Title:
Monolithic pour joