WO2010037211A1

WO2010037211A1 - Apparatus and methods for lining concrete structures with flexible liners of textile or the like

Info

Publication number: WO2010037211A1
Application number: PCT/CA2009/001347
Authority: WO
Inventors: George David Richardson; Semion Krivulin
Original assignee: Cfs Concrete Forming Systems Inc.
Priority date: 2008-10-01
Filing date: 2009-10-01
Publication date: 2010-04-08

Abstract

Flexible liners are provided for lining a surface of a structure fabricated from concrete, other cementitious materials or other curable materials. The flexible liner comprises a flexible lining material and a bonding mechanism located on an interior surface of the flexible lining material. The bonding mechanism is capable of adhering to the curable material as the curable material solidifies to line the surface of the resultant structure with the flexible lining material. The bonding mechanism may comprise a chemical or physical structure suitable for bonding to the concrete, a roughened or piled texture suitable for bonding to concrete and/or one or more anchors which extend into the curable material prior to curing to thereby anchor the flexible lining material to the resultant structure as the curable material solidifies. Methods are providing for use of the flexible liners.

Description

APPARATUS AND METHODS FOR LINING CONCRETE STRUCTURES WITH FLEXIBLE LINERS OF TEXTILE OR THE LIKE

Technical Field [0001] This application claims the benefit of the priority of US application No. 61/101993 filed 1 October 2008 entitled APPARATUS AND METHODS FOR LINING CONCRETE STRUCTURES WITH FLEXIBLE LINERS OF TEXTILE OR THE LIKE, US application No. 61/143151 filed 7 January 2009 entitled METHODS AND APPARATUS FOR RESTORING, REPAIRING, REINFORCING AND/OR PROTECTING STRUCTURES USING CONCRETE and US application No. 61/223378 filed 6 July 2009 entitled METHODS AND APPARATUS FOR RESTORING, REPAIRING, REINFORCING AND/OR PROTECTING STRUCTURES USING CONCRETE, all of which are incorporated herein by reference.

Technical Field

[0002] The invention disclosed herein relates to the fabrication of structures from concrete, other cementitious materials and/or similar curable materials. Particular embodiments of the invention provide methods and apparatus for providing flexible linings or claddings on the surfaces of concrete structures during, or after, fabrication thereof. Concrete structures lined or cladded in this manner may comprise pre-cast and/or cast-in-place structures.

Background [0003] It is known to make a wide variety of structures from concrete. By way of non- limiting example, such structures may include walls (e.g. for buildings, tanks or other storage containers), structural components (e.g. supports for bridges, buildings or elevated transportation systems), tunnels or the like. In many applications, the concrete used to make such structures is unsuitable or undesirable as a surface of the structure or it is otherwise desired to line one or more surfaces of the structure with material other than concrete.

[0004] By way of non-limiting example, consider the use of concrete to form tilt-up walls. Concrete tilt-up walls represent an example of a pre-cast concrete structure which is cast in a certain location/orientation and then moved into its desired location/orientation after the concrete solidifies (cures). Tilt-up walls are typically formed in a generally horizontal plane (e.g. on a horizontal table) and then tilted to a generally vertical plane. A form is created on the table by suitably fastening form-work members to the table such that the form-work members extend upwardly from the horizontal surface of the table. Concrete is then introduced into the form. The form- work members (including the horizontal surface of the table) retain the liquid concrete in the desired shape. Some tables are configured to vibrate to assist with an even distribution of liquid concrete. When the concrete solidifies (cures), the concrete structure is hoisted from the form and tilted from the generally horizontal orientation of the table into a generally vertical orientation by a crane, a suitably configured winching apparatus or the like.

[0005] A drawback with prior art tilt-up walls is that the wall surfaces are bare concrete. Bare concrete surfaces have a number of limitations. Bare concrete may be aesthetically unpleasing. Consequently, prior tilt-up walls may not be suitable for certain applications where there is a desire to have an aesthetically pleasing finished surface on the walls. In addition, bare concrete typically has a somewhat porous or otherwise non-smooth surface which is difficult to clean and which provides spaces for dirt to accumulate and bacteria and other organisms to grow. Consequently, prior art tilt-up walls may not be suitable for certain applications where there is a desire to provide a sanitary environment. Bare concrete may be susceptible to degradation or damage from exposure to various chemicals or conditions, such as, by way of non- limiting example, ultraviolet radiation, salt, various acids, animal excrement and whey. Consequently, prior art tilt-up walls may not be suitable for certain applications where the wall might be exposed to such chemicals or conditions. [0006] There is a general desire to provide methods and/or apparatus for lining or cladding one or more surfaces of concrete structures with material other than concrete. There is a particular desire to provide methods and apparatus for lining or cladding one or more surfaces of concrete structures with flexible materials, such as textile or the like. [0007] From time to time, various structures may require repair, restoration, reinforcement and/or protection. For example, structures made of concrete (e.g. building walls and floors, bridge supports, dams, columns, raised platforms and the like) are often formed using embedded reinforcement bars (typically referred to as rebar) or similar steel reinforcement material, which provides the resultant structure with increased strength. Over time, corrosion of the embedded reinforcement material can impair the integrity of the embedded reinforcement material, the surrounding concrete and the overall structure. Similar degradation of structural integrity can occur with or without corrosion over long periods of time, in structures subject to large forces, in structures deployed in harsh environments or the like. Similar degradation can occur in structure made from or comprising materials other than concrete - e.g. structural steel, creosote-soaked timber and the like.

[0008] There is a general desire to provide methods and/or apparatus for repairing, restoring and/or reinforcing structures (concrete structures and/or structures made from other materials(s)) which have been degraded or which are otherwise in need of repair and/or restoration. [0009] Structures made from concrete (or from other materials) may be damaged by the conditions in the environment where such structures are deployed. By way of non-limiting example, structures fabricated from metal or concrete can be damaged when they are deployed in environments that are in or near salt water or in environments where the structures are exposed ultraviolet radiation or in environments where the structures are exposed to salt or other chemicals used to de-ice roads. There is a general desire to protect structures (concrete structures and/or structures made from other materials) from damage which may be caused by, or related to, the environment in which the structure is deployed.

Brief Description of Drawings

[0010] In drawings which illustrate non-limiting embodiments of the invention:

Figure 1 is a cross-sectional view of a portion of a concrete structure lined with a flexible liner according to a particular embodiment of the invention; Figures IA is a magnified cross-sectional view of the anchor of the Figure

1 flexible liner;

Figures IB-I J are cross-sectional views of a variety of anchors each having one or more corresponding anchoring features which may be used in other example embodiments of the Figure 1 flexible liner; Figure 2 is a partial plan view of the Figure 1 flexible liner taken from the perspective of line 2-2 (Figure 1);

Figure 3 is a partial plan view of a flexible liner according to another embodiment of the invention from a perspective similar to that of Figure 2;

Figure 4 is a cross-sectional view of a portion of a concrete structure lined with a flexible liner according to another embodiment of the invention;

Figure 4A is a magnified view of an anchor used in the flexible liner of Figure 4;

Figure 4B is a cross-sectional view of a portion of a concrete structure lined with a flexible liner according to another embodiment; Figures 5 A and 5B are an exploded cross-sectional view and a conventional cross-sectional view of a portion of a concrete structure lined with a flexible liner according to another particular embodiment of the invention;

Figures 5C-5E are cross-sectional views of a variety of anchor/receptacle pairs which may used in other embodiments of the flexible liner of Figure 5B; Figures 6A-6D (collectively, Figure 6) represent non-limiting examples of damaged structures which may be repaired, restored, reinforced and/or protected in accordance with particular embodiments of the invention;

Figures 7A-7D (collectively, Figure 7) respectively show examples of cast-in-place repair structures comprising flexible liners which may be used to repair, restore, reinforce and/or protect the existing structures of Figures 6A-6D according to particular embodiments of the invention;

Figure 8A represents a rebar-supporting structural anchor which may be used to anchor a repair structure incorporating a flexible liner to an existing structure according to a particular embodiment;

Figure 8B represents a rebar-supporting structural anchor which may be used to anchor a repair structure incorporating a flexible liner to an existing structure according to another particular embodiment;

Figures 9 A and 9B respectively represent a top view and a cross-sectional view along the line 9B-9B of a structural anchor which may be used to anchor a repair structure incorporating a flexible liner to an existing structure according to another particular embodiment;

Figure 1OA is a plan view of a mounting component of a structural anchor which may be used to anchor a repair structure incorporating a flexible liner to an existing structure according to another particular embodiment;

Figure 1OB is a cross-section of the Figure 1OA mounting component taken along the line 10B- 1OB;

Figure 1OC is a cross-section of the Figure 1OA mounting component taken along the line 10C- 1OC; Figure 1OD is an isometric view of the Figure 1OA mounting component;

Figure 1OE is an isometric view of an anchor component which may be used with the Figure 1OA mounting component to provide a structural anchor which may be used to anchor a repair structure to an existing structure according to another particular embodiment; Figure 1OF is an end view of the Figure 1OE anchor component;

Figure 1OG is an end view of the Figure 1OA mounting component connected to the Figure 1OE anchor component;

Figure 1 IA is an isometric view of a spacer component which may be used with the Figure 1OA mounting component to provide a spacer which may be used to maintain the spacing of a repair structure formed from flexible stay-in- place form;

Figure 1 IB is an end view of the Figure 1OA mounting component connected to the Figure 1 IA spacer component;

Figure 11C is a top view of a repair structure formed from flexible stay-in- place form.

