Composite systems and methods for anchoring walls

Construction systems and methods for anchoring a structural member of a building to a base member of a building including one or more anchoring devices, each anchoring device having a first portion and a second portion. The first portion of each anchoring device is fixedly attached to the structural member and the second portion of each anchoring device is fixedly attached to the base member. Each anchoring device preferably including a fiber composite material.

BACKGROUND OF THE INVENTION

The present invention relates generally to construction systems and methods for use in new and existing structures and, more specifically, to composite systems and methods for anchoring walls to footings, foundations, roofs, and slabs.

In new construction and retrofit and repair applications it is often necessary to strengthen or reinforce masonry, concrete, and timber walls such that they are capable of withstanding flexural loads caused by, for example, the wind or seismic activity. It is also often necessary to strengthen or reinforce the positive connection between such walls and footings or slabs, enabling the walls to withstand and transfer shear loads as well. Masonry, concrete, and timber walls are typically strengthened using steel reinforcing members, such as reinforcing bar (“rebar”). For example, rebar may be inserted into the cavities of the concrete masonry units (“CMUs” or “cinder blocks”) of a masonry wall, or in the collar joints of a brick structure. The CMU cores may then be filled with grout. The rebar may extend vertically downward and mate with dowel holes drilled in the footing or it may extend vertically upward and mate with dowel holes drilled in the slab. Although marginally effective, in retrofit and repair applications these systems and methods may require the face shells of the CMUs to be temporarily removed. Thus, such systems and methods may be obtrusive, labor-intensive, and expensive.

More desirable systems and methods for strengthening or reinforcing masonry, concrete, and timber walls involve the use of high-strength composite materials. The flexural and shear load capability of a wall may be increased by adhering a thin composite fiber sheet or laminate impregnated with an epoxy resin or polymer to its surface. Typical composite laminates include glass, carbon, or aramid fibers. Such composite materials are 5 to 10 times stronger per unit weight than comparable traditional materials. These systems and methods, however, do little to increase the strength of the connection between a wall and a footing, foundation, floor, roof, or slab because they do not interface the wall with its supporting structure. Thus, what is needed are systems and methods utilizing composites for strengthening and reinforcing the positive connection between reinforced or unreinforced walls and footings or slabs. Further, what is needed are systems and methods that are unobtrusive, relatively simple to implement, and inexpensive.

BRIEF SUMMARY OF THE INVENTION

The present invention provides composite systems and methods for strengthening and reinforcing the positive connection between reinforced or unreinforced walls and footings or slabs. These systems and methods may be utilized in new construction and retrofit and repair applications.

In one embodiment, a construction system for anchoring a structural member of a building to a base member of a building includes one or more anchoring devices, each anchoring device having a first portion and a second portion, the first portion of each anchoring device fixedly attached to the structural member and the second portion of each anchoring device fixedly attached to the bas e member. Each anchoring device preferably includes a fiber composite material.

In another embodiment, a construction system for anchoring a structural member of a building to a base member of a building includes a structural member comprising one of a reinforced wall and an unreinforced wall; a base member comprising a member selected from the group consisting of a footing, a foundation, a floor, a roof, and a slab; and one or more anchoring devices, each anchoring device having a first portion and a second portion, the first portion of each anchoring device fixedly attached to the structural member and the second portion of each anchoring device fixedly attached to the base member. Each anchoring device preferably includes a fiber composite material.

In a further embodiment, a construction method for anchoring a structural member of a building to a base member of a building includes fixedly attaching a first portion of a composite fiber anchor to the structural member and fixedly attaching a second portion of the composite fiber anchor to the base member. Each composite fiber anchor preferably has a sufficient strength to transfer a predetermined load from the structural member to the base member.

DETAILED DESCRIPTION OF THE INVENTION

A typical load-bearing wall used in residential or commercial construction may be made of a building material, such as a plurality of CMUs/cinder blocks, clay blocks, clay bricks, clay tiles, concrete, prefabricated or modular panels, or it may be framed using wood or the like. Such walls are used to transfer loads from a roof, slab, or beam to a footing or foundation. Referring toFIG. 1, a structural member10, i.e. a wall, may be subjected to a variety of loads, including lateral loads, transverse loads, axial loads11, flexural loads, shear loads12, coupling loads (including tension loads14and compression loads16), etc. These loads may be caused by, for example, the general structural configuration of a building, gravity, the wind, or seismic activity. Structural members10may initially be designed to withstand only limited predetermined loading conditions and in retrofit and repair applications, as well as in new construction, it is often necessary to strengthen or reinforce masonry, concrete, and timber walls such that they are capable of withstanding increased predetermined loading conditions. It may also be necessary to strengthen or reinforce the positive connection between such structural members10and a base member18, such as a footing, foundation, roof, or slab, enabling the walls to withstand increased loads, such as shear loads12, tension loads14, and compression loads16. As such, the base member18provides a support capable of withstanding the given predetermined loading conditions. As discussed above, masonry walls, such as those typically used in commercial structures, are often strengthened or reinforced using rebar. More desirable systems and methods, however, involve the use of high-strength composite materials. The flexural load capability of a structural member10may be increased by adhering a thin composite fiber sheet or laminate impregnated with an epoxy resin or polymer to its surface28. Typical composite laminates include glass, carbon, or aramid fiber composites. These systems and methods, however, do little to increase the shear load transfer between a structural member10and a base member18.

