EP2271597A1

EP2271597A1 - Use of flexible sealing slurries for the aftertreatment of fresh concrete slabs

Info

Publication number: EP2271597A1
Application number: EP09738011A
Authority: EP
Inventors: Josef Weichmann
Original assignee: Construction Research and Technology GmbH
Current assignee: Construction Research and Technology GmbH
Priority date: 2008-04-29
Filing date: 2009-04-17
Publication date: 2011-01-12
Also published as: WO2009132967A1; DE102008021451A1; AU2009242229A1; CN102015581A; CA2721223A1; JP2011518753A; US20110033625A1

Abstract

The invention relates to the use of a sealing slurry, which is flexible after it has cured and contains, as component a), a system containing a hydraulic binder and, as component b), an elasticizing plastic for the aftertreatment of the entire surface of a concrete slab with a residual moisture content of > 2 CM %. The claimed sealing slurries, which contain, as component a), preferably a cement mortar and, as component b), a homopolymer, copolymer or terpolymer preferably in the form of a liquid polymer dispersion, bring about a greater strength and less shrinkage of the concrete slab surface treated therewith. The concrete slabs, treated therewith, are protected against water infiltration, an ingress of water under pressure and spray, especially in areas exposed to moisture.

Description

Use of flexible sealing slurries for the aftertreatment of young concrete bodies

The present invention is the use of a flexible after curing curing slurry for the aftertreatment of a concrete body.

The use of flexible sealing slurries is well known in construction. The requirements that are placed on suitable products in this context are, for example, in the "Guidelines for the planning and execution of waterproofing, earth-contacting components with flexible sealing slurries" of Deutsche Bauchemie eV Furthermore, flexible sealing slurries when laying tiles and plates Baikonons and terraces are used, where the sealing slurry is applied directly to the concrete substrate and then a layer of tiles and slabs laid on it.

In the general sense are sealing slurries in construction for sealing and protection of underlying substrates such. B. masonry but especially concrete bodies and screeds used before penetrating water. To name a few, here is the PCI Seccoral ^® 1 K and 2K product range of PCI Augsburg GmbH. These Seccoral products are primarily used for crack-bridging under ceramic coverings on balconies, terraces and showers, which are fine cement mortars with elastifizierenden plastic shares. The products are applied in a dry layer thickness of at least 2 mm. In another variant, the Seccoral products are used for sealing basement exterior walls, but also foundations. They also serve in particular for crack-bridging sealing under ceramic coverings in showers or rooms with floor drains. Swimming pools, therapy pools and saltwater baths with water depths of up to 15 m and in particular against the water pressing from the inside.

The order for flexible sealing slurries is made according to the state of the art on so-called slip-proof substrates. If this is a concrete body, and here usually cement screeds, the term "ready for use" means that the concrete body should have a residual moisture content of on average <2 CM-%.

The CM measurement is suitable for determining the moisture content of mineral building materials. The measurement process can be carried out completely uncomplicated on site and provides reliable results. Since a sample has to be taken for the measurement, the CM method is a "destructive" method, in which a measuring sample of about 10 to 50 g is taken from the mineral component to be tested, depending on the suspected moisture penetration Precise weighing of the sample is then pulverized and, with the addition of 4 steel balls, mixed with an ampoule of calcium carbide in a steel bottle with a manometer by vigorous shaking. bids with water releases acetylene gas. After about 15 minutes, a constant pressure is created, with the help of which and taking into account the amount of sample taken directly on the manometer or by calculation and reading in a table, the water content of the sample can be determined. By the test material is selectively removed, it is also possible, individual component layers, for. B. plastered walls, to examine their moisture.

