Composition and application of novel sprayable phosphate cement (grancrete) that bonds to styrofoam
A dry mix particulate composition of a calcined oxide of Mg and/or Ca, an acid phosphate, and fly ash or equivalent, wherein the calcined oxide is present in the range of from about 17% to about 40% by weight and the acid phosphate is present in the range of from about 29% to about 52% by weight and the fly ash or equivalent is present in the range of from about 24% to about 39% by weight when sand is added to the dry mix, it is present in the range of from about 39% to about 61% by weight of the combined dry mix and sand. A method of forming a structural member is also disclosed wherein an aqueous slurry of about 8–12 pounds of water is added to dry mix and sand.
1. A dry mix particulate composition, comprising a calcined oxide of Mg and/or Ca, an acid phosphate, and fly ash or equivalent, wherein said calcined oxide is present in the range of from about 17% to about 40% by weight and said acid phosphate is present in the range of from about 29% to about 52% by weight and said fly ash or equivalent is present in the range of from about 24% to about 39% by weight and wherein the weight ratio of calcined oxide to acid phosphate is about 1.
2. The dry mix particulate composition of claim 1 , wherein said calcined oxide is present in the range of from about 32% to about 36% by weight and said acid phosphate is present in the range of from about 33% to about 37% by weight and fly ash or equivalent is present in the range of from about 29% to about 33% by weight.
3. The dry mix particulate composition of claim 1 and further including sand present in the range of from about 39% to about 61% by weight of the combined dry mix and sand.
4. The dry mix particulate composition of claim 2 , wherein said oxide is MgO and said acid phosphate is KH 2 PO 4 .
5. The dry mix particulate composition of claim 1 , wherein the equivalent to fly ash is volcanic ash.
6. An aqueous slurry comprising the dry mix particulate composition of claim 3 , wherein the weight ratio of calcined oxide to acid phosphate is about one and water is present in the range of from about 8 to about 12 pounds per 100 pounds of dry mix and sand to form an aqueous slurry.
7. The aqueous slurry of claim 6 , wherein boric acid or sodium borate is present in the dry mix and sand.
8. The aqueous slurry of claim 6 , wherein high aspect fibers are present in the dry mix and sand.
9. The aqueous slurry of claim 6 , wherein said sand is screened to sieve size of 30 mesh.
10. The aqueous slurry of claim 6 , wherein an acrylate is present in the dry mix and sand.
11. A method of forming a vertical structural member, comprising applying an aqueous slurry of a dry mix of a calcined oxide of Mg and/or Ca and an acid phosphate and fly ash or an equivalent and sand, wherein the calcined oxide is present in the range of from about 17% to about 40% by weight and the acid phosphate is present in the range of from about 29% to about 52% by weight and the fly ash or equivalent is present in the range of from about 24% to about 39% by weight and sand is present in the range of from about 39% to about 61% by weight of the dry mix and sand to a substrate, the weight ratio of calcined oxide to acid phosphate being about 1,
and allowing the slurry to cure, the slurry being of a consistency so as not to drip or sag and starting to harden upon application.
12. The method of claim 11 , wherein water is present in the range of from about 8 to about 12 pounds per 100 pounds of dry mix and sand.
13. The method of claim 12 , wherein the substrate is styrofoam coated with acrylic.
14. The method of claim 12 , wherein the substrate is cement.
15. The method of claim 12 , wherein the aqueous slurry is sprayed onto a vertical surface.
16. The method of claim 11 , wherein boric acid or sodium borate is present to control the cure rate of the slurry.
17. The method of claim 12 , wherein the calcined oxide is present in the range of from about 32% to about 36% by weight and the acid phosphate is present in the range of from about 33% to about 37% by weight and fly ash or equivalent is present in the range of from about 29% to about 33% by weight of the dry mix.
18. The method of claim 17 , wherein the oxide is MgO and the acid phosphate is KH 2 PO 4 .
19. The method of claim 17 , wherein an acrylate is present in the dry mix.
20. A dry mix particulate composition, comprising a calcined MgO, a potassium acid phosphate, and fly ash or equivalent, wherein said calcined MgO is present in the range of from about 17% to about 40% by weight and said potassium acid phosphate is present in the range of from about 29% to about 52% by weight and said fly ash or equivalent is present in the range of from about 24% to about 39% by weight, and wherein the weight ratio of calcined MgO to potassium acid phosphate is about one.