Accelerator powder and quick-setting binder composition

Abstract

An accelerator powder for cement and also rapid-setting binder compositions which contain the accelerator powder and the use in mortar or concrete. The accelerator powder includes from 10 to 99.7% by weight of a water-insoluble mineral powder P and from 0.3 to 90% by weight of at least one compound V selected from the group consisting of alkali metal halides and alkaline earth metal halides, alkali metal nitrates and alkaline earth metal nitrates, alkali metal nitrites and alkaline earth metal nitrites, alkali metal thiocyanates and alkaline earth metal thiocyanates and hydroxyalkylamines or salts thereof, and mixtures thereof.

Claims

1. A mortar mixture comprising: from 55 to 85 parts by weight of sand having a particle size of not more than 4 mm, from 15 to 45 parts by weight of cement, from 5 to 45% by weight of mineral powder P, based on the weight of the cement, the mineral powder P having an average particle size in a range of from 1.1 to 8 μm, from 0.15 to 5.0% by weight of at least two different compounds V, based on the weight of the cement, the at least two different compounds V including a first compound V that is a hydroxyalkylamine or a salt thereof, wherein any further compounds V are selected from the group consisting of an alkali metal halide, an alkaline earth metal halide, an alkali metal nitrate, an alkaline earth metal nitrate, an alkali metal nitrite, an alkaline earth metal nitrite, an alkali metal thiocyanate, and an alkaline earth metal thiocyanate, from 0 to 1.0% by weight of plasticizer, based on the weight of the cement, from 0 to 1.0% by weight of retarder, based on the weight of the cement, and from 0 to 5% by weight of further additives, based on the weight of the cement, with all constituents being calculated as water-free components.

2. The mortar mixture according to claim 1, wherein the retarder is present in an amount in a range of from 0.1 to 0.8 w %, based on the weight of the cement.

3. The mortar mixture according to claim 1, wherein the mineral powder P is selected from the group consisting of calcium carbonate, dolomite, metakaolin and quartz flour.

4. The mortar mixture according to claim 1, wherein the hydroxyalkylamine has been partially or completely neutralized with an inorganic or organic acid.

5. The mortar mixture according to claim 1, wherein the retarder includes a hydroxycarboxylic acid.

6. The mortar mixture according to claim 1, wherein the retarder includes at least one selected from the group consisting of tartaric acid, citric acid, gluconic acid, and a salt thereof.

7. The mortar mixture according to claim 6, wherein the retarder includes tartaric acid or a salt thereof.

8. The mortar mixture according to claim 1, wherein the further additives include at least one selected from the group consisting of an antifoam, a wetting agent, a dye, a preservative, a plasticizer, a retarder, a polymer, an air pore former, a rheological auxiliary, a viscosity modifier, a shrinkage reducer, and a combination thereof.

9. A method of producing a shaped body comprising: mixing the mortar mixture according to claim 1 with water to form an aqueous mixture and curing the aqueous mixture to form the shaped body.

10. The method according to claim 9, wherein, after mixing the mortar mixture with water, the aqueous mixture has a commencement of setting of less than 90 minutes and an end of setting of less than 3 hours, measured using an automatic Vicat needle apparatus in accordance with DIN EN 196-3 at 20° C.

11. The method according to claim 9, wherein, after mixing the mortar mixture with water, the aqueous mixture has a viscosity in a range of from 1 to 100 Pa's at a shear rate of 10 s.sup.−1, where the viscosity is determined on a mortar sample which has a maximum particle size of 2 mm, using a rheometer.

12. A shaped body produced from the mortar mixture according to claim 1 after mixing with water and curing the resulting mixture.

Description

EXAMPLES

(1) Working examples which are intended to illustrate the invention described in more detail are set forth below. Of course, the invention is not restricted to these working examples described.

(2) 1. Materials Used

(3) Omyalite® 90 is a fine calcium carbonate powder having an average particle size D50 of 1.5 μm, obtainable from Omya, Switzerland. Nekafill® 15 is a fine calcium carbonate powder obtainable from Kalkfabrik Netstal, Switzerland.