Description

[0011] Throughout the following description, specific details are set forth in order to provide a more thorough understanding to persons skilled in the art. However, well known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. Accordingly, the description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

[0012] Particular aspects of the invention provide apparatus and methods for lining one or more surfaces of concrete structures with flexible lining materials. In this description and the accompanying claims, the word lining and similar words should understood to include cladding and a lining may be applied to any surface of a structure (e.g. an interior surface, an exterior surface, a top surface and/or a bottom surface). In some embodiments, flexible liners are applied to the concrete structures during fabrication (e.g. before the concrete solidifies or cures); in other embodiments, flexible liners are applied to the concrete structures after fabrication (e.g. after the concrete solidifies or cures). In this description and the accompanying claims, the word solidifies and similar words are used interchangeably with the word cures and similar words and these words should be understood to have commensurate meaning. In some embodiments, existing structures (which may be fabricated from any suitable material) are repaired, restored, reinforced and/or protected using concrete lined with flexible liners. [0013] In particular embodiments, flexible liners comprise flexible lining material together with a bonding mechanism which permits the flexible lining material to bond to the concrete structure. The flexible lining material may generally comprise any flexible material, such as a textile or the like. In some embodiments, the bonding mechanism comprises the flexible lining material itself, which may comprise a chemical or physical structure suitable for bonding to liquid concrete as it cures (e.g. acrylonitrile butadiene styrene (ABS) plastic or the like). In some embodiments, the bonding mechanism may comprise a physical surface characteristic of the flexible lining material. For example, the flexible lining material may comprise an interior surface or interior coating that has a relatively rough texture (e.g. a piled texture) to help bond to liquid concrete as it cures. In some embodiments, the bonding mechanism of the flexible liner comprises one or more anchors which extend into the concrete structure to secure the flexible lining material to the structure. In some embodiments, the anchors may be mounted or otherwise connected to the flexible lining material. In some embodiments, in addition to bonding the flexible lining material to the concrete structure, anchors maybe used to provide the concrete structure with additional structural integrity and/or reinforcement. [0014] The anchors may comprise, at least in part, a material that is relatively rigid in comparison to the flexible lining material. The anchors may comprise a stem located at, or extending to, a location, proximate to the surface of the concrete structure and one or more anchoring features at locations on an interior of, or further (relative to the stem) into, the concrete structure. The anchoring features may have dimensions (in directions generally parallel with the surface of the concrete structure) which are greater than corresponding dimensions of the stem. The anchors may extend into the concrete from an inner surface of the flexible lining material or from an exterior of the flexible lining material. To the extent that the anchors extend into the concrete structure from an exterior of the flexible lining material, the anchors may deform the flexible lining material such that the liner also extends into the concrete and/or the anchors may penetrate through the flexible lining material and into the concrete. [0015] Flexible liners according to various embodiments of the invention may generally be used to line any structure formed from concrete, other cementitious materials or similar curable materials. Such concrete structures may comprise so-called "cast-in-place" structures, where the structure is fabricated in the place where it will be used, or so-called "pre-cast" structures, where the structure is fabricated and then moved to the location where it will be used. Flexible liners may be used to line any /all surface(s) of particular structure(s). [0016] One particular non-limiting example of a pre-cast concrete structure which may be lined in accordance with particular embodiments of the invention is the interior and/or exterior surface of a tilt-up wall structure. A structural form for a tilt-up wall may be assembled on a table or a similar horizontal surface. In particular embodiments, a flexible liner (comprising flexible lining material and one or more bonding mechanisms) is placed within the form to cover at least a portion of the horizontal table surface. The one or more bonding mechanisms may include the physical/chemical properties of the interior (upper) flexible lining material and/or one or more anchors. To the extent that the flexible liner comprises anchors, the anchors may be oriented on the table to project upwardly from the table surface. In some embodiments, flexible liner may be placed in the structural form to line other surfaces thereof, such that the anchors project inwardly into the form. One or more layers of liquid concrete are the introduced into the form. In some embodiments, a top layer of flexible liner may be laid atop the liquid concrete with the bonding mechanisms (e.g. anchors or piled surface) oriented downwardly into the wall segment or may be temporarily coupled to a top piece of form-work which may be laid atop the liquid concrete such that the anchors extend downwardly into the wall segment. As the concrete solidifies, the bonding mechanisms (e.g. anchors) bond the flexible lining material to the resultant wall segment which may then be tilted from the generally horizontal table surface into a desired orientation (e.g. vertical) and moved (if necessary) into a desired location. [0017] One particular non-limiting example of a cast-in-place concrete structure which may be lined in accordance with particular embodiments of the of the invention is a cast-in-place wall structure. A structural form for the cast-in-place wall may be assembled in the location where the wall is to be located. In particular embodiments, a flexible liner (comprising flexible lining material and one or more bonding mechanisms) is placed within the form to cover the form surface(s) corresponding to the surface(s) of the wall which are to be lined. The one or more bonding mechanisms may include the physical/chemical properties of the interior (upper) flexible lining material and/or one or more anchors. The anchors may be oriented such that they project inwardly into the form. In some embodiments, the flexible liner is temporarily attached to the surfaces of the structural form or to some other relatively rigid structure. In some embodiments, tensile forces are applied to the flexible liner. Concrete is then introduced to the structural form. In some embodiments, a top layer of flexible liner may be laid atop the liquid concrete with the bonding mechanisms (e.g. anchors or piled surface) oriented downwardly into the wall segment or may be temporarily coupled to a top piece of form-work which may be laid atop the liquid concrete such that the anchors extend downwardly into the wall. As the concrete solidifies (cures), the bonding mechanism (e.g. anchors) bond the flexible lining material to the resulting wall surface(s). [0018] Flexible liners according to various embodiments may be used to line cast-in-place structures (made from concrete, other cementitious materials or other curable materials), which may be used to repair, restore, reinforce and/or protect existing structures. For the sake of brevity and clarity, cast-in-place structures used to repair, restore, reinforce and/or protect existing structures are referred to herein (without loss of generality) as "repair structures". Existing structures which may be repaired, restored, reinforced and/or protected using such repair structures may themselves be fabricated from concrete, but this is not necessary. In general, such existing structures may be fabricated from any material. In accordance with particular embodiments, a structural form is assembled adjacent the repair location and one or more surface(s) of the structural form are lined with flexible liners (comprising flexible lining material and one or more bonding mechanisms). In some embodiments, the flexible liner is temporarily attached to the surfaces of the structural form or to some other relatively rigid structure. In some embodiments, tensile forces are applied to the flexible liner. Concrete is then introduced into the structural form. As the concrete solidifies, the bonding mechanisms bond the flexible lining material to the resulting surface(s) of the repair structure. In some embodiments, prior to introducing concrete into the structural form, structural anchors are attached to the existing structure and configured to extend into, or through, the form region such that when the concrete solidifies, the structural anchors anchor the repair structure to the existing structure. [0019] Figure 1 is a cross-sectional view of a flexible liner 20 lining a surface

26 A of a concrete structure 26 according to a particular embodiment of the invention. Flexible liner 20 comprises a flexible lining material 22 and one or more anchors 24. Concrete structure 26 may generally comprise any concrete structure, such as, by way of non-limiting example, a wall (e.g. for buildings, tanks or other storage containers), a stractural component (e.g. supports for bridges, buildings or elevated transportation systems), a tunnel or the like. Concrete structure 26 may be formed according to a precast process or a cast-in-place process. Concrete structure 26 may be a repair structure used to repair, restore, reinforce and/or protect an existing structure made of concrete and/or other material.

[0020] Flexible lining material 22 comprises a material that is deformable or is otherwise flexible or of low stiffness such as a textile, fabric or the like. In particular embodiments, flexible lining material 22 comprises a synthetic-based textile, such as a fabric made from PVC, nylon or other suitable polymers or plastics. In other embodiments flexible lining material 22 comprises a mineral-based textile, such as fabric made from glass fibers or metal fibers. Flexible lining material 22 is not limited to a woven material and may generally be fabricated using any suitable process, such as, by way of non-limiting example, extrusion, molding, spin-coating, spray-coating or the like. [0021] Flexible lining material 22 may be sufficiently thin and/or flexible to deform in an inward-outward direction (indicated by double-headed arrow 25) under the application of minimal external force. In particular embodiments, flexible lining material 22 is sufficiently thin (in inward-outward direction 25) and/or flexible such that any piece of material larger than 1 m² held aloft in one corner will deform significantly (e.g. over 90°) under its own weight. In still other embodiments, flexible lining material 22 is sufficiently thin (in inward-outward direction 25) and/or flexible such that any piece of material larger than 0.25 m² held aloft in one corner will deform significantly (e.g. over 90°) under its own weight. In still other embodiments, flexible lining material 22 is sufficiently thin (in inward-outward direction 25) and/or flexible such that any piece of material larger than 0.0625 m² held aloft in one corner will deform significantly (e.g. over 90°) under its own weight.

[0022] In particular embodiments, flexible lining material 22 is sufficiently thin (in inward-outward direction 25) and/or flexible such that it may be bent over 180° with a radius of curvature less than 10 times its inward-outward direction thickness without structural breakdown or damage to the material. In other embodiments, flexible lining material 22 is sufficiently thin (in inward-outward direction 25) and/or flexible such that it may be bent over 180° with a radius of curvature less than 5 times its inward-outward direction thickness without structural breakdown or damage to the material. In still other embodiments, flexible lining material 22 is sufficiently thin (in inward-outward direction 25) and/or flexible such that it may be bent over 180° with a radius of curvature less than 3 times its inward-outward direction thickness without structural breakdown or damage to the material.

[0023] Because of its high degree of flexibility, flexible lining material 22 (and thus flexible liner 20) can conform to the shape of a wide variety of forms to line the surfaces of concrete structures 26 having a wide variety of shapes. [0024] In some embodiments, interior surface 22A of flexible lining material 22 may be provided with a non-smooth texture (e.g. roughened and/or piled texture) or other bondable surface (not explicitly shown) to facilitate bonding of flexible lining material 22 to concrete structure 26 during fabrication thereof (e.g. as the concrete in structure 26 solidifies). In particular embodiments, the non-smooth texture of interior surface 22A may have a dimension (in inward-outward direction 25) that is greater than 2.5% of the thickness of flexible lining material 22 in inward-outward direction 25. In particular embodiments, the non-smooth texture of interior surface 22A may have a dimension (in inward-outward direction 25) that is greater than 1% of the thickness of flexible lining material 22 in inward-outward direction 25. In other embodiments, the non-smooth texture of interior surface 22A may have a dimension (in inward-outward direction 25) that is greater than 0.25% of the thickness of flexible lining material 22 in inward- outward direction 25. In some embodiments, flexible lining material 22 (and/or its inner surface) may comprise a material having physical or chemical properties that bonds naturally to concrete as the concrete solidifies (e.g. acrylonitrile butadiene styrene (ABS) plastic or the like).

[0025] In the illustrated embodiment, flexible liner 20 also comprises a plurality of anchors 24. Anchors 24 comprise, at least in part, a material that is relatively more rigid than flexible lining material 22. For example, given similarly shaped samples of the anchor material and of the flexible lining material, the anchor material would be relatively more rigid than the flexible lining material (i.e. greater force would be required to deform the anchor material than the flexible lining material). In some embodiments, anchors 24 are fabricated entirely from material that is relatively more rigid than flexible lining material 22. In some embodiments, anchors 24 are fabricated principally from a material that is relatively more rigid than flexible lining material 22, but are coated in some locations with an elastomeric material. In particular embodiments, anchors 24 may be fabricated from relatively rigid PVC, other suitable plastics, steel, other suitable alloys or the like. Anchors 24 extend inwardly from flexible lining material 22 into concrete structure 26 to anchor flexible lining material 22 to concrete structure 26 as described in more detail below.