Alternatively, the curing time is used as a criterion for the ready-made. For example, DIN 18 157 defines the required time span between the freshly applied substrate and the occupation with tiles. For laying with cementitious tile adhesives on concrete substrates a period of 6 months and on cement screeds of 28 days for the laying of tiles and slabs with cementitious tile adhesives is to be adhered to. However, the waiting times and their characteristics are generally dependent on various factors, such as thickness Concrete body, the W / Z (water / cement) value of the concrete body, the humidity and temperature, etc. is dependent. Further information on the proof of use can be found in the BEB leaflet "Assessment and preparation of substrates" and in DIN 18560 Part I "Screeds in construction - terms, general requirements, testing".

The material composition of commonly used flexible sealing slurries describe, for. The publications EP 1 306 357 A1, DE 100 37 951 and DE 198 29 537. The binder system consists in two-component systems of cement and a liquid aqueous polymer dispersion and in one-component systems of cement and a polymer dispersion powder. In order for the required flexibility to be achieved, a plastic / cement ratio of> 0.6 is required. The flexibility of the sealing slurries serves to bridge potential surface cracks in the concrete body. This means that the waterproofness achieved by the sealing slurry can not be affected or lost by the formation of cracks. This is the difference between flexible sealing slurries and conventional rigid mineral sealing slurries.

The post-treatment of concrete bodies serves to improve the properties of the treated body, which is usually a cement screed or other substrate. In particular, the strength development, the shrinkage behavior and the tendency of the bodies treated with it to crack are improved. The aftertreatment can be carried out according to the prior art using a variety of methods:

So z. For example, so-called curing agents are applied or else films are applied. Thus, for example, the published patent application DE 2 042 735 describes a plastic film serving for sealing purposes on buildings, which has rib webs projecting on one side with respect to the film. This as plaster or foil The plastic film which can be used is designed as a wave-web foil, wherein the rib webs projecting on one side are designed as waveguide ribs which continue uninterruptedly in the longitudinal direction of the film and which, in plan view, are substantially meandering. CH 630 984 describes a film which has been folded to form anchoring projections and which is sunk into the uncured concrete. This Isolierverkleidung, which is particularly attached to interior walls, has at its rear side and at a mutual distance from each other extending fastening ribs. The cladding preferably consists of an elastic foil in which the fastening ribs and the joints are formed by folding. In this way, the Isolierverkleidung can be stretched when mounted on the wall transverse to their ribs to the desired cover length.

Particular attention should be paid to the published patent application DE 103 43 970 A1. Described is a method for treating a concrete body to prevent evaporation of not readily bound water. The treatment is carried out with the help of a special leaf material, which is applied to the not quite fresh concrete body and firmly connected to it. This is done by pressing the sheet material, which may be a foil, into the concrete body with a surface having structural parts. The purpose of the described method for the aftertreatment of fresh concrete is to be seen in the fact that concrete components develop by drying out through the concrete surface through fading and thus deform. These deformations can subsequently cause fracture of the concrete structure and cracking resulting in static failure and wet penetration. The drying and the fading phenomena should be prevented by the application of the sheet material.

A disadvantage of the known process for the aftertreatment of concretes by ringers is that they can not remain permanently on the treated substrate due to the usually adhesion-resistant surfaces. Thus, for example, no further coverings or surface finishes in the form of plaster or the laying of tiles and plates can be applied. However, such additional surface finishes can take over a reliable and permanent sealing of the building against water penetration, which is excluded due to the disadvantages of Curing means described, however.

A disadvantage of the use of conventional and used for post-treatment film materials is that they also do not remain permanently connected to the ground. Rather, they would have to be removed after curing of the concrete body in the rule. In addition, the application of a subsequent surface coating is not possible due to the material properties of the film materials. With regard to the sheet material used according to DE 103 453 979, it is considered difficult to process it, since it is bonded to the concrete body mandatory, which represents an additional step. In addition, the sheet material as needed to adapt the structures of the concrete body, for example by cutting. If tiles and boards are finally applied to the sheet material described, an additional gluing step must follow.

