WO2001006072A1

WO2001006072A1 - Joint sealing system

Info

Publication number: WO2001006072A1
Application number: PCT/AU2000/000870
Authority: WO
Inventors: William Claudio Bona
Original assignee: William Claudio Bona
Priority date: 1999-07-20
Filing date: 2000-07-20
Publication date: 2001-01-25
Also published as: AUPQ171799A0; NZ517378A

Abstract

A method of sealing a joint (10, 10A, 10B, 10C, 10D, 10E, 10F, 10G and 10H) which includes the steps of (i) application of a debonding material (20, 20B) suitably in strip form to the joint which has a joint aperture (7). The debonding material (20, 20B) is applied to each side of the joint aperture (7) and/or within or over the joint aperture (7). Finally, an elastomer (21) is applied to the debonding material (20, 20B) which debonding material (20, 20B) is maintained permanently within the joint (10, 10A, 10B, 10C, 10D, 10E, 10F, 10G and 10H) being sealed.

Description

"JOINT SEALING SYSTEM"

THIS INVENTION relates to a joint sealing system.

Conventional sealing systems for joints are well known and one particular sealing system in use is marketed under the SIKADUR-

COMBIFLEX trade mark. This sealing system comprises principally two

components, i.e. an epoxy resin based adhesive and a resilient tape or

strip having a thickness of 2-3 mm or thicker made from elastomer or synthetic rubber which was usually marketed under the trade mark

HYPALON. This elastomer was made by substitution of chlorine and

sulfonyl chloride into polyethylene and usually required application of an

activator or curing agent before use.

Such conventional sealing systems can be applied to dry or damp substrates which were formed from concrete, iron, steel or timber. The sealing system would be applied to internal joints in new or

refurbished concrete water tanks, reservoirs, pipelines, aquariums,

sewers and swimming pools as well as sealing underwater joints in situ,

large decks of multi-storey carparks, tunnels, silos, roofs as well as

expansion joints that have more movement than can be accommodated

by conventional elastomeric wet applied sealants.

In use, the SIKADUR-COMBIFLEX sealing system was

applied as shown in FIG. 1 herein and this is described in detail

hereinafter.

In use, the aforementioned conventional sealing systems

were found to be satisfactory in a number of situations but were subject to the following disadvantages:-

(a) use of the HYPALON tape along an elongate joint was not endless and thus there were overlapping sections forming joints of the tape at spaced intervals along the length of the tape. These overlapping joints were connected usually by heat welding and provided

areas of structural weakness;

(b) the conventional sealing systems as described above

were found to be expensive and time consuming in installation because of the use of an initial coat of

adhesive followed by HYPALON tape and a final coat

of adhesive;

(c) use of a sandwich type joint involving bottom coat and top coat of adhesive separated by HYPALON

tape did not provide complete bonding integrity; and

(d) the conventional sealing systems had different

installation procedures which were dependent on the

width of gap or joint aperture and thus a standardized

versatile sealing system was not provided.

It is therefore an object of the invention to provide a joint

sealing system which is seamless or not subject to overlapping joints or sections as described and which is simple and effective in use.

The method of the invention includes the following steps:-

(i) application of a debonding material suitably in strip form to a joint having a joint aperture wherein the debonding material is applied to each side of the joint or aperture and/or within or over the joint aperture; and (ii) application of an elastomer to the debonding material

which debonding material is maintained permanently within the joint being sealed.

The invention also provides a sealing system for gaps which

comprises an initial application of debonding material which is retained within the gap by a subsequent coat of elastomer.

Preferably in relation to the process of the invention, the joint surface was usually cleaned mechanically and was then primed by

application of a suitable primer. Such a primer may be selected from water based acrylics, solvent bases, silanes, cementitious epoxy resins,

epoxy resins, isocyanates, PVC, styrene-butadiene resins or

polyvinylacetate coatings.

Subsequently the debonding material is applied to the joint.

The debonding material is preferably flexible and is usually in the form of

a strip or tape, such as masking tape, duct tape or electrical tape.

