Abstract:
A water resistant expansion joint system for installation into a building joint in vertical and horizontal configurations is designed such that it can be used for either an inside or outside corner. The system comprises open celled foam having a water-based acrylic chemistry infused therein. A layer of an elastomer is disposed on the open celled foam and is tooled to define a profile to facilitate the compression of the expansion joint system when installed between coplanar substrates. The system is delivered to a job site in a pre-compressed state ready for installation into the building joint.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/121,590, filed on Dec. 11, 2008, the contents of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates generally to joint systems for use in concrete and other building systems and, more particularly, to expansion joints for accommodating thermal and/or seismic movements in such systems. 
     BACKGROUND OF THE INVENTION 
     Concrete structures and other building systems often incorporate joints that accommodate movements due to thermal and/or seismic conditions. These joint systems may be positioned to extend through both interior and exterior surfaces (e.g., walls, floors, and roofs) of a building or other structure. 
     In the case of an exterior joint in an exterior wall, roof, or floor exposed to external environmental conditions, the expansion joint system should also, to some degree, resist the effects of the external environment conditions. As such, most external expansion joints systems are designed to resist the effects of such conditions (particularly water). In vertical joints, such conditions will likely be in the form of rain, snow, or ice that is driven by wind. In horizontal joints, the conditions will likely be in the form of rain, standing water, snow, ice, and in some circumstances all of these at the same time. Additionally, some horizontal systems may be subjected to pedestrian and/or vehicular traffic. 
     Many expansion joint products do not fully consider the irregular nature of building expansion joints. It is common for an expansion joint to have several transition areas along the length thereof. These may be walls, parapets, columns, or other obstructions. As such, the expansion joint product, in some fashion or other, follows the joint as it traverses these obstructions. In many products, this is a point of weakness, as the homogeneous nature of the product is interrupted. Methods of handling these transitions include stitching, gluing, and welding. In many situations, it is difficult or impossible to prefabricate these expansion joint transitions, as the exact details of the expansion joint and any transitions and/or dimensions may not be known at the time of manufacturing. 
     In cases of this type, job site modifications are frequently made to facilitate the function of the product with regard to the actual conditions encountered. Normally, one of two situations occurs. In the first, the product is modified to suit the actual expansion joint conditions. In the second, the manufacturer is made aware of issues pertaining to jobsite modifications, and requests to modify the product are presented to the manufacturer in an effort to better accommodate the expansion joint conditions. In the first situation, there is a chance that a person installing the product does not possess the adequate tools or knowledge of the product to modify it in a way such that the product still performs as designed or such that a transition that is commensurate with the performance expected thereof can be effectively carried out. This can lead to a premature failure at the point of modification, which may result in subsequent damage to the property. In the second case, product is oftentimes returned to the manufacturer for rework, or it is simply scrapped and re-manufactured. Both return to the manufacturer and scrapping and re-manufacture are costly, and both result in delays with regard to the building construction, which can in itself be extremely costly. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to water resistant expansion joint systems for installation into building joints. In one aspect, the present invention resides in a system for use in vertical or horizontal configurations and is designed such that it can be used for either an inside or outside corner. The system comprises open celled foam having a water-based acrylic chemistry infused therein. A layer of an elastomer is disposed on the open celled foam and is tooled to define a profile to facilitate the compression of the expansion joint system when installed between coplanar substrates. The system is delivered to a job site in a pre-compressed state ready for installation into the building joint. 
     In another aspect, the present invention resides in a vertical expansion joint system comprising a first section of open celled foam extending in a horizontal plane and a second section of open celled foam extending in a vertical plane. An insert piece of open celled foam is located between the first and second sections, the insert piece being configured to transition the first section from the horizontal plane to the vertical plane of the second section. The foam is infused with a water-based acrylic chemistry. A layer of an elastomer is disposed on the foam to impart a substantially waterproof property thereto. The vertical expansion joint system is pre-compressed and is installable between horizontal coplanar substrates and vertical coplanar substrates. Although the vertical expansion joint system is described as having an angle of transition from horizontal to vertical, it should be understood that the transition of the angles is not limited to right angles as the vertical expansion joint system may be used to accommodate any angle. 
     In another aspect, the present invention resides in a horizontal expansion joint system, the system being pre-compressed and installable between horizontal coplanar substrates. The system comprises first and second sections of open celled foam extending in a horizontal plane, the sections being joined at a miter joint. The open celled foam is infused with a water-based acrylic chemistry. A layer of an elastomer is disposed on the foam, the elastomer imparting a substantially waterproof property to the foam. Although the horizontal expansion joint system is described as transitioning right angles in the horizontal plane, it should be understood that the transition of the angles is not limited to right angles as the system may be used to accommodate any angle and may also be used in planes that are not horizontal. 
