Abstract:
Using crystalline silica, mixed with cement powder, to reduce the heating of the cement paste caused by the hydration of said powder, during a process of packaging of radioactive waste, a formulation for the packaging of radioactive waste by cementing, which comprises such silica, a method for packaging radioactive waste implementing this formulation, and a package for packaging of radioactive waste which is obtained by this method.
Abstract:
A method of cementing in a subterranean formation comprises: introducing a cement composition into a wellbore penetrating the subterranean formation, wherein at least a portion of the subterranean formation has a temperature less than or equal to the freezing point of an aqueous liquid, and wherein the cement composition comprises: (A) cement; (B) water; and (C) a pozzolan, wherein the cement composition has a heat of hydration of less than 50 BTU per pound; and causing or allowing the cement composition to set in the wellbore after the step of introducing. The pozzolan can have a calcium oxide concentration of less than 15% by weight of the pozzolan, and the pozzolan can have a concentration of at least 15% by weight of the cement. Gas hydrates can be present in or adjacent to a portion of the well.
Abstract:
A cement admixture and a cement composition having a carbonation suppressing effect and a heat-of-hydration suppressing effect are provided. A cement admixture containing one or more non-hydraulic compounds selected from the group consisting of γ-2CaO.SiO2, α-CaO.SiO2 and calcium magnesium silicate, a cement composition containing said admixture, and a carbonation suppressing method by use of said cement admixture or cement composition. According to the present invention, a remarkable carbonation suppressing effect can be obtained particularly when used in portland blast-furnace slag cement. This leads to an effective use of steelmaking slag and the like, and the load of clinker can be reduced, so that a cement composition of a low environmental load type can be attained. Further, this is suitable for cements in conformity with the EN standards, which are used in civil engineering and building industries.
Abstract:
A burned product containing 100 parts by weight of C2S, 10 to 100 parts by weight of C2AS, and 20 parts by weight or less of C3A; a cement admixture prepared by grinding the burned product; and a cement containing 100 parts by weight of ground portland cement clinker and 5 to 100 parts by weight of a ground product of the burned product.
Abstract translation:含有100重量份C 2 S的燃烧产物,10-100重量份C 2 AS和20重量份或更少的C 2 O 3, 3 A> 通过研磨烧制品制备的水泥外加剂; 和含有100重量份的地硅酸盐水泥熟料和5至100重量份的烧制产品的研磨产物的水泥。
Abstract:
A cement admixture of a low environmental load type, capable of reducing hexavalent chromium, having a small slump loss or heat of hydration, hardly neutralized and capable of suppressing autogenous shrinkage to a low level; a cement composition; and cement concrete employing it, are presented. The cement admixture comprises a slowly cooled slag powder which contains melilite as the main component and which has a carbon dioxide absorption of at least 2%, has a CO2 absorption of at least 2%, has a loss on ignition of at most 5%, contains at least 0.5% of sulfur present as non-sulfuric acid form sulfur and/or has a concentration of non-sulfuric acid form sulfur to elute, of at least 100 mg/l, and further, preferably, has a degree of vitrification of at most 30%, a melilite lattice constant a of from 7.73 to 7.82 and/or a Blaine specific surface area of at least 4,000 cm2/g.
Abstract:
Disclosed are a multifunctional cement hydration heat control material and a manufacturing method therefor. The cement hydration heat control material in is a comb polymer having three side chain structures, the three side chain structures are respectively a carboxyl group, a sugar alcohol group, and a polyether structure, and the main chain of the polymer is a carbon chain structure formed by free-radical polymerization of a double bond in a double bond compound monomer. The multifunctional cement hydration heat control material can achieve integration of cement hydration heat control performance, water reduction performance, and shrinkage reduction performance in a same molecule, can achieve control focusing on a performance by means of structural adjustment, does not need multi-component compounding during use, and is more convenient. The control material is non-toxic and water-soluble, can be made to have an appropriate concentration, and is convenient to use.
Abstract:
A method of cementing in a subterranean formation comprises: introducing a cement composition into a wellbore penetrating the subterranean formation, wherein at least a portion of the subterranean formation has a temperature less than or equal to the freezing point of an aqueous liquid, and wherein the cement composition comprises: (A) cement; (B) water; and (C) a pozzolan, wherein the cement composition has a heat of hydration of less than 50 BTU per pound; and causing or allowing the cement composition to set in the wellbore after the step of introducing. The pozzolan can have a calcium oxide concentration of less than 15% by weight of the pozzolan, and the pozzolan can have a concentration of at least 15% by weight of the cement. Gas hydrates can be present in or adjacent to a portion of the well.
Abstract:
A cement admixture and a cement composition having a carbonation suppressing effect and a heat-of-hydration suppressing effect are provided. A cement admixture containing one or more non-hydraulic compounds selected from the group consisting of γ-2CaO.SiO2, α-CaO.SiO2 and calcium magnesium silicate, a cement composition containing said admixture, and a carbonation suppressing method by use of said cement admixture or cement composition. According to the present invention, a remarkable carbonation suppressing effect can be obtained particularly when used in portland blast-furnace slag cement. This leads to an effective use of steelmaking slag and the like, and the load of clinker can be reduced, so that a cement composition of a low environmental load type can be attained. Further, this is suitable for cements in conformity with the EN standards, which are used in civil engineering and building industries.
Abstract:
A cement admixture and a cement composition having a carbonation suppressing effect and a heat-of-hydration suppressing effect are provided. A cement admixture containing one or more non-hydraulic compounds selected from the group consisting of null-2CaO.SiO2, null-CaO.SiO2 and calcium magnesium silicate, a cement composition containing said admixture, and a carbonation suppressing method by use of said cement admixture or cement composition. According to the present invention, a remarkable carbonation suppressing effect can be obtained particularly when used in portland blast-furnace slag cement. This leads to an effective use of steelmaking slag and the like, and the load of clinker can be reduced, so that a cement composition of a low environmental load type can be attained. Further, this is suitable for cements in conformity with the EN standards, which are used in civil engineering and building industries.
Abstract:
A method for manufacturing an aerated autoclaved concrete material. A quick-stiffening mixture is prepared by combining a silica containing material, quicklime, a rising agent, gypsum, cement and water. The mixture is deposited into a mold and is allowed to form a stiffened body. The stiffened body is removed from the mold and placed in an autoclave station in which it is steam cured at elevated temperature and pressure. The quicklime which is used to form the quick-stiffening mixture is modified with a chemical modifier to provide a desired degree of chemical reactivity in the quick-stiffening mixture.