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, preferably during the grinding thereof, (a) at least one water reducer comprising a polyoxyalkylene polymer; (b) a sugar; and (c) an alkali or alkaline earth metal chloride. In further exemplary embodiments, the polyoxyalkylene polymer preferably comprises a comb polymer having a backbone and pendant groups. Optionally, an amine may be included with the additives. Exemplary additives and cements and cementitious compositions, preferably blended cements, and more most preferably pozzolanic cements, comprising the additives are also disclosed.
Abstract:
To an unhardened concrete containing at least a cement, an aggregate and water, an alkali silicate is added in a weight ratio of from 0.2% to 5.0%, preferably from 0.2% to 2.0%, with respect to the cement on a solid content basis. The concrete containing the alkali silicate is placed into formwork as a temporary structure that confines the concrete to a predetermined shape and predetermined dimensions and supports the concrete until it attains suitable strength, thereby constructing a concrete structure. The amount of formwork materials used is reduced, and the operating efficiency and the physical properties of the concrete are improved.
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:
A method for improving early strength of cements comprising introducing into a cement, preferably during the grinding thereof, (a) at least one water reducer comprising a polyoxyalkylene polymer; (b) a sugar; and (c) an alkali or alkaline earth metal chloride. In further exemplary embodiments, the polyoxyalkylene polymer preferably comprises a comb polymer having a backbone and pendant groups. Optionally, an amine may be included with the additives. Exemplary additives and cements and cementitious compositions, preferably blended cements, and more most preferably pozzolanic cements, comprising the additives are also disclosed.
Abstract:
A method for improving early strength of cements comprising introducing into a cement, preferably during the grinding thereof, (a) at least one water reducer comprising a polyoxyalkylene polymer; (b) a sugar; and (c) an alkali or alkaline earth metal chloride. In further exemplary embodiments, the polyoxyalkylene polymer preferably comprises a comb polymer having a backbone and pendant groups. Optionally, an amine may be included with the additives. Exemplary additives and cements and cementitious compositions, preferably blended cements, and more most preferably pozzolanic cements, comprising the additives are also disclosed.
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:
The present invention relates to a hydraulic binder comprising: 25 to 60 % by mass of Portland clinker; 5 to 15 % by mass of a first mineral addition selected from: o mineral additions reacting with at least 400 mg/g of CaO according to the method at 90°C described in the NF P 18-513 Standard of December 30, 201 1, in Appendix A, and o latent hydraulic materials; a second mineral addition reacting with less than 400 mg/g of CaO according to the method described herein above; and either a third mineral addition with a base of calcium carbonate or calcium sulphate, or both; the hydraulic binder comprising at least 1 % by mass of reactive aluminium, which is to say that contributes to the development of strengths.