GB1570396A

GB1570396A - Waterstop apparatus

Info

Publication number: GB1570396A
Application number: GB309276A
Authority: GB
Original assignee: WR Grace Ltd
Current assignee: GCP Products UK Ltd
Priority date: 1976-11-25
Filing date: 1976-11-25
Publication date: 1980-07-02

Description

(54) WATERSTOP APPARATUS (71) We, W. R GRACE LIMITED, a British Company of Elveden Road, Park Royal, London N.W.10, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to waterstop apparatus and to a method of preparing a concrete mass using such apparatus.

It is well known that concrete tends to crack on drying out after pouring. It is also well known to control the locations of the cracks by introducing zones of weakness, known as "dummy joints" in the concrete. Further, it is known to use waterstops in the cracks so introduced, the waterstops being fixed in position before the concrete is poured and being effective, after the concrete has dried out, to prevent water passing through the crack formed at the dummy joint. Some previously proposed waterstops have been of integral cruciform cross-section, having a part extending generally perpendicular to the plane of the concrete to define the dummy joint, and to be within the resulting crack, and waterstopping parts extending sideways therefrom into the concrete.

One aim of the present invention is to provide an improved waterstop.

According to the present invention, we provide waterstop apparatus for use in inducing cracks in cast concrete and preventing water passing through the induced cracks, such apparatus including a waterstop strip in the form of an extruded or moulded strip of rubber or other moisture and water resistant flexible plastics material and separate crack inducing fillets attachable to the sides of the strip by gripping means which include sections provided on both sides of the strip.

The assembled apparatus comprising the strip and fillets will have a cruciform crosssection.

Various advantages are provided by such a construction. Firstly, difficulty has been encountered in extruding cruciform sections, and this difficulty is removed. Secondly, the crack inducing section of the waterstop apparatus, that is the fillets, can now be made relatively rigid compared to the waterstop strip, as is desirable. In integral constructions, this difference in rigidity is not readily achieved so that a compromise of the desired properties of the waterstop strip and the integral crack inducing extensions has had to be made.

The sections can be attached to or integral with the strip at the centre thereof, and may be upstanding therefrom.

It preferably has integrally moulded continuous longitudinally extended ribs projecting from both sides at or near each edge. The sections are preferably continuous and integrally moulded with the waterstop strip, and preferably, each of the sections has a cross-section comprising a pair of elastically deformable arms which are curved towards each other and between which can be located an enlarged part on the end of the associated fillet. In preferred forms, the sections on the two sides of the waterstop have the same cross-sectional shape. The waterstop strip is preferably symmetrical about a plane running from edge to edge and it suitably has a dumbell cross-section. A suitable material for the strip is plasticised polyvinyl chloride. When the fillets are assembled with the strip, they will be at right angles thereto.

Preferably, the fillets are extruded or moulded strips or organic polymeric material, for instance, rigid (i.e. unplasticised) polyvinyl chloride or polyethylene. The distance between the free edges of the fillets may be 0.75 to 1.25 times the width of the waterstop strip. When assembled, the water stop apparatus is preferably symmetrical about the plane running from edge to edge of the strip. The fillets may also be of dumbell configuration so that it will not matter which side is inserted in the gripping means on the strip when these, as preferred, comprise a pair of arms curved towards one another.

The invention also extends to a method of preparing a concrete mass containing a dummy joint sealed by a waterstop within the thickness of the concrete, which method involves securing such waterstop apparatus of the invention at a desired position within the bay into which concrete is to be poured, pouring the concrete into the bay and allowing the concrete to set whereupon a dummy joint is formed in the concrete along the plane of weakness induced by the fillets.

In this aspect of the invention it is preferred for the concrete to be reinforced concrete and for the waterstop apparatus to be secured in place by means of ties secured to the protruding edges of the fillets and connected to reinforcements of the concrete.

In the preferred cases where the fillets are enlarged along both edges, the ties may be secured thereto by means of spring clips placed around the enlarged edge portions.

The invention is suitable for use in concrete poured to form floors, and is also useful in concrete poured to form walls wherein the waterstop apparatus can readily be secured in position prior to pouring.

Alternative attachment means could, of course, be used for instance other arrangements engaging the rigid fillets and/or arrangements engaging the edges of the waterstop strip.

The invention will be more clearly understood from the following description of one embodiment thereof, given by way of example, with reference to the accompanying drawings in which: Figure 1 is a cross-sectional view of waterstop apparatus disassembled; Figure 2 is a similar view of the apparatus of Figure 1 when assembled; Figure 3 is a similar view of the apparatus in use after concrete has been poured.

As will be seen in the Figures, the apparatus includes a waterstop strip 10 of dumbell configuration. Midway between its longitudinal edges the strip has, on each side, a pair of integral inwardly curved gripping arms 11. There are also two relatively rigid fillets 12, again of dumbell configuration. The ribs along the edges df the fillets fit in between the gripping arms to assemble the apparatus into the form shown in Figure 2.

Figure 3 shows the apparatus in use, located within concrete 13 which has just been poured. The concrete is reinforced as at 14. Prior to the pouring of the concrete, the apparatus was located by means of spring clips encircling the enlarged free edges of the rigid strips. The clips 13 are attached to reinforcement 14. When the concrete dries out, the presence of the rigid fillets will cause it to crack generally within the plane occupied by the fillets. However, the crack will be bridged by the more flexible waterstop strip 10 tending to prevent the passage of water in to or out of the structure of which the concrete forms a part.

