Method of reinforcing an existing metal structure, method of reinforcing pipes and method of addition or spur lines to pipelines

1. A method of reinforcing a panel that has been reduced in thickness in use and is part of an existing metal structure comprising the steps of:

providing a reinforcing metal layer in spaced apart relation to said panel to form at least one cavity between said panel and said reinforcing metal layer;

injecting an intermediate layer comprised of an uncured plastics material into said at least one cavity; and

curing said plastics material so that it adheres to said panel and said reinforcing metal layer with sufficient shear strength to transfer shear forces between said panel and said reinforcing metal layer such that said panel, said reinforcing metal layer and said intermediate layer act mechanically together as a composite structural member,

wherein supporting members are arranged in said at least one cavity in contact with said panel and said reinforcing metal layer, and

wherein said step of providing a reinforcing metal layer comprises the steps of: adhering at least one spacer to said panel, and adhering said reinforcing metal layer to said at least one spacer, and

wherein said at least one spacer is metallic and said steps of adhering comprise welding.

2. The method of claim 1 , wherein said panel is part of a tunnel lining, a bridge deck, a cargo hold, a ship deck, a bulkhead, an external ship structure, a containment vessel, a building structure, a ship hull, or an off-shore structure or a smaller metal part of such an existing structure.

3. A method according to claim 1 , wherein said at least one spacer is a plate spacer, a spacer made of plastic, a lashing pot collar or a backing bar.

4. A method according to claim 1 , wherein before said providing step said panel is shot- or grit-blasted and cleaned.

5. A method according to claim 1 , wherein said reinforcing metal layer is less than 20 mm thick.

6. A method according to claim 1 , wherein said intermediate layer is at least 10 mm thick.

7. A method according to claim 1 , wherein said plastics material is an elastomer.

8. A method according to claim 1 , wherein said existing metal structure is part of a larger existing structure.

9. A method according to claim 1 , wherein said panel is supported by beams, girders or bulb flats and said reinforcing metal layer is arranged such that said beams, girders or bulb flats are positioned between said panel and said reinforcing metal layer.

10. A method according to claim 9 , wherein said reinforcing metal layer is bent such that said reinforcing metal layer is further from said panel in the proximity of said beams or bulb flats than in other positions.

11. A method according to claim 10 , wherein said reinforcing metal layer is attached to said beams or bulb flats on a surface opposite a surface on which said beams or bulb flats are attached to said panel.

12. A method according to claim 11 wherein said reinforcing metal layer is attached to said beams or bulb flats via a spacer.

13. A method according to claim 9 , wherein said reinforcing metal layer is attached to said beams or bulb flats on a surface opposite a surface on which said beams or bulb flats are attached to said panel.

14. The method of claim 1 , wherein said plastics material is such that, when cured, it provides inherent damping and sound insulation.

15. The method of claim 1 , wherein said plastics material, when cured, adheres to said panel and said reinforcing metal layer with a bond strength of at least 0.5 MPa.

16. The method of claim 1 , wherein said plastics material, when cured, adheres to said panel and said reinforcing metal layer with a bond strength of at least 6 MPa.

17. The method of claim 1 , wherein the tear, compression and tensile strengths as well as the elongation of the intermediate layer are such as to enable the composite structural member to absorb energy in unusual load events, such as impacts.

18. The method of claim 1 , wherein said plastics material, when cured, has a modulus of elasticity of at least 250 MPa.

19. The method of claim 1 , wherein said plastics material, when cured, has a modulus of elasticity of at least 275 MPa.

20. The method of claim 1 , wherein said plastics material, when cured, has a tensile strength of at least 2 MPa.

21. The method of claim 1 , wherein said plastics material, when cured, has a tensile strength of at least 20 MPa.

22. The method of claim 1 , wherein said plastics material, when cured, has a shear modulus of at least 92 MPa.

23. The method of claim 1 , wherein said plastics material, when cured, has a ductility at the lowest operating temperature greater than that of said panel or reinforcing layer.

24. The method of claim 1 , wherein said plastics material, when cured, has a coefficient of thermal expansion such as not to cause de-lamination from said panel or reinforcing layer during temperature fluctuations in use or during welding.

25. The method of claim 1 , wherein said panel is a part of a ship hull and said plastics material, when cured, has a tensile bond strength to said panel and said reinforcing layer high enough to withstand negative hydrostatic pressure and de-laminating forces from metal connections.

26. The method of claim 1 , wherein said plastics material, when cured is hydrostatically stable to both sea and fresh water and/or has a chemical resistance to oils.

27. The method of claim 1 , wherein said plastics material, when cured, has a compressive strength sufficient to maintain structural integrity under impact.

28. A method of reinforcing a panel that has been reduced in thickness in use and is part of an existing metal structure comprising the steps of:

providing a reinforcing metal layer in spaced apart relation to said panel to form at least one cavity between said panel and said reinforcing metal layer;

injecting an intermediate layer comprised of an uncured plastics material into said at least one cavity;

curing said plastics material so that it adheres to said panel and said reinforcing metal layer with sufficient shear strength to transfer shear forces between said panel and said reinforcing metal layer such that said panel, said reinforcing metal layer and said intermediate layer act mechanically together as a composite structural member,

wherein said panel is supported by beams, girders or bulb flats and said reinforcing metal layer is arranged such that said beams, girders or bulb flats are positioned between said panel and said reinforcing metal layer;

wherein said reinforcing metal layer is attached to said beams or bulb flats on a surface opposite a surface on which said beams or bulb flats are attached to said panel; and

wherein said reinforcing metal layer is attached to said beams or bulb flats via a spacer.