     In any embodiment, the construction or assembly of the systems described herein is generally carried out off-site, but elements of the system may be trimmed to appropriate length on-site. By constructing or assembling the systems of the present invention in a factory setting, on-site operations typically carried out by an installer (who may not have the appropriate tools or training for complex installation procedures) can be minimized. Accordingly, the opportunity for an installer to effect a modification such that the product does not perform as designed or such that a transition does not meet performance expectations is also minimized. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a vertical expansion joint system of the present invention. 
         FIG. 2  is an end view of the vertical expansion joint system taken along line  2 - 2  of  FIG. 1 . 
         FIG. 3  is an end view of the vertical expansion joint system installed between two substrates. 
         FIG. 4  is a perspective view of an assembly of foam laminations being prepared to produce the vertical expansion joint system of  FIG. 1 . 
         FIG. 5  is a perspective view of the assembly of foam laminations being further prepared to produce the vertical expansion joint system of  FIG. 1 . 
         FIG. 6  is a perspective view of four sections of the vertical expansion joint system used in a building structure. 
         FIG. 7  is a perspective view of a horizontal expansion joint system of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention provides a resilient water resistant expansion joint system able to accommodate thermal, seismic, and other building movements while maintaining water resistance characteristics. The present invention is especially suited for use in concrete buildings and other concrete structures including, but not limited to, parking garages, stadiums, tunnels, bridges, waste water treatment systems and plants, potable water treatment systems and plants, and the like. 
     Referring now to  FIGS. 1-3 , one embodiment of the present invention is an expansion joint system oriented in a vertical plane and configured to transition corners at right angles. This system is designated generally by the reference number  10  and is hereinafter referred to as “vertical expansion joint system  10 .” It should be noted, however, that the vertical expansion joint system  10  is not limited to being configured at right angles, as the products and systems of the present invention can be configured to accommodate any desired angle. The vertical expansion joint system  10  comprises sections of open celled polyurethane foam  12  (hereinafter “foam  12 ”) that have been infused with a water-based acrylic chemistry. It should be understood, however, that although the present invention is described as comprising polyurethane foam, the open celled foam can be any other suitable type of foam. 
     As is shown in  FIG. 2 , the foam  12  comprises individual laminations  14  of foam, one or more of which are infused with a suitable amount of the acrylic chemistry. It should be noted that the present invention is not so limited as other manners of constructing the foam  12  are also possible. For example, the foam  12  of the present invention is not limited to individual laminations  14  assembled to construct the laminate, as the foam  12  may comprise a solid block of non-laminated foam of fixed size depending upon the desired joint size, laminates comprising laminations oriented horizontally to adjacent laminations, or combinations of the foregoing. 
     Also as is shown in  FIG. 3 , the vertical expansion joint system  10  is positionable between opposing substrates  18  (which may comprise concrete, glass, wood, stone, metal, or the like) to accommodate the movement thereof. In particular, opposing vertical surfaces of the foam  12  are retained between the edges of the substrates  18 . The compression of the foam  12  during the installation thereof between the substrates  18  enables the vertical expansion system  10  to be held in place. 
     In any embodiment, when individual laminations  14  are used, several laminations, the number depending on the expansion joint size (e.g., the width, which depends on the distance between opposing substrates  18  into which the vertical expansion system  10  is to be installed), are compiled and then compressed and held at such compression in a fixture. The fixture, referred to as a coating fixture, is at a width slightly greater than that which the expansion joint will experience at the greatest possible movement thereof. 
     In the fixture, the assembled infused laminations  14  are coated with a waterproof elastomer  20 . The elastomer  20  may comprise, for example, at least one polysulfide, silicone, acrylic, polyurethane, poly-epoxide, silyl-terminated polyether, combinations and formulations thereof, and the like. The preferred elastomer  20  for coating laminations  14  for a horizontal deck application where vehicular traffic is expected is PECORA 301 (available from Pecora Corporation, Harleysville, Pa.) or DOW 888 (available from Dow Corning Corporation, Midland, Mich.), both of which are traffic grade rated silicone pavement sealants. For vertical wall applications, the preferred elastomer  20  for coating the laminations  14  is DOW 790 (available from Dow Corning Corporation, Midland, Mich.), DOW 795 (also available from Dow Corning Corporation), or PECORA 890 (available from Pecora Corporation, Harleysville, Pa.). A primer may be used depending on the nature of the adhesive characteristics of the elastomer  20 . 