[0026] Figure IA shows a magnified view of a particular anchor 24A of the Figure 1 flexible liner 20. Anchor 24A comprises a base 32A, a stem 28A and an anchor feature 30A. As shown best in Figure 1, base 32A of anchor 24A is attached to flexible lining material 22. hi the illustrated embodiment, base 32A is coupled to interior surface 22A of flexible lining material 22 by a suitable fastening technique such as welding (e.g. plastic welding), for example, hi other embodiments, other suitable fastening techniques could be used to attach base 32A to interior surface 22 A of flexible lining material 22. By way of non-limiting example, such fastening techniques could include non-penetrative techniques such as hook and loop fasteners (particularly where interior surface 22A of flexible lining material 22 has a piled texture), suitable adhesives or tapes and/or techniques which involve penetration through flexible lining material 22 and/or base 32A, such as stitching, staples, rivets or the like. Anchor attachment techniques which involve penetration through flexible lining material 22 may involve an application of sealant, seam taping or the like to cover the penetration holes in flexible lining material 22 and minimize or prevent leakage of fluids therethrough.

[0027] As shown best in Figure IA, the illustrated anchor 24A comprises a stem 28A which extends inwardly from base 32A into concrete structure 26 and an anchoring feature 30A at a location spaced inwardly apart from flexible lining material 22. In the illustrated embodiment, anchoring feature 30A extends from stem 28 A in directions parallel to surface 26A of structure 26. This is not necessary, however, and anchoring features 30A according to various embodiments may extend in other directions. In some embodiments, anchoring features 30A extend in direction(s) which provide anchoring features 30A with dimensions parallel to the surface 26A of concrete structure 26 that are greater than corresponding dimensions of stem 28A. This shape of concrete anchoring features 30A provides concavities 33A between anchoring feature 30A and base 32A (or lining material 22). As explained in more detail below, this relative shape of anchoring feature 3OA and stem 28A helps to anchor flexible lining material 22 to concrete structure 26. [0028] hi operation of the Figure 1 embodiment, flexible liner 20 is applied to concrete structure 26 during fabrication of concrete structure 26. Flexible liner 20 is spread out in a manner in which the exterior surface 22B of flexible lining material 22 lines at least a desired portion of the form (not shown) in which structure 26 will be cast. Ih cases where the surface 26A of structure 26 to be lined is horizontally oriented (e.g. when lining one of the surface of a tilt-up wall), flexible lining material 22 may rest unfastened atop the form. In other circumstances (e.g. where surface 26A to be lined is oriented in a non- horizontal direction), it may be desirable to temporarily secure flexible liner 20 to a part of the form or to some other relatively rigid structure, such that flexible liner 20 does not move significantly within the form upon introduction of concrete to the form. In one non- limiting example, exterior surface 22B of flexible lining material 22 may be secured to the form using a suitable temporary adhesive or suitable fasteners (e.g. hook and loop fasteners, stitching, staples, screws, rivets or the like). To the extent that penetrative fastening techniques are used to secure flexible liner 20 in place within the form, suitable sealant, taping or the like may be used to cover the penetration holes, hi another non- limiting example, flexible liner 20 may extend beyond the edges of the form and the portion extending beyond the edges of the form may be fastened to the form or to other structures using any suitable fastening technique (e.g. adhesive, hook and loop fasteners, stitching, staples, screws, rivets, rope, twine, wire, cable or the like). Once the concrete cures in the form, the excess flexible liner material may be trimmed to the dimension of - l i the form. Flexible liner 20 may also be secured to some relatively rigid structure when surface 26A is horizontally oriented.

[0029] Once the desired surfaces of the form are lined with flexible liner 20, concrete is introduced into the form. The concrete fills the form and occupies the concavities 33A surrounding stem 28 A of anchors 24 between anchoring features 30A and base 32A. When the concrete solidifies, anchoring features 30A are encased in concrete and anchor flexible liner 20 to concrete structure 26. The form may then be removed and, in the case of pre-cast structures, the structure may be moved to its desired location. [0030] In some embodiments, it may be desirable to connect edges of flexible liner 20 to one another. For example, where a single flexible liner extends around structure 26, it may be desirable to connect its edges to one another. As another example, it may be desirable to connect the edges of similar flexible liners on adjacent surface(s) of structure 26. Such connection may be done before or after concrete is added to the form and before or after the concrete solidifies. This edge-to-edge connection of flexible liners may be accomplished using any suitable technique, which may include, by way of non-limiting example, welding techniques, stitching techniques, lacing techniques, weaving techniques, clasps, buckles, clips, hooks, "snap-together" fasteners, hook and loop fasteners, adhesives, suitable tapes, fasteners (e.g. staples, rivets, bolts or the like), one or more zippers or the like. In some embodiments, the edges of flexible liner(s) may overlap one another (e.g. in a region where they are connected). Such overlap may facilitate edge- to-edge connection of flexible liner(s) and may also prevent concrete from the structure from interfering with the connection mechanism.

[0031] Figure 2 is a partial plan view of the Figure 1 flexible liner 20 taken from the perspective of line 2-2 (Figure 1). The Figure 2 plan view shows exterior surface 22B of flexible lining material 22. The Figure 2 plan view also shows (in dotted outline), the locations of anchors 24 according to a particular embodiment of the invention. In the illustrated embodiment, anchors 24 are provided in an array 35 of spaced apart locations. In the illustrated embodiment, array 35 is a generally symmetric and evenly spaced array in directions 34, 36 that define surface 22B. This is not necessary. Array 35 could have non-symmetric and/or unevenly spaced anchor locations. In the illustrated Figure 2 embodiment, each individual anchor 24 extends approximately equally in each of the orthogonal directions 34, 36 that define surface 22B. While in the illustrated Figure 2 embodiment, anchors 24 are shown as being approximately square (in directions 34, 36), this is not necessary and anchors 24 may have other shapes. [0032] Figure 3 is a partial plan view of a flexible liner 20' taken from a similar perspective to that of Figure 2. The Figure 3 plan view shows exterior surface 22B' of flexible lining material 22'. The Figure 3 plan view also shows (in dotted outline), the locations of anchors 24' according to a particular embodiment of the invention. In the illustrated embodiment, anchors 24' are provided in an array 35' of spaced apart locations. In the illustrated embodiment, array 35' is generally evenly spaced array in direction 36. This is not necessary, and array 35' could have unevenly spaced anchor locations. Flexible liner 20' (Figure 3) differs from flexible liner 20 (Figure 2) in that in flexible liner 20', each individual anchor 24' is substantially longer in direction 34 than it is in direction 36. That is, anchors 24' are elongated in one (direction 34) of the orthogonal directions 34, 36 that define surface 22B'.

[0033] Anchors 24' that are elongated in one direction may provide the additional characteristics of stiffening flexible lining material 22' or otherwise preventing flexible lining material 22' from folding in on itself in at least one direction. For example, in the illustrated embodiment of Figure 3, where anchors 24' are elongated in direction 34', it will be relatively difficult to fold flexible lining material 22' in on itself in direction 34'. This characteristic may be advantageous when attempting to line a form with flexible liner 20', particularly when the form surface to be lined is not horizontal and the force of gravity will tend to cause flexible lining material 22' to fold in on itself. [0034] hi the illustrated embodiment of Figure 3, anchors 24' are all elongated in one direction (i.e. in direction 34'). This is not necessary. In some embodiments, it may be desirable to provide a single flexible liner 20' with a plurality of elongated anchors 24' which are elongated in different directions. For example, it may be desirable to have an array of anchors similar to anchors 24' shown in the illustrated embodiment but oriented to be elongated in the orthogonal direction 36'. Such an array of orthogonally oriented anchors could be designed to engage anchors 24' or to fit in the spaces between anchors 24'.

[0035] hi some embodiments (not shown) the relative stiffness of anchors may be used to provide some shape to flexible liners. For example, if it is known that flexible liners are going to be used to line a round column with a certain diameter, then elongated anchors having appropriately arcuate radii of curvature may be used to provide the flexible liner with the desired shape and with some degree of stiffness in that shape. It will appreciated that the relative stiffness of anchors may be used to provide other shapes to flexible liners. [0036] hi addition to providing one possible bonding mechanism for bonding flexible lining material 22 to concrete structure 26, anchors 24A may reinforce or otherwise increase the structural integrity of concrete structure 26 when anchor features 30A are encased in concrete. However, anchors 24A are not necessary in all embodiments, hi some embodiments, the bonding mechanism for bonding flexible lining material 22 to concrete structure 26 may additionally or alternatively be provided by the physical and/or chemical properties of flexible lining material 22 which may bond naturally to concrete. For example, an interior surface of flexible lining material 22 may be coated with ABS, which bonds naturally to concrete as it cures, hi other embodiments, the bonding mechanism for bonding flexible lining material 22 to concrete structure 26 may additionally or alternatively be provided by a roughened or piled interior surface of flexible lining material 22.

[0037] Figure IA shows an anchor 24A according to one particular embodiment of the invention. As discussed above, anchor 24A comprises a stem 28A, anchoring feature 30A and base 32A. Figures 1B-1H show other anchors 24B-24H according to other non- limiting example embodiments of the invention which may be used in connection with the Figure 1 flexible liner 20. In the illustrated embodiments, anchors 24B-24H of Figures IB- IH are similar to anchor 24 A of Figure IA in that they each comprise at least one stem 28B-28H, at least anchoring feature 30B-30H and a base 32B-32H. hi the illustrated embodiments of Figures 1B-1H, stems 28B-28H extend inwardly from bases 32B-32H into the concrete structure and anchoring features 30B-30H are provided at locations spaced inwardly apart from bases 32B-32H. Like anchor 24A described above, anchoring features 30B-30H may have one or more dimensions parallel to bases 32B- 32H that are greater than corresponding dimensions of stems 28B-28H to provide concavities 33B-33H between anchoring features 30B-30H and bases 32B-32H. As described above, the relative shape of anchoring features 30B-30H and stems 28B-28H helps to anchor the flexible lining material to the concrete structure when anchoring features 30B-30H are encased in concrete. [0038] Figures II and IJ depict other anchors 241, 24 J according to other non-limiting example embodiments of the invention. Anchors 241, 24.T differ slightly from the previously described anchors 24A-24H in that anchors 241, 24J do not have stems. Rather anchors 241, 24 J comprise anchoring features 301, 30J which extend directly from bases 321, 32J to provide concavities 331, 33J between anchoring features 301, 30J and bases 321, 32J. It will be appreciated by those skilled in the art that there are many possible implementations of anchors 24 which may be used in conjunction with the Figure 1 flexible liner 20 and that anchors 24A-24J shown in Figures IA-I J represent non-limiting exemplary embodiments.

[0039] Figure 4 is a cross-sectional view of a portion of a concrete structure 126 lined with a flexible liner 120 according to another embodiment of the invention. Flexible liner 120 is similar in many respects to flexible liner 20 (Figure 1) and similar reference numerals are used to refer to similar features of flexible liner 120, except that features of flexible liner 120 are preceded by the numeral "1". Like flexible liner 20, flexible liner 120 comprises a flexible lining material 122 and one or more anchors 124. Flexible lining material 122 may be substantially similar to flexible lining material 22 described above. hi particular, flexible lining material 122 may comprise a material with similar deformability/flexibility/stiffhess characteristics as flexible lining material 22, flexible lining material 122 may comprise an interior surface 122A that has a non-smooth (e.g. piled or roughened) texture similar to that of flexible lining material 22 and the relative flexibility of flexible lining material 122 and anchors 124 may be similar to that of flexible lining material 22 and anchors 24.

