Anhydrous Calcium Sulfate-Containing Inorganic Polymer Compositions and Methods of Making Same
Inorganic polymer compositions and methods for their preparation are described herein. The compositions include the reaction product of a reactive powder, anhydrous calcium sulfate, an activator, and optionally a retardant. The reactive powder includes fly ash and no more than 10% by weight portland cement. The anhydrous calcium sulfate is present in an amount of 2% or greater by weight of the reactive powder. Also described herein are building materials including the compositions.
1 . An inorganic polymer composition, comprising the reaction product of:
reactive powder comprising 85% by weight or greater fly ash and no more than 10% by weight portland cement;
anhydrous calcium sulfate in an amount of 2% or greater by weight of the reactive powder;
an activator, wherein the activator includes one or more of sodium hydroxide and citric acid; and
optionally a retardant.
2 . The composition of claim 1 , wherein greater than 75% of the fly ash comprises Class C fly ash.
3 . The composition of claim 1 , wherein greater than 95% of the fly ash comprises Class C fly ash.
4 . The composition of claim 1 , wherein the anhydrous calcium sulfate comprises from 2.5% to 7% by weight of the reactive powder.
5 . The composition of claim 1 , wherein the anhydrous calcium sulfate comprises from 3.5% to 6% by weight of the reactive powder;
6 . The composition of claim 1 , wherein the fly ash is present in an amount of greater than 95% by weight of the reactive powder.
7 . The composition of claim 1 , wherein the fly ash includes a calcium oxide content of from 23% to 30% by weight.
8 . The composition of claim 1 , wherein the activator includes citric acid.
9 . The composition of claim 1 , wherein the activator includes sodium hydroxide.
10 . The composition of claim 1 , wherein the composition comprises a retardant and the retardant includes borax, boric acid, gypsum, phosphates, gluconates, or a mixture of these.
11 . The composition of claim 1 , wherein the water to binder ratio is less than 0.15.
12 . The composition of claim 1 , wherein the reactive powder includes 5% by weight or less of portland cement.
13 . The composition of claim 1 , wherein the reactive powder includes 3% by weight or less of portland cement.
14 . The composition of claim 1 , wherein the reactive powder further comprises calcium aluminate cement.
15 . The composition of claim 14 , wherein the calcium aluminate cement is present in an amount of 5% or less by weight of the reactive powder.
16 . The composition of claim 1 , further comprising aggregate.
17 . The composition of claim 16 , wherein the aggregate includes lightweight aggregate.
18 . The composition of claim 1 , further comprising fibers.
19 . The composition of claim 1 , further comprising water.
20 . The composition of claim 1 , wherein the composition is substantially free of retardants.
21 . The composition of claim 1 , further comprising a photocatalyst.
22 . A building material comprising the composition of claim 1 .
23 . The building material of claim 22 , wherein the building material is selected from the group consisting of a roofing tile, a ceramic tile, a synthetic stone, a thin brick, a brick, a paver, a panel, or an underlay.
24 - 31 . (canceled)
32 . The composition of claim 1 , wherein the reactive powder is substantially free from portland cement.
33 . The composition of claim 1 , wherein the activator is selected from the group consisting of citrates, hydroxides, metasilicates, carbonates, aluminates, sulfates, tartrates, and mixtures thereof.
34 . A mixture, comprising:
reactive powder comprising 85% by weight or greater fly ash and no more than 10% by weight portland cement;
anhydrous calcium sulfate in an amount of 2% to 15% by weight of the reactive powder;
an activator, wherein the activator includes one or more of sodium hydroxide and citric acid; and
optionally a retardant,
wherein said composition has a pH of from 12 to 13.5.
35 . The composition of claim 34 , wherein the reactive powder is substantially free from portland cement.
36 . The composition of claim 34 , wherein the activator is selected from the group consisting of citrates, hydroxides, metasilicates, carbonates, aluminates, sulfates, tartrates, and mixtures thereof.