Structural assembly board and method of manufacturing same
A composition for use in making a structural assembly board, a structural assembly made from the composition, and a method of making the structural assembly board is provided. The composition includes magnesium oxide; magnesium sulfate; and water. The composition includes reinforcing fibers. The composition and method of making the structural assembly board promote formation of 5MgO.MgSO 4 .2H 2 O to improve structural qualities of the structural assembly board.
1. A composition for use in making a structural assembly board comprising:
Magnesium oxide;
Magnesium sulfate;
water;
reinforcing fibers;
adhesive;
organic acid being 0.1 wt % to 2.5 wt % of the composition; and
aggregate, wherein the aggregate is at least one of fly ash and perlite.
2. The composition of claim 1 , wherein the reinforcing fibers are at least one of basalt, polypropylene, hemp, and/or flax.
3. The composition of claim 1 , wherein the reinforcing fibers are 1-2 wt % of the composition.
4. The composition of claim 1 , further comprising polycarboxylates and polyol polymers.
5. The composition of claim 1 , wherein the organic acid comprises at least one of citric acid, tartaric acid, sodium malate, adipic acid, and potassium tartrate.
6. A structural assembly board made from the composition of claim 1 .
7. A method of manufacturing a structural assembly board, the method comprising:
dissolving magnesium sulfate in water to form a brine solution;
dissolving magnesium oxide in the brine solution to form a cement mixture;
mixing the cement mixture with reinforcing fibers;
curing the cement mixture in a mould; and
dissolving organic acid into the solution to promote formation of phase-5 crystalline structure in the cement mixture, the organic acid being 0.1 wt % to 2.5 wt % of the cement mixture.
8. The method of claim 7 , wherein the cement mixture is cured with at least one conditions selected from 50-90% humidity, 20-35° C., an atmosphere enriched in CO 2 , and a curing time of at least 13 days.
9. The method of claim 7 , wherein the water is about 40° C. before magnesium sulfate is dissolved into the water.
10. The method of claim 7 , wherein a molar ratio of MgSO 4 :H 2 O is 1:18-23.
11. The method of claim 7 , further comprising adding aggregate and reinforcing fibers to the solution.
12. The method of claim 7 , further comprising cooling the solution to a temperature less than or equal to 35° C. before dissolving magnesium oxide in the solution.
13. The method of claim 12 , wherein the solution is at about 25° C. to 45° C. when the magnesium oxide is dissolved in the solution.
14. The method of claim 7 , wherein the magnesium sulfate comprises magnesium sulfate particles having at least two different surface areas.
15. The method of claim 14 , wherein the magnesium sulfate particles comprises a first magnesium sulfate particle having a surface area of about 30 m 2 /g and a second magnesium sulfate particle having a surface area of about 70 m 2 /g.
16. The method of claim 7 , further comprising adding at least one of carboxylic functionalized amphiphilic molecules, phosphonic functionalized amphiphilic molecules, and/or polymers.
17. The method of claim 7 , wherein the organic acid is at least one of citric acid, tartaric acid, sodium malate, adipic acid, and potassium tartrate.