High early strength pozzolan cement blends

• US 7,799,128 B2
• Filed: 10/08/2009
• Issued: 09/21/2010
• Est. Priority Date: 10/10/2008
• Status: Active Grant

• Current Assignee: Roman Cement, LLC
• Original Assignee: Roman Cement, LLC
• Inventors: Guynn, John M., Hansen, Andrew S.
• Primary Examiner(s): MARCANTONI, PAUL D
• Application Number:
  US12/576,117
• Publication Number:
  US 20100089293A1
• Time in Patent Office: 348 Days
• Field of Search: 106/705, 106/DIG.1
• US Class Current: 106/705
• CPC Class Codes: C04B 14/14 Minerals of vulcanic origin granite C04B14/048
• CPC Class Codes: C04B 18/08 Flue dust , i.e. fly ash
• CPC Class Codes: C04B 20/0076 characterised by the grain distribution
• 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 2103/0088 Compounds chosen for their latent hydraulic characteristics, e.g. pozzuolanes
• CPC Class Codes: C04B 2103/10 Accelerators; Activators
• CPC Class Codes: C04B 2103/20 Retarders
• CPC Class Codes: C04B 2103/302 Water reducers
• CPC Class Codes: C04B 2103/44 Thickening, gelling or viscosity increasing agents
• CPC Class Codes: C04B 22/064 of the alkaline-earth metals
• CPC Class Codes: C04B 28/02 containing hydraulic cements other than calcium sulfates
• CPC Class Codes: C04B 28/18 containing mixtures of the silica-lime type
• CPC Class Codes: C04B 7/02 Portland cement
• CPC Class Codes: Y02W 30/91 Use of waste materials as fillers for mortars or concrete
• CPC Class Codes: Y10S 106/01 Fly ash

Abstract

A high early strength pozzolan cement includes larger sized pozzolan particles and smaller sized hydraulic cement particles which contain tricalcium silicate (e.g., Portland cement). Particles larger than 10 μm are predominantly (50%, 65%, 75%, 85% or 95%) pozzolan particles, and particles smaller than 10 μm are predominantly (50%, 65%, 75%, 85% or 95%) hydraulic cement particles. Excess calcium from the hydraulic cement forms calcium hydroxide available for reaction with the pozzolan particles, optionally in combination with supplemental lime. At least 30%, 40%, 45%, 55%, 65% or 75% of the pozzolan cement (combined pozzolan and hydraulic cement particles) consists of pozzolan, and less than 70%, 60%, 55%, 45%, 35% or 25% consists of hydraulic cement.

Claims

1. A pozzolan cement composition comprising:

a distribution of differently sized pozzolan particles capable of reacting with calcium hydroxide in the presence of water in order to form solid hydration products having cementitious properties, the pozzolan particles having a D₁₅ greater than about 5 μ

m and a D₉₀ less than about 120 μ

m; and

a distribution of differently sized hydraulic cement particles at least partially comprised of tricalcium silicate and/or dicalcium silicate that provide excess calcium hydroxide when mixed with water and that is available for reaction with at least a portion of the pozzolan particles, the hydraulic cement particles having a D₈₅ in a range of about 5 μ

m to about 20 μ

m,

wherein the fineness of the hydraulic cement particles is about 1.25 to about 50 times greater than the fineness of the pozzolan particles,

wherein at least about 65% of the combined pozzolan and cement particles larger than about 20 μ

m comprise pozzolan particles and less than about 35% of the combined pozzolan and cement particles larger than about 20 μ

m comprise hydraulic cement particles.

2. A pozzolan cement composition as in claim 1, the hydraulic cement particles having a D₉₀ in a range from about 7.5 μ

m to about 20 μ

m and wherein at least about 75% of the combined pozzolan and cement particles larger than about 20 μ

m comprise pozzolan particles and less than about 25% of the combined pozzolan and cement particles larger than about 20 μ

m comprise hydraulic cement particles.

3. A pozzolan cement composition as in claim 1, the hydraulic cement particles having a D₉₅ in a range from about 10 μ

m to about 20 μ

m and wherein at least about 85% of the combined pozzolan and cement particles larger than about 20 μ

m comprise pozzolan particles and less about 15% of the combined pozzolan and cement particles larger than about 20 μ

m comprise hydraulic cement particles.

4. A pozzolan cement composition as in claim 1, the hydraulic cement particles having a D₈₅ in a range of about 5 μ

m to about 15 μ

m and wherein at least about 65% of the combined pozzolan and cement particles larger than about 15 μ

m comprise pozzolan particles and less than about 35% of the combined pozzolan and cement particles larger than about 15 μ

m comprise hydraulic cement particles.

5. A pozzolan cement composition as in claim 1, the hydraulic cement particles having a D₉₀ in a range from about 7.5 μ

m to about 15 μ

m and wherein at least about 75% of the combined pozzolan and cement particles larger than about 15 μ

m comprise pozzolan particles and less than about 25% of the combined pozzolan and cement particles larger than about 15 μ

m comprise hydraulic cement particles.

