SEALANT FOR A CONCRETE ELEMENT AND METHOD FOR PRODUCING A SEALANT

Abstract

A sealant for a concrete element, having a planar carrier and an active substance applied onto the carrier, wherein the active substance is designed to be chemically reactive with water. The carrier is flexible.

Claims

1. A sealant for a concrete element, comprising a planar carrier and an active substance applied onto the carrier, wherein the active substance is designed to be chemically reactive with water, and wherein the carrier is flexible.

2. The sealant as claimed in claim 1, wherein the sealant is at least slightly water-permeable after the production thereof.

3. The sealant as claimed in claim 1, wherein the carrier is selected from the group consisting of a geomembrane, a geotextile, a film, a nonwoven fabric, a PE woven fabric, a PP woven fabric, and a nonwoven fabric-woven fabric combination.

4. The sealant as claimed in claim 1, wherein the active substance comprises at last one of the following: a cement, quartz, a silicate, an ash, a calcium hydroxide, a carbonate, a non-hydrogen carbonate, and a calcium carbonate.

5. The sealant as claimed in claim 1, wherein the active substance contains an adhesion promoter.

6. The sealant as claimed in claim 1, wherein the active substance contains an elasticizer.

7. The sealant as claimed in claim 1, wherein the active substance comprises at least one type of a dispersing phase.

8. The sealant as claimed in claim 1, wherein the active substance comprises a water-swellable polymer.

9. The sealant as claimed in claim 1, wherein the carrier comprises the active substance on one flat side or on both of flat sides.

10. The sealant as claimed in claim 1, wherein the sealant has a predefined minimum roughness on at least one flat side of the carrier.

11. The sealant as claimed in claim 1, wherein the sealant comprises a water- and/or gas-impermeable covering on at least one flat side of the carrier.

12. A method for producing a sealed concrete element, comprising the following steps: a) equipping one side of a formwork with a sealant as claimed in claim 1, and b) pouring concrete against the side of the formwork equipped with the sealant.

13. The method as claimed in claim 12, wherein the sealant is stapled onto the side of the formwork.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.

[0075] In the drawings, wherein similar reference characters denote similar elements throughout the several views:

[0076] FIG. 1 shows a sealant according to the invention;

[0077] FIG. 2 shows the sealant with a substance applied to both sides of the carrier;

[0078] FIG. 3 shows the sealant according the invention with a covering; and

[0079] FIG. 4 shows a formwork having the sealant and concrete attached thereto.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0080] Further features and advantages of the invention result from the following detailed description of the invention, with reference to the drawings. Further features and advantages of the invention also result from variants of the method according to the invention, and from the claims.

[0081] The individual features can be implemented individually, or they can be combined in any possible manner to form variants of the invention.

[0082] FIG. 1 shows a sealant 1 for a concrete element. The sealant 1 comprises a planar carrier 2. The carrier 2 has an active substance 3, which is applied onto the carrier. The substance 3 is designed to be chemically reactive with water. The carrier 2 is flexible.

[0083] Whereas in FIG. 1 the substance 3 is applied to only one side of carrier 2, in FIG. 2 the substance 3 is applied to both sides of the carrier 2.

[0084] FIG. 3 shows the sealant 1 of FIG. 1. However, in this case a covering 4 is also applied to the sealant 1. The covering 4 may be water- and/or gas impermeable.

[0085] FIG. 4 shows a formwork 10 and a sealant 1 being attached to the 20 formwork 10. The sealant 1 comprises the substance 3, which is facing towards a gap 11. On the other side of the gap 11 there is an existing structure 12, which may for example be a concrete wall. Concrete may be poured into the gap 11 such that concrete is poured against the side of the formwork 10 equipped with the sealant 1.

Production

[0086] Initially, a flexible carrier, for example a geotextile, can be provided as the base for the sealant. Alternatively, a flexible polymer can also be formed in a planar manner, in particular as a type of netting. In this exemplary embodiment, a netting-like or meshed, flexible geotextile can be provided as the carrier, so that the carrier itself is water-permeable.

[0087] Subsequent thereto, in order to produce the active substance, an adhesion promoter, in particular in the form of a plastic dispersion, and cement and a liquid dispersion polymer are initially mixed with each other.

