Means and method for sealing concrete construction joints and method for manufacturing such sealing means

Abstract

The invention relates to new means for sealing concrete construction joints, comprising an expansible sealing strip, which is both water expansible and expansible by injection of concrete or the like into a cavity of said sealing strip; in particular a sealing strip involving a combination of an expansible outer skin (4) based on filled rubber composition (preferably bentonite filled synthetic rubber) which swells in contact with water but does not dissolve in water, and an inner injection tube (preferably comprising a micro-porous, open structure), within the filled rubber skin, for injecting resin dispersions and/or micro-fine cements. The invention also relates to a sealing method using such sealing means and a manufacturing method for such sealing means.

Description

The invention relates to a “system” (a method/combination of means) for sealing concrete construction joints.

Concrete constructions, in particular concrete constructions consisting of several concrete parts with construction joints between the individual parts, are currently made impervious (protected against the infiltration of water and other liquids/fluids) by sealing the cavities, interstices and slits in the concrete construction, in particular the joints between the concrete parts. This sealing is for instance achieved by placing expansible sealing strips into said cavities, joints, interstices, slits and the like.

Such expansible sealing strips are currently known of two different types, namely

water expansible sealing strips consisting of expansible rubber material, such as bentonite rubber, which swells in contact with water, and

strips of micro-porous injection tubes which can be post injected with cement and/or resin compositions, in order to expand the strip and fill the cavities. In order to achieve a satisfactory sealing effect it is often necessary to apply both types of strips next to each other, which is quite laborious and time consuming and furthermore leads to very irregular joints/seals.

It is the objective of the present invention to remedy to the drawbacks of the known methods for sealing concrete construction joints, by providing new sealing means for concrete construction joints, by providing a simplified method for applying those means, and by providing a method for manufacturing such means.

To achieve this objective the invention provides means for sealing concrete construction joints comprising an expansible sealing strip, which means constitute a sealing strip which is both water expansible and expansible by injection of concrete or the like into a cavity of said sealing strip.

According to a preferred feature of the invention, the new sealing means may in particular constitute an expansible sealing strip involving a combination of

an expansible outer skin based on “bentonite rubber” (filled rubber composition made of synthetic rubber and bentonite) which swells to a maximum of 400% in contact with water but does not dissolve in water and

an inner injection tube (within the bentonite rubber skin) for injecting resin dispersions (such as acrylate dispersions) and/or micro-fine cements, for providing additional expansion in places where the space to be sealed is larger than the swelling capacity of the bentonite rubber element.

According to a further preferred feature of the invention, the inner injection tube may, in particular, have a micro-porous, open structure, consisting for instance of a filtrating membrane.

In a preferred embodiment of the invention the sealing means may in particular involve a three layer composite product made up of:

a bentonite rubber outer skin;

an inner reinforcement metal (in particular steel) wire spiral (preventing the collapse of the expansion tube and hence the blockage of the injection channel);

a filtrating membrane between the reinforcement spiral and the bentonite rubber outer skin (preventing the silting up of the injection channel due to swelling of the bentonite rubber into the inner tube).

To achieve the objective stated above, the invention also provides a method for sealing concrete construction joints involving placing an expansible sealing strip in concrete constructions joints, in which a sealing strip/sealing strips is/are used which is/are both water expansible and expansible by injection of cement and/or resin compositions into a cavity of said sealing strip.

According to preferred features of said method, use is made of sealing strips corresponding to the preferred sealing means according to the invention, disclosed here above.

To achieve the further objective stated above, the invention finally also provides a method for manufacturing sealing means comprising a strip which is water expansible and expansible by injection of cement and/or resin compositions, by producing a composite comprising a filtrating membrane and a bentonite rubber skin, or a composite comprising a reinforcement spiral, a filtrating membrane and a bentonite rubber skin.

According to a preferred feature of the invention the manufacturing method involves the extrusion of a bentonite rubber layer onto a micro-porous injection tube (possibly reinforced, for instance by means of a metal (steel) wire spiral), well known in itself.

The sealing means according to the invention thus provide a combination of a hydrophilic bentonite strip and a post-injectable injection tube constituting a single system for sealing construction joints in concrete.

The sealing means according to the invention are designed for secure sealing of construction joints, cold joints and working joints, where there is a deficiency in the concrete works. The sealing means are ideally suited for concrete constructions with limited wall thicknesses.

The sealing means according to the invention can be used to replace combinations of two or more passive construction joint sealing systems.

The sealing means according to the invention, in particular the preferred sealing means as set forth here above, provide two combined actions/effects in one single system:

preventive action:

• • resulting from the expansive outer skin based on bentonite rubber (such as the material “Bentorub +” commercialised by the company “de neef-conchem”);
  • swelling in contact with water to a maximum of 400% of its original dry volume;
  • not dissolving in water and non-polluting. curative action:
  • resulting from the micro-porous injection tube on the inside (such as the products “Infiltra-stop”/“Injecto” commercialised by the company “de neef-conchem”);
  • the system can be injected at any given time under low pressure;
  • sealing effect will happen in those places where the contact area was larger than the total swelling capacity of the bentonite rubber element (leading to local leakage, e.g. so called honeycombing);
  • the injection tube has an open structure over its full length and can in particular be injected with resins/acrylates, such as those commercialised by the company “de neef-conchem” and/or with micro-fine cements.

