Biopolymer Cement Additive

Abstract

The present invention is directed to a biopolymer cement additive, a biopolymer cement composition containing the additive, the use of the additive for the production of, mortar or concrete and a process for the preparation of concrete or mortar implementing the biopolymer cement additive.

Claims

1. Biopolymer cement additive which allows a spread increase of at least 20% when admixed to a concrete or mortar product comprising a beta-glucan with a molecular weight distribution with a maximum of from 0.1 to 5.0 Million Daltons (MegaDaltons).

2. Biopolymer cement additive according to claim 1, wherein the beta-glucan has been produced by a fungus belonging to the genus Aureobasidium.

3. Biopolymer cement additive according to claim 1, wherein the biopolymer cement additive is a dry composition and further contains from 10 to 80 wt.-% melanin.

4. Biopolymer cement additive according to claim 1, wherein the additive is a liquid formulation containing from 85 to 99.9 wt.-% water and from 0.1 to 15 wt.-% of the beta-glucan with a molecular weight distribution with a maximum of from 0.1 to 5.0 Million Daltons (MegaDaltons).

5. Biopolymer cement additive according to claim 4 containing from 0.05 to 10 g/l melanin.

6. Biopolymer cement additive according to claim 4, wherein the pH value of the liquid formulation is selected from the range of from pH 2 to pH 8.

7. Biopolymer cement additive according to claim 4, containing one or more metal ions selected from the group consisting of Al3+, Fe3+, Ca2+, Mg2+and Mn2+ in a concentration of from 1 to 100 mmol.

8. Biopolymer cement composition containing the biopolymer cement additive according to claim 1.

9. Biopolymer cement composition according to claim 8, wherein the cement is hydraulic or non-hydraulic cement.

10. Biopolymer cement composition according to claim 9, wherein the hydraulic cement is Portland cement.

11. Biopolymer cement composition according to claim 8, wherein the composition further contains at least one component selected from the group consisting of fillers such as silica sand, quartz sand, quartz flour, calcium carbonate, dolomite, aluminum silicates, talc or mica, or light weight fillers such as pumice, foamed glass, aerated concrete, perlites or vermiculites; alkali metal hydroxides and/or alkaline earth metal hydroxides such as zinc oxide, zinc hydroxide and zinc hydroxide carbonate; accelerators such as lithium carbonate or tartaric acid; defoamers; liquefiers; dispersants; and mixtures thereof.

12. Biopolymer cement composition according to claim 8, wherein the biopolymer cement additive is present in a concentration of from 0.0005 to 0.1 wt.-%.

13. Biopolymer cement composition according to claim 8, wherein the biopolymer cement composition contains from 0.001 to 0.1 wt.-% (weight KAl(SO.sub.4).sub.2x12H.sub.2O to weight biopolymer cement composition) KAl(SO.sub.4).sub.2x12H.sub.2O.

14. Biopolymer cement composition according to claim 8, wherein the biopolymer composition contains from 0.0005 to 5 wt.-% of a clay mineral.

15. Biopolymer cement composition according to claim 14, wherein the composition contains (i) from 0.0005 to 0.005 wt.-% of a biopolymer cement additive which allows a spread increase of at least 20% when admixed to a concrete or mortar product, the additive comprising a beta-glucan with a molecular weight distribution with a maximum of from 0.1 to 5.0 Million Daltons (MegaDaltons), and (ii) from 0.0005 to 0.005 wt.-% of a clay mineral selected from sheet silicates selected from the group consisting of halloysite (Al.sub.2Si.sub.2O.sub.5(OH).sub.4), kaolinite (Al.sub.2Si.sub.2O.sub.5(OH).sub.4), illite ((K, H.sub.3O)(Al, Mg, Fe).sub.2(Si, Al).sub.4O.sub.10[(OH).sub.2, (H2O)]), montmorillonite ((Na, Ca).sub.0.33(Al, Mg).sub.2Si.sub.4O.sub.10(OH).sub.2.nH.sub.2O), vermiculite ((MgFe, Al).sub.3(Al, Si).sub.4O.sub.10(OH).sub.2..sub.4H.sub.2O), talc (Mg.sub.3Si.sub.4O.sub.10(OH).sub.2), sepiolite (Mg.sub.4Si.sub.6O.sub.15(OH).sub.2..sub.6H.sub.2O), attapulgite ((Mg, Al).sub.2Si.sub.4O.sub.10(OH)..sub.4(H.sub.2O)), pyrophyllite (Al.sub.2Si.sub.4O.sub.10(OH).sub.2) and mixtures thereof.