In one embodiment, the composite wall anchoring system20of the present invention includes one or more anchoring devices22, each anchoring device22including a first portion24fixedly attached to a structural member10and a second portion26fixedly attached to a base member18, such as the footing, foundation, roof, or slab of a structure. Each anchoring device22preferably includes a composite member, such as a thin, flexible, uncured composite sheet or laminate, or a rigid, preformed plate. Each composite sheet or laminate may be as thin as about 0.023 in., although other thicknesses may be utilized. The fibers of the composite sheet or laminate may be aligned such that the sheet or laminate is able to withstand predetermined loading conditions along or around a given axis of the structural member10. Multiple composite layers may be utilized, and the orientation of each layer may be varied. The composite laminate anchors22may be attached to the structural member10and base member18by means of mechanical fasteners or a bonding mechanism/adhesive, such as an epoxy resin or a polymer. The bonding mechanism is preferably a strucutural adhesive of sufficient viscosity to allow it to be used to fill a channel or groove. The composite laminate anchors22may be attached to a reinforced or unreinforced structural member10. For example, the structural member10may be reinforced with rebar or an existing composite sheet or laminate adhered to its surface28. Thus, one or more anchoring devices22form a composite fiber anchoring system20having a sufficient strength to transfer predetermined loads from a structural member10to a base member18.

Each composite laminate anchor22may be attached to and cover a portion of the surface28of the structural member10, vertically and/or horizontally. Alternatively, a single composite laminate anchor22may be attached to and cover the entire surface28of the structural member10, vertically and/or horizontally. For example, as shown inFIG. 1, a plurality of composite laminate anchors22may be utilized such that the first portion24of each extends partially or entirely up the surface28of the structural member10and the second portion26of each is fixedly attached to a surface30of the base member18or disposed within a groove32located in the base member18. Alternatively, a single composite laminate anchor22may be used such that the first portion24of the anchor22extends partially or entirely up the surface28of the structural member10and the second portion26of the anchor22is fixedly attached to a surface30of the base member18or disposed within a groove32located in the base member18. Composite laminate anchors22may also be utilized on more than one surface of the structural member10.

Referring toFIG. 2, in one embodiment, the first portion24of the composite laminate anchor22may be fixedly attached to the structural member10, such as by using an adhesive. The second portion26of the composite laminate anchor22may be disposed and fixedly attached within a groove32cut into or integrally formed within the base member18. The groove32preferably has two substantially parallel vertically-extending side portions34and a horizontally-extending bottom portion36. The groove32may be, for example, about 0.50 in. to about 1.50 in. wide and about 2.00 in. to about 5.00 in. deep and, more preferably, about 0.75 in. to about 1 in. wide and about 3.50 in. to about 4.00 in. deep. It should be noted, however, that a groove32with other dimensions may be utilized. The groove32may also have a predetermined longitudinal or lateral measurement. The groove32may be formed using, for example, a saw or an angle grinder with a diamond blade. Preferably, the groove32is formed such that it is adjacent to and in line with the surface28of the structural member10. The second portion26of the composite laminate anchor22may be disposed within the groove32and contacted with an adhesive such that it is fixedly attached to the two vertically-extending side portions34and the horizontally-extending bottom portion36. The adhesive may further fill the spaced-apart region between the side portions34. Optionally, an elongated member38, such as a predetermined length of rebar, a cured composite rod, or the like, may be disposed within the groove32. The elongated member38is preferably made of a material that is compatible with the material comprising the composite laminate anchor22, minimizing corrosion, maximizing adhesion, etc. The elongated member38is sized to provide a clamping or wedging force, securing the second portion26of the composite laminate anchor22within the groove32. The groove32may be filled with a filling compound33, such as grout or the like, and made flush with the surface30of the base member18. It should be noted that this and all embodiments may be used to anchor structural members to roofs and slabs, as well as footings, foundations, and floors.

The first portion24and second portion26of each composite laminate anchor22, and especially the second portion26in contact with the base member18, are sized such that each anchoring device22is able to withstand all of a predetermined portion of the predetermined load associated with a given structural member10or structure.

Referring toFIG. 3, in a related embodiment, the first portion24of the composite laminate anchor22may be fixedly attached to the structural member10using a bonding mechanism/adhesive. The second portion26of the composite laminate anchor22may be disposed within a groove32cut into or integrally formed within the base member18. The second portion26of the composite laminate anchor22may be contacted or impregnated with an adhesive and disposed within the groove32such that it is fixedly attached to the vertically-extending side portion40directly adjacent to the structural member10. Optionally, a mechanical fastener42, such as a bolt or a pin, may be inserted through a washer member41, a securing member43, the second portion26of the composite laminate anchor22, and the base member18, securing the second portion26of the composite laminate anchor22within the groove32. The securing member43may be, for example, a non-ferrous plate when a carbon composite laminate anchor22is used. The groove32may be filled with a filling compound33, such as grout or the like, and made flush with the surface30of the base member18.

