Rapid-hardening admixture and method for producing same

Patent metadata

Field	Value
Publication number	US-10829416-B2
Application number	US-201716088354-A
Country	US
Kind code	B2
Filing date	Mar 31, 2017
Priority date	Mar 31, 2016
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

The present invention provides a rapid-hardening admixture for accelerating hardening of a cement composition and a method for producing the same. The rapid-hardening admixture includes calcium aluminate, inorganic sulfate, and a setting modifier, in which the calcium aluminate has an average particle diameter in a range of 8 μm to 100 μm, and the setting modifier has an average particle diameter of 5 μm or less.

First claim

What is claimed is:

1. A rapid-hardening admixture, comprising:
calcium aluminate;
inorganic sulfate; and
a setting modifier,
wherein the calcium aluminate has an average particle diameter in a range of 8 μm to 100 μm, and the setting modifier has an average particle diameter of 5 μm or less,
the inorganic sulfate is anhydrous gypsum, and
the setting modifier comprises at least one selected from the group consisting of inorganic carbonate, oxycarboxylic acid, sodium aluminate, and sodium sulfate.

2. The rapid-hardening admixture according to claim 1 ,
wherein the calcium aluminate has one or more compositions selected from the group consisting of 12CaO·7Al 2 O 3, 11CaO·7Al 2 O 3 ·CaF 2 , and CaO·Al 2 O 3 , and
the calcium aluminate has a vitrification rate of 80% or more.

3. The rapid-hardening admixture according to claim 1 ,
wherein the inorganic sulfate has a Blaine specific surface area of 8,000 cm 2 /g or more.

4. The rapid-hardening admixture according to claim 1 ,
wherein, with respect to 100 parts by mass of the calcium aluminate, the inorganic sulfate is contained in a range of 50 parts by mass to 200 parts by mass, and the setting modifier is contained in a range of 0.1 parts by mass to 10 parts by mass.

5. A method for producing a rapid-hardening admixture, the method comprising:
mixing and crushing a clinker comprising calcium aluminate and a setting modifier to obtain a mixed and crushed product; and
mixing the mixed and crushed product with inorganic sulfate,
wherein
the inorganic sulfate is anhydrous gypsum, and
the setting modifier comprises at least one selected from the group consisting of inorganic carbonate, oxycarboxylic acid, sodium aluminate, and sodium sulfate.

6. The method according to claim 5 ,
wherein the clinker before the mixing and crushing has an average particle diameter in a range of 1 mm to 30 mm,
the setting modifier before the mixing and crushing has a particle diameter in a range of 150 μm to 500 μm, and
the mixing and crushing is carried out until a Blaine specific surface area of the mixed and crushed product falls within a range of 3,000 cm 2 /g to 5,500 cm 2 /g.

Assignees

• Mitsubishi Materials Corp

Inventors

• Kamitani Kiyoshi
• Tokunaga Kenji
• Tawara Hideo

Classifications

• C04B22/10

  containing carbon in the anion, e.g. carbonates · CPC title

• C04B28/06 Primary

  Aluminous cements (monolithic refractories or refractory mortars C04B35/66) · CPC title

• C04B40/0028

  Aspects relating to the mixing step of the mortar preparation · CPC title

• C04B2103/14

  Hardening accelerators · CPC title

• C04B28/065 Primary

  Calcium aluminosulfate cements, e.g. cements hydrating into ettringite · CPC title