Preferably the debonding tape is in the form of an adhesive tape having

one broad surface which had an adhesive applied thereto. The tape may be formed from any suitable plastics material or could be formed from fabric inclusive of linen or cotton or even metal in some cases. It is,

however, useful to use a tape which is inert to the coat of elastomer and does not restrict elongation or flexing of the elastomer in use. The debonding tape may also be formed from non-woven or woven fabric, geotextile material, material from low density or high density polyethylene

or even paper or cardboard in appropriate circumstances. The debonding

material functions to space or separate the final elastomer coat from the joint surface(s) and/or gap aperture.

In some cases, a filler cord may be applied to the joint before application of the debonding agent. The filler cord may be formed

from compressible or resilient material, such as extruded polystyrene, polystyrene foam, rubber, rubber composites, polysulphate or polyurethane material. Alternatively, a filler rod made of rigid material could be utilised. Such rigid material could be metal or plastic mateπal.

The use of the filler cord is appropriate when it is desired to provide the

debonding tape with a hump or concave shape as hereinafter described.

In other situations, the filler cord may be omitted and the

debonding tape may be applied to the joint so that the debonding tape forms a U-shape or trough shape within the gap aperture.

Finally, an elastomer is applied to the joint and this may

comprise any suitable elastomer which may be formed from a synthetic

elastomer which may comprise polyurea, polyurethane, epoxy resins,

bituminous compounds, polyvinyl chloride, rubber including synthetic rubber as well as natural rubber and thermoplastic elastomers. Acrylic elastomers, butyl rubber, chlorosulfonate polyethylene, ethylene-

propylene rubber, fluorinated elastomers, neoprene, nitrite rubber, polybutadiene, polyethers, polyisoprene, SBRs or polypentenamers may be utilized and especially those that are susceptible for spray on

application. However, it will be appreciated that the elastomer may also

be applied to the debonding material by brush, roller or other suitable

means.

In another variation, the elastomer may be pre-applied to

the debonding material prior to application to the joint and this is

described in detail hereinafter.

A particularly preferred elastomer is a polyurea elastomer

marketed under the trade mark ENVIROLASTIC which is marketed by EnviroChem Technologies, Forth Worth, Texas, U.S.A. The specification

for this material describes it as "based on proprietary urethane polymers and an amine type curing mechanism". It has high strength and high impact and abrasion resistance and is seamless and flexible. It may be

applied to concrete or metal substrates.

The joint sealing system of the invention may be applied to

joints or gaps in tunnels, pipes, pits, floors, walls, ceilings, tanks,

reservoirs, basins, aqueducts, roofs, culverts and internal or external surfaces of buildings. The sealing system of the invention may also be applied to timber, geotextile fabrics, metals, plastics and any other type of

surface.

Reference may now be made to a preferred embodiment as

shown in the drawings, wherein:-

FIGS. 1A, 1B, 1C, 1D, 1E, 1 F and 1 G are schematic drawings showing the various steps applicable to application of a prior art joint sealing system described herein;

FIGS. 2A, 2B, 2C, 2D and 2E are similar views to FIGS. 1A- 1 G showing the various steps applicable to one embodiment of a joint

sealing system of the invention;

FIGS. 3A, 3B, 3C, 3D, 3E, 3F and 3G are similar views to FIGS. 2A-2E showing the various steps applicable to another

embodiment of the joint sealing system of the invention;

FIG. 4 is a cross section of a raised joint using a filler cord;

FIG. 5 is a cross section of one type of recessed joint

wherein a filler cord is omitted;

FIG. 6 is a cross section of another type of recessed joint to

which the sealing system of the invention has been applied;

FIG. 7 is a cross section of a joint located at the junction of a

floor and wall which has been sealed in accordance with the invention;

FIG. 8 is a similar view to FIG. 7 showing another type of

joint located at the junction of a floor and wall which has been sealed in

accordance with the invention;

FIG. 9 is a view similar to FIG. 8 showing a different

embodiment of the invention;