[0040] Anchors 124 may also be similar in many respects to anchors 24 described above. A magnified view of anchor 124 is shown in Figure 4 A. In the illustrated embodiment, anchor 124 comprises a base 132, a stem 128 and a plurality of anchoring features 130. In the illustrated embodiment, anchoring features 130 extend in directions parallel to base 132 (and to exterior surface 126 A of concrete structure 126) at locations spaced apart from base 132 to provide concavities 133 between anchoring features 130 and base 132. In other embodiments, anchors 124 may comprise anchoring features 130 which extend in other directions, but which have dimensions that extend parallel to base 132 (and to exterior surface 126 A of concrete structure 126) such that the dimensions of anchoring features 130 in direction parallel to surface 126A are greater than that of stem 128 and such that anchoring features 130 provide concavities 133.. [0041] Flexible liner 120 differs principally from flexible liner 20 in that anchors 124 extend from an outer surface 122B of flexible lining material 122 into concrete structure 126. As shown in Figure 4, flexible lining material 122 deforms around anchors 124 at locations (bights) 122C as anchors 124 project into concrete structure 126. [0042] In operation, anchors 124 may be temporarily fastened, glued or otherwise connected to the interior surface of a structural form or positioned in suitable receptacles provided on the interior surface of the form and then flexible lining material 122 is inserted into the form on an interior of attached anchors 124. In some embodiments, particularly when flexible liner 120 is to be applied to a non-horizontal surface, flexible lining material 122 may be temporarily fastened, welded, glued or otherwise secured to the form (or to some other rigid structure) to mitigate against displacement of flexible lining material 122 relative to the form. Concrete is then introduced into the form. The concrete will fill the gaps in the form, causing flexible lining material 122 to deform around anchors 124 at bights 122C (see Figure 4). To the extent that anchors 124 provide concavities 133 between their bases 132 and their anchoring features 130, concrete may fill or partially fill these concavities 133 as shown at 138 in Figure 4. Flexible lining material 122 may be subjected to some tension (e.g. via attachment to the form or to some other rigid structure) when it is inserted on the interior of anchors 124. However, the deformability of flexible lining material 122 and/or the amount of tension applied to flexible lining material 122 may be selected to permit deformation of flexible lining material 122 at locations 122C under the weight of the concrete introduced to the form. Deformation of flexible lining material 122 under the weight of the concrete may or may not involve stretching of flexible lining material 122. When the concrete solidifies to provide concrete structure 126, anchors 124 serve to anchor flexible lining material 122 to outer surface 126A of concrete structure 126. [0043] Anchors 124 may be sized, shaped and/or arranged in a manner similar to anchors 24 of flexible liner 20 shown in Figures 2 and 3. More particularly, anchors 124 may be elongated in one dimension or may be of similar size in multiple dimensions. Anchors 124 may be arranged in various suitable patterns as desired to achieve desired bonding of flexible lining material 122 to concrete structure 126.

[0044] In some embodiments, portions of anchors 124 may be coated or lined with elastomeric material, in particular where anchors 124 contact flexible lining material 122. Such elastomeric material may be more flexible than flexible lining material 122 and may prevent anchors 124 from tearing or otherwise damaging flexible lining material 122. [0045] It will be appreciated by those skilled in the art that the particular anchor 124 illustrated in flexible liner 120 of Figures 4 and 4A represents a particular example of an anchor which may be used. In general and without limitation, any of the anchors 24A-24J illustrated in Figures IA-U could be used in connection with flexible liner 120 of Figure 4. Similarly, anchor 124 of Figures 4 and 4A could be used with flexible liner 20 of Figure 1.

[0046] In some embodiments, it may be desirable to have an anchor which actually penetrates from exterior surface 122A of flexible lining material 122 through to the interior of flexible lining material 122 and into concrete structure 126. A flexible liner 120' according to such an embodiment is shown at Figure 4B. It will be noticed that for flexible liner 120', anchor 124 (Figure 4) is replaced with anchor 24B (Figure IB) which is sharper and therefore facilitates penetration through flexible lining material 122 at locations 122D. Flexible lining material 122 may generally be punctured before or after adding concrete to form structure 126. [0047] Figure 5A is an exploded cross-sectional view of a flexible liner 220 according to another embodiment of the invention. Figure 5B is a cross-sectional view of a portion of a concrete structure 226 lined with flexible liner 220. Flexible liner 220 is similar in many respects to flexible liner 20 (Figure 1) and flexible liner 120 (Figure 4). Similar reference numerals are used to refer to similar features of flexible liner 220, except that the features of flexible liner 220 are preceded by the numeral "2". Like flexible liner 20 and flexible liner 120, flexible liner 220 comprises a flexible lining material 222 and one or more anchors 224. Flexible lining material 222 may be substantially similar to flexible lining material 22 described above. In particular, flexible lining material 222 may comprise a material with similar deformability/flexibility/stiffness characteristics as flexible lining material 22, flexible lining material 222 may comprise an interior surface 222A that has a non-smooth (e.g. roughened or piled) texture similar to that of flexible lining material 22 and the relative flexibility of flexible lining material 222 relative to anchors 224 (and flexible lining material 222 relative to receptacles 240) may be similar to that of flexible lining material 22 and anchors 24. [0048] While only one anchor 224 is visible in the illustrated views of Figures 5 A, 5B, flexible liner 220 may generally comprise one or more anchors 224. Anchor 224 may also be similar in many respects to anchors 24 and anchors 124 described above. In the illustrated embodiment, anchor 224 is similar to anchor 241 of Figure II and comprises a base 232 and anchoring features 230 shaped to provide concavities 233 between anchoring features 230 and base 232.

[0049] As shown best in Figure 5B, flexible liner 220 is similar to flexible liner 120 in that anchors 224 extend from an outer surface 222B of flexible lining material 222 into concrete structure 226. Flexible lining material 222 deforms around anchors 224 at locations (bights) 222C as anchors 224 project into concrete structure 226. Flexible lining material 222 may or may not stretch as it deforms around anchors 224. Flexible liner 220 differs principally from flexible liners 20 and 120 in that flexible liner 220 comprises one or more receptacles 240 for receiving anchors 224 and the deformed bight 222C of flexible lining material 222. [0050] hi operation according to some embodiments, receptacles 240 are formed in concrete structure 226 as structure 226 is fabricated and then, after structure 226 solidifies, anchors 224 are inserted into receptacles to secure flexible liner 222 in place against surface 226A. In such embodiments, receptacles 240 may be temporarily fastened, glued or otherwise connected to desired interior surface(s) of a form prior to introduction of concrete to the form. When concrete is introduced to the form, the concrete will fill the gaps in the form and will retain receptacles 240 in structure 226 as it solidifies. As described in more detail below, receptacles 240 may incorporate features which help to ensure that the receptacles 240 are retained in structure 226 as the concrete solidifies. After the concrete of structure 226 solidifies, flexible lining material 222 may be placed over surface 226A of structure 226 and anchors 224 may be inserted into receptacles 240 causing bights 222C of flexible lining material 222 to deform into receptacles 240 as shown in Figure 5B. Flexible lining material 222 may be subjected to some tension prior to insertion of anchors 224 into receptacles 240. Depending on the amount of tension applied to flexible lining material 222, flexible lining material 222 may or may not stretch as it deforms around anchors 224. Anchors 224 received in receptacles 240 serve to anchor flexible lining material 222 to outer surface 226A of concrete structure 226.

[0051] It is not necessary that anchors 224 be inserted into receptacles 240 after the concrete of structure 226 has solidified, hi some embodiments, anchors 224 are fastened, glued or otherwise temporarily connected to the interior surface of a form, flexible lining material 222 is inserted into the form on an interior of anchors 224 and then receptacles 240 are pressed onto anchors 224 to cause bights 222C of flexible lining material 222 to deform into receptacles 240. Concrete is then introduced to the form. The concrete will bond to receptacles 240 as discussed above and may bond to interior surface 22A of flexible lining material 222. Flexible lining material 222 may be subjected to some tension prior to insertion of anchors 224 into receptacles 240. Flexible lining material 222 may or may not stretch as it deforms around anchors 224. When the concrete solidifies to provide concrete structure 226, anchors 224 received in receptacles 240 serve to anchor flexible lining material 222 to outer surface 226A of concrete structure 226. [0052] Anchors 224 and receptacles 240 may be sized, shaped and/or arranged in a manner similar to anchors 24 of flexible liner 20 shown in Figures 2 and 3. More particularly, anchors 224 and receptacles 240 may be elongated in one dimension or may be of similar size in multiple dimensions. Anchors 224 and receptacles 240 may be arranged in various suitable patterns as desired to achieve desired bonding of flexible lining material 222 to concrete structure 226.

[0053] In some embodiments, portions of anchors 224 and/or receptacles 240 may be coated or lined with elastomeric material, in particular where anchors 224 and/or receptacles 240 contact flexible lining material 222. Such elastomeric material may be more flexible than flexible lining material 222 and may prevent anchors 224 and/or receptacles from tearing or otherwise damaging flexible lining material 222 and may also help to secure the connection between anchors 224 and receptacles 240. [0054] In the illustrated embodiment of Figures 5 A and 5B (flexible liner 220), receptacle 240 is shaped to correspond to the shape of anchor 224 and to make a friction fit with anchor 224. In some embodiments, insertion of anchors 224 into corresponding receptacles 240 comprises deforming one or both of anchors 224 and receptacles 240. For example, in the case of anchor 224 of Figure 5 A, insertion of anchor 224 into receptacle 240 may involve deformation of anchoring features 230 toward one another as shown by arrows 242. Preferably, anchors 224 and/or receptacles 240 are fabricated from materials that are resilient, such that deformation of anchors 224 and/or receptacles 240 to insert anchors 224 into receptacles 240 results in restorative forces which tend to return anchors 224 and/or receptacles 240 to their original shape. Such restorative deformation forces may increase the friction in the fit between anchors 224 and receptacles 240 or may otherwise provide a "snap-together" type fit between anchors 224 and receptacles 240. [0055] In some embodiments, including the illustrated embodiment of Figure 5 A, exterior surface 254 of receptacle 240 is shaped to define one or more concavities 250 and to provide one or more convexities 252 wherein concavities 250 are located further into concrete structure 226 than convexities 252. This shape of exterior surface 254 of receptacle 240 can help retain anchors 224 in receptacles 240. More particularly, concavities 250 can accept anchoring features 230 and convexities 252 can extend into concavities 233 between anchoring features 230 and bases 232.

