GB1562661A

GB1562661A - Seals for construction joints in concrete slabs or other concrete structures

Info

Publication number: GB1562661A
Application number: GB3370/77A
Authority: GB
Original assignee: BURMAH IND PROD Ltd
Current assignee: BURMAH IND PROD Ltd
Priority date: 1977-01-27
Filing date: 1977-01-27
Publication date: 1980-03-12
Also published as: NZ186220A; ES238140Y; ES465779A1; AU3166077A; DK41878A; AU509778B2; ES238140U; ZA777351B

Description

(54) SEALS FOR CONSTRUCTION JOINTS IN CONCRETE SLABS OR OTHER CONCRETE STRUCTURES (71) We, BURMAH INDUSTRIAL PRODUCTS LIMITED, a British Company of 147 London Road, Kingston-upon Thames, Surrey so 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: When it is necessary to seal a construction joint in concrete slab or other concrete structure at an exposed face of the slab or structure, it is usual to form a groove or rebate in the concrete along the joint and then either to fill the groove or rebate with a liquid sealing compound which subsequently sets, or to compress a sealing strip of rubber or elastomeric plastics material and insert it in its compressed condition into the groove or rebate.

The operation of filling the groove or rebate with the sealing compound or inserting the compressed strip into the groove or rebate is, however, time consuming and in consequence expensive.

The aim of the present invention is to provide a method of sealing a construction Joint in a concrete slab or other concrete structure at an exposed face of the structure, the sealing operation being carried out during the construction of the joint so that subsequent sealing operations are avoided.

The present invention consists in a method of sealing a construction joint in a concrete slab or other concrete structure, in which stop end shuttering is fixed along the line of the joint, a seal comprising an elongate extruded strip of rubber or elastomeric plastics material, the strip having two opposed faces, one of which has a projecting rib extending along it and the other of which has a groove extending along it, both the rib and the groove being spaced from the longitudinally extending edges of the opposed faces and both the rib and the groove being of dove-tailed or other undercut cross-section, is fixed to the stop end shuttering with one of the two opposed faces of the strip directed towards a face of the shuttering and a longitudinal edge of the strip, which extends between the two opposed faces, extending along the joint, concrete is cast against the shuttering and against the strip with an exposed face of the concrete at the stop end shuttering substantially flush with the said edge of the strip, the strip being keyed to the concrete by the undercut rib or groove and then, after the concrete has hardened, the stop end shuttering is removed leaving the strip in position and further concrete is cast against the face of the concrete previously defined by the stop end shuttering and against the strip.

By the use of this technique, a construction joint is formed between the two separately cast masses of concrete along the plane of the stop end shuttering in the usual way, but as the joint is formed, the strip is cast into the joint at the exposed face of the slab or other structure and the strip is keyed to the concrete on one side of the joint by the rib and to the concrete on the other side of the joint by the concrete which penetrates in the groove which is, as already mentioned, undercut.

Preferably the strip, apart from the rib and groove, is of rectangular cross-section, the length of the rectangle being at least twice its width. The rib extends from one of the two longer faces of the rectangle and the groove is formed in the other of the longer faces. Both the rib and the groove are preferably located so that their centre-lines lie on the transverse centreline of the rectangle.

To ensure that the concrete will penetrate satisifactorily into the groove to provide the necessary key, the minimum width of the groove is preferably at least twice the minimum width of the rib and is also preferably at least half an inch.

In use in forming and sealing a construction joint, the strip forming the seal is preferably fixed to the stop end shuttering with its face in which the groove is formed against the shuttering. Accordingly the rib is keyed into the first mass of concrete which is cast on one side of the joint and then, after the shuttering has been removed, the second mass of concrete pentrates into the groove to produce the second key. It is much easier to fix the strip to the stop end shuttering in this way than to fix it with the ribbed face of the strip against the shuttering as this would necessitate forming a groove in the shuttering for receiving the rib of the sealing strsP1ing strip.

Preferably the sealing strip is fixed to the shuttering by means of a fixing strip which is nailed to the shuttering and the strip which forms the seal has its groove push-fitted over the fixing strip. The fixing strip may be continuous along the whole length over which the strip which forms the seal extends along the stop end shuttering, but the fixing strip may alternatively be divided into a number of discontinuous short lengths so that the sealing strip is only intermittently fixed to the shuttering.

The provision of such a fixing strip greatly facilitates the fixing of the strip which forms the seal to the shuttering in such a way that the shuttering can subsequently be removed leaving the strip which forms the seal in position. The present invention accordingly also includes a sealing assembly comprising a seal in accordance with the invention as already described in combination with a fixing strip which is a firm push-fit in the undercut groove of the seal and has at intervals along its length holes for receiving fastenings to enable it to be fixed to shuttering.

Particularly when a concrete slab or other concrete structure is formed against waterbearing ground, it is necessary not only to seal construction joints at an exposed face of the slab or other structure as already described, but also to seal the construction joint against the passage of water through it from the ground which lies against the face of the slab or other structure remote from the exposed face.

For this purpose, the construction joint is preferably sealed by a water-stop in addition to being sealed by the seal in accordance with the invention. The water-stop may be centrally placed, but it is preferably of the surface type and is applied across the joint at the said exposed face of the concrete.

When the water-stop is of the surface type, it may be placed in position and the stop end may then be fixed along the centre-line of the water-stop. The concrete on each side of the construction joint is cast up against both the surface water-stop and against the elongate extruded strip of rubber or elastomeric plastics material and is keyed to both the water-stop and the strip.

