Geopolymer activator composition and geopolymer binder, paste and concrete prepared therewith

Abstract

The present invention relates to geopolymer compositions comprising additives selected from sugars and derivatives thereof and/or organic acids and salts thereof. The geopolymer compositions of the present invention have sufficient strength to be used for construction purposes. To facilitate the production method of geopolymer paste and concrete compositions the present invention further provides solid and liquid geopolymer activator compositions.

Claims

1. A geopolymer activator composition comprising: a) alkaline activator having a molarity of 1.0 to 20 M; and b) additives having a molarity in the range of 0.001 to 0.10 M, wherein the additives are selected from the group consisting of a sugar and derivatives thereof and/or an organic acid and salts thereof.

2. The geopolymer activator composition according to claim 1, wherein the molarity of the alkaline activator is 1.0 to 10 M.

3. The geopolymer activator composition according to claim 1, wherein the molarity of the alkaline activator is 2.0 to 4.0 M.

4. The geopolymer activator composition according to claim 1, further comprising soluble silicate.

5. The geopolymer activator composition according to claim 1, wherein the molarity of the soluble silicate is less than 3.0 M.

6. The geopolymer activator composition according to claim 4, wherein the molarity of the soluble silicate is 0.01 to 2.0 M.

7. The geopolymer activator composition according to claim 1, wherein molarity of the additives is 0.002 to 0.05 M.

8. The geopolymer activator composition according to claim 1, wherein molarity of the additives is 0.02 to 0.04 M.

9. The geopolymer activator composition according to claim 1, wherein the alkaline activator is an alkaline bicarbonate activator, an alkaline silicate activator and/or an alkaline hydroxide activator.

10. The geopolymer activator composition according to claim 1, wherein the alkaline activator is an alkali metal hydroxide selected from the group consisting of sodium hydroxide and/or potassium hydroxide.

11. The geopolymer activator composition according to claim 1, wherein the sugar is selected from the group consisting of monosaccharides, disaccharides, oligosaccharides and polysaccharides and/or the organic acid is selected from carboxylic acids.

12. The geopolymer activator composition according to claim 1, wherein the sugar is selected from the group consisting of glucose, fructose, galactose, sucrose, maltose, lactose, dextrin, maltodextrin, starch, cellulose, dextran, sugar polymer, molasses and combinations thereof.

13. The geopolymer activator composition according to claim 1, wherein the additives are selected from the group consisting of sugar alcohols, natural sugar substitutes and synthetic sugar substitutes.

14. The geopolymer activator composition according to claim 1, wherein the additives are selected from the group consisting of sorbitol, lactitol, glycerol, isomalt, maltitol, mannitol, stevia, xylitol, aspartame, alitame, dulcin, glucin, cyclamate, saccharin, sucralose, lead acetate and combinations thereof.

15. The geopolymer activator composition according to claim 1, wherein the sugar is sucrose, fructose and/or lactose.

16. The geopolymer activator composition according to claim 1, wherein the organic acids are oxalic acid, ascorbic acid, lactic acid, uric acid, citric acid, tartaric acid and combinations thereof.

17. The geopolymer activator composition according to claim 1, wherein the organic acids are tartaric acid and/or ascorbic acid.

18. The geopolymer activator composition according to claim 1, wherein the salts are calcium citrate, sodium citrate and/or sodium gluconate.

19. The geopolymer activator composition according to claim 1, wherein the additives are sucrose, fructose, lactose, tartaric acid, ascorbic acid, sodium gluconate and combinations thereof.

20. The geopolymer activator composition according to claim 1, wherein the geopolymer activator composition does not comprise soluble silicate.

Description

EXAMPLES

(1) Fine and coarse aggregate, powder coal fly ash and blast furnace slag were mixed with a solution of sodium hydroxide, sodium silicate and additives selected from sucrose, glucose, ascorbic acid, citric acid and tartaric in a rotating pan mixer for 3 minutes. After mixing the geopolymer mortar was pored in moulds, for curing over time at ambient temperatures. Compressive strength was measured on cubic blocks of 40 by 40 by 40 mm.

(2) Tables 1-9 give an overview of the compressive strengths, after a curing period of 28 days (at 20° C.), of the geopolymer mixtures of the present invention prepared by the method given above. The compressive strengths are compared with a geopolymer mixture (hereinafter the “reference”), without comprising additives of the present invention, containing: 1350 gram fine and coarse aggregate; 350 gram powder coal fly ash; 100 gram blast furnace slag; and 160 ml alkaline liquid solution comprising 5.6 M sodium hydroxide and 0.125 M sodium silicate and water.

(3) The reference mixture was cured under the same conditions as the geopolymer mixtures of the present invention. The strength of the reference mixture was measured after 28 days as well.