Referring toFIG. 4, in an embodiment typically involving a floor or a slab44, the first portion24of the composite laminate anchor22may be fixedly attached to the structural member10using a bonding mechanism/adhesive. The second portion26of the composite laminate anchor22may be disposed within a channel46cut into or integrally formed within the slab44. The second portion26of the composite laminate anchor22may be contacted or impregnated with an adhesive and disposed within the channel46such that it is fixedly attached to a vertically-extending side portion48of the channel46directly adjacent to the structural member10. Optionally, a third, horizontally-extending portion50of the composite laminate anchor22may be fixedly attached to the lower surface51of the slab44. The channel46may be filled with a filling compound33, such as grout or the like, and made flush with the upper surface52and the lower surface51of the slab44.

Referring toFIG. 5, in another embodiment, the groove32cut into or integrally formed within the base member18may have two vertically-extending side portions34and a horizontally-extending bottom portion36that form a wedge shape having a predetermined lateral measurement. The second portion26of the composite laminate anchor22may be contacted or impregnated with a bonding mechanism/adhesive and disposed within the groove32such that it is fixedly attached to the vertically-extending side portion40directly adjacent to the structural member10. Optionally, an elongated member38, such as a predetermined length of rebar, a cured composite rod, or the like, may be disposed within the wedge-shaped groove32. The elongated member38provides a clamping or wedging force, securing the second portion26of the composite laminate anchor22within the groove32. The groove32may be filled with a filling compound33, such as grout or the like, and made flush with the surface30of the base member18.

In a similar embodiment, the groove32cut into or integrally formed within the base member18may have three substantially parallel vertically-extending side portions, a horizontally-extending bottom portion, and a horizontally-extending top portion which form a partially enclosed channel. The second portion26of the composite laminate anchor22may be shaped or formed such that it has a hook portion on its end, the hook portion suitable for engaging the partially enclosed channel. The second portion26of the composite laminate anchor22may be contacted or impregnated with a bonding mechanism/adhesive and disposed within the groove32such that it is fixedly attached to the two vertically-extending side portions and the horizontally-extending bottom portion. The groove32may be filled with a filling compound33, such as grout or the like, and made flush with the surface30of the base member18.

Referring toFIG. 6, in a further embodiment, the composite laminate anchor22may include a T-shaped member66which is partially disposed within a groove68cut into or integrally formed within the structural member10directly adjacent to the base member18. The T-shaped member66is preferably made of a rigid, preformed composite material and may be, for example, a fiber-reinforced polymer (FRP) pultruded T-shape. Both the T-shaped member66and the groove68may have a predetermined lateral measurement. The T-shaped member66may be fixedly attached or bonded to the surface30of the base member18or floor using an adhesive. The T-shaped member66may also be fixedly attached to the structural member10using an adhesive. A composite sheet or laminate70may be fixedly attached to the structural member10and the T-shaped member66using an adhesive. This embodiment is advantageous because the groove68may be cut or formed into the bottom mortar joint72of the structural member10, maximizing simplicity and minimizing expense. The groove68may also increase the composite laminate anchor's uplift and shear load capacity by utilizing the weight of the structure.

In each of the above embodiments, all surfaces to which a composite laminate anchor22is attached, including the surface of a structural member, a footing, a foundation, a floor, a roof, or a slab, are preferably cleaned and primed prior to the application of an epoxy resin or polymer adhesive. After a composite laminate anchor22is fixedly attached to a surface, a groove, or a channel, the composite laminate anchor22may be trimmed as necessary.

It is apparent that there have been provided, in accordance with the present invention, systems and methods for anchoring reinforced and unreinforced walls to footings, foundations, floors, roofs, and slabs using composite materials. The present invention permits masonry (including concrete masonry unit (CMU), concrete brick, clay brick, clay block, and clay tile), concrete, and timber walls, and the positive connection between such walls and other structural members, to be reinforced or strengthened such that they are capable of withstanding predetermined flexural loads, shear loads, axial loads, lateral loads, and coupling loads (including tension loads and compression loads). While the present invention has been particularly shown and described in conjunction with preferred embodiments thereof, it will be appreciated that variations in and modifications to the present invention may be effected by persons of ordinary skill in the art without departing from the spirit or scope of the present invention. For example, the type of composite material, the number and orientation of fiber layers, the thickness of the composite material, the dimensions of the first and second anchor portions, and the type of affixing mechanism may all vary depending upon the given materials involved, the environmental conditions, and the predetermined loading conditions. Further, it is to be understood that the principles related to composite fiber systems and methods for anchoring reinforced and unreinforced walls described herein apply in a similar manner, where applicable, to all preferred embodiments.