An example of a method, in accordance with the invention, will now be described with reference to the accompanying drawings, in which: Figure 1 is a cross-section through the seal, the fixing strip and other parts necessary for forming and sealing a construction joint in a concrete slab; and, Figure 2 is a cross-section through the completed slab showing the sealed construction joint.

A sealing strip 1 is made by extrusion out of PVC of a rubber-like resilience and this strip has a dove-tailed rib projecting from one of its upright faces and a dove-tailed groove 3 formed in an opposite face. Apart from the rib 2 and the groove 3, the sealing strip 1 is of rectangular cross-section. A fixing strip 4 is of a size such that it is a firm push-fit within the groove 3 and is provided with holes through it at intervals along its length. In use, the fixing strip 4 is nailed by nails 5 to the face of timber stop end shuttering 6. In Figure 1 the strip 4 is shown in the course of being fixed to the shuttering 6 with the nail 5 only partially driven.

When the strip 4 has been fixed to the shuttering 6, the sealing strip 1 is fixed in position to the stop end shuttering 6 by having its groove 3 push-fitted over the strip 4.

A water-stop 7 of the surface type is set on over-site concrete, which is not shown, with its centreline extending in a vertical plane in which a construction joint is to be formed. The stop end shuttering 6 is then set in position on top of the water-stop 7 with a face 8 immediately above the centreline 9 of the water-stop 7, that is to say with its face 8 in a position just to the right of that shown in Figure 1 of the drawings.

When the shuttering 6 has been secured in position, a first mass of concrete 10 as shown in Figure 2 is placed against the stop end shuttering 6, against the right-hand half of the water-stop 7 and against the sealing strip 1 so that the rib 2 is keyed into the concrete 10 and so also is a rib 11 of the water-stop 7.

When the mass of concrete 10 has hardened sufficiently, the stop end shuttering 6 is removed and in so doing the fixing strip 4 is pulled from the groove 3 and the sealing strip 1 remains in position being keyed to the concrete 10 by the rib 2. A second mass of concrete 12 is then placed so that a construction joint 13 is formed between the masses of concrete 10 and 12. The mass of concrete 12 is keyed to the sealing strip 1 by penetration of part of the mass of concrete 12 into the dove-tailed groove 3 and a second rib 14 of the water-stop 7 is also keyed into the concrete 12 so that the water-stop 7 seals the joint 13 against the ingress of water from below.

WHAT WE CLAIM IS; 1. A method of sealing a construction joint in a concrete slab or other concrete structure, in which stop end shuttering is fixed along the line of the joint, a seal comprising an elongate extruded strip of rubber or elastomeric plastics material, the strip having two opposed faces, one of which has a projecting rib extending along it and the other of which has a groove extending along it, both the rib and the groove being spaced from the longitudinally extending edges of the opposed faces and both the rib and the groove being of dove-tailed or other undercut cross-section, is fixed to the stop end shuttering with one of the two opposed faces of the strip directed towards a face of the shuttering and a longitudinal edge of the strip, which extends between the two opposed faces, extending along the joint, concrete is cast against the shuttering and against the strip with an exposed face of the concrete at the stop end shuttering substantially flush with the said edge of the strip, the strip being keyed to the concrete by the undercut rib or groove and then, after the concrete has hardened, the stop end shuttering is removed leaving the strip in position and further concrete is cast against the face of the concrete previously defined by the stop end shuttering and against the strip.

2. A method according to Claim 1, in which the strip, apart from the rib and groove, is of rectangular cross-section, the length of the rectangle being at least twice its width, the rib extending from one of the two longer faces of the rectangle and the groove being formed in the other of the longer faces.

3. A method according to Claim 2, in which both the rib and the groove are located so that their centrelines lie midway between the ends of the rectangle.

4. A method according to Claim 2 or Claim 3, in which the minimum width of the groove is at least twice the minimum width of the rib.

5. A method according to any one of the preceding claims, in which the strip is fixed to the stop end shuttering with the face of the strip in which the groove is formed against the shuttering.

6. A method according to Claim 5, in which the strip is fixed to the shuttering by means of a fixing strip which is nailed to the shuttering and the strip of the seal has its groove push-fitted over the fixing strip.

7. A method according to any one of the preceding Claims, in which the construction joint is additionally sealed by a water-stop.

8. A method according to Claim 7, in which the water-stop is of the surface type and is applied across the joint at a face of the structure remote from the said exposed face.

9. A method according to Claim 1, substantially as described with reference to the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. second rib 14 of the water-stop 7 is also keyed into the concrete 12 so that the water-stop 7 seals the joint 13 against the ingress of water from below. WHAT WE CLAIM IS;

1. A method of sealing a construction joint in a concrete slab or other concrete structure, in which stop end shuttering is fixed along the line of the joint, a seal comprising an elongate extruded strip of rubber or elastomeric plastics material, the strip having two opposed faces, one of which has a projecting rib extending along it and the other of which has a groove extending along it, both the rib and the groove being spaced from the longitudinally extending edges of the opposed faces and both the rib and the groove being of dove-tailed or other undercut cross-section, is fixed to the stop end shuttering with one of the two opposed faces of the strip directed towards a face of the shuttering and a longitudinal edge of the strip, which extends between the two opposed faces, extending along the joint, concrete is cast against the shuttering and against the strip with an exposed face of the concrete at the stop end shuttering substantially flush with the said edge of the strip, the strip being keyed to the concrete by the undercut rib or groove and then, after the concrete has hardened, the stop end shuttering is removed leaving the strip in position and further concrete is cast against the face of the concrete previously defined by the stop end shuttering and against the strip.