     During or after application of the elastomer  20  to the laminations  14 , the elastomer is tooled or otherwise configured to create a “bellows,” “bullet,” or other suitable profile such that the vertical expansion joint system  10  can be compressed in a uniform and aesthetic fashion while being maintained in a virtually tensionless environment. The elastomer  20  is then allowed to cure while being maintained in this position, securely bonding it to the infused foam lamination  14 . 
     Referring now to  FIGS. 4 and 5 , when the elastomer  20  has cured in place, the infused foam lamination  14  is cut in a location at which a bend in the vertical expansion system  10  is desired to accommodate a corner. The cut, which is designated by the reference number  24  and as shown in  FIG. 4 , is made from the outside of the desired location of the bend to the inside of the desired location of the bend using a saw or any other suitable device. The cut  24  is stopped such that a distance d is defined from the termination of the cut to the previously applied coating of the elastomer  20  on the inside of the desired location of the bend (e.g., approximately one half inch from the previously applied coating of elastomer  20  on the inside of the bend). Referring now to  FIG. 5 , the lamination  14  is then bent to an appropriate angle A, thereby forming a gap G at the outside of the bend. Although a gap of 90 degrees is shown in  FIG. 5 , the present invention is not limited in this regard as other angles are possible. 
     Still referring to  FIG. 5 , a piece of infused foam lamination constructed in a manner similar to that described above is inserted into the gap G as an insert piece  30  and held in place by the application of a similar coating of elastomer  20  as described above. In the alternative, the insert piece  30  may be held in place using a suitable adhesive. Accordingly, the angle A around the corner is made continuous via the insertion of the insert piece  30  located between a section of the open celled foam extending in the horizontal plane and a section of the open celled foam extending in the vertical plane. Once the gap has been filled and the insert piece  30  is securely in position, the entire vertical expansion system  10  including the insert piece  30  is inserted into a similar coating fixture with the previously applied elastomer  20  coated side facing down and the uncoated side facing upwards. The uncoated side is now coated with the same (or different) elastomer  20  as was used on the opposite face. Again, the elastomer  20  is then allowed to cure in position. Furthermore, the insert piece  30  inserted into the gap is not limited to being a lamination  14 , as solid blocks or the like may be used. 
     After both sides have cured, the vertical expansion system  10  as the final uninstalled product is removed from the coating fixture and packaged for shipment. In the packaging operation the vertical expansion system  10  is compressed using a hydraulic or mechanical press (or the like) to a size below the nominal size of the expansion joint at the job site. The vertical expansion system  10  is held at this size using a heat shrinkable poly film. The present invention is not limited in this regard, however, as other devices (ties or the like) may be used to hold the vertical expansion system  10  to the desired size. 
     Referring now to  FIG. 6 , portions of the vertical expansion system  10  positioned to articulate right angle bends are shown as they would be positioned in a concrete expansion joint located in a tunnel, archway, or similar structure. Each portion defines a foam laminate that is positioned in a corner of the joint. As is shown, the vertical expansion joint system  10  is installed between horizontal coplanar substrates  18   a  and vertical coplanar substrates  18   b.    
     Referring now to  FIG. 7 , an alternate embodiment of the invention is shown. In this embodiment, the infused foam, the elastomer coating on the top surface, and the elastomer coating on the bottom surface are similar to the first embodiment. However, in  FIG. 7 , the expansion joint system designated generally by the reference number  110  is oriented in the horizontal plane rather than vertical plane and is hereinafter referred to as “horizontal expansion system  110 .” As with the vertical expansion system  10  described above, the horizontal expansion system  110  may be configured to transition right angles. The horizontal expansion system  110  is not limited to being configured to transition right angles, however, as it can be configured to accommodate any desired angle. 
     In the horizontal expansion system  110 , the infused foam lamination is constructed in a similar fashion to that of the vertical expansion system  10 , namely, by constructing a foam  112  assembled from individual laminations  114  of foam material, one or more of which is infused with an acrylic chemistry. Although the horizontal expansion system  110  is described as being fabricated from individual laminations  114 , the present invention is not so limited, and other manners of constructing the foam  112  are possible (e.g., solid blocks of foam material). 
     In fabricating the horizontal expansion system  110 , two pieces of the foam  112  are mitered at appropriate angles B (45 degrees is shown in  FIG. 7 , although other angles are possible). An elastomer, or other suitable adhesive, is applied to the mitered faces of the infused foam laminations. The individual laminations are then pushed together and held in place in a coating fixture at a width slightly greater than the largest joint movement anticipated. At this width the top is coated with an elastomer  20  and cured. Following this, the foam  112  is inverted and then the opposite side is likewise coated. 
