DD265615A1 - MIXTURE FOR PREVENTING BZW. ELIMINATION OF SULFATIVE EXCLUSIONS - Google Patents

Abstract

The invention relates to a mixture for the prevention or elimination of sulphatic Ausbluehungen to buildings or structural parts, mainly to Hintermauerwerk. The mixture is a combination of 30-75% sulfate-free hydraulic binder with an SO3 content1150.5% 5 -15 water-soluble barium compounds (based on barium oxide) 10 -50% quartz sand with a grain size of 0.2 mm 0.05-0.5 concrete caustic 0.1 - 3 stabilizing additive-sulfate-free binders: alumina cement, cement clinker flour without gypsum additive, reactive pozzolanic binder systems alone or mixed. Pozzolanic binder systems: fumed SiO2 with hydrated lime, highly milled fly ash, SiO2 dusts from ferrosilicon production with a bulk density of 150-250 kg / m3 and a specific surface area (Blaine) of 3 500-6 000 cm2 / g.

Description

2 * 5615

Mixture for the prevention or elimination of sulphatic efflorescence

field of use

The invention relates to a mixture for the prevention or elimination of sulphatic efflorescence of buildings or structural parts, mainly on the background of masonry.

Characteristic of the known state of the art 3ei buildings or building parts made with the building materials concrete and / or brick products, mortar and plaster it is often due to their Ausfangastoffe and environmental influences, u. a. Pollutants, wind, temperature, humidity, bleeding, of which SuAfat efflorescence is the most common.

Prevention of hypoxia has long been achieved by the use of soluble salts of barium, in that soluble sulfates are converted into insoluble ear oil sulfide (for example, DE-OS 2018756).

The use of soluble barium compounds can be used either directly as rope solution or in mixtures with Portland cement as a paint.

In DE-OS '108856 a mortar or egg bitch of 3 - 5 % barium oxide and Portland cement and the application to masonry is described. The soluble sulphates in the masonry are converted into insoluble Bariun.su If at. A major disadvantage of this method is that it uses naphtha-containing Portland cement. These SjIfatkomponenten contained in AntlueeblUhmittel bind already during the smelling a portion of the effective barium salts by precipitation as barium sulfate.

In DE-PS 23 ^ 8081 a special cement u. a. proposed in the production of mortar mixtures instead of commercial cements. The mixture becomes sparingly soluble

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Barium compounds added, which are normal to zürn. Setting de3 mortars are not able to react with the calcium sulfate added as setting regulator. Barium silicate hydrate, barium oxalate, barium fluoride or mixtures thereof are added to the mortar mixture of all kinds. The solubility product of these barium compounds is smaller than that of the calcium sulfate and larger than that of the barium sulfate. Experiments have shown that both the effects of sulphate binding and the control of the setting process are unsatisfactory.

US Pat. No. 3,045,763 describes a mixture for preventing or eliminating bleeding in Portland cement products using a high molecular weight polyvinyl alcohol and barium oxide or barium hydroxide in a 10: 2 weight ratio. It forms a barium hydroxide-polyvinyl alcohol complex in a mortar mix with Portland cement or Mixture of clinker, sand and water. Here, too, calcium sulfates of the Portland cement react when the powder is mixed with water, which reduces the activity of the mixture.

It is intended to develop a technically and economically effective mixture for the prevention or elimination of sulphatic bleedings, which at the same time is storable and has good processing properties.

Essence of the invention

The invention is based on a mixture using barium compounds which, when stirred with the mixing water, has no effect on the mixing water and complies with the processing properties within the required limits.

With a hydraulic binder, quartz sand, a water soluble bar compound, concrete admixtures and other known stabilizing additives. Ir. becomes the task

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solved according to the invention by the mixture combination

30 - 75% sulphate-free hydraulic binder with a S0 ₃ content ί 0.5%

5-15% water-soluble barium compounds (based

on barium oxide)

10 - 50 % quartz sand - 0.2 mm particle size 0.05 - 0.5 % Concrete plasticizer 0.1 -3 7 «stabilizing additives.