FIG. 10 is a view similar to FIG. 8 showing a different

embodiment of the invention; and

FIG. 11 is a view similar to FIG. 8 showing a different

embodiment of the invention. In FIG. 1 , the prior art method refers to application of the conventional sealing system described herein under the SIDADUR-

COMBIFLEX trade mark which is applied to joint 10 having a gap 7 which

is bounded by top surfaces 11 and 12 of concrete walls 8. After surface cleaning and priming, a base coat 9 of adhesive is then painted or otherwise applied to each top surface 11 and 12 after application of

primer 6. The adhesive utilized in the prior art method was not an elastomer and, in fact, comprised an epoxy resin which was noted for its

adhesive or bonding ability as well as high chemical resistance

properties.

Subsequently a debonding material was applied to the

adhesive usually on one side only of the joint aperture 7. However, it was

to be appreciated that the masking tape could also be applied to both

sides of gap 7 or over gap 7. This debonding material was masking tape

14. In some cases, at the preference of the contractor, the masking tape 14 could be applied prior to application of base coat adhesive 9 and was

then removed after application of base coat 9. In other circumstances, the

masking tape 14 was applied after application of base coat 9. Usually a

filler cord 15 was applied to gap 7 prior to masking tape 14 although the

filler cord could be omitted if it was desired to provide a depressed U-

shaped joint.

Thereafter, a membrane in the form of HYPALON tape 16

was applied across gap 7 as shown after removal of masking tape 14.

This membrane then cured within a period at least one hour after application of curing agent. The HYPALON tape 16 has a median strip 17 and edge apertures 18 which facilitate attachment to surfaces 11 and 12

by adhesive 9 extruding through apertures 18 and forming a series of

spaced "pin locks".

Subsequently a top coat 19 of adhesive is applied to the

surfaces 11 and 12 on top of tape 16 and thereafter median strip 17 was removed before setting of top coat 19.

From the foregoing, it will be appreciated that the prior art

method shown in FIGS. 1A-1G required the application of an initial coat

or base coat of non-elastomeric epoxy resin or adhesive as well as a final

coat 19 of non-elastomeric epoxy resin. Any debonding material was

removed from the joint 10 prior to application of HYPALON tape 16 which

required at least one hour to cure after application of curing agent.

In contrast, the method of the invention as shown in FIGS.

2A-2E after cleaning and priming of surfaces 11 and 12 comprises application of debonding material 20 across gap 7 although in some

cases it may only be necessary to apply debonding mateπal to surfaces

11 and 12 leaving gap 7 clear. A filler cord 15 may also be used if it is desired to have an elevated or raised joint. Finally, a coat of elastomer 21

is applied to joint 10 suitably by spraying by spray gun 22.

It therefore will be appreciated that the method of the

invention is much simpler than the prior art method in not requiring the

use of base and top coats of non-elastomeric adhesive nor the use of

HYPALON tape 16 which requires at least one hour of curing agent. The sealing method of the invention can be universally applied to apertures of any size and is not dependent upon the width of gap 7. The sealing method of the invention also provides a seamless finish not having any

welded joints. It is also relevant that in the prior art method shown in

FIGS. 1A-1G the debonding material is removed wherein in the method of

the invention, the debonding material is retained permanently within the finished joint.

In FIG. 3, there is shown another embodiment similar to the

FIG. 2 embodiment, with the exception that steps shown in FIGS 2D and

2E are varied by the steps shown in FIGS. 3D-3G. In FIG. 3D a layer 20A of adhesive or bonding agent is applied to surfaces 11 and 12 prior to

application of a debonding membrane 20B, which has had a layer 21 of

elastomer applied thereto prior to application to surfaces 11 and 12. Then in FIG. 3F a final layer of elastomer 20D is applied, preferably by

brush or roller, on each side of membrane 20B.

FIG. 3G shows a cross sectional view of what is illustrated

in FIG. 3F.

The debonding membrane 20B may be formed of any

suitable debonding material, as described above, inclusive of fabric,

geotextile material and plastics material. Conventional masking tape may

also be used.

As shown in FIG. 4, the joint 10A of the invention has

elastomer 21 applied over debonding layer 20 which covers filler cord 15.