16. Biopolymer cement composition according to claim 14, wherein the ratio of the concentration of the biopolymer cement additive to the concentration of the clay mineral is selected from the range of from 1:9 to 9:1 and wherein the total concentration of the biopolymer cement additive and the clay mineral within the biopolymer cement composition is from 0.0005% to 0.1 wt.-%.

17. Process for the production of concrete or mortar comprising the steps (a) providing from 100 to 10000 kg sand and/or gravel; (b) addition of from 2.5 to 40 wt.-% (weight of cement to weight sand and/or gravel) cement to the sand and/or gravel; (c) addition of from 3 to 20 wt.-% (weight of water to total weight of sand and/or gravel and cement) (d) of water to the sand and/or gravel; and cement; (e) addition of from 0.001 to 0.1 wt.-% (weight of biopolymer to total weight of water, sand and/or gravel and cement) (f) of the biopolymer cement additive according to claim 4; to the sand and/or gravel; cement and water; (g) mixing components (a) to (d) for a time period of from 5 minutes to 5 hours.

18. Process for the production of concrete or mortar comprising the steps (a) providing from 100 to 10000 kg sand and/or gravel; (b) addition of from 2.5 to 40 wt.-% of the biopolymer cement composition according to claim 8 to the sand and/or gravel; (c) addition of from 3 to 20 wt.-% of water to the sand and/or gravel; and biopolymer cement composition; (d) mixing components (a) to (d) for 5 minutes to 5 hours.

19. Process for the production of concrete or mortar comprising the steps (a) providing from 100 to 10000 kg sand and/or gravel; (b) addition of from 2.5 to 40 wt.-% cement to the sand and/or gravel; (c) addition of from 0.00001 to 0.001 wt.-% of the biopolymer cement additive according to claim 1; to the sand and/or gravel; and cement; (d) addition of from 3 to 20 wt.-% of water to the sand and/or gravel; cement and biopolymer cement additive; (e) mixing components (a) to (d) for a time period of from 5 minutes to 5 hours.

20. (canceled)

Description

MATERIALS

[0090]

TABLE-US-00001 TABLE 1.1 Biopolymer cement compositions Mix 1 Mix 2 Mix 3 Mix 4 Mix 5 Mix 6 Mix 7 Mix 8 Sand  1350 g  1350 g  1350 g  1350 g  1350 g  1350 g  1350 g  1350 g Cement   540 g   540 g   540 g   540 g   540 g   540 g   540 g   540 g Water 216.5 g 216.5 g 216.5 g 216.5 g 216.5 g 216.5 g 216.5 g 216.5 g Liquefier  2.6 g  2.6 g  2.6 g  2.6 g  2.6 g  2.6 g  2.6 g  2.6 g Rehydrated    6 g biopolymer cement additive dry composition with 0.5 wt.-% beta glucan Biopolymer    6 g cement additive containing 0.5 wt.-% beta glucan Biopolymer    6 g cement additive containing 0.5 wt.-% beta glucan and 0.6 wt.-% melanin 5 g/l rehydrated    6 g Kelco-Crete 5 g/l rehydrated    6 g Xanthan Actigum CS6    6 g Ceratofix XXMG    6 g

TABLE-US-00002 TABLE 1.2 Mortar compositions cont. Mix 9 Mix 10 Mix 11 Mix 12 Mix 13 Mix 14 Sand  1350 g  1350 g  1350 g  1350 g  1350 g  1350 g Cement   540 g   540 g   540 g   540 g   540 g   540 g Water 216.5 g 216.5 g 216.5 g 216.5 g 216.5 g 211.5 g Liquefier  2.6 g  2.6 g  2.6 g  2.6 g  2.6 g  2.6 g Bentone EW    6 g Biopolymer    3 g    3 g    6 g    6 g    6 g cement additive containing 0.5 wt.-% beta glucan Bentone EW    3 g    6 g Potassium alum  0.1 g Potassium alum  0.1 g dissolved in 4.9 g water

TABLE-US-00003 TABLE 2 Standard sand size distribution mesh Sieve transition in Mass percent 4.0 100 2.0  90-100 1.0 60-90 0.5 40-75 0.25 25-50 0.125 10-30 0.063  0-10

[0091] The added water was demineralized water.