As a sulfate-free hydraulic binder k inside Tonerdemmelzzement, cement clinker flour without gypsum additive, reactive pozzolanic binder systems alone or in combination to Einsat κ. Pozzolanic binder systems can be:

- fumed silica with hydrated lime, or

- Highly-favored fly ash or

- Silica dusts from the production of ferrosilicon with a bulk density of 150 - 250 kg / m ³ and a special surface (Blaine) of 3 500 - 6 000 cmVg or mixtures with cement clinker flour and / or hydrated lime.

Particularly suitable as concrete plasticizers are powder-form products based on sulfonated lignin-naphthalene or melamifonnaldehyde condensates and lignosulfonates, oxicarboxylic acid and polyglycol derivatives.

Stabilizing additives are in particular those for improving the water retention capacity based on oligomeric cellulose ethers, eg. B. HethyIce 1lulose, Hydroxalprop ylcellulose and polyvinyl alcohol and polyalkylene oxides.

With the percentage composition according to the invention, surprisingly good results are shown in the prevention or elimination of sulfatic blooms. In addition, the mixture to be processed is characterized by very good processing properties and also improves the

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Adhesive strength of Putzunterprundes.

The recipe components are mixed in a mixing unit without any effect. The powdery mixture has a good shelf life. Beirr. Mixing the powder with water, the mixture is adjusted to a sprayable consistency, with Wasser Festatoffwerte of 0.6 to 1.8 are observed.

Exemplary embodiments

1 . 46 % clinker flour

46 % quartz sand (0.5 mm) 5% Ba (OH) ₂

3% polyvinyl alcohol (PVA 55/02 VEB Chemische Werke Buna) 0.25 % calcium lignosulfonate (Grölipel, VEB ZeIIstoffwerk Grödi ⁺ r.)

Weed suspensions are worth a solid in water

W (-) of 1.0.

2. 39.4 % SiO ₂ from the production of ferrosilicon 4 7.6 % Ca (OH) ₂ 3.0 % Ba (OH) ₂

1.0 % Wotamol (sulfonated naphthalene formaldehyde resin from VEB Chemiekombinat Bitterfeld)

Preparation of aqueous suspensions with -r = 1.4

3. 48.5 % clinker flour

21.7 % SiO ₂ from the ferrosilicon production

17.6 % Ca (OH) ₂

10.0% Ba (OH) ₂

2.2 % polyvinyl alcohol

1.0% Wotamol

Mature suspensions are produced at ττ - 1.8.

2656

H. 43.5 % clinker flour Ό, 5% quartz sand (O - 0.5 mm) 10.0% BaCl ₂ 3.0 % polyvinyl alcohol 0.5 % wotamol

Aqueous suspensions are prepared with a - = 0.6

Claims (5)

1. Mixture for preventing or eliminating sulfatic acid bleedings using the components hydraulic binder quartz sand Water soluble barium compounds Concrete plasticizer stabilizing additives characterized in that it is a mixture combination of 30 - 75% sulphate-free hydraulic binder with a SOj content * 0.5 %
5-15% water-soluble barium compounds (based on Barium oxide) 10 - 50 % quartz sand with a grain size - 0.2 mm 0.05 - 0.5% stabilizing additives is. 2. Mixture according to claim 1, characterized gekennzeichent that are used as a sulfate-free binder alumina cement, cement clinker flour without gypsum additive, reactive pozzolanisehe binder systems alone or in admixture. 2 (556 15 claims 3. Mixture according to Claims 1 and 2, characterized in that as pozzolanic Bindemi t telcy stars highly dispersed SiO ₂ with hydrated lime or - Highly ground fly ash or SiO ₂ dusts from the ferrosilicon product. with a bulk density of 150 - 250 kg / m ³ and a special surface (Blaine) of 3 500 - 6 000 cmVg be used. Ί. Mixture according to claims 1-3), characterized in that as a concrete plasticizer powdery products based on sulfonated lignin naphthalene or. Melamine-formaldehyde condensates or lignosulfonates or oxycarboxylic acid 6 5 6 15 and Polyglyco! derivatives. 5. Mixture according to claim 1, characterized in that as stabilizing additives oiigomere cellulose ethers, in particular methyl cellulose, hydroxypropyl cellulose or polyvinyl alcohols or polyalkylene oxides are used.