AT8344U1 - HEATING AND CURING ACCUMULATOR FOR HYDRAULIC BINDER - Google Patents

Abstract

For use in the wet spraying process suitable solidification and hardening accelerators for hydraulic binders, obtainable by a process in which the following components component a: basic aluminum salts and / or aluminum hydroxide component b: aluminum sulfate and / or sulfuric acid component c: organic carboxylic acids or mixtures of at least two of organic carboxylic acids component d: aluminum salts of organic carboxylic acids component e: organic and / or inorganic sulfates and / or hydrogen sulfates and / or carbonates and / or bicarbonates and / or alkaline earth oxides and / or alkaline earth metal oxides are reacted at temperatures up to 150 ° C in water , so that thereby a solution is obtained, wherein 1. all components or a selection of components react with each other, so that the molar ratios of aluminum to sulfate in the final product 0.83 to 13.3 and the molar ratios of aluminum to the organic carboxylic acid 0.67 b is 33.3 or 2. all components except component e or a selection of the components except component e react with each other so that the molar ratios of aluminum to sulfate in the final product 0.83 to 13.3 and the molar ratios of aluminum to organic carboxylic acid in Or 3. the component e is subsequently dissolved in the reaction product according to item 2.

Description

2 AT 008 344 U1

The present invention provides stable solidification and hardening accelerators for hydraulic binders in dissolved form, as well as their preparation and use.

EP 0 76 927 B1 discloses an alkali-free setting accelerator based on aluminum-5-hydroxyd. The further constituents of this composition are according to claim 1 at least one water-soluble sulfate and / or nitrate and / or formate of alkaline earth and transition metals, which are added to the main component by simple admixing. From page 2, line 55 it is also clear that this agent is a powdery mixture which is added to the hydraulic binder in solid form. 10

Merely to avoid excessive dust development, water-swellable compounds are added to the mixture.

DD 266 344 A1 describes cationic aluminum salts obtained by the reaction of a precipitated aluminum hydroxide with concentrated formic, acetic or nitric acid, which are mixed into the corresponding hydraulically setting cement or mortar in the form of a powder. The compounds resulting from the reaction of the aluminum hydroxide with the corresponding acids can be described by a general formula, e.g. Al (OH) 2 R x H 2 O, Al (OH) 2 x H 2 O or AIR 3 x H 2 O. These aluminum salts 20 contain no sulfate and chloride ions.

FR-2,471,955 describes a process for the accelerated setting of cement, characterized in that the accelerating agent used is bisulfite-formaldehyde, calcium formate and calcium nitrate in the form of a solution, e.g. see page 3, from 25 lines 19, examples.

Finally, EP 0 657 398 A1 has also disclosed a process for accelerating the setting of hydraulic binders, which is characterized in that the accelerating agent is a mixture comprising at least one water-soluble sulfate of a multivalent cation, in particular of aluminum, and another water-insoluble component , eg Calcium sulfoaluminate, calcium aluminate, basic aluminum sulfate and at least one other component. This further component may be according to claim 24, a dispersant, an inorganic binder, a condenser or a deaerating agent. 35

The setting accelerator should also be able to be applied in the form of an aqueous dispersion.

Tying accelerators are particularly interesting for the practice when they are usable in liquid form 40.

Compared to the solid accelerators is essentially their better dosability, the faster release of the active substance (s) and of course the negligible dust or aerosol development during handling. 45

The classic liquid alkaline accelerators, e.g. Sodium aluminate and waterglass are corrosive not only because of their high pH, but also lead to the high alkali metal entry into the concrete to z.T. massive drop in final strength. More recent, liquid accelerators consist mainly of aqueous suspensions of basic aluminum sulfates. They are, however, generally not frost-stable, tend to sedimentation and show, although they would be applicable in liquid form in the wet spraying process, insufficient early strength development and also act depending on the type of cement only weakly accelerating. 55 3 AT 008 344 U1

Other commercially available concentrated aluminum salt solutions, e.g. Al 2 (SO 4) 3 with approx. 8% Al 2 O 3 or aluminum triformate solutions with approx. 5% Al 2 O 3 are not suitable at least for the wet spraying process because they have an undesirably low water content because of the increased water input into the concrete mass and the associated increased water-cement factor Pressure resistance condition.