[0092] The cement was of the type CEM II/A-S 32,5 purchased from Schwenk.

[0093] The liquefier was Conpaq 149s purchased from Peramin.

[0094] Potassium alum is Aluminium potassium sulfate dodecahydrate (KAl(SO.sub.4).sub.2x12H.sub.2O) and was purchased from Sigma-Aldrich.

[0095] Xanthan was purchased from Sigma-Aldrich

[0096] Ceratofix XXMG (montmorrilonite clay mineral product) was purchased from Clariant and Bentone EW (saponite clay mineral product) was purchased from Elementis.

[0097] Potassium alum was purchased from Sigma-Aldrich.

[0098] All solid additives were rehydrated by vigorous stirring for 1 h and subsequent storage at 40° C. for 16 h.

Example 1

[0099] 1350 g standard sand according to DIN EN 480-13 was placed in a mixing bowl. 540 g of cement was added. The components were mixed with an electric mixer for 30 s. Over the course of 30 s the residual components as aqueous solution containing the components as listed in Table 1.1 and Table 1.2 were added to the stirred sand/cement mixture. The mixing was subsequently continued for one minute, followed by a pause of 1 minute and an additional mixing of one minute. The final mixture was then added to a flow mold with a bottom radius of 5 cm placed on a flow table. The excess material was leveled off. The flow mold was lifted, and the diameter of the resulting cake was measured. This gave the spread before shaking (see Table 3). The flow table was then raised and dropped 12.5 mm 15 times in 15 seconds and the diameter of the mortar cake was measured again and gave the spread after shaking (Table 3). The data are shown in FIG. 1. The spread increase as defined above is depicted in FIG. 2.

TABLE-US-00004 TABLE 3 Measured spreads before and after shaking. Spread before shaking [cm] Spread after shaking [cm] Mix 1 23 26 Mix 2 18,5 23,5 Mix 3 18,5 24 Mix 4 15,5 21,5 Mix 5 20,5 24 Mix 6 19 22 Mix 7 23,5 27 Mix 8 23,5 26,5 Mix 9 19,5 22 Mix 10 19,5 24,5 Mix 11 21 26 Mix 12 20 24,5 Mix 13 17 23 Mix 14 17 23

Example 2

[0100] 350 g standard sand according to DIN EN 480-13 and 1000 g gravel (Gravel 2/8 purchased from Schwenk) was placed in a mixing bowl. 540 g of cement was added. The components were mixed with an electric mixer for 30 s. Over the course of 30 s an aqueous solution containing 216.5 g water, 2.6 g liquefier and 6 g of 5 g/l beta glucan containing fermentation broth were added to the stirred sand/cement mixture. The mixing was subsequently continued for one minute, followed by a pause of 1 minute and an additional mixing of one minute. The final mixture was then added to a flow mold with a bottom radius of 5 cm placed on a flow table. The excess material was leveled off. The flow mold was lifted, and the diameter of the resulting cake was measured. The spread increase was 28%.

Example 3

[0101] 1350 g standard sand according to DIN EN 480-13 was placed in a mixing bowl. 540 g of cement was added. 60 mg of a 60% melanin containing dry biopolymer cement additive was added to the mixing bowl. The components were mixed with an electric mixer for 30 s. Over the course of 30 s an aqueous solution containing 216.5 g water and 2.6 g PCE added to the stirred sand/cement mixture. The mixing was subsequently continued for one minute, followed by a pause of 1 minute and an additional mixing of one minute. The final mixture was then added to a flow mold with a bottom radius of 5 cm placed on a flow table. The excess material was leveled off. The flow mold was lifted, and the diameter of the resulting cake was measured. The spread increase was 33%.