     After both coatings of elastomer  20  have cured, the horizontal expansion system  110  is removed from the coating fixture and packaged for shipment. In the packaging operation, the horizontal expansion system  110  is compressed using a hydraulic or mechanical press (or the like) to a size below the nominal size of the expansion joint at the job site. The product is held at this size using a heat shrinkable poly film (or any other suitable device). 
     In the horizontal expansion system  110 , the installation thereof is accomplished by adhering the foam  112  to a substrate (e.g., concrete, glass, wood, stone, metal, or the like) using an adhesive such as epoxy. The epoxy or other adhesive is applied to the faces of the horizontal expansion system  110  prior to removing the horizontal expansion system from the packaging restraints thereof. Once the packaging has been removed, the horizontal expansion system  110  will begin to expand, and the horizontal expansion system is inserted into the joint in the desired orientation. Once the horizontal expansion system  110  has expanded to suit the expansion joint, it will become locked in by the combination of the foam back pressure and the adhesive. 
     In any system of the present invention, but particularly with regard to the vertical expansion system  10 , an adhesive may be pre-applied to the foam lamination. In this case, for installation, the foam lamination is removed from the packaging and simply inserted into the expansion joint where it is allowed to expand to meet the concrete (or other) substrate. Once this is done, the adhesive in combination with the back pressure of the foam will hold the foam in position. 
     The vertical expansion system  10  is generally used where there are vertical plane transitions in the expansion joint. For example, vertical plane transitions can occur where an expansion joint traverses a parking deck and then meets a sidewalk followed by a parapet wall. The expansion joint cuts through both the sidewalk and the parapet wall. In situations of this type, the vertical expansion system  10  also transitions from the parking deck (horizontally) to the curb (vertical), to the sidewalk (horizontal), and then from the sidewalk to the parapet (vertical) and in most cases across the parapet wall (horizontal) and down the other side of the parapet wall (vertical). Prior to the present invention, this would result in an installer having to fabricate most or all of these transitions on site using straight pieces. This process was difficult, time consuming, and error prone, and often resulted in waste and sometimes in sub-standard transitions. 
     In one example of installing the vertical expansion system  10  in a structure having a sidewalk and a parapet, the installer uses several individual sections, each section being configured to transition an angle. The installer uses the straight run of expansion joint product, stopping within about 12 inches of the transition, then installs one section of the vertical expansion system  10  with legs measuring about 12 inches by about 6 inches. If desired, the installer trims the legs of the vertical expansion system  10  to accommodate the straight run and the height of the sidewalk. Standard product is then installed across the sidewalk, stopping short of the transition to the parapet wall. Here another section of the vertical expansion system  10  is installed, which will take the product up the wall. Two further sections of the vertical expansion system  10  are used at the top inside and top outside corners of the parapet wall. The sections of the vertical expansion system  10  are adhered to each other and to the straight run expansion joint product in a similar fashion as the straight run product is adhered to itself. In this manner, the vertical expansion system  10  can be easily installed if the installer has been trained to install the standard straight run product. It should be noted, however, that the present invention is not limited to the installation of product in any particular sequence as the pieces can be installed in any suitable and/or desired order. 
     In one example of installing the horizontal expansion system  110 , the system is installed where there are horizontal plane transitions in the expansion joint. This can happen when the expansion joint encounters obstructions such as supporting columns or walls. The horizontal expansion system  110  is configured to accommodate such obstructions. Prior to the present invention, the installer would have had to create field transitions to follow the expansion joint. 
     To extend the horizontal expansion system  110  around a typical support column, the installer uses four sections of the horizontal expansion system. A straight run of expansion joint product is installed and stopped approximately 12 inches short of the horizontal transition. The first section of the horizontal expansion system  110  is then installed to change directions, trimming as desired for the specific situation. Three additional sections of horizontal expansion system  110  are then joined, inserting straight run pieces as desired, such that the horizontal expansion system  110  extends around the column continues the straight run expansion joint on the opposite side. As with the vertical expansion system  10 , the sections may be installed in any sequence that is desired. 
     The present invention is not limited to products configured at right angles, as any desired angle can be used for either a horizontal or vertical configuration. Also, the present invention is not limited to foam laminates, as solid foam blocks and the like may alternatively or additionally be used. 
     Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those of skill in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed in the above detailed description, but that the invention will include all embodiments falling within the scope of the appended claims.