Processed mineral additive for reducing concrete permeability and increasing strength

• US 20140020602A1
• Filed: 09/20/2013
• Published: 01/23/2014
• Est. Priority Date: 01/24/2012
• Status: Active Grant

• Current Assignee: CenterStar, Inc.
• Original Assignee: CenterStar, Inc.
• Inventors: Anderson, Terry L., Berke, Neal S.
• Granted Patent: US 8,758,503 B2
• Time in Patent Office: Days
• US Class Current: 106/409
• CPC Class Codes: C04B 14/02 Granular materials , e.g. microballoons
• CPC Class Codes: C04B 14/06 Quartz; Sand
• CPC Class Codes: C04B 14/185 expanded
• CPC Class Codes: C04B 16/00 Use of organic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of organic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
• CPC Class Codes: C04B 2103/0088 Compounds chosen for their latent hydraulic characteristics, e.g. pozzuolanes
• CPC Class Codes: C04B 2111/2084 Thermal shock resistance
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: Y10S 106/02 Perlite
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

A concrete additive includes expanded perlite with a volume weighted mean particle size of approximately 10-100 μm. The perlite further includes at least one additional component to improve workability and compensate for the natural tendency of expanded perlite to absorb water from the concrete mix. The additional component can include: water; a superplasticizer such as polycarboxylates, naphthalene sulfonate, and melamine sulfonate; or a hydrophobic compound such as salts of fatty acids, fatty acids, silanes, and siloxanes. The additive can be made in the form of a flowable powder or a flowable slurry. Concrete containing this additive displays superior properties to conventional concrete, including extremely high thermal resistance and high strength, low chloride ion permeability, and good early strength. The expanded perlite is a readily available raw material and the finished concrete is extremely cost effective for applications where a high strength structural concrete must withstand high temperatures.

Claims

1. A concrete additive comprising:

a flowable powder comprising expanded perlite with a volume weighted mean particle size of approximately 10-100 μ

m and a moisture content of 10 to 50% by weight.

2. The concrete additive of claim 1 wherein said moisture content is 25 to 50% by weight.

3. The concrete additive of claim 1 wherein said expanded perlite has 100% of the particles less than 200 μ

m, 90% below 80 μ

m, and a volume weighted mean of approximately 38 μ

m.

4. The concrete additive of claim 1 further comprising a superplasticizer in an amount equal to about 0.025 to 0.8°

A) on a solids basis.

5. The concrete additive of claim 4 wherein said superplasticizer is selected from the group consisting of:

polycarboxylates, naphthalene sulfonate, and melamine sulfonate

6. The concrete additive of claim 1 further comprising a moisture-retentive package that may be directly added to a concrete mix.

7. The concrete additive of claim 6 wherein said package is selected from the group consisting of:

pulpable bags, and bags that dissolve at a pH of 11 or higher.

8. A concrete additive comprising:

a flowable powder comprising expanded perlite with a volume weighted mean particle size of approximately 10-100 μ

m, and,

a hydrophobic compound applied to at least part of the accessible surface area of said expanded perlite.

9. The concrete additive of claim 8 wherein said hydrophobic compound is selected from the group consisting of:

salts of fatty acids, fatty acids, metal salts of dioic acids, silanes, and siloxanes.

10. The concrete additive of claim 8 wherein said expanded perlite has 100% of the particles less than 200 μ

m, 90% below 80 μ

m, and a volume weighted mean of approximately 38 μ

m.

11. The concrete additive of claim 8 wherein said hydrophobic compound is applied to said surface area by mixing said perlite with an aqueous mixture of said hydrophobic compound and evaporating excess water.

12. A concrete additive comprising:

a flowable powder comprising expanded perlite with a volume weighted mean particle size of approximately 10-100 μ

m, and,

at least one additional component selected from the group consisting of;

water in an amount of 10 to 50% by weight;

superplasticizer in an amount of about 0.025 to 0.8% on a solids basis; and

,

a hydrophobic compound applied to at least part of the accessible surface area of said expanded perlite.

13. The concrete additive of claim 12 wherein said expanded perlite has 100% of the particles less than 200 μ

m, 90% below 80 μ

m, and a volume weighted mean of approximately 38 μ

m.

14. A concrete additive comprising:

a flowable slurry comprising expanded perlite with a volume weighted mean particle size of approximately 10-100 μ

m and a water content of at least five times that of said perlite by weight.