[0056] In some embodiments, including the illustrated embodiment of Figure 5 A, interior surface 244 of receptacle 240 defines one or more concavities 246 and provides one or more convexities 248 wherein convexities 248 are located further into concrete structure 226 than concavities 246. This shape of interior surface 244 of receptacle 240 can help to facilitate bonding of receptacle 240 to concrete structure 226. More particularly, prior to curing concrete can flow into concavities 246 and then, once the concrete is solidified in concavities 246, convexities 248 prevent removal of receptacles 240 from structure 226. [0057] It will be appreciated by those skilled in the art that the particular anchor 224 and corresponding receptacle 240 of flexible liner 220 illustrated in the embodiment of Figures 5 A and 5B represents a particular example of an anchor/receptacle pair. In general and without limitation, any of the anchors 24A-24J illustrated in Figures 1 A-IJ or anchor 124 of Figure 4A could be used with correspondingly shaped receptacles (not explicitly shown) in connection with flexible liner 220 of Figures 5.

[0058] Figures 5C and 5D show further examples of suitable anchors 224C, 224D and corresponding receptacles 240C, 240D which may be used in connection with flexible liner 220 (Figure 5B) according to other embodiments. In the illustrated embodiments of Figures 5C and 5D, anchors 224C, 224D comprise anchoring features 230C, 230D which define concavities 233C, 233D between anchoring features 230C, 230D and bases 232C, 232D. In the illustrated embodiments of Figures 5C and 5D, receptacles 240C, 240D comprise interior surface convexities 248C, 248D and interior surface concavities 246C, 246D which function in a manner similar to interior surface convexities 248 and interior surface concavities 246 of receptacle 240 (Figure 5A). In the illustrated embodiments of Figures 5C and 5D, receptacles 240C, 240D comprise exterior surface convexities 252C, 252D and exterior surface concavities 250C, 250D which function in a manner similar to exterior surface convexities 252 and exterior surface concavities 250 of receptacle 240 (Figure 5A). [0059] Figure 5E shows a further example of a suitable anchor 224E and corresponding receptacle 240E which may be used in connection with flexible liner 220 (Figure 5B) according to another embodiment. In the illustrated embodiment of Figure 5E, anchor 224E comprises anchoring features 230E which define concavities 233 E between anchoring features 230E and base 232E. In the illustrated embodiment of Figures 5E, receptacle 240E comprises exterior surface convexities 252E and exterior surface concavities 250E which function in a manner similar to exterior surface convexities 252 and exterior surface concavities 250 of receptacle 240 (Figure 5A). Receptacle 240E differs from the previously described embodiments in that its interior surface comprises a supplementary anchoring feature 260E which defines supplementary concavities 262E useful for retaining receptacle 240E in concrete structure 226. In the illustrated embodiment, supplementary anchoring features 260E is similar to anchoring feature 30A of anchor 24 (Figure IA). In other embodiments, however, supplementary anchoring feature 260E could comprise any of the other anchoring features described herein. [0060] It will be appreciated by those skilled in the art that there are many possible implementations of anchors 224 and receptacles 240 which may be used in conjunction with the Figure 5B flexible liner 220 and that the anchors and receptacles described herein represent non-limiting exemplary embodiments. [0061] In a manner similar to the embodiment shown in Figure 4B, in some embodiments comprising anchor/receptacle pairs, it may be desirable to have an anchor 224 which actually penetrates from exterior surface 222A of flexible lining material 222 through to the interior of flexible lining material 222 and into receptacle 240. As shown in Figure 4B, it may be desirable to use a relatively sharp anchor to facilitate penetration through flexible lining material 222. [0062] One particular non-limiting example of a cast-in-place structure which may be lined using the various flexible liner embodiments of the invention is a repair structure (formed from concrete, other cementitious materials or other similar curable materials). As discussed above, repair structures may be used to repair, reinforce, restore and/or protect an existing structure. Figures 6A-6D represent top views of non-limiting examples of existing structures 300A-300D which are damaged in regions 302A-302D and may be repaired, restored, reinforced and/or protected by casting suitable repair structures lined with flexible liners in accordance with particular embodiments of the invention.

[0063] Figure 6 A shows a column 300A having a generally rectangular cross-section. Column 300A is damaged in region 302 A. In the illustrated example, column 300A is a concrete column and the damage to region 302 A has exposed some rebar 304A. Figure 6B shows a portion of a flat wall 300B which is damaged in region 302B to expose rebar 304B. While the exemplary column 300A and flat wall 300B shown in Figures 6A and 6B are fabricated from concrete, this is not necessary. Column 300A and flat wall 300B could generally be fabricated from any suitable material, such as masonry, steel, wood or the like. Figure 6C shows a round column 300C that is damaged in region 302C. Figure 6D shows a portion of a curved wall 300D that is damaged in region 302D. Round column 300C and curved wall 300D may generally be fabricated from any suitable material, such as masonry, steel, wood or the like. [0064] Figures 7A-7D respectively show examples of cast-in-place repair structures 308A-308D comprising flexible liners 320A-320D which may be used to repair, restore, reinforce and/or protect the existing structures 300A-300D of Figures 6A-6D according to particular embodiments of the invention. Flexible liners 320A-320D may be substantially similar to any of the flexible liner embodiments 20, 120, 220 described above and may incorporate flexible lining materials, anchors and any other features and/or variations of these embodiments. However, for the sake of clarity, details of flexible liners 320A-320D are not shown in the illustrated views of Figures 7A-7D. In the case of rectangular cross-section column 300A (Figure 7A) and circular cross-section column 300C (Figure 7C), respective repair structures 308A, 308C and flexible liners 320A, 320C extend all of the way around the damaged columns 300A, 300C. In the case of flat wall 300B (Figure 7B) and curved wall 300D (Figure 7D), respective repair structures 308B, 308D and flexible liners 320B, 320D extend just beyond respective damaged regions 302B, 302D.

[0065] In some cases, the concrete of repair structures (e.g. repair structures 308A-308D) will bond directly to existing structures (e.g. existing structures 300A-300D) as the concrete of the repair structures is cast in place. For example, where existing structures 300A-300D are fabricated from brick or concrete, concrete repair structures 308A-308D may bond directly to existing structures 300A-300D as concrete structures 308A-308D are cast in place. In other cases, however, existing structures 300A-300D are fabricated from other materials (e.g. steel or wood or the like) to which the concrete of repair structures 308A-308D does not easily bond. In some cases (for example, columns 300A, 300C of Figures 7A, 7C), repair structures 308 A, 308C extend all of the way around existing columns 300A, 300C, such that the concrete of repair structures 308A, 308C may actually bond to itself to hold itself in place relative to existing columns 300A, 300C.

[0066] In other cases (for example, walls 300B, 300D of Figures 7B, 7D), repair structures 308B, 308D are localized and do not extend all of the way around existing structures. In cases where repair structures are localized and the concrete of the repair structures does not bond sufficiently well to the existing structure or in any other case where a high degree of bonding between the repair structure and the existing structure is desired, repair structures may be anchored to existing structures 300B, 300D using structural anchors. In general, structural anchors are fastened or otherwise connected to the existing structures and extend from the existing structures into and/or through the repair structure form, such that when concrete solidifies in the repair structure form, the structural anchors are anchored into the concrete of the repair structure to bond the repair structure to the existing structure.

[0067] Figure 8 A shows a structural anchor 350A which may be used to anchor a repair structure incorporating a flexible liner to an existing structure according to another particular embodiment. Structural anchor 350A of the Figure 8 A embodiment is suitable for applications where existing structures are formed from concrete or masonry, for example. In the Figure 8 A embodiment, structural anchor 350A is a two-piece anchor comprising an anchor nut 352A, which engages the existing structure, and an eye-bolt 354A, which engages anchor nut 352A at one end and extends into the repair structure form to engage rebar (not shown) at its opposing end. In other embodiments, structural anchor 350A may comprise a single piece component or a multi (i.e. more than two) piece component which performs the functions described herein. [0068] ha the illustrated embodiment, anchor nut 352 A comprises one or more concrete-engaging features 356A and a threaded bore 358A. Concrete-engaging features 356A may comprise a plurality of radially extending ridges around an exterior circumference of anchor nut 352A. In the illustrated anchor nut 352A, concrete-engaging features 356A extend in radial directions when threaded shaft 360A of eye bolt 354A is received in threaded bore 358A. It will be appreciated by those skilled in the art that there are a wide variety of concrete anchors known in the art, and that where the existing structure is fabricated from concrete, structural anchor 350A could make use of any such concrete anchors.

[0069] Eye bolt 354A of the Figure 8 A embodiment comprises a threaded shaft 360A and a rebar-retaining feature 362 A. In the illustrated embodiment, rebar-retaining feature 362A comprises a curved bight 364 A which defines an aperture 366A through which rebar may optionally extend.

[0070] In operation, one or more structural anchors 350A are connected to an existing structure. Optionally, once structural anchors 350A are connected to the existing structure, rebar may be threaded through apertures 366A of structural anchors 350A. A repair structure form is then assembled in the region to be repaired, restored, reinforced and/or protected. A suitable flexible liner can then be inserted into the repair structure form to line desired surface(s) of the repair structure form as described above. It will be appreciated that eye bolt 354A extends outwardly from the existing structure and into the repair structure form (not shown). Concrete is then introduced to the repair structure form. Even without optional rebar, when concrete solidifies in the repair structure form, at least a portion of eye bolt 354A will be encased in the concrete of the repair structure and will anchor the repair structure to the existing structure. When optional rebar is threaded through apertures 366A of structural anchors 350A, the rebar may provide the resultant repair structure with increased strength and may also improve the bonding of the repair structure to the existing structure. [0071] Figure 8B illustrates a structural anchor 350B which may be used to anchor a repair structure incorporating a flexible liner to an existing structure according to another particular embodiment. Structural anchor 350B of the Figure 8B embodiment comprises an anchor nut 352B and a J-bolt 354B which are similar to anchor nut 352A and eye bolt 354 A of the Figure 8 A structural anchor 350A. J-bolt 354B comprises a threaded shaft 360B and a rebar-retaining feature 362B comprising a curved bight 364B which defines a concavity 367B. Structural anchor 350B functions in a manner similar to that of structural anchor 350A described above. It will be appreciated by those skilled in the art that eye bolt 354A or J-bolt 354B could be provided with other rebar-retaining features in the place of rebar-retaining features 362 A, 362B. [0072] It will be appreciated by those skilled in the art that the particular features of structural anchors will depend on the nature of the existing structures to which they will be connected. For example, for existing structures fabricated from steel or wood, it may be desirable to use structural anchors which incorporate rebar-retaining features similar to rebar-retaining features 362A, 362B of structural anchors 350A, 350B, but which comprise connection features that are specific for attaching to steel or wood at their opposing ends.