6. A pozzolan cement composition as in claim 1, the hydraulic cement particles having a D₈₅ in a range of about 5 μ

m to about 10 μ

m and wherein at least about 65% of the combined pozzolan and cement particles larger than about 10 μ

m comprise pozzolan particles and less than about 35% of the combined pozzolan and cement particles larger than about 10 μ

m comprise hydraulic cement particles.

7. A pozzolan cement composition as in claim 1, the pozzolan particles comprising at least 30% by volume of combined pozzolan and hydraulic cement particles and the hydraulic cement particles comprising up to 70% by volume of the combined pozzolan and hydraulic cement particles.

8. A pozzolan cement composition as in claim 1, further comprising at least one of a fine aggregate, a coarse aggregate, lime, lye, water reducing admixture, accelerant, retardant, hydration stabilizer, rheology-modifying agent, or water.

9. A pozzolan cement composition as in claim 1, the pozzolan cement composition having a Blaine fineness in a range of about 280 m²/kg to about 600 m²/kg.

10. A pozzolan cement composition as in claim 1, the pozzolan cement composition having a Blaine fineness in a range of 300 m²/kg to about 500 m²/kg.

11. A pozzolan cement composition as in claim 1, the hydraulic cement particles having a Blaine fineness greater than about 650 m²/kg and that is about 1.5 to about 30 times greater than a Blaine fineness of the pozzolan particles.

12. A pozzolan cement composition as in claim 1, the hydraulic cement particles having a Blaine fineness greater than about 800 m²/kg and that is about 1.75 to about 20 times greater than a Blaine fineness of the pozzolan particles.

13. A pozzolan cement composition comprising:

pozzolan particles capable of reacting with calcium hydroxide in the presence of water in order to form solid hydration products having cementitious properties; and

hydraulic cement particles at least partially comprised of tricalcium silicate and/or dicalcium silicate that provide excess calcium hydroxide when mixed with water and that is available for reaction with at least a portion of the pozzolan particles,

wherein the hydraulic cement particles have a D₉₀ in a range of about 5 μ

m to about 20 μ

m and a Blaine fineness that is at least about 1.25 times greater than a Blaine fineness of the pozzolan particles such that at least about 75% by volume of combined pozzolan and hydraulic cement particles greater than about 20 μ

m are composed of pozzolan particles and less than about 25% by volume of combined pozzolan and hydraulic cement particles greater than about 20 μ

m are composed of hydraulic cement particles.

14. A pozzolan cement composition as in claim 13, wherein the hydraulic cement particles have a D₉₀ in a range of about 5 μ

m to about 15 μ

m and a Blaine fineness that is at least about 1.5 times greater than a Blaine fineness of the pozzolan particles such that at least about 75% by volume of the combined pozzolan and hydraulic cement particles greater than about 15 μ

m are composed of the pozzolan particles and less than about 25% by volume of the combined pozzolan and hydraulic cement particles greater than about 15 μ

m are composed of the hydraulic cement particles.

15. A pozzolan cement composition as in claim 13, wherein the pozzolan comprises at least one member selected from the group consisting of fly ash, trass, natural pozzolan, and volcanic ash.

16. A pozzolan cement composition comprising:

fly ash and/or natural pozzolan particles comprising an amorphous or glassy phase capable of reacting with calcium hydroxide in the presence of water in order to form solid hydration products having cementitious properties; and

hydraulic cement particles at least partially comprised of tricalcium silicate and/or dicalcium silicate that provide excess calcium hydroxide when mixed with water and that is available for reaction with at least a portion of the fly ash and/or natural pozzolan particles,

wherein the hydraulic cement particles have a D₉₀ in a range of about 5 μ

m to about 20 μ

m and a Blaine fineness that is at least about 1.25 times greater than a Blaine fineness of the fly ash and/or natural pozzolan particles such that at least about 75% by volume of combined fly ash and/or natural pozzolan particles and hydraulic cement particles greater than about 20 μ

m are composed of fly ash and/or natural pozzolan particles and less than about 25% by volume of combined fly ash and/or natural pozzolan particles and hydraulic cement particles greater than about 20 μ

m are composed of hydraulic cement particles.

17. A pozzolan cement composition as in claim 16, wherein the hydraulic cement particles have a D₉₀ in a range of about 5 μ

m to about 15 μ

m and a Blaine fineness that is at least about 1.5 times greater than a Blaine fineness of the fly ash and/or natural pozzolan particles such that at least about 75% by volume of combined fly ash and/or natural pozzolan particles and hydraulic cement particles greater than about 15 μ

m are composed of fly ash and/or natural pozzolan particles and less than about 25% by volume of combined fly ash and/or natural pozzolan particles and hydraulic cement particles greater than about 15 μ

m are composed of hydraulic cement particles.

18. A pozzolan cement composition as in claim 16, wherein the pozzolan cement composition comprises fly ash and substantially no natural pozzolan.

19. A pozzolan cement composition as in claim 16, wherein the pozzolan cement composition comprises natural pozzolan and substantially no fly ash.

20. A pozzolan cement composition as in claim 16, further comprising ground slag.

21. A pozzolan cement composition as in claim 16, further comprising at least one of a fine aggregate, a coarse aggregate, lime, lye, water reducing admixture, accelerant, retardant, hydration stabilizer, rheology-modifying agent, or water.