(4) Sika® ViscoCrete®: pulverulent high-performance plasticizer Sika® ViscoCrete®-225 P based on modified polycarboxylate, obtainable from Sika Deutschland GmbH.

(5) RW füller is an uncompacted microsilica (amorphous SiO.sub.2) obtainable from RW silicium GmbH, Germany.

(6) 2. Composition and Production of the Accelerator Powders and Binder compositions

(7) Accelerator Powder B1 (Comparative Mixture)

(8) 0.8 g of sodium nitrate and 0.2 g of sodium thiocyanate were mixed.

(9) Accelerator Powder B2 (Comparative Mixture)

(10) 1.0 g of sodium nitrate and 1.0 g of sodium thiocyanate were mixed.

(11) Accelerator Powder B3 (Comparative Mixture)

(12) 0.25 g of sodium nitrate, 0.14 g of sodium thiocyanate, 0.11 g of N-methyldiethanolamine and 0.7 g of Sika® ViscoCrete®-225 P were mixed.

(13) Accelerator Powder B4 (According to the Invention)

(14) 10 g of Omyalite® 90 were mixed with 0.2 g of N-methyldiethanolamine. Accelerator powder B5 (According to the Invention) 10 g of Omyalite® 90 were mixed with 1.0 g of sodium nitrate and 0.2 g of N-methyldiethanolamine.

(15) Accelerator Powder B6 (According to the Invention)

(16) 10 g of Omyalite® 90 were mixed with 0.25 g of sodium nitrate, 0.14 g of sodium thiocyanate, 0.11 g of N-methyldiethanolamine and 0.7 g of Sika® ViscoCrete®-225 P.

(17) Accelerator Powder B7 (According to the Invention)

(18) 10 g of Nekafill® 15 were mixed with 0.25 g of sodium nitrate, 0.14 g of sodium thiocyanate, 0.11 g of N-methyldiethanolamine and 0.7 g of Sika® ViscoCrete®-225 P.

(19) Accelerator Powder B8 (According to the Invention)

(20) 10 g of Omyalite® 90 were mixed with 0.2 g of sodium nitrate, 0.13 g of sodium thiocyanate, 0.1 g of N-methyldiethanolamine and 0.2 g of Sika® ViscoCrete®-225 P.

(21) Accelerator Powder B9 (According to the Invention)

(22) 20 g of Omyalite® 90 were mixed with 0.2 g of sodium nitrate and 0.8 g of sodium thiocyanate.

(23) Accelerator Powder B10 (According to the Invention)

(24) 10 g of Omyalite® 90 were mixed with 1.0 g of sodium nitrate, 0.2 g of sodium thiocyanate and 0.1 g of N-methyldiethanolamine.

(25) Accelerator Powder B11 (According to the Invention)

(26) 5 g of RW füller were mixed with 1.0 g of sodium nitrate, 0.2 g of sodium thiocyanate and 0.1 g of N-methyldiethanolamine.

(27) Accelerator Powder B12 (According to the Invention)

(28) 10 g of Omyalite® 90 were mixed with 1.0 g of sodium nitrate, 0.2 g of sodium thiocyanate, 0.1 g of N-methyldiethanolamine and 0.05 g of tartaric acid.

(29) Accelerator Powder B13 (According to the Invention)

(30) 10 g of Omyalite® 90 were mixed with 1.0 g of sodium nitrate, 0.2 g of sodium thiocyanate and 0.1 g of triethanolamine.

(31) Rapid-Setting Binder Composition M1 (According to the Invention)

(32) 90 g of cement (CEM I 52.5) were mixed with 10.63 g of accelerator powder B8.

(33) Rapid-Setting Binder Compositions M2 and M3 (According to the Invention)

(34) M2 and M3 were produced like M1 but 0.2 g of tartaric acid in the case of M2 and 0.4 g of tartaric acid in the case of M3 were added to the accelerator powder B8. Correspondingly, 10.83 g of accelerator powder in the case of M2 and 11.03 g of accelerator powder in the case of M3 were mixed with 90 g of cement.