[0073] Figures 9A and 9B respectively depict top and cross-sectional views of a structural anchor 380 which may be used to anchor a repair structure incorporating a flexible liner to an existing structure according to another particular embodiment. Structural anchor 380 is advantageous, because it can be used for existing structures made from a wide variety of materials by selecting appropriate fasteners (not shown), as explained in more detail below. Structural anchor 380 may be fabricated from any suitably strong material (e.g. plastic, metal, nylon, fiberglass or the like). Structural anchor 380 may be fabricated using any suitable manufacturing process, including, by way of non-limiting example, extrusion, injection molding or the like. Structural anchor 380 comprises a base 382 which is perforated at spaced apart locations by apertures 384. Between apertures 384, structural anchor 380 comprises anchors 385. In the illustrated embodiment, anchors 385 are similar to anchor 24B of Figure IB and, each anchor 385 comprises a stem 386 and anchoring features 388. Anchoring features 388 may have dimensions in directions generally parallel to the surface of the existing structure which are wide in comparison to the corresponding dimension of stem 386 to provide concavities 389. [0074] Structural anchors 380 may be used to anchor a repair structure (e.g. repair structures 308A-308D) to an existing structure (e.g. existing structures 300A-300D) to facilitate lining the repair structure with a flexible liner as described herein. One or more structural anchors 380 may be mounted to an existing structure using suitable fasteners which project through apertures 384 such that the underside 382A of base 382 abuts against the structure. The particular fasteners chosen to mount structural anchor(s) 380 to the existing structure may depend on the material from which the existing structure is fabricated. By way of non-limiting example, if the existing structure is made from concrete, then the fasteners may be similar to the concrete fasteners shown on structural 350A, 350B of Figures 7A, 7B, but if the existing structure is made from steel or the like, then the fasteners used to mount structural anchor(s) 380 may comprise rivets or other suitable fasteners for steel. It is not necessary that structural anchors 380 be mounted to existing structures using fasteners. In some embodiments, it may be desirable to mount structural anchors 380 to existing structures using suitable adhesives. hi such embodiments, apertures 384 may not be required. A repair structure form is then assembled in the region to be repaired, restored, reinforced and/or protected. A suitable flexible liner can then be inserted into the repair structure form to line desired surface(s) of the repair structure form as described above. It will be appreciated that anchor(s) 385 of structural anchors 380 extends outwardly from the existing structure and into the repair structure form (not shown). Concrete is then introduced to the repair structure form. Concrete fills the repair form including concavities 389. Once the concrete solidifies, the concrete in the cavities of structural anchors 380 bonds the repair structure to the existing structure.

[0075] In some embodiments, stem 386 of structural anchor 380 may be provided with one or more apertures (not shown), through which rebar may be extended to provide additional strength to the repair structure. While structural anchor 380 of the illustrated embodiment incorporates an anchor 385 similar to anchor 24B of Figure IB, it will be appreciated by those skilled in the art that structural anchor 380 may easily be modified to additionally or alternatively incorporate any of the other anchors shown in Figures IA- U, 4A or 5C-5E. [0076] Figures 10A- 1OG depict various views of a two-part structural anchor 400 which may be used to anchor a repair structure incorporating a flexible liner to an existing structure according to another particular embodiment. Two-part structural anchor 400 (shown best in Figure 10G) comprises an anchor component 402 and a mounting component 404. Anchor component 402 and mounting component 404 may be fabricated from any suitably strong material (e.g. plastic, metal, nylon, fiberglass or the like). Anchor component 402 and mounting component 404 may be fabricated using any suitable manufacturing process, including, by way of non-limiting example, extrusion, injection molding or the like. [0077] Mounting component 404 is shown best in Figures 10A- 10D. In the illustrated embodiment, mounting component 404 is elongated in a longitudinal direction (indicated by double-headed arrow 406) and has a relatively narrow width in a transverse direction (indicated by double-headed arrow 408). As shown best in Figures 1 OB-I OC, mounting component 404 comprises an interior wall 410, an optional intermediate wall 412, sidewalls 414A, 414B and connector component wall(s) 415. Interior wall 410 is penetrated at longitudinally spaced apart intervals by apertures 418, intermediate wall 412 is penetrated at longitudinally spaced apart intervals by apertures 420 and connector component walls 415 are penetrated at longitudinally spaced apart intervals by apertures 422. Interior wall apertures 418, intermediate wall apertures 420 and connector component wall apertures 422 are generally aligned with one another and may have co-axial centers. As shown best in Figure 1 OC, interior wall apertures 418 may have a smaller area than intermediate wall apertures 420 and/or connector component wall apertures 422. Connector component walls 415 provide a pair of connector components 416 which are shaped or otherwise configured to engage corresponding connector components 424 of anchor component 402, as described in more detail below. [0078] As shown best in Figure 1OF, anchor component 402 comprises a connector region 426, a stem 428 and an anchor region 430. In the illustrated embodiment, anchor region 430, which is located at one end of stem 428, comprises anchoring features 430A and 430B which respectively provide concavities 432A, 432B. In other embodiments, anchor region 430 may comprise anchoring features(s) similar to any of the other anchoring features (e.g. anchoring features 30A-30J, anchoring features 130, anchoring features 230, 230C-230E or the like) described herein. Connector region 426 is located at the opposing end of stem 428 and, in the illustrated embodiment, provides connector components 424. Connector components 424 of anchor component 402 are shaped or otherwise configured to engage corresponding connector components 416 of mounting component 404, as shown best in Figure 1OF. In the illustrated embodiment, connector components 424 of anchor component 402 comprise T-shaped male connector components which are shaped to be slidably inserted into female J-shaped connector components 416 of mounting component 404. In other embodiments, the connection between mounting component 404 and anchor component 402 may be implemented using other types of connecting techniques and/or connector components. [0079] Structural anchors 400 may be used to anchor a repair structure (e.g. repair structures 308A-308D) to existing structures (e.g. existing structures 300A-300D) to facilitate lining the repair structure with a flexible liner as described herein. One or more mounting components 404 may be mounted to an existing structure using suitable fasteners which project through apertures 418, 420, 422 such that interior wall 410 abuts against the existing structure. In particular embodiments, intermediate apertures 420 and connector component wall apertures 422 are larger (in cross-section) than interior apertures 418 to permit the extension of fasteners and corresponding tools through apertures 420, 422, but to permit fasteners to extend only partially through interior apertures 418. The particular fasteners chosen to mount mounting components 404 to the existing structure may depend on the material from which the existing structure is fabricated. By way of non-limiting example, if the existing structure is made from concrete, then the fasteners may be similar to the concrete fasteners shown on structural 350A, 350B of Figures 7A, 7B, but if the existing structure is made from steel or the like, then the fasteners used to mount mounting components 404 may comprise rivets or other suitable fasteners for steel. It is not necessary that mounting components 404 be mounted to existing structures using fasteners. In some embodiments, it may be desirable to mount mounting components 404 to existing structures using suitable adhesives. In such embodiments, apertures 418, 420, 422 may not be required.

[0080] Once mounting components 404 are mounted to the existing structure, then anchor components 402 may be coupled to mounting components by engaging connector components 416 of mounting components 404 with corresponding connector components 424 of anchor components 402. In the illustrated embodiment, male T-shaped connector components 424 are slidable into female J-shaped connector components 416. A repair structure form is then assembled in the region to be repaired, restored, reinforced and/or protected. A suitable flexible liner can then be inserted into the repair structure form to line desired surface(s) of the repair structure form as described above. It will be appreciated that anchor component(s) 402 of structural anchors 400 extends outwardly from the existing structure and into the repair structure form (not shown). Concrete is then introduced to the repair structure form. Concrete fills the repair form including concavities 432A₅ 432B in structural anchors 400. Once the concrete solidifies, the concrete in the cavities of structural anchors 400 bonds the repair structure to the existing structure.

[0081] Figure 1 IA shows a spacer component 450 which may be used with mounting component 404 (Figures 10A- 10D) as shown in Figure 1 IB to provide a two-part spacer 452. As explained in more detail below and as shown in Figure 11C, spacers 452 may be used to maintain the spacing between an existing structure and a repair structure formed using a flexible stay-in-place form - i.e. a form that does not require rigid form components or external bracing. In the illustrated embodiment, spacer component 450 comprises a connector region 454, a stem 456 incorporating flow-through apertures 458 to permit concrete flow therethrough and an abuttment region 460. Connector region 454 is located one end of stem 456 and, in the illustrated embodiment, comprises connector components 462. Connector components 462 of spacer component 450 are shaped or otherwise configured to engage corresponding connector components 416 of mounting component 404, as shown best in Figure 1 IB. In the illustrated embodiment, connector components 462 of spacer component 450 comprise T-shaped male connector components which are shaped to be slidably inserted into corresponding female J-shaped connector components 416 of mounting component 404. In other embodiments, the connection between mounting component 404 and spacer component 450 may be implemented using other types of connecting techniques and/or connector components. In still other embodiments, spacers that function in a manner similar to two-part spacer 452 may be fabricated from unitary components (e.g. similar to one-part anchors 380 of Figures 9A-9B, except that spacers may have abuttment features in the place of anchor features).

[0082] Abuttment region 460 is located at the opposing end of stem 456 and comprises one or more abuttment features which may abut against the repair structure form. In the illustrated embodiment, abuttment feature 464 comprises an H-shaped feature. In general, however, abuttment feature 464 may have a variety of shapes which may abut against the repair structure form as described below. In some embodiments, abuttment feature 464 may be wider in the transverse direction (shown by double-headed arrow 466) than the corresponding transverse dimension of stem 456. This relatively wide shape of abuttment feature 464 may provide concavities which may also help to anchor the repair structure to the existing structure when such concavities are filled with concrete. In some embodiments, abuttment feature 464 is not necessary and the abutting functionality of abuttment feature 464 may be provided by one end of stem 456. [0083] Spacer 452 (which, in the illustrated embodiment, comprises spacer component 450 and mounting component 404) may be used to maintain the spacing between an existing structure and a repair structure formed using a flexible stay-in-place form - i.e. a form that does not require rigid form components. An example of such an implementation is shown in Figure 11C. In the Figure 11C embodiment, it is desired to repair, restore, reinforce and/or protect an existing structure 480 without using rigid form components or external bracing. In the particular illustrated embodiment, existing structure 480 is a column having a round cross-section, but this is not necessary and existing structures may have other shapes. First, one or more mounting components 404 are mounted to the exterior surface of existing structure 480 as described above. In the Figure 11C example, a plurality of mounting components 404 are mounted to the exterior surface of existing structure at spaced apart locations. Then, a number of spacer components 450 are connected to selected mounting components 404 to provide two-part spacers 452 and a number of anchor components 402 are optionally connected to selected mounting components 404 to provide two-part structural anchors 400. [0084] Once spacers 452 and optionally structural anchors 400 are assembled and mounted, a flexible liner 482 is wrapped around an exterior of spacers 452. Flexible liner 482 may be similar to any of the flexible liners described above. As flexible liner 482 is wrapped around the exterior of spacers 452, the edges 486A, 486B of flexible liner 482 are connected to one another at edge-connector 488 to enclose a repair structure region 490 and to provide a flexible repair structure form 484. The connection of flexible liner edges 486A, 486B at edge-connector 488 may be accomplished using any of the edge- connection techniques described above, including, without limitation, welding techniques, stitching techniques, lacing techniques, weaving techniques, clasps, buckles, clips, hooks, "snap-together" fasteners, hook and loop fasteners, adhesives, suitable tapes, fasteners (e.g. staples, rivets, bolts or the like), one or more zippers or the like. In some embodiments, flexible liner edges 486A, 486B may overlap one another in a region of edge-connector 488. Such overlap may facilitate edge-to-edge connection of flexible liner edges 486A, 486B and may also prevent concrete from the structure from interfering with the connection mechanism, hi the illustrated embodiment, flexible liner 482 comprises a plurality of anchors 24B which are attached to the interior surface of flexible liner 482 at spaced apart locations and which are elongated in the longitudinal direction of existing structure 480. In the illustrated embodiment, anchors 24B are similar to anchors 24B shown in Figure IB and function to bond flexible liner 482 to the repair structure. Anchors 24B may also provide some stiffness which prevents flexible liner 482 from folding in on itself. While not shown in the illustrated embodiment, shape- providing anchors (e.g. with an arcuate shape for the example of the cylindrical column shown in Figure 11C, but which may generally have other shapes ) may be provided on an interior surface of flexible liner 482. In some embodiments, shape-providing stiffeners (e.g. with an arcuate shape for the example of the cylindrical column shown in Figure 11 C, but which may generally have other shapes ) may be permanently or temporarily provided on an exterior of flexible liner 482.