From the described prior art, the object of the present invention is to provide a suitable new system for the aftertreatment of a concrete body having a defined residual moisture content. The system in question should be inexpensive. The main focus was on reliably preventing the penetration of water from outdoor areas into a concrete body. In addition, after the use of the system according to the invention, a subsequent rigid surface coating, such. B. by tile and tile coverings, be possible within a short period of time after completion of the concrete body.

This problem was solved by the use of a flexible after curing curing slurry containing as component a) a system with a proportion of hydraulic binder and as component b) an elasticizing plastic, for the comprehensive treatment of a concrete body with a residual moisture content of> 2 CM-% ,

Surprisingly, it has been found that not only the task could be fully satisfied by the use of the invention, but that by using the flexible sealing slurries in addition a decoupling of the still dwindling substrate with a rigid coating in the form of tiles or plates is guaranteed.

The benefits were unpredictable in this form.

For the purposes of the present invention, the term "elasticizing" is understood to mean the plasto-elastic behavior of the plastic component, which can subsequently deform when tensile forces are applied, which usually manifests itself in a stretching behavior but not completely back to its original shape, but there remains a slight deformation.

The present use preferably a variant in which the sealing slurry contains as component a) a mortar, preferably a cement mortar and in particular a fine cement mortar. The cement component may, according to the invention, be a Portland cement, a high-alumina cement or mixtures thereof. The present invention also encompasses a variant in which the sealing slurries as component b) comprise at least one member of the series homo-, co- or terpolymers based on styrene, butadiene, vinyl acetate, vinyl propionate, vinyl laurate, vinyl versatate, vinyl chloride, vinylidene chloride, ethylene , Acrylates and mixtures thereof.

Preferably, the flexible sealing slurry should be two-component, with the components a) and b) being present separately. The property of the two-component nature thus relates primarily to the two components a) and b) of the sealing slurries.

Their positive properties are developed by the claimed flexible sealing slurry, in particular when component b) is a liquid polymer dispersion having a preferred polymer content of not more than 60% by weight. The proportion of polymer should not fall below 20% by weight and preferably between 25 and 50% by weight, values of 30, 40 and 45% by weight being regarded as particularly preferred.

The plastic / cement (K / Z) ratio of component b) to component a) should be between 0.5 and 2.0. A range between 0.7 and 1.4 is to be regarded as preferred. In addition to the described components a) and b), the flexible sealing slurry according to the invention additionally comprises at least one member selected from the group of fillers, additives, pigments, flow agents, thickeners, rheological aids, setting accelerators, setting retarders, defoamers, wetting agents, dispersants, plasticizers, film formers and surfactants. As concrete representatives here come in particular as fillers silicates and carbonates with a particle size of 0.06 mm to 0.5 mm, pigments based on titanium dioxide or iron hydroxide, rheological aids such as starch ethers, cellulose fibers, polyacrylamides, phyllosilicates, setting accelerators such as lithium carbonate, calcium carbonate, calcium nitrate Calcium formate, retardants such as alhaliphyrophosphates, complex phosphates,

Borsalze or Ca sulfates, sucrose, glucoses, fructoses, malic acids, gallic acid, gluconic acids, tartaric acids and citric acids and their salts in question.

The flexible sealing sludge according to the invention develops its advantageous properties, in particular on concrete bodies which have a residual moisture content of> 4 CM-%.

Basically, the claimed use is not limited to certain concrete bodies. However, application to cement screeds or to balcony and terrace surfaces has proven particularly suitable. The underground should be accessible in general form, d. H. be resilient to a certain weight limit.

The flexible sealing slurry is usually on the nachzubehandelnden concrete body, with the help of z. As smoothing trowels or tooth scrapers applied. The layer thickness should achieve a minimum layer thickness. The present invention includes a wet layer thickness of the sealing slurries of> 1, 0 mm, preferably> 1, 5 mm and particularly preferably> 2.0 mm. The concrete body may be a cement screed and in particular a screed on a release liner or a screed on insulating layer. Screeds on separating layer are on a hafthindernden edition, the so-called release layer, on z. As bituminous film or cardboard or plastic films, applied to the supporting concrete body as a substrate. As a result, a horizontal power transmission of the screed on the concrete body is prevented. The separating layer is usually carried out as a moisture or vapor barrier. Screeds on insulating layer, so-called floating screeds are applied to an insulating layer.