It is an object of the present invention to provide a concentrated solidification and hardening accelerator for hydraulic binders dissolved in water which does not have the disadvantages of the classical liquid accelerators such as sodium aluminate or water glass and which is well suited for the wet spraying process ,

Surprisingly, the problem could be solved by new liquid solidification and hardening accelerators for hydraulic binders, such as cement, which are obtainable by a process which is characterized in that the following components 15

Component a: Component b: Component c: Component d: Component e: 20 basic aluminum salts and / or aluminum hydroxide aluminum sulfate and / or sulfuric acid organic carboxylic acids or mixtures of at least two of the organic carboxylic acids

Aluminum salts of organic carboxylic acids organic and / or inorganic sulfates and / or hydrogen sulfates and / or carbonates and / or bicarbonates and / or alkaline earth oxides and / or alkaline earth metals are reacted at temperatures up to 150 ° C in water, thereby obtaining a solution in which all components or a selection of the components react with one another such that the molar ratios of the aluminum to sulfate in the end product are from 0.83 to 13.3 and the molar ratios of the aluminum to the organic carboxylic acid are from 0.67 to 33.3 or 2. all components except component e or a selection of components other than component e react with each other such that the molar ratios of aluminum to sulfate in the final product are 0.83 to 13.3 and the molar ratios of aluminum to organic carboxylic acid in the final product is 0.67 to 33.3, or 3. the component e is subsequently dissolved in the reaction product according to point 2. The basic aluminum salts used are preferably the basic sulfates, carbonates, carbonate sulfates and nitrates and mixtures of at least two of these components.

The organic carboxylic acids are essentially the monocarboxylic acids, hydroxycarboxylic acids and dicarboxylic acids, e.g. Formic acid, acetic acid, glycolic acid, lactic acid and mixtures thereof.

The inorganic and organic sulfates or hydrogen sulfates used are the alkaline earth salts and / or triethanolamine salts and / or diethanolamine salts of sulfuric acid. But also the alkali salts of sulfuric acid come as sulfate or hydrogen sulfate for Ver 45 turn.

As carbonates and / or bicarbonates, the alkaline earth metal salts can be used. Furthermore, it is also possible to use alkaline earth oxides or alkaline earth metal hydroxides. Thus, the setting accelerators according to the invention may be used together with other compounds, e.g. Retarders, condensers and rebound reducers are used.

The following examples illustrate the subject matter of the invention in more detail without limiting it: 55 4 AT 008 344 U1

Preparation Examples:

EXAMPLE 5 5,755 g of basic aluminum carbonate (17.77% Al 2 O 3) were slurried in 90 g of formic acid 85% and admixed with 324 g of aluminum sulfate (17.5% Al 2 O 3). With stirring, a nearly clear solution was obtained at a temperature of 50 to 60 ° C after 1.5 hours. The solution is stable for a period of more than 3 months. Example 2 490 g of basic aluminum sulphate (16.7% Al 2 O 3) were slurried in 36.9 g of lactic acid 80%, and 375 g of aluminum sulphate (17.5% Al 2 O 3) were added. With stirring, a slightly turbid solution was obtained at a temperature of 51 to 72 ° C after 1.5 hours. 15

Example 3 To 500 g of basic aluminum sulfate (17.8% Al 2 O 3) was added 76 g of oxalic acid dihydrate and 375 g of aluminum sulfate (17.5% Al 2 O 3). With stirring, a clear solution was obtained at a temperature of 20 75 ° C after 1 hour. The solution was concentrated to a weight of 846.5 g.

Example 4 25 101 kg of basic aluminum carbonate (19.15% Al 2 O 3) were dissolved in 8.2 kg of water and 15.2 kg

Formic acid 85% slurried and mixed with 72 kg of aluminum sulfate (17.5% Al203). With stirring, an almost clear solution was obtained at a temperature of 35 to 80 ° C after 3 hours. The solution is stable for a period of more than 3 months. EXAMPLE 5 101 kg of basic aluminum carbonate (19.15% Al 2 O 3) were suspended in 85% strength in 8.3 kg of water and 14.5 kg of formic acid, and 65.1 kg of aluminum sulfate (17.5% Al 2 O 3) were added. With stirring, an almost clear solution was obtained at a temperature of 33 to 62 ° C after 4 hours.

Example 6

In 500 g of the solution from Example 5 were dissolved 67.7 g of magnesium sulfate (27.5 MgO). 40

Example 7 105.5 g of aluminum triformate (11.7% Al, 61.3% formic acid) were mixed with 356.3 g of basic aluminum carbonate sulfate (18.4% Al 2 O 3) and 375 g of aluminum sulfate (17.5% Al 2 O 3). 45 A slightly turbid solution was obtained with stirring at a temperature of 75 ° C. after 90 minutes.

Comparative Example 1: dispersion of a basic aluminum carbonate sulfate with 16.5% Al 2 O 3 Comparative Example 2

Dispersion of a basic aluminum sulfate with 16% Al 2 O 3 55 5 5 5 AT 008 344 U1

Table 1: 10 15 20

Effect of the compounds according to the invention on the setting times Accelerator from Konz, Portland cement Cement Setting beginning (sec) Setting end (sec) Example 1 10% A 195 390 Example 2 10% A 240 450 Example 3 10% A 240 360 Example 4 7.3% B 75 180 Example 5 5% C 135 240 Example 6 7.5% B 80 200 Example 7 6.5% B 90 240 Comparative Example 1 5% A> 500 nb Comparative Example 1 10% A> 500 n.b. Comparative Example 2 5% A> 500 n.b. Comparative Example 2 10% A> 500 n.b. Comparative Example 1 10% B> 500 n.b. Comparative Example 1 10% C> 500 n.b. 25 A, B and C are Portland cements from different manufacturers.

