High early strength pozzolan cement blends
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.
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 D 15 greater than about 5 μm and a D 90 less than about 120 μm; 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 D 85 in a range of about 5 μm to about 20 μm,
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 μm comprise pozzolan particles and less than about 35% of the combined pozzolan and cement particles larger than about 20 μm comprise hydraulic cement particles.
2. A pozzolan cement composition as in claim 1 , the hydraulic cement particles having a D 90 in a range from about 7.5 μm to about 20 μm and wherein at least about 75% of the combined pozzolan and cement particles larger than about 20 μm comprise pozzolan particles and less than about 25% of the combined pozzolan and cement particles larger than about 20 μm comprise hydraulic cement particles.
3. A pozzolan cement composition as in claim 1 , the hydraulic cement particles having a D 95 in a range from about 10 μm to about 20 μm and wherein at least about 85% of the combined pozzolan and cement particles larger than about 20 μm comprise pozzolan particles and less about 15% of the combined pozzolan and cement particles larger than about 20 μm comprise hydraulic cement particles.
4. A pozzolan cement composition as in claim 1 , the hydraulic cement particles having a D 85 in a range of about 5 μm to about 15 μm and wherein at least about 65% of the combined pozzolan and cement particles larger than about 15 μm comprise pozzolan particles and less than about 35% of the combined pozzolan and cement particles larger than about 15 μm comprise hydraulic cement particles.
5. A pozzolan cement composition as in claim 1 , the hydraulic cement particles having a D 90 in a range from about 7.5 μm to about 15 μm and wherein at least about 75% of the combined pozzolan and cement particles larger than about 15 μm comprise pozzolan particles and less than about 25% of the combined pozzolan and cement particles larger than about 15 μm comprise hydraulic cement particles.
6. A pozzolan cement composition as in claim 1 , the hydraulic cement particles having a D 85 in a range of about 5 μm to about 10 μm and wherein at least about 65% of the combined pozzolan and cement particles larger than about 10 μm comprise pozzolan particles and less than about 35% of the combined pozzolan and cement particles larger than about 10 μm 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 m 2 /kg to about 600 m 2 /kg.
10. A pozzolan cement composition as in claim 1 , the pozzolan cement composition having a Blaine fineness in a range of 300 m 2 /kg to about 500 m 2 /kg.
11. A pozzolan cement composition as in claim 1 , the hydraulic cement particles having a Blaine fineness greater than about 650 m 2 /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 m 2 /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 D 90 in a range of about 5 μm to about 20 μm 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 μm are composed of pozzolan particles and less than about 25% by volume of combined pozzolan and hydraulic cement particles greater than about 20 μm are composed of hydraulic cement particles.
14. A pozzolan cement composition as in claim 13 , wherein the hydraulic cement particles have a D 90 in a range of about 5 μm to about 15 μm 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 μm 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 μm 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 D 90 in a range of about 5 μm to about 20 μm 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 μm 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 μm are composed of hydraulic cement particles.
17. A pozzolan cement composition as in claim 16 , wherein the hydraulic cement particles have a D 90 in a range of about 5 μm to about 15 μm 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 μm 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 μm 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.