The sealing means according to the invention are simple and quick to install. The injection of resins/cements (such as in particular “Bento-ject” injection compositions commercialised by the company “de neef-conchem”) into the sealing means according to the invention can be performed at any time after their installation.

Concrete constructions will not be damaged due to the installation or the injection of the sealing means according to the invention.

There is no interruption in the building activities due to the installation of sealing means according to the invention or to using the method according to the invention.

The sealing means and sealing method according to the invention can very appropriately be applied in combination with “Bento-ject” wire mesh profile and/or placed on irregular cold joints and construction joints in combination with “Bentostic” levelling mastic, both commercialised by the company “de neef-conchem”.

The sealing means and the sealing method according to the invention are essentially applied in a similar way as known, state of the art, expansible sealing means, using procedures and conditions well known per se in the art and to the skilled art worker.

Further features and details of the invention will become apparent from the following description of a specific embodiment of the invention, given by way of mere illustrative example, having reference to the attached drawings. It should be observed that the details of these embodiments do not involve any limitation of the scope of the invention as disclosed in the above text and as expressed in the claims here below.

In the drawings,

FIG. 1 represents a view, in perspective, of a piece of sealing strip according to the invention;

FIG. 2 represents a view, in cross-section, of a sealing strip according to the invention;

The sealing strips shown in the figures, indicated by reference numeral 1, comprise:

an inner reinforcement metal (in particular steel) wire spiral—2—(preventing the collapse of the expansion tube and hence the blockage of the injection channel);

a bentonite rubber outer skin—4—made of natural sodium bentonite and synthetic rubber; this outer skin swells in contact with penetrating water and will thus seal hair line cracks and small voids in the joint;

a filtrating membrane—3—between the reinforcement spiral—2—and the bentonite rubber outer skin—4—(preventing the silting up of the injection channel due to swelling of the bentonite rubber into the inner tube).

The sealing strip represented in the figures as example shows

• • a diameter of the total strip—1—of approximately 16 mm,
  • an outer diameter of the spiral—2—of approximately 8 mm, and

a thickness of the bentonite rubber skin—4—of approximately 4 mm, as well as the following technical date/properties:

	Value	Norm
Swelling capacity	Swells at least 400% of	Test report KUL
in contact with water	its original dry volume	University
Density	Approx. 1.48 kg/dm3	ASTM D71-84
Weight	Approx. 0.283 kg/m
Expansion pressure	>0.70 N/mm2	Test report KUL
under complete		University
enclosure
Resistance against	Up to 50 meter water	Test report DNC
hydrostatic pressure	column = 5 bar
Installation	−15° C. to 60° C.	Test report DNC
temperatures
Operating	−45° C. to 120° C.	Test report DNC
temperatures
Properties of the injection tube:
Consumption during	minimum 190 g/m to fill the tube
injection:
Tensile Strength steel:	±1800 N/mm2

Claims

1. Means for sealing concrete construction joints comprising an expansible sealing strip which is both water expansible and expansible by injection of concrete or the like into a cavity of said sealing strip characterised in that said expansible sealing strip constitutes a combination of an expansible outer skin based on a bentonite filled rubber composition which swells in contact with water but does not dissolve in water and of an inner injection tube having a microporous, open structure, within the filled rubber skin, for injecting resin dispersions and/or micro-fine cements.

2. Sealing means according to claim 1, characterised in that said inner injection tube comprises a filtrating membrane.

3. Sealing means according to any one of claims 1 and 2, characterised in that said means involve a three layer composite comprising a bentonite rubber outer skin; an inner reinforcement metal wire spiral; a filtrating membrane between the reinforcement spiral and the bentonite rubber outer skin.

4. Method for sealing concrete construction joints involving placing (an) expansible sealing strip(s) in concrete constructions joints, said sealing strip(s) being both water expansible and expansible by injection of cement and/or resin compositions into a cavity thereof, characterised in that a sealing strip/sealing strips is/are used which constitue(s) a combination of an expansible outer skin based on a bentonite filled rubber composition which swells in contact with water but does not dissolve in water and of an inner injection tube having a microporous, open structure, within the filled rubber skin, for injecting resin dispersions and/or micro-fine cements.

5. Method according to claim 4, characterised in that a sealing strip according to any one of claims 2 and 3.

6. Method for manufacturing sealing means comprising a strip which is water expansible and expansible by injection of cement and/or resin compositions, characterised in that a composite product is produced comprising a filtrating membrane and a bentonite rubber skin or a composite product comprising a reinforcement spiral, a filtrating membrane and a bentonite rubber skin.

7. Manufacturing method according to claim 6, characterised by the extrusion of a bentonite rubber layer onto a micro-porous injection tube.

8. Manufacturing method according to claim 6, characterised by extrusion of a bentonite rubber layer onto a reinforced micro-porous injection tube.