Cementitious formulations and products
View Patent ↗Cementitious formulations and their products with enhanced reactivity are provided. Formulations in certain embodiments may include at least one calcium source, a reactant and a filler in a hydrated environment, wherein the reactant, in one form, is crystalline silica that has been modified for reactivity. Enhancement of a reactant may include one or more modifications to its content, grind and/or the cement to silica ratio, as well as addition of one or more additives in the formulation, additives in the form of at least one alumina source, defoamer, catalyst and/or a clay.
1. A cured cementitious formulation comprising:
silicon dioxide, wherein the silicon dioxide comprises reacted silicon dioxide and unreacted residual silicon dioxide;
calcium oxide; and
a filler, wherein the calcium oxide to total silicon dioxide molar ratio is between about 0.80 and 1.80, wherein the calcium oxide to the unreacted residual silicon dioxide molar ratio is between about 1.0 and 8.0.
2. The formulation of claim 1 , wherein the silicon dioxide is a pozzolan provided at a wt. % less than 25% and is greater than 500 m 2 /kg Blaine.
3. The formulation of claim 1 , wherein the silicon dioxide comprises crystalline silica.
4. The formulation of claim 1 , wherein the unreacted residual silicon dioxide content is less than about 15% by weight.
5. The formulation of claim 1 , wherein the formulation under hydrothermal conditions forms advanced calcium silicate hydrate phases selected from the group consisting of tobermorite, katoite, hydrogarnet and combinations thereof.
6. The formulation of claim 1 , wherein the formulation further comprises a catalyst, said catalyst is provided as a compound that lowers the activation energy of the reactant and promotes interaction between reactant and calcium source.
7. The formulation of claim 1 , wherein the filler has a particle size of less than 50 microns and a density of between about 90 to 130 kg/m 3 .
8. The formulation of claim 1 , wherein the filler is generally non-reactive and does not undergo substantial dissolution.
9. The formulation of claim 1 , wherein the filler comprises the calcium source.
10. The formulation of claim 1 , wherein the formulation has an calcium oxide to residual silicon dioxide molar ratio near about 1.0.
11. The formulation of claim 1 , wherein the formulation further comprises one or more additives in an amount between about 5 and 50 wt. % based on total dry ingredients.
12. The formulation of claim 11 , wherein the one or more additives are in the form of one or more catalysts, defoaming agents, clay, alumina source, low density modifiers and fibrous materials.
13. The formulation of claim 1 , wherein the formulation has an unreacted residual silicon dioxide content of less than 5%.
14. The formulation of claim 1 , wherein the formulation is hydrothermally cured.