The setting times were determined on the basis of the Vicat method. In each case, 290 g of Portland cement and 2.9 g of liquefier (1%) were used. The W / Z value was 0.41. The cement was stirred for 30 minutes and then accelerated.

Experiments in the wet spraying process with the setting accelerators according to the invention

Machine: Schwing concrete pump PB 750 RE with accelerator metering device Top-Shot 35 nozzle 40 45 50

Hose diameter 65 mm Spray hose diameter 50 mm Spraying hose length 5 m Material throughput in kg / min 162 rebound in% 3,5 Sieving line B8 Cement content of PZ-C in kg / m3 425 W / Z value 0,485 Condenser in% 1,3 Retarder in% 0, 1 Accelerator from example 5, 6.6% early strength Kaindl-Meyco method hardened concrete test core 0 10 cm slump approx. 50 cm 55

Claims (9)

6 AT 008 344 U1 Table 2: Compressive strengths in N / mrr? Time Accelerator from example 5, 6.6% without accelerator 1 h 1.4 - 2h 2.0 - 4h 3.7 - 6 h 6.9 - 8 h 9.5 - 24 h 14.1 - 2 d 29 - 7 d 36 - 28 e 51 55 All data are based on 2 parallel experiments Table 3: Effect of compounds of the invention on early strength development Early strengths in N / mrr? with accelerators off: Time (h) Ex.4 (5.9%) Ex.6 (6.7%) Ex 4 (Freeze 5.9%) Ex 6 (Freeze 6) 2 1.41 1 , 56 1.5 1.6 6 4.5 5.4 4.9 6.2 8 5.8 7.2 6.1 8.2 24 17.9 21.8 19.0 22.5 The strengths were in accordance with DIN 1164, part 7 examined. The following modifications were made: Surcharge: 0-8 mm W / Z Value: 0.55 Liquifier: 1.5% Accelerator addition: 60 min after the concrete is made Portland cement: 400 kg / m3 (grade B) Claims: 1. For the Use in the wet spraying process suitable solidification and hardening accelerators for hydraulic binders, obtainable by a process which is characterized in that the following components component a: basic aluminum salts and / or aluminum hydroxide component b: aluminum sulfate and / or sulfuric acid component c: organic carboxylic acids or mixtures at least Component d: Aluminum salts of organic carboxylic acids Component e: organic and / or inorganic sulfates and / or hydrogen sulfates and / or carbonates and / or bicarbonates and / or alkaline earth oxides and / or alkaline earth hydroxides at temperatures up to 150 ° C are reacted in water, so that there is a Lö is obtained, wherein 1. all components or a selection of components react with each other, so that the molar ratios of aluminum to sulfate in the final product 0.83 to 13.3 and the molar ratios of aluminum to the organic carboxylic acid from 0.67 to 33.3 or 2. all components except component e or a selection of the components except component e react with each other, so that the molar ratios of aluminum to sulfate in the final product 0.83 to 13.3 and the molar ratios of aluminum to the organic carboxylic acid in the final product 0.67 to 33.3 or 3. the component e is subsequently dissolved in the reaction product according to point 2. 2. solidification and hardening accelerator for hydraulic binders according to claim 1, characterized in that are used as basic aluminum salts, the basic sulfates, carbonates, carbonate sulfates and nitrates and mixtures of at least two of these components. 3. solidification and hardening accelerator for hydraulic binders according to claims 1 and 2, characterized in that are used as organic carboxylic acids monocarboxylic acids, hydroxycarboxylic acids and dicarboxylic acids and mixtures thereof. 4. solidification and hardening accelerator for hydraulic binders according to claims 1 to 3, characterized in that are used as sulfates or hydrogen sulfates, the alkaline earth metal salts and / or triethanolamine salts and / or diethanolamine salts of sulfuric acid. 5. solidification and hardening accelerator for hydraulic binders according to claims 1 to 4, characterized in that the carbonates are the alkaline earth metal carbonates and hydrogencarbonates used as the Erdalkalihydrogencarbonate. 6. solidification and hardening accelerator for hydraulic binders according to claims 1 to 5, characterized in that are used as organic carboxylic acids formic acid, acetic acid, glycolic acid, lactic acid and mixtures of mind. Two of these components. 7. solidification and hardening accelerator for hydraulic binders according to claims 1 to 6, characterized in that are used as sulfates or hydrogen sulfates, the alkali metal salts of sulfuric acid. A solidification and hardening accelerator for hydraulic binders according to claims 1 to 7, characterized in that it can be used in combination with other compounds, e.g. with setting retarders, condensers or rebound reducers. 9. cement, mortar and concrete containing the solidification and hardening accelerator according to claims 1 to 8. No drawing