Concrete containing aqueous slurry of ground calcium carbonate

• US 6,402,831 B1
• Filed: 04/27/2000
• Issued: 06/11/2002
• Est. Priority Date: 10/30/1998
• Status: Expired due to Fees

• Current Assignee: Fimatec Ltd.
• Original Assignee: Fimatec Ltd.
• Inventors: Katayama, Seiji, Yamauchi, Tadashi, Morishita, Hidetoshi, Takase, Yumiko, Sawara, Haruya
• Primary Examiner(s): Wood, Elizabeth D.
• Application Number:
  US09/560,022
• Time in Patent Office: 775 Days
• Field of Search: 106/400, 106/464, 106/738, 106/770, 106/816, 106/817
• US Class Current: 106/738
• CPC Class Codes: C04B 14/28 of calcium
• CPC Class Codes: C04B 18/146 Silica fume
• CPC Class Codes: C04B 20/0084 Conditioning, e.g. preparing suspensions thereof C04B18/148 takes precedence
• CPC Class Codes: C04B 20/026 Comminuting, e.g. by grinding or breaking; Defibrillating fibres other than asbestos
• CPC Class Codes: C04B 2103/408 Dispersants
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: Y02P 40/10 Production of cement, e.g. improving or optimising the production methods; Cement grinding
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete

Abstract

Concrete characterized by containing aqueous slurry of ground calcium carbonate which has a mean particle diameter of 0.5-3 micrometers produced by wet pulverization of the limestone. By adding fine powder of ground calcium carbonate, fluidity of the concrete is increased and workability thereof is improved.

Claims

1. A method of preparing concrete having improved fluidity, the method comprises mixing cement with an aqueous slurry of limestone particles having a mean particle diameter of 0.5-3 micrometers and produced by wet pulverization of the limestone, wherein the ratio of water to the limestone in the aqueous slurry is 0.25 to 1.0 by weight and an amount of the limestone in the concrete is 5-150 kg/m³ of the concrete.

2. The method of claim 1, which further comprises mixing silica fume with the cement and aqueous slurry, wherein the silica fume comprises silica particles having a mean particle diameter of 0.1-0.3 micrometers in a weight ratio of 0.1-9 to the limestone.

3. The method of claim 1, wherein the aqueous slurry further comprises a dispersant for the limestone particles.

4. The method of claim 1, which further comprises mixing aggregate with the cement and aqueous slurry.

5. The method of claim 1, wherein the amount of limestone is 10-100 kg/m³.

6. The method of any one of claim 1, to 5, wherein the content of the limestone particles having a particle size of 2 micrometers or less in the aqueous slurry is 60% or more based on the total weight of the limestone.