(4) Table 10 gives an overview of the compressive strengths, after a curing period of 14 days (at 20° C.), of the geopolymer mixtures of the present invention prepared by the method given above. The compressive strengths are compared with the strength of the above-mentioned reference mixture measured after 14 days as well.

(5) TABLE-US-00001 TABLE 1 Geopolymer mixtures (G1-G6) with different concentrations sodium hydroxide Ref. G1 G2 G3 G4 G5 G6 (grams) Aggregate.sup.a 1350 1350 1350 1350 1350 1350 1350 PCFA.sup.b 350 350 350 350 350 350 350 Slag.sup.c 100 100 100 100 100 100 100 10M NaOH 90 90 140 120 70 40 20 1M Sodium silicate 20 20 20 20 20 20 20 Water 50 50 0 20 70 100 120 Sucrose 0 1 1 1 1 1 1 Molarity sucrose 0 0.018 0.018 0.018 0.018 0.018 0.018 Molarity NaOH 5.6 5.6 8.75 7.5 4.3 2.5 1.25 Strength (N/mm.sup.2) 23.8 42.2 37.9 37.7 32.6 0.4 0.0 Ratio (1.00 = reference) 1.00 1.77 1.59 1.58 1.37 0.02 0.00 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(6) TABLE-US-00002 TABLE 2 Geopolymer mixtures (G7-G11) with different concentrations sucrose Ref. G7 G8 G9 G10 G11 (grams) Aggregate.sup.a 1350 1350 1350 1350 1350 1350 PCFA.sup.b 350 350 350 350 350 350 Slag.sup.c 100 100 100 100 100 100 10M NaOH 90 90 90 90 90 90 1M Sodium silicate 20 20 20 20 20 20 Water 50 50 50 50 50 50 Sucrose 0 0.5 1 2 4 8 Molarity sucrose 0 0.009 0.018 0.036 0.073 0.146 Wt-% sucrose 0 0.11 0.22 0.44 0.89 1.78 Strength (N/mm.sup.2) 23.8 35.0 42.2 34.9 21.5 0.6 Ratio (1.00 = reference) 1.00 1.47 1.77 1.47 0.90 0.03 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(7) TABLE-US-00003 TABLE 3 Geopolymer mixtures (G12-G16) with different additives Ref. G12 G13 G14 G15 G16 (grams) Aggregate.sup.a 1350 1350 1350 1350 1350 1350 PCFA.sup.b 350 350 350 350 350 350 Slag.sup.c 100 100 100 100 100 100 10M NaOH 90 90 90 90 90 90 1M Sodium silicate 20 20 20 20 20 20 Water 50 50 50 50 50 70 Additive 0 1 1 1 4 1 Additive — Sucrose Glucose Ascorbic Citric Tartaric acid acid acid Molarity additive 0 0.018 0.035 0.036 0.130 0.037 Strength (N/mm.sup.2) 23.8 42.2 29.9 40 25.9 32.3 Ratio (1.00 = reference) 1.00 1.77 1.26 1.68 1.23 1.36 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(8) TABLE-US-00004 TABLE 4 Geopolymer mixtures (G17-G22) with different concentrations sodium silicate Ref. G17 G18 G19 G20 G21 G22 (grams) Aggregate.sup.a 1350 1350 1350 1350 1350 1350 1350 PCFA.sup.b 350 350 350 350 350 350 350 Slag.sup.c 100 100 100 100 100 100 100 Alkaline liquid solution 160 160 160 160 160 160 160 Sucrose 0 1 1 1 1 1 1 Molarity sucrose 0 0.018 0.018 0.018 0.018 0.018 0.018 Molarity NaOH 5.6 5.6 5.6 5.6 5.6 5.6 5.6 Molarity sodium silicate 0.125 0 0.125 0.250 0.5 1.0 2.0 Strength (N/mm.sup.2) 23.8 39.3 42.2 39.9 42.4 38.9 34.4 Ratio (1.00 = reference) 1.00 1.65 1.77 1.68 1.78 1.63 1.45 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(9) TABLE-US-00005 TABLE 5 Geopolymer mixtures (G23-G28) with different PCFA/Slag ratio Ref. G23 G24 G25 G26 G27 G28 (grams) Aggregate.sup.a 1350 1350 1350 1350 1350 1350 1350 PCFA.sup.b 350 425 400 375 350 325 300 Slag.sup.c 100 25 50 75 100 125 150 10M NaOH 90 90 90 90 90 90 90 1M Sodium silicate 20 20 20 20 20 20 20 Water 50 50 50 50 50 50 50 Sucrose 0 1 1 1 1 1 1 Wt-% slag 22 6 11 17 22 28 33 Strength (N/mm.sup.2) 23.8 17.2 25.5 37.2 41.8 49.9 