INORGANIC BINDER SYSTEM COMPRISING BLAST FURNACE SLAG AND SOLID ALKALI METAL SILICATE

Abstract

The present invention relates to an inorganic binder system comprising blast furnace slag, and at least one solid alkali metal silicate, wherein the inorganic binder system is obtainable by co-grinding a mixture comprising the blast furnace slag and the at least one solid alkali metal silicate.

Claims

1. An inorganic binder system comprising (i) blast furnace slag, and (ii) at least one solid alkali metal silicate having the empirical formula m SiO.sub.2.n M.sub.2O, wherein M is selected from the group consisting of Li, Na, K and mixtures thereof, and wherein the inorganic binder system is obtained by co-grinding a mixture comprising the blast furnace slag and the at least one solid alkali metal silicate.

2. The inorganic binder system according to claim 1, wherein the blast furnace slag comprises from 30 to 45% by weight of CaO, 4 to 17% by weight of MgO, 30 to 45% by weight of SiO.sub.2, and 5 to 15% by weight of Al.sub.2O.sub.3.

3. The inorganic binder system according to claim 1, wherein the molar ratio of m:n is ≤4.0.

4. The inorganic binder system according to claim 1, wherein the weight ratio of the blast furnace slag and the at least one solid alkali metal silicate is in the range from 500:1 to 1:5.

5. The inorganic binder system according to claim 1, having a Blaine value in the range from 200 to 1000 m.sup.2/kg, as determined according to DIN EN 196-6.

6. The inorganic binder system according to claim 1, wherein co-grinding is performed using a ball mill, a planetary mill, a disc mill, a rotor mill, a vertical mill or a mortar grinder.

7. The inorganic binder system according to claim 1, wherein the blast furnace slag is granulated blast furnace slag or ground granulated blast furnace slag.

8. The inorganic binder system according to claim 1, further comprising at least one additional inorganic binder selected from the group consisting of hydraulic binders, latent hydraulic binders, pozzolanic binders and mixtures thereof.

9. The inorganic binder system according to claim 8, wherein the pozzolanic binder is selected from the group consisting of precipitated silica, pyrogenic silica, microsilica, ground glass, brown coal fly ash, mineral coal fly ash, metakaolin, pozzolana, tuff, trass, volcanic ash, natural and synthetic zeolites and mixtures thereof.

10. The inorganic binder system according to claim 1, wherein the inorganic binder system further comprises at least one additive.

11. A process for the manufacture of the inorganic binder system as defined in claim 1, comprising co-grinding a mixture comprising (i) the blast furnace slag, and (ii) the at least one solid alkali metal silicate, and optionally mixing the obtained co-ground mixture with at least one additional inorganic binder and/or at least one additive, to obtain the inorganic binder system.

12. The process according to claim 11, wherein the blast furnace slag comprises from 30 to 45% by weight of CaO, 4 to 17% by weight of MgO, 30 to 45% by weight of SiO.sub.2 and 5 to 15% by weight of Al.sub.2O.sub.3.

13. The process according to claim 11, wherein the co-grinding is performed using a ball mill, a planetary mill, a disc mill, a rotor mill, a vertical mill or a mortar grinder.

14. The process according to claim 11, wherein co-grinding is performed until the co-ground mixture has a Blaine value in the range from 200 to 1000 m.sup.2/kg, as determined according to DIN EN 196-6.

15. An inorganic binder system, obtained according to the process according to claim 1.

16. A method of utilizing the inorganic binder system as defined in claim 1 for improving the mechanical properties and/or the durability of construction materials.

17. A method of utilizing the inorganic binder system as defined in claim 1 as a constituent of construction material formulations and/or building products.

18. A cement, mortar or concrete containing the inorganic binder system as defined in claim 1.

19. The inorganic binder system according to claim 3, wherein the molar ratio of m:n is ≤3.8.

20. The inorganic binder system according to claim 4, wherein the weight ratio of the blast furnace slag and the at least one solid alkali metal silicate is in the range from 30:1 to 1:1.

21. The inorganic binder system according to claim 10, wherein the at least one additive is selected from the group consisting of grinding aids, fillers, accelerators, retarders, rheology modifiers, plasticizers, fibers, alkaline activators, surfactants and mixtures thereof.

22. The method of claim 17 wherein the construction material formulations and/or building products are selected from the group consisting of concrete, finished concrete parts, concrete goods, concrete blocks and also on-site concrete, sprayed concrete, ready-mixed concrete, building adhesives and thermal insulation composite system adhesives, concrete repair systems, one-component and two-component sealing slurries, screeds, knifing fillers and self-levelling compositions, tile adhesives, plasters and renders, adhesives and sealants, coating systems, in particular for tunnels, wastewater channels, spray protection and condensate lines, dry mortars, joint grouts, drainage mortars, repair mortars and mixtures thereof.

Description

EXAMPLES

[0093] Sample Preparation

[0094] All dry substances are first homogenized and then mixed with water. The mixing is done with a drill and a disc stirrer at medium speed. The mixture is first stirred for about one minute until a homogeneous mass is obtained. After allowing the mixture to stand for three minutes, the mixture is stirred up again and applied in to a mold, so that specimens having 20 mm in diameter and 40 mm height are obtained. The mold is covered to prevent drying. The specimens are removed from the mold after storage for 24 hours (at 23° C.) and then stored for further 6 days (at 23° C. and 50% relative humidity). After a total of seven days, resistance tests are carried out on the specimens.

[0095] Resistance Tests

[0096] For resistance tests, a specimen is weighed and placed in a plastic bottle (250 ml) filled with 200 g of a medium. 50 g of coarse quartz sand is added to the bottle to provide abrasion during the test. Thereafter, the bottle is rotated for 2.5 hours in an overhead mixer. The specimen is then removed from the bottle, dried and weighed again. The percentage of mass before and after the resistance test is used to assess the resistance. The resistance is tested in three media: water, 1 molar NaOH and 1 molar HCl.

Example 1

[0097] In Example 1, two reference mortars were prepared with the ingredients shown in Table 1.

TABLE-US-00001 TABLE 1 (all ingredient units are given in grams) Ingredients M1 M2 Blast furnace slag 150 150 Metakaolin 90 90 Quartz sand 622 639 Sodium water glass (modulus 1.0) 23 6 Potassium water glass (modulus 3.6) 115 Potassium water glass (modulus 2.4) 115 Water 250 200

Example 2

[0098] In Example 2, the potassium water glass used for references M1 and M2 was co-ground with the blast furnace slag used for references M1 and M2 for two minutes using a planetary ball mill. The obtained co-ground powder was then used in the formulations M1a and M2a shown in Table 2.

TABLE-US-00002 TABLE 2 (all ingredient units are given in grams) Ingredients M1a M2a Metakaolin 90 90 Quartz sand 622 639 Sodium water glass (modulus 1.0) 23 6 Co-ground potassium water glass 265 (modulus 3.6) including blast furnace slag Co-ground potassium water glass 265 (modulus 2.4) including blast furnace slag Water 250 200

[0099] The resistances are shown in Table 3. Particularly, the resistances in NaOH significantly increased from 11% (M1) to 90% (M1a), as well as from 13% (M2) to 96% (M2a).

TABLE-US-00003 TABLE 3 Medium M1 M1a M2 M2a 1M HCl 88% 88% 96% 96% 1M NaOH 11% 90% 13% 96% Water 23% 95% 42% 98%