and especially dry mortars.