WHAT WE CLAIM IS: 1. Waterstop apparatus for use in inducing cracks in cast concrete and preventing water passing through the induced cracks, such apparatus including a waterstop strip in the form of an extruded or moulded strip of rubber or other moisture and water resistant flexible plastics material and separate crack inducing fillets attachable to the sides of the strip by gripping means which include sections provided on both sides of the strip.

2. Apparatus according to claim 1, wherein the sections are attached to or integral with the strip at the centre thereof and are upstanding from the strip.

3. Apparatus according to claim 2, wherein the sections are continuous and integral with the strip 4. Apparatus according to claim 2 or 3, wherein each section has a cross-section comprising a pair of elastically deformable arms curved towards each other.

5. Apparatus according to any preceding claim, wherein the waterstop strip is symmetrical about a plane running from edge to edge.

6. Apparatus according to any preceding claim, wherein the strip has integral continuous longitudinal ribs on both sides at or near each edge.

7. Apparatus according to claim 6, wherein the strip is of dumbell configuration.

8. Apparatus according to any preceding claim, wherein the waterstop strip is of plasticised polyvinyl chloride.

9. Apparatus according to any preceding claim, wherein the fillets are of an organic polymeric material.

10. Apparatus according to claim 9, wherein the fillets are of rigid (i.e. unplasticised) polyvinyl chloride or polyethylene.

11. Apparatus according to any preceding claim wherein the distances between the free edges of the fillets are from 0.75 to 1.25 times the width of the waterstop strip.

12. Apparatus according to any preceding claim, wherein the fillets are of dumbell configuration.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. stop apparatus is preferably symmetrical about the plane running from edge to edge of the strip. The fillets may also be of dumbell configuration so that it will not matter which side is inserted in the gripping means on the strip when these, as preferred, comprise a pair of arms curved towards one another. The invention also extends to a method of preparing a concrete mass containing a dummy joint sealed by a waterstop within the thickness of the concrete, which method involves securing such waterstop apparatus of the invention at a desired position within the bay into which concrete is to be poured, pouring the concrete into the bay and allowing the concrete to set whereupon a dummy joint is formed in the concrete along the plane of weakness induced by the fillets. In this aspect of the invention it is preferred for the concrete to be reinforced concrete and for the waterstop apparatus to be secured in place by means of ties secured to the protruding edges of the fillets and connected to reinforcements of the concrete. In the preferred cases where the fillets are enlarged along both edges, the ties may be secured thereto by means of spring clips placed around the enlarged edge portions. The invention is suitable for use in concrete poured to form floors, and is also useful in concrete poured to form walls wherein the waterstop apparatus can readily be secured in position prior to pouring. Alternative attachment means could, of course, be used for instance other arrangements engaging the rigid fillets and/or arrangements engaging the edges of the waterstop strip. The invention will be more clearly understood from the following description of one embodiment thereof, given by way of example, with reference to the accompanying drawings in which: Figure 1 is a cross-sectional view of waterstop apparatus disassembled; Figure 2 is a similar view of the apparatus of Figure 1 when assembled; Figure 3 is a similar view of the apparatus in use after concrete has been poured. As will be seen in the Figures, the apparatus includes a waterstop strip 10 of dumbell configuration. Midway between its longitudinal edges the strip has, on each side, a pair of integral inwardly curved gripping arms 11. There are also two relatively rigid fillets 12, again of dumbell configuration. The ribs along the edges df the fillets fit in between the gripping arms to assemble the apparatus into the form shown in Figure 2. Figure 3 shows the apparatus in use, located within concrete 13 which has just been poured. The concrete is reinforced as at 14. Prior to the pouring of the concrete, the apparatus was located by means of spring clips encircling the enlarged free edges of the rigid strips. The clips 13 are attached to reinforcement 14. When the concrete dries out, the presence of the rigid fillets will cause it to crack generally within the plane occupied by the fillets. However, the crack will be bridged by the more flexible waterstop strip 10 tending to prevent the passage of water in to or out of the structure of which the concrete forms a part. WHAT WE CLAIM IS:

1. Waterstop apparatus for use in inducing cracks in cast concrete and preventing water passing through the induced cracks, such apparatus including a waterstop strip in the form of an extruded or moulded strip of rubber or other moisture and water resistant flexible plastics material and separate crack inducing fillets attachable to the sides of the strip by gripping means which include sections provided on both sides of the strip.

3. Apparatus according to claim 2, wherein the sections are continuous and integral with the strip

4. Apparatus according to claim 2 or 3, wherein each section has a cross-section comprising a pair of elastically deformable arms curved towards each other.

13. Waterstop apparatus constructed and

arranged substantially as hereinbefore described with reference to and illustrated in the accompanying drawings.

14. A method of preparing a concrete mass containing a dummy joint sealed by a waterstop within the thickness of the concrete, which method involves securing waterstop apparatus according to any one of claims 1 to 13 at a desired position within a bay into which concrete is to be poured, pouring the concrete into the bay, allowing the concrete to set whereupon a dummy joint is formed in the concrete along the plane of weakness induced by the fillets.

15. A method according to claim 14, wherein the concrete is to be reinforced concrete and the waterstop apparatus is secured in place by means of ties secured to the protruding edges of the fillets and connected to reinforcements of the concrete.

16. A method according to claim 15, wherein the fillets are enlarged along both edges and the ties are secured thereto by means of spring clips placed around the enlarged edge portions.

17. A method of preparing a concrete mass substantially as hereinbefore described with reference to the accompanying drawings.