(35) 3. Use Tests

(36) The commencement of setting and the end of setting were determined by means of an automatic Vicat needle apparatus in accordance with DIN EN 196-3, at 20° C.

(37) The setting time is for the purposes of this document the time interval between the end of mixing and the commencement or end of setting.

(38) The compressive strength was determined on test specimens having dimensions of 40×40×160 mm in accordance with DIN EN 196-1. The test specimens were stored covered in the mold at 20° C. until testing was carried out.

(39) 3.1 Testing of the Accelerator Powders in Cement Paste

(40) The cement and the accelerator powder were mixed for 30 seconds in a mixer (KitchenAid model ARTISAN, 5KSM150). The water in which the fluidizer had been dissolved was subsequently added and the cement paste was mixed for a further 3 minutes.

(41) The composition of the cement pastes and the setting times measured and also compressive strengths after 2 hours are reported in Table 1 and Table 2.

(42) TABLE-US-00001 TABLE 1 T1* T2* T3* T4* T5 T6 T7 Cement CEM I 100 90 100 100 90 90 80 52.5 R (g) Accelerator — Omya- B1 B2 B4 B5 B9 powder lite ® 90 Amount (g) — 10.0 1.0 2.0 10.2 11.2 21.0 Sika ® 0.2 0.2 0.2 0.2 0.2 0.2 0.2 ViscoCrete ® (g) Water (g) 23 23 23 23 23 23 23 Commencement  8:38 4:01 3:42 3:57 0:03 0:02 2:09 of setting (h:min) End of setting 10:53 6:38 7:31 7:17 0:13 0:07 5:39 (h:min) *Reference mixture

(43) TABLE-US-00002 TABLE 2 T8 T9 T10 T11 Cement CEM I 90 95   90 90 52.5 R (g) Accelerator B10 B11 B12 B13 powder Amount (g)   11.3  6.3. 11.35 11.3 Sika ®   0.2 0.2 0.2 0.2 ViscoCrete ® (g) Water (g) 23 25.sup.1) .sup.  23 23 Commencement 0:03 0:07 0:07  n.m..sup.2) of setting (h:min) End of setting 0:07 0:10 0:11 n.m. (h:min) Compressive   10.4 8.5 10.7 n.m  strength after 2 hours (MPa) .sup.1)In order to be able to process the cement paste, 25 g of water rather than 23 g of water had to be added. .sup.2)n.m: not measurable; setting commences during mixing.

(44) 3.2 Testing of the Rapid-Setting Binder Compositions M1 to M3

(45) The binder compositions M1, M2 and M3 were mixed in the amounts indicated in Table 2 with water in a mixer (KitchenAid model ARTISAN, 5KSM150) for 3 minutes. Commencement of setting and end of setting of the mixtures were subsequently determined. The values found are reported in Table 3.

(46) TABLE-US-00003 TABLE 3 T12 T13 T14 Binder composition M1 M2 M3 Amount (g) 100.63 100.83 101.03 Water (g) 22.5 22.5 22.5 Commencement of setting 0:11 0:18 0:41 (h:min) End of setting (h:min) 0:16 0:36 1:26

(47) 3.3 Testing of the Accelerator Powders in a Mortar Mixture

(48) The cement was homogeneously mixed with the accelerator powder in a mixer (KitchenAid model ARTISAN, 5KSM150). The sand and the water were subsequently added and the mortar was mixed again for 3 minutes. The composition of the mortars and the setting times measured are reported in Table 4.

(49) TABLE-US-00004 TABLE 4 T15* T16* T17* T18* T19 T20 Sand 0.08/2 300 300 300 300 300 300 mm (g) Cement CEM I 100 100 100 100 100 100 52.5 (g) Accelerator — B3 Omya- Nekafill ® B6 B7 powder lite ® 90 15 Amount (g) —    1.2 10 10   11.2   11.2 Sika ® 0.5 — 0.7 0.7 — — ViscoCrete ® (g) Water (g) 39  39 39 39  39  39 Commencement 5:49 4:09 5:40 7:10 0:12 0:13 of setting (h:min) End of setting 8:39 6:58 7:34 9:27 0:44 1:17 (h:min) *Reference mixture