Abstract:
Cements or hydraulic binders may be prepared by adding an aqueous suspension comprising a ground mineral filler and at least one grinding aid agent to a cement or hydraulic binder. The resulting cement or hydraulic binder has very appreciably improved mechanical properties, particularly the property of nullstrength at young ages.null The grinding aid agent may be a natural or synthetic homopolymer and/or copolymer.
Abstract:
Cements or hydraulic binders may be prepared by adding an aqueous suspension comprising a ground mineral filler and at least one grinding aid agent to a cement or hydraulic binder. The resulting cement or hydraulic binder has very appreciably improved mechanical properties, particularly the property of nullstrength at young ages.null The grinding aid agent may be a natural or synthetic homopolymer and/or copolymer.
Abstract:
A hydraulic binder includes a Portland clinker having a Blaine specific surface of 4000 to 5500 cm2/g, from 2.5 to 8% of sulphate expressed by mass of SO3 relative to the mass of clinker, from 1.5 to 10% of calcium nitrite and/or calcium nitrate expressed as anhydrous mass relative to the mass of clinker and from 15 to 50% of a mineral addition including calcium carbonate by mass relative to the total mass of binder.
Abstract:
The invention provides a cementitious composition comprising a cement component comprising (i) an accelerant, (ii) a calcium sulphate source and (iii) an ettringite forming cement; an aggregate; and optionally water; wherein the cement has a minimum unconfined compressive strength of 1500 psi when tested in accordance with ASTM C1140 and/or C1604 at 15 minutes after placement; methods for its use and concrete formed from it.
Abstract:
A method for improving early strength of cements, comprising introducing into a cement during the grinding thereof (a) at least one water reducer comprising a polyoxyalkylene polymer; (b) a sugar; (c) an alkali or alkaline earth metal chloride; and (d) an amine. Additives and cement compositions are also disclosed.
Abstract:
This invention relates to enhancing the compressive strength of cements after 1, 3, 7 and 28 days following hydration and to improving porosity and finished surfaces of the hardened cements and concretes made therefrom. The improved cements are prepared using certain hydroxylamine additives in amounts of up to 0.1% which preferably are added during grinding of the cement in which case the amines further act as grinding aids.
Abstract:
A composition is supplied for filling pot holes and other types of structural deterioration. The composition consist of hydraulic cement and an alkali metal silicate. The silicate includes a molar ratio of silican dioxide to alkali metal oxide from 0.4 to 4.0. The silicate is in a concentration ranging from 0.2 to 20 percent by weight of the cement. A method is also provided which comprises repairing a deteriorating structure by inserting therein a cementitious composition and controlling the rate of setting of the composition by the inclusion therein of sodium silicate in the molar ratio of silicon dioxide to sodium oxide of from 0.4 to 4.0.
Abstract:
A rapid setting cementitious composition useful for making cement boards employs an insoluble form of anhydrous calcium sulfate (anhydrite) to accelerate setting and to permit reducing the amount of high alumina cement usage.
Abstract:
The present invention provides the early strengthening agent for hydraulic compositions containing a compound (a) obtained by reacting (A) one or more compounds selected from polyhydric alcohols having 3 to 20 hydroxy groups and alkylene oxide adducts thereof with (B) a sulfating agent, and the additive composition for hydraulic compositions containing the compound (a).
Abstract:
The present invention relates to ahydraulic binder comprising a Portland clinker having a Blaine specific surface of 4000 to 5500 cm²/g, from 2.5 to 8 % of sulphate expressed by mass of SO 3 relative to the mass of clinker, from 1.5 to 10 % of calcium nitrite and/or calcium nitrate expressed as anhydrous mass relative to the mass of clinker and from 15 to 50 % of a mineral addition comprising calcium carbonate by mass relative to the total mass of binder.