Durable concrete and method for producing the same

• US 8,915,997 B2
• Filed: 11/12/2013
• Issued: 12/23/2014
• Est. Priority Date: 05/16/2013
• Status: Active Grant

• Current Assignee: Ashok H. Shah
• Original Assignee: NAVS, LLC
• Inventors: Shah, Ashok H.
• Primary Examiner(s): Olsen, Kaj K
• Assistant Examiner(s): HIJJI, KARAM Y
• Application Number:
  US14/078,327
• Publication Number:
  US 20140338568A1
• Time in Patent Office: 406 Days
• Field of Search: 106/409, 106/605, 106/672
• US Class Current: 106/409
• CPC Class Codes: C04B 14/24 porous, e.g. foamed glass
• CPC Class Codes: C04B 14/301 porous or hollow
• CPC Class Codes: C04B 16/0633 Polypropylene
• CPC Class Codes: C04B 16/0641 Polyvinylalcohols; Polyvinylacetates
• CPC Class Codes: C04B 18/08 Flue dust , i.e. fly ash
• CPC Class Codes: C04B 18/082 Cenospheres
• CPC Class Codes: C04B 18/146 Silica fume
• CPC Class Codes: C04B 20/002 Hollow or porous granular materials
• CPC Class Codes: C04B 20/0036 Microsized or nanosized
• CPC Class Codes: C04B 20/004 inorganic
• CPC Class Codes: C04B 20/0056 Hollow or porous fibres
• CPC Class Codes: C04B 20/008 Micro- or nanosized fillers, e.g. micronised fillers with particle size smaller than that of the hydraulic binder colloidal silica C04B14/062 ; silica fume C04B18/146
• CPC Class Codes: C04B 2103/10 Accelerators; Activators
• CPC Class Codes: C04B 2103/20 Retarders
• CPC Class Codes: C04B 2103/30 Water reducers, plasticisers, air-entrainers, flow improvers
• CPC Class Codes: C04B 2111/29 Frost-thaw resistance
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete

Abstract

A concrete mix for producing freeze-thaw durable concrete having enhanced strength properties, like compressive strength, abrasion resistance, impact strength, toughness, is disclosed. The novel concrete mix contains deformable solid elements in place of 4-8% entrained air for good durability of concrete under freeze-thaw cycles.

Claims

1. A concrete mix for producing a freeze-thaw durable concrete, comprising cement, inorganic, hollow, spherical, deformable solid elements, which elements are deformable by crushing at a pressure of <

1000 psi, and optionally water, wherein said inorganic deformable solid elements are either included in said concrete mix in a dry state, or mixed with said cement at the time of preparing a wet concrete mix, are present at a level of less than or equal to about 2 vol % and 1.56 wt % relative to the volume of said wet concrete mix or a green concrete or a subsequently hardened concrete formed therefrom, or less than 1.7 wt % in the dry state based on the total weight of all dry materials, and have a maximum dimension of less than about 300 micrometers.

2. The concrete mix of claim 1, further comprising sand, aggregates, admixtures, or reinforcing fibers or combinations thereof.

3. The concrete mix of claim 1, wherein a total deformable space of said inorganic deformable solid elements is at least 9% of capillary pores volume, wherein the capillary pores volume is equal to the volume of water in excess of 36% by weight of cement in wet concrete mix.

4. The concrete mix of claim 1, wherein the total volume of said deformable elements is sufficient to accommodate expansion caused by water freezing in capillary pores of said subsequently hardened concrete during a freezing event.

5. The concrete mix of claim 1, wherein water is present at a water-to-cement weight ratio in said wet concrete mix of at least about 26%.

6. The concrete mix of claim 5, wherein the water-to-cement weight ratio in said wet concrete mix is 26 to 40%.

7. The concrete mix of claim 5, wherein water is present at a water-to-cement weight ratio in said wet concrete mix from about 40% to about 60%.

8. The concrete mix of claim 2, wherein said admixtures include one or more of retarders, accelerators, plasticizers, fillers, silica fumes, fly ash, other pozzolanic materials or combinations thereof.

9. The concrete mix of claim 1, wherein said inorganic deformable solid elements have a rigid shell.

10. The concrete mix of claim 9, wherein said inorganic deformable solid elements are made of materials selected from the group of glass, ceramic and silica and combinations thereof.

11. The concrete mix of claim 10, wherein said inorganic deformable solid elements are cenospheres.

12. The concrete mix of claim 1, wherein said inorganic deformable solid elements are glass spheres having rigid shells and a crush strength of <

1000 psi.

13. The concrete mix of claim 1, wherein the deformable solid elements have diameters from about 10 micrometers to about 200 micrometers.