50.2 Ratio (1.00 = reference) 1.00 0.72 1.07 1.56 1.76 2.10 2.11 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(10) TABLE-US-00006 TABLE 6 Geopolymer mixtures (G29-G33) with different amounts of alkaline liquid solution Ref. G29 G30 G31 G32 G33 (grams) Aggregate.sup.a 1350 1350 1350 1350 1350 1350 PCFA.sup.b 350 350 350 350 350 350 Slag.sup.c 100 100 100 100 100 100 Alkaline liquid solution 160 120 140 160 180 200 Sucrose 0 1 1 1 1 1 Molarity sucrose 0 0.024 0.021 0.018 0.016 0.015 Molarity NaOH 5.6 5.6 5.6 5.6 5.6 5.6 Molarity sodium silicate 0.125 0.125 0.125 0.125 0.125 0.125 Wt-% alkaline liquid 8.16 6.25 7.22 8.16 9.09 10.0 Wt-% sucrose 0 0.17 0.19 0.22 0.25 0.28 Strength (N/mm.sup.2) 23.8 33 41.6 45.1 34.7 25.8 Ratio (1.00 = reference) 1.00 1.39 1.75 1.89 1.46 1.08 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(11) TABLE-US-00007 TABLE 7 Geopolymer mixtures (G34-G40) with different amounts of binders (same slag ratio) Ref. G34 G35 G36 G37 G38 G39 G40 (grams) Aggregate.sup.a 1350 1350 1350 1350 1350 1350 1350 1350 PCFA.sup.b 350 195 273 350 428 506 583 661 Slag.sup.c 100 55 77 100 122 144 167 189 Alkaline liquid solution 160 130 150 160 180 200 220 240 Sucrose 0 1 1 1 1 1 1 1 Molarity sucrose 0 0.022 0.019 0.018 0.016 0.015 0.013 0.012 Molarity NaOH 5.6 5.6 5.6 5.6 5.6 5.6 5.6 5.6 Molarity sodium silicate 0.125 0.125 0.125 0.125 0.125 0.125 0.125 0.125 Wt-% binders 23.0 14.5 18.9 23.0 26.4 29.5 32.3 34.8 Strength (N/mm.sup.2) 23.8 37.5 33 42.1 46 50 48.8 48 Ratio (1.00 = reference) 1.00 1.58 1.39 1.77 1.93 2.10 2.05 2.02 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(12) TABLE-US-00008 TABLE 8 Geopolymer mixtures (G41-G44) comprising a combination of sucrose and acids Ref. G41 G42 G43 G44 (grams) Aggregate.sup.a 1350 1350 1350 1350 1350 PCFA.sup.b 350 350 350 350 350 Slag.sup.c 100 100 100 100 100 Alkaline liquid solution 160 160 160 160 160 Sucrose 0 1 1 1 1 Acid 0 1 1 1 1 Acid — Citric Tartaric Ascorbic Oxalic acid acid acid acid Molarity acid and sucrose 0 0.033 0.042 0.035 0.069 Strength (N/mm.sup.2) 23.8 38.5 40.5 38.3 35.2 Ratio (1.00 = reference) 1.00 1.62 1.70 1.61 1.48 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(13) TABLE-US-00009 TABLE 9 Geopolymer mixtures (G45-G47) with different additives Ref. G45 G46 G47 (grams) Aggregate.sup.a 1350 1350 1350 1350 PCFA.sup.b 350 350 350 350 Slag.sup.c 100 100 100 100 Alkaline liquid solution 160 160 160 160 Additive 0 1 1 1 Additive — Fructose Lactose Sodium gluconate Molarity NaOH 5.0 5.0 5.0 5.0 Molarity sodium silicate 0.125 0.125 0.125 0.125 Strength (N/mm.sup.2) 23.8 38.7 30.1 33.7 Ratio (1.00 = reference) 1.00 1.63 1.26 1.42 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag

(14) TABLE-US-00010 TABLE 10 Geopolymer mixtures (G48-G50) with different concentrations sodium hydroxide Ref. G48 G49 G50 (grams) Aggregate.sup.a 1350 1350 1350 1350 PCFA.sup.b 350 350 350 350 Slag.sup.c 100 100 100 100 Alkaline liquid solution 160 140 140 140 Sucrose 0 1 1 1 Molarity sucrose — 0.021 0.021 0.021 Molarity NaOH 5.6 1.0 2.0 3.0 Molarity sodium silicate 0.125 0.125 0.125 0.125 Strength (N/mm.sup.2) 18.4 5.3 28.0 31.0 Ratio (1.00 = reference) 1.00 0.29 1.52 1.68 .sup.aAggregate = mix of fine and coarse aggregate; .sup.bPCFA = powder coal fly ash; .sup.cSlag = blast furnace slag