[0085] Concrete is then introduced into repair structure region 490 between flexible liner 482 and existing structure 480. Flexible liner 482 acts as a flexible repair structure form 484 - i.e. flexible liner 482 performs the function of a form without rigid form components or external bracing. More particularly, as concrete is introduced into repair structure region 490, it creates outward pressure on flexible liner 482. Under the outward pressure caused by the introduction of concrete, flexible liner 482 may move relative to existing structure 480. However, spacers 452 abut against the interior surface of flexible liner 482 to prevent flexible liner 482 from moving excessively relative to existing structure 480. The tensile strength of flexible liner 482 and the strength of edge- connector 488 may be designed to be sufficient to support the pressure caused by the weight of the concrete. As the concrete solidifies, anchors 24B bond flexible liner 482 to the resultant repair structure 492 and structural anchors 400 and spacers 452 bond repair structure 492 to existing structure 480. In this manner, flexible liner 482 provides a flexible stay-in-place form 484 (i.e. a form without rigid form components) which may be used to fabricate repair structure 492.

[0086] In some embodiments, two-part spacers 452 and/or two-part structural anchors 400 may be replaced with unitary spacers and/or unitary structural anchors, hi some embodiments, structural anchors 400 may not be required, as the concrete of repair structure 492 may surround existing structure to bond to itself or existing structure 480 may comprise a material to which the concrete of repair structure 492 will bond, thereby obviating the need for additional structural anchors between repair structure 492 and existing structure 480. In some embodiments, anchors 24B are not necessary. As discussed above, in some embodiments, the flexible lining material of flexible liner 482 may comprise a suitably roughened or piled interior surface to which concrete may bond directly or the flexible lining material of flexible liner 482 may be fabricated from a material having a chemical or physical composition to which concrete bonds directly. In some embodiments, anchors 24B may be replaced with anchors having other anchoring features, such as, by way of non-limiting example, the anchoring features of any of the other types of anchors described herein. In some embodiments, existing structure 480 may have other shapes. For example, existing structure may comprise a rectangular cross- section column. In such applications, it may be desirable to fabricate the corners of flexible liner 482 using relatively rigid materials or to mount relatively rigid braces in the corners of flexible liner 482. Such rigidity could be provided by suitable configured corner anchors. Existing structures may also comprise a section of a surface (e.g. a section of a curved or flat wall surface), in which case edges 486A, 486B of flexible liner 482 may be connected to the existing structure rather than to one another. [0087] As will be apparent to those skilled in the art in light of the foregoing disclosure, many alterations and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. For example:

• In some embodiments, it is not necessary that there be structural form- work to form the upper surface of the structure as it is being cast - e.g. where gravity can be used to ensure that liquid concrete is formed to have the desired shape. For example, it is not necessary that there be structural form-work to provide the top surface of tilt-up walls cast on a horizontal surface. In such embodiments, it may be possible to lay flexible liners according to particular embodiments described herein atop the liquid concrete, such that the flexible lining material lines the upper surface of the structure and the anchors project downwardly into the liquid concrete as the concrete solidifies.

• In the embodiments described herein, the structural material used to fabricate the structures is concrete. This is not necessary. In some applications, the flexible liners described herein may be used to line other structural materials

(e.g. other cementitious materials or other curable materials) which may be initially be introduced into forms and may subsequently solidify or cure. It will be understood that references to concrete in this description should be understood to incorporate such other cementitious or curable materials. • Embodiments incorporating receptacles and anchors (e.g. as shown Ln Figures 5A and 5B) can be modified for use with rigid lining materials. For example, concrete structures can be fabricated with receptacles bonded thereto in a similar manner to that described above. Rigid lining materials may be provided with anchors on their interior surfaces (e.g. anchors may be integrally formed on interior surfaces of the rigid lining materials or attached in a suitable manner to the interior surfaces of the rigid lining materials). The rigid lining materials may then be connected to the concrete structure by inserting anchors into corresponding receptacles.

• It will be appreciated that for embodiments incorporating receptacles and anchors (e.g. as shown in Figures 5A and 5B) that the anchors can be removed from the receptacles (e.g. by breaking the anchor or by suitable deformation). In this manner, the lining material (flexible or rigid) can be replaced if desired. While structures 300A-300D of Figures 6A-6D and 7A-7D are damaged in regions 302A-302D, this is not necessary. Repair structures incorporating flexible liners according to various embodiments of the invention may be applied to non- damaged existing structures. Such "repair" structures may be used, for example, to protect and/or strengthen existing structures which are not yet damaged.

• The bonding mechanisms for flexible lining material 122 (Figure 4) and flexible lining material 222 (Figure 5A) may additionally or alternatively be provided by the physical and/or chemical properties of flexible lining material 122/222 which may bond naturally to concrete and/or by a roughened or piled interior surface of flexible lining material 122/222.

• Structural anchors 350A, 350B of Figures 8 A, 8B are shown and described above as having rebar-retaining feature 362 A, 362B which retain rebar and thereby anchor the repair structure to the existing structure. This is not necessary. In some embodiments, structural anchors 350A, 350B may comprise other anchor features in the place of rebar-retaining features 362A₃ 262B. Such anchor features could comprise characteristics similar to any of the characteristics of any of the anchor features described herein.

Accordingly, the scope of the invention should be understood in accordance with the following claims.

Claims

WHAT IS CLAIMED IS:

1. A flexible liner for lining a surface of a structure fabricated from a curable material, the flexible liner comprising: a flexible lining material; and a bonding mechanism; wherein at least a portion of the bonding mechanism engages the flexible lining material and the curable material to bond the flexible lining material to the curable material as the curable material solidifies and to thereby line the surface of the resultant structure with the flexible lining material.

2. A flexible liner according to claim 1 wherein the bonding mechanism comprises a chemical or physical structure of an interior surface of the flexible lining material, the chemical or physical structure suitable for bonding to the curable material as the curable material solidifies.

3. A flexible liner according to any one of claims 1 to 2 wherein the bonding mechanism comprise a texture of an interior surface of the flexible lining material that is roughened or piled for helping to bond the flexible lining material to the curable material as the curable material solidifies.

4. A flexible liner according to claim 3 wherein the texture of the interior surface of the flexible lining material comprises texture dimensions greater than 1% of the thickness of the flexible lining material.

5. A flexible liner according to any one of claims 1 to 4 wherein the bonding mechanism comprises one or more anchors which extend into the curable material prior to curing to thereby anchor the flexible lining material to the resultant structure as the curable material solidifies.

6. A flexible liner according to claim 5 wherein the one or more anchors extend from an interior surface of the flexible lining material into the curable material.

7. A flexible liner according to claim 6 wherein the one or more anchors are mounted to the interior surface of the flexible lining material by a non-penetrative mounting technique which mounts the anchors to the interior surface of the flexible lining material without penetrating through the flexible lining material.

8. A flexible liner according to claim 7 wherein the non-penetrative mounting technique comprises welding the anchors to the flexible lining material.

9. A flexible liner according to claim 7 wherein the interior surface of the flexible lining material comprises a piled texture and the non-penetrative mounting technique comprises hook and loop fasteners, wherein the one or more anchors are provided with hooks to engage the piled texture of the flexible lining material.

10. A flexible liner according to claim 6 wherein the one or more anchors are mounted to the interior surface of the flexible lining material by a penetrative mounting technique which involves penetrating through the flexible lining material and wherein the flexible liner comprises one or more seals for sealing penetration holes associated with the mounting of corresponding anchors.

11. A flexible liner according to claim 5 wherein the one or more anchors are located on an exterior of the flexible lining material and the flexible lining material deforms around the anchors as the anchors extend into the curable material.

12. A flexible liner according to claim 5 wherein the one or more anchors penetrate from an exterior of the flexible lining material through to an interior of the flexible lining material to extend into the curable material.

13. A flexible liner according to any one of claims 5 to 12 wherein each of the one or more anchors comprises one or more anchor features shaped to provide one or more concavities, the concavities shaped to accept curable material prior to curing, such that when the curable material cures, the curable material located in the concavities bonds the anchor to the resultant structure.

14. A flexible liner according to claim 13 wherein each of the one or more anchors comprises a stem which projects into the curable material and wherein the one or more anchor features have dimensions that are relatively wide in transverse directions generally parallel to the surface of the structure when compared to corresponding dimensions of the stem.

15. A flexible liner according to any one of claims 13 to 14 wherein the concavities are located relatively close to the surface of the structure when compared to the anchor features.

16. A flexible liner according to any one of claims 5 to 15 wherein the flexible lining material is relatively flexible in comparison to the one or more anchors.

17. A flexible liner according to claim 16 wherein the one or more anchors are located on an exterior of the flexible lining material and wherein the one or more anchors comprise elastomeric material on surfaces fo the anchors in contact with the flexible lining material.

18. A flexible liner according to any one of claims 5 to 17 wherein the one or more anchors comprises a plurality of anchors and each anchor comprises a pair of orthogonal transverse cross-sectional dimensions that are at least approximately equal to one another.

19. A flexible liner according to any one of claims 5 to 17 wherein each of the one or more anchors comprises a pair of orthogonal transverse cross-sectional dimensions, wherein a first one of the orthogonal transverse cross-sectional dimensions is elongated in comparison to a second one of the orthogonal transverse cross-sectional dimensions.