This is an example of an elevated joint as opposed to a depressed joint 10B shown in FIG. 5 wherein filler cord 15 is omitted and debonding material 20 is applied to gap 7 (i.e. layer 20A) as well as being applied to surfaces 11 and 12.

In some cases, a steel plate may extend across joints sealed in accordance with the invention, such as joint 10C in FIG. 6

wherein steel plate 22A is attached to top surface 27 of joint 10C by fasteners 28. Also, when appropriate, it may be useful to apply over joint

10C a layer of polyethylene foam 23.

FIG. 7 shows application of joint 10D to a wall to floor joint

wherein wall 8A is located adjacent floor 8B.

FIG. 8 also shows application of joint 10E to a wall to floor

joint, wherein there is used a filler cord 15 to provide a raised joint. Filler

cord 15 is round in cross section. However, filler cord 15 may also be

quadrant shaped in cross section as shown in FIG. 9, triangular in cross

section as shown in FIG. 10 or square in cross section as shown in FIG.

11. Fig. 9, 10 and 11 show joints 10F, 10G and 10H.

Having regard to the preferred embodiment of the invention as shown in the drawings, it is noted that debonding material 20 or

debonding membrane 20B not only spaces elastomer 21 from surfaces 11

and 12 but also provides a firm support for the elastomer 21 and allows

the elastomer 21 to flex as may be required when external forces are

applied to the joint 10. It will also be appreciated from the drawings that

elastomer 21 also bonds securely to surfaces 11 and 12 on either side of the joint 10 to provide a joint with substantial bonding integrity. It will also be appreciated that the joint sealing system of the invention may be applied to gaps of between 1 mm up to 300mm.

It will also be appreciated that in another variation of the invention there may be applied a kit comprising membrane 20B which already has elastomer 21 applied thereto, primer, adhesive and elastomer as a final coat. The kit may also include filler cord 15 when an elevated

joint is required.

DATED this Twentieth day of July 2000.

WILLIAM CLAUDIO BONA.

by his Patent Attorneys,

FISHER ADAMS KELLY.

Claims

1. A method of sealing a joint which includes the following steps:

(i) application of a debonding material suitably in strip

form to the joint which has a joint aperture wherein the debonding material is applied to each side of the joint aperture and/or within or over the joint aperture; and

(ii) application of an elastomer to the debonding material

which debonding materials is maintained permanently within the joint being sealed.

2. A method as claimed in claim 1 wherein in step (ii)

the elastomer is applied to the debonding material subsequent to step (i).

3. A method as claimed in claim 1 wherein in step (ii)

the elastomer is applied to the debonding material prior to step (i).

4. A method as claimed in claim 1 wherein prior to step

(i) a filler cord is applied to the joint aperture.

5. A method as claimed in claim 1 wherein each side of

the joint aperture is cleaned and primed prior to step (i).

6. A method as claimed in claim 1 wherein in step (i)

debonding material is applied to the joint only on both sides of the joint

aperture.

7. A method as claimed in claim 1 wherein in step (i)

debonding material is applied to the joint above or over the joint aperture.

8. A method as claimed in claim 1 wherein in step (i) debonding material is applied to the joint so that the debonding material is located within the joint aperture.

9. A method as claimed in claim 3 wherein a strip of debonding material is applied to the joint over the joint aperture which

strip has already been coated with elastomer.

10. A method as claimed in claim 9 wherein a layer of

adhesive is applied to the joint on each side of the joint aperture prior to application of debonding material.

11. A method as claimed in claim 9 wherein a final coat

of elastomer is applied to the joint on each side of the joint aperture after

application of debonding material.

12. A joint sealed by the method of claim 1.

13. A joint having a layer of debonding material applied thereto which is covered by a coat of elastomer.

14. A kit for sealing a joint having a joint aperture which

comprises:

(i) a strip of debonding material having a coat of

elastomer applied thereto; and

(ii) elastomer.

15. A kit as claimed in claim 14 also including adhesive.

16. A kit as claimed in claim 15 which includes filler cord.