After their application, the flexible sealing slurries according to the use according to the invention should cover the surface of the concrete body to> 80%, preferably to> 90% and particularly preferably to> 95% without gaps.

Finally, the present invention also takes into account that the sealing slurry applied to the concrete body is provided with a rigid layer and preferably with tiles. In this case, the mentioned rigid layer can be applied to the not yet cured sealing slurry. In general, however, the subsequent coating is applied after hardening of the sealing slurry. A covering of tiles and slabs is laid with a conventional tile adhesive.

As a special use variant of the present invention, the aftertreatment in wet-stressed area and preferably against leachate, against pressurized water and spray has been found.

Surprisingly, it has been found in the use according to the invention that a mere treatment of the water vapor-permeable and flexible sealing slurries already a post-treatment of the concrete body is achieved. The concrete body treated with the sealing sludge shows in its entirety a higher strength and also a lower shrinkage. This makes it particularly suitable for the final order of a rigid surface layer, which can be introduced directly into the still fresh bed of Dichtschlämme, which eliminates additional steps. It is also possible, however, to allow the flexible sealing sludge to harden and then to provide it with a rigid covering, which is done by the additional application of an adhesive layer.

In particular, in the laying of tiles and slabs, the advantage of the use of the invention is clear, since thus a simultaneous treatment of the concrete body, a bonding of the plate covering, a seal against penetrating or rising water, and a decoupling of the substrate is achieved by the rigid coating. Especially advantageous is the invention proper use on cement screeds. Here is the decoupling of the screed from the rigid topping prevents deformation of the screed. Deformation occurs when a rigid top coat is applied to an uncured screed. Due to shrinkage due to shrinkage of the screed and the anti-shrinkage top layer, the screed area facing away from the upper side of the screed is shortened. The screed shows a convex deformation or bulge, which can lead to damage.

The following examples demonstrate the advantages of the present invention.

Examples

Example 1 :

For the following embodiment, the product PCI Seccoral ^® 2K PCI Augsburg GmbH was used. This product is a two-component composition consisting of a modified acrylate dispersion as a liquid component and a special cement mortar with sealing plastics as a powder component.

First, a cement screed (4 cm layer thickness) was applied to release layer. The area was 2X2m; the insulation consisted of 3 cm thick Styrofoam ^® panels, which were covered with PE-FoNe. Edge trim strips were applied at the edges. As soon as the screed was passable after approx. 12 hours, the sealing slurries were applied according to the manufacturer's instructions using a tooth trowel and smoothing trowel in a wet layer thickness of 3 mm. The applied surface was cured after a further 16 hours and fully accessible.

Parallel and in the same way a cement screed was introduced, which, however, was not subjected to aftertreatment. This screed showed after 2 months, in contrast to the screed treated with PCI Seccoral ^® as a screed cracking and also a bowl (concave curvature). The latter effect is understood to mean that the corner and edge regions of the screed bulge relative to the screed surface center. This happens mainly because screeds on separating layer on its side facing the separation layer due to a reduced or prevented there water outlet dwindle less than the separation layer facing away from the top of the screed. Due to the shrinkage of the top it comes to a length reduction in relation to the bottom and thus to the bowl. The tapping was determined by placing a bar over the entire screed surface.

Example 2:

First, a cement screed (4 cm layer thickness) was applied to release layer. The area was 2X2m, the insulation consisted of 3 cm thick Styrofoam ^® panels, which were covered with PE-FoNe. Edge trim strips were applied at the edges. As soon as the screed was passable after approx. 12 hours, the sealing slurries were applied to it with a tooth trowel and smoothing trowel in a wet layer thickness of 3 mm according to the manufacturer's instructions. The surface thus applied was cured after a further 16 hours and accessible. After this 16 h, a tile topping consisting of 60X60cm fine stone tile with a conventional Tile adhesive (PCI FT adhesive mortar) laid. Another 16 hours later, the joints (joint width 3mm) were closed with grout.