20. A flexible liner according to claim 19 wherein the one or more anchors comprise a plurality of anchors and the elongated first one of the orthogonal transverse cross-sectional dimensions are substantially parallel for each of the plurality of anchors.

21. A flexible liner according to claim 19 wherein the one or more anchors comprise a plurality of anchors and the elongated first one of the orthogonal transverse cross-sectional dimensions of a first subset of the plurality of anchors are oriented substantially orthogonally to the elongated first one of the orthogonal transverse cross-sectional dimensions of a second subset of the plurality of anchors.

22. A flexible liner according to any one of claims 1 to 21 wherein the bonding mechanism comprises: one or more outwardly opening receptacles which extend into the curable material prior to curing and which are anchored to the resultant structure as the curable material solidifies; and one or more anchors located on an exterior of the flexible lining material, each anchor insertable into a corresponding one of the outwardly opening receptacles such that a bight of the flexible lining material deforms around the anchors and is anchored between the anchor and the receptacle.

23. A flexible liner according to any one of claims 1 to 21 wherein the bonding mechanism comprises: one or more outwardly opening receptacles which extend into the curable material prior to curing and which are anchored to the resultant structure as the curable material solidifies; and one or more anchors, each anchor penetrating from an exterior of the flexible lining material through to an interior of the flexible lining material to extend into a corresponding one of the outwardly opening receptacles, the extension of the anchor into the corresponding one of the outwardly opening receptacles anchoring the flexible lining material to the object.

24. A flexible liner according to any one of claims 22 to 23 wherein each receptacle comprises an exterior surface comprising one or more exterior surface convexities and one or more exterior surface concavities wherein the one or more exterior surface convexities are located relatively close to the surface of the structure in comparison to the one or more exterior surface concavities.

25. A flexible liner according to claim 24 wherein each of the one or more anchors is deformed upon insertion into its corresponding receptacle to permit passage of at least a portion of the anchor beyond the one or more exterior surface convexities and wherein restorative deformation forces cause the anchor to expand from its deformed state to occupy the one or more exterior surface concavities when the anchor is completely inserted into its corresponding receptacle.

26. A flexible liner according to any one of claims 22 to 25 wherein each receptacle comprises an interior surface comprising one or more interior surface concavities and one or more interior surface convexities wherein the one or more interior surface concavities are located relatively close to the surface of the structure in comparison to the one or more interior surface convexities.

27. A flexible liner according to claim 26 wherein the one or more interior surface concavities are shaped to accept curable material prior to curing, such that when the curable material cures, the curable material located in the interior surface concavities bonds the receptacle to the resultant structure.

28. A flexible liner according to any one of claims 22 to 27 wherein each of the one or more receptacles comprises one or more anchor features shaped to provide one or more anchor feature concavities, the anchor feature concavities shaped to accept curable material prior to curing, such that when the curable material cures, the curable material located in the anchor feature concavities bonds the receptacle to the resultant structure.

29. A flexible liner according to claim 28 wherein the one or more anchor feature concavities are located relatively close to the surface of the structure when compared to the anchor features.

30. A flexible liner according to any one of claims 1 to 29 wherein the structure is a cast-in-place structure.

31. A flexible liner according to any one of claims 1 to 29 wherein the structure is a pre-cast structure.

32. A flexible liner according to claim 30 wherein the structure is a repair structure used to repair, restore, reinforce or protect an existing structure.

33. A flexible liner according to claim 32 used in conjunction with one or more structural anchors, each structural anchor mounted to the existing structure and extending into the curable material prior to curing to thereby anchor the repair structure to the existing structure as the curable material solidifies.

34. A flexible liner for lining a surface of a structure fabricated from a curable material, the flexible liner comprising: a flexible lining material; and one or more outwardly opening receptacles which extend into the curable material prior to curing and which are anchored to the resultant structure as the curable material solidifies; and at least one of: one or more anchors located on an exterior of the flexible lining material, each anchor inserted into a corresponding one of the outwardly opening receptacles such that a bight of the flexible lining material deforms around the anchors and is anchored between the anchor and the receptacle; and one or more anchors, each anchor penetrating from an exterior of the flexible lining material through to an interior of the flexible lining material to extend into a corresponding one of the outwardly opening receptacles, the extension of the anchor into the corresponding one of the outwardly opening receptacles anchoring the flexible lining material to the object.

35. A method for lining a surface of a structure with a flexible liner, the method comprising: providing a form shaped to define at least a portion of the structure, the form including a form surface shaped to define the surface of the structure to be lined with the flexible liner; providing a flexible lining material; inserting the flexible lining material into the form such that at least a portion of the flexible lining material abuts against the form surface; introducing curable material into the form; permitting at least a portion of a bonding mechanism to engage the flexible lining material and the curable material in the form to bond the flexible lining material to the curable material as the curable material solidifies within the form, thereby lining the surface of the resultant structure with the flexible lining material.

36. A method according to claim 35 wherein permitting the bonding mechanism to engage the flexible lining material and the curable material in the form comprises permitting a chemical or physical interaction between an interior surface of the flexible lining material and the curable material which bonds the interior surface of the flexible lining material to the curable material as the curable material solidifies.

37. A method according to claim 35 wherein permitting the bonding mechanism to engage the flexible lining material and the curable material in the form comprises providing an interior surface of the flexible lining material with a texture that is roughened or piled for helping to bond the flexible lining material to the curable material as the curable material solidifies.

38. A method according to claim 35 wherein permitting the bonding mechanism to engage the flexible lining material and the curable material in the form comprises providing one or more anchors which extend into the curable material prior to curing to thereby anchor the flexible lining material to the resultant structure as the curable material solidifies.

39. A method according to claim 38 wherein the one or more anchors extend from an interior surface of the flexible lining material into the curable material.

40. A method according to claim 39 comprising mounting the one or more anchors to the interior surface of the flexible lining material using a non-penetrative mounting technique that does not penetrate through the flexible lining material.

41. A method according to claim 40 wherein mounting the one or more anchors to the interior surface of the flexible lining material comprises welding the anchors to the flexible lining material.

42. A method according to claim 40 wherein mounting the one or more anchors to the interior surface of the flexible lining material comprises providing the interior surface of the flexible lining material with a piled texture and providing the one or more anchors with hooks to engage the piled texture of the flexible lining material using a hook and loop fastening technique.

43. A method according to claim 39 comprising: mounting the one or more anchors to the interior surface of the flexible lining material using a penetrative mounting technique which involves penetrating through the flexible lining material; and sealing penetration holes associated with the mounting of corresponding anchors.

44. A method according to claim 38 wherein the one or more anchors are located on an exterior of the flexible lining material and permitting the bonding mechanism to engage the flexible lining material and the curable material in the form comprises deforming the flexible lining material around the anchors as the anchors extend into the curable material.

45. A method according to claim 38 wherein the one or more anchors penetrate from an exterior of the flexible lining material through to an interior of the flexible lining material to extend into the curable material.

46. A method according to any one of claims 38 to 45 comprising providing each of the one or more anchors with one or more anchor features shaped to provide one or more concavities and wherein permitting the bonding mechanism to engage the flexible lining material and the curable material in the form comprises permitting curable material to enter the concavities, such that when the curable material cures, the curable material located in the concavities bonds the anchor to the resultant structure.

47. A method according to claim 46 comprising providing each of the one or more anchors with a stem which projects into the curable material and wherein the one or more anchor features have dimensions that are relatively wide in transverse directions generally parallel to the form surface when compared to corresponding dimensions of the stem.

48. A method according to any one of claims 46 to 47 wherein the concavities are located relatively close to the form surface when compared to the anchor features.

49. A method according to any one of claims 38 to 48 wherein the flexible lining material is relatively flexible in comparison to the one or more anchors.

50. A method according to any one of claims 38 to 49 comprising temporarily attaching the flexible lining material to at least one of: the form and another relatively rigid structure prior to introducing the curable material into the form.

51. A method according to claim 50 comprising detaching the flexible lining material after the curable material solidifies.

52. A method according to any one of claims 38 to 51 comprising connecting two or more edges of the flexible lining material to one another.

53. A method according to claim 52 wherein connecting two or more edges of the flexible lining material to one another is performed prior to introducing the curable material into the form.

54. A method according to claim 52 wherein connecting two or more edges of the flexible lining material to one another is performed after the curable material solidifies.

55. A method according to any one of claims 38 to 54 wherein the structure is a repair structure used to repair, restore, reinforce or protect an existing structure and the method comprises: locating the form in a vicinity of the existing structure; and prior to introducing the curable material into the form, mounting one or more structural anchors to the existing structure, the one or more structural anchors extending outwardly from the existing structure such that the one or more structural anchors anchor the repair structure to the existing structure as the curable material solidifies within the form.

56. A method according to claim 55 wherein mounting the one or more structural anchors to the existing material is performed prior to locating the form in the vicinity of the existing structure.

57. A method for lining a surface of a structure with a flexible liner, the method comprising: providing a form shaped to define at least a portion of the structure, the form including a form surface shaped to define the surface of the structure to be lined with the flexible liner; inserting one or more receptacles into the form, such that the receptacles open toward the form surface; introducing curable material into the form such that the one or more receptacles are bonded to the curable material as the curable material solidifies within the form; aligning a flexible lining material against the form surface to cover the openings of the one or more receptacles; and at least one of: inserting one or more anchors located on an exterior of the flexible lining material into corresponding receptacles, such that for each anchor, a corresponding bight of the flexible lining material deforms around the anchor and is anchored between the anchor and the corresponding receptacle; and penetrating one or more anchors from an exterior of the flexible lining material through to an interior of the flexible lining material and extending into corresponding receptacles, such that for each anchor, the extension of the anchor into the corresponding one of the receptacles anchors the flexible lining material to the object.

58. A method for repairing, restoring, reinforcing or protecting an existing structure using a repair structure fabricated from a curable material and lined with a flexible lining material, the method comprising: mounting one or more spacers to the existing structure, the one or more spacers extending outwardly from the existing structure; assembling a flexible liner around the existing structure and the one or more spacers, the flexible liner comprising a flexible lining material and one or more anchors that extend inwardly from the flexible lining material; connecting edges of the flexible lining material to one another to define a flexible form; introducing curable material to the flexible form; wherein the curable material bonds to the one or more anchors as the curable material solidifies to form the repair structure, thereby bonding the flexible lining material to the repair structure.

59. A method according to claim 58 wherein the one or more spacers bond the repair structure to the existing structure as the curable material solidifies to form the repair structure.

60. A method according to any one of claims 58 to 59 comprising mounting one or more structural anchors to the existing structure, the one or more structural anchors extending outwardly from the existing structure and wherein the one or more structural anchors bond the repair structure to the existing structure as the curable material solidifies to form the repair structure.