[0088] The active substance is then applied onto the carrier, for example being sprayed thereon. In particular due to the liquid dispersion polymer and due to the adhesion promoter, the active substance adheres to the carrier, and therefore the active substance can be more easily applied onto the carrier. The water-permeability of the sealant can be adjusted by way of the selection of the mesh width of the carrier and by way of the amounts of active substance applied in specific areas. In this exemplary embodiment, the water-permeability is adjusted in such a way that the sealant is at least slightly water-permeable.

[0089] The sealant is subsequently dried until the active substance fixedly adheres on the carrier.

[0090] Subsequent thereto, a covering is removably applied onto the sealant, on both sides thereof.

[0091] In one alternative variant, the sealant is completely dried and a covering is dispensed with.

Application

[0092] A concrete element to be sealed, for example a concrete element of a wall, can be protected and sealed as follows:

[0093] Initially, the covering which may be present is removed on one side. The sealant is placed onto the concrete element in a planar manner and is lightly pressed thereon, if necessary. Due to the flexibility of the carrier, the sealant conforms to the surface of the concrete element. If a concrete element having a large surface area is to be sealed, it suffices to loosely overlap one portion of the sealant with a further portion to be situated next thereto, wherein at least one corresponding portion of the covering is first removed from the other side, if applicable. The portions of the sealant generally do not need to be bonded or adhered to each other, or in any other way sealed with respect to each other. A bond is established between the sealant and the concrete element, in particular by way of a portion of the cement contained in the active substance, and therefore the sealant is permanently fixed on the concrete element.

[0094] Subsequent thereto, if applicable, the remainder of the covering is detached or is removed from the sealant.

[0095] If a concrete element is to be produced and sealed using formwork technology, then, in one variant of the method, initially at least one side or, depending on the sealing need, multiple sides of the formwork is/are equipped with the sealant. The covering is removed in advance, for this purpose, as needed. The sealant is then stapled to the formwork using tacker clamps. Subsequent thereto, concrete is poured against the formwork and the concrete element is thereby produced. The formwork is removed once the concrete has cured.

[0096] According to the findings made by the inventor, it should be noted that the sealant adheres on the concrete and/or interlocks on and in the concrete during the concreting and/or the curing.

[0097] If the formwork is subsequently removed, the stapled sealant detaches from the formwork and remains on the concrete element.

[0098] The concrete element is initially not hermetically sealed against moisture or water. Instead, water can penetrate up to the component, due to the water-permeability of the sealant. Active substance can also chemically react with the water.

[0099] Over the course of time, the sealant passes through essentially three phases, in particular.

[0100] At the beginning or in a first phase, the concrete edge zone of the concrete element is improved by means of the carrier. Water cavities and pore structures are at least partially compensated for or are reduced.

[0101] In a second phase, active substance or one or multiple components of the active substance is/are transported to the concrete element by the moisture or water flow passing through the sealant, in particular at the beginning. This transport takes place, in particular, at the points at which there is a need for repair, i.e., in particular at cracks, defective spots, and the like. Since the flexible carrier conforms to the concrete element, the situation is avoided in which the active substance or the components is/are rinsed out through a gap that may otherwise be present between the sealant and the concrete element, and the transport path is kept so short that a sufficient amount of the active substance or the components reaches the concrete element.

[0102] The liquid dispersion polymer, in particular, swells during the water flow and therefore reduces the water flow through the sealant.

[0103] In a third phase and, in particular, in conjunction with the moisture remaining on the concrete element, the transported active substance or the components chemically react on and/or with the concrete element. Depending on the active substance or the components, a sintering takes place, for example, whereby cracks, defective spots, and the like are permanently plugged and, therefore, sealed.

[0104] In addition, the carrier reinforces the concrete element on the concrete edge zone and, as a result, additionally minimizes the risk of cracks forming in the future.

[0105] Whereas, in the case of a conventional fresh concrete composite film, damage, even local damage such as, for example, a small crack, generally results in an extensive loss of the sealing effect, the sealant according to the invention can still largely ensure a sealing effect or protection of the concrete element. Since the sealing effect is not guaranteed solely by way of the tightness of the sealant itself, but rather also by way of the interplay of the sealant, the transported active substance and the self-healing of the concrete element at damaged areas induced thereby, the sealing effect remains largely retained.

[0106] An improved, long-lasting and, in particular, active protection of the concrete element is therefore made possible by the sealant according to the invention.