In parallel, a screed was introduced in the same way, but it was not subjected to any subsequent treatment with flexible sealing slurries. The tiling was laid as described above with fine stoneware and grouted.

After 6 months, the screed surface without the aftertreatment with sealing sludge showed a bulge in the center of the screed (convex curvature). For individual tiles there was a detachment (especially in the middle area of the screed area) and cracking. The bulge is caused by the fact that the cement screed shrinks in the course of its hardening (water loss but above all chemical shrinkage). The combination of the screed with the rigid and non-shrinking surface covering made of fine stoneware hinders the shrinkage on the screed surface facing the tile covering. The shortening of the screed is thus lower at the surface than at the surface facing away from the underside of the screed. It comes to the bulge of the screed, d. H. the screed center is higher compared to the corner and edge area.

When screed body provided with sealing sludge no convex curvature could be found. Tile detachment and cracking did not occur.

Claims

claims

1. Use of a flexible after curing sealing slurry containing as component a) a system with a proportion of hydraulic binder and as

Component b) an elasticizing plastic, for comprehensive treatment of a concrete body with a residual moisture content of> 2 CM-%.

2. Use according to claim 1, characterized in that the sealing slurries as component a) contains a mortar, preferably a cement mortar and in particular a fine cement mortar.

Use according to claim 2, characterized in that the cement component is a Portland cement, a high-alumina cement or mixtures thereof.

4. Use according to any one of claims 1 to 3, characterized in that the sealing slurry as component b) at least one member of the series homo-, co- or terpolymer based on styrene, butadiene, vinyl acetate, vinyl propionate, vinyl laurate, Vinylversatat , Vinyl chloride, vinylidene chloride, ethylene, acrylates.

5. Use according to one of claims 1 to 4, characterized in that the sealing slurry is two-component, wherein the components a) and b) are present separately.

6. Use according to claim 5, characterized in that it is a liquid polymer dispersion in the component b), with a preferred polymer content of max. 60% by weight.

7. Use according to one of claims 1 to 5, characterized in that the plastic / cement (K / Z) ratio of component b) to component a) is between 0.5 and 2.0 and preferably between 0.7 and 1, 8 lies.

8. Use according to one of claims 1 to 7, characterized in that the sealing slurry additionally min. A representative selected from the series fillers, aggregates, pigments, flow agents, thickeners, rheological aids, setting accelerators, setting retarders, defoamers, wetting agents, dispersants, plasticizers , Film former and surfactants.

9. Use according to one of claims 1 to 8, characterized in that the concrete body has a residual moisture content> 4 CM-%.

10. Use according to one of claims 1 to 9, characterized in that the concrete body is a cement screed or a balcony or Teras- senuntergrund.

1 1. Use according to one of claims 1 to 10, characterized in that the sealing slurry in a wet layer thickness of> 1 mm, preferably

> 1, 5 mm and particularly preferably> 2 mm, is applied to the concrete body.

12. Use according to one of claims 1 to 11, characterized in that the sealing slurry, the surface of the concrete body to> 80%, preferably to

> 90% and especially preferably> 95% covered.

13. Use according to one of claims 1 to 12, characterized in that the applied to the concrete body sealing slurry is provided with a rigid layer and preferably with a plaster, with tiles and slabs or mixtures thereof.

14. Use according to one of claims 12 or 13, characterized in that the rigid layer is applied to the not yet cured sealing slurry.

15. Use according to claim 14, characterized in that applied to the uncured sealing slurry is a flat elastic element, preferably in the form of a nonwoven, a net, a fabric or a film and in particular is pressed into this.

16. Use according to one of claims 1 to 15 for post-treatment in the wet-stressed area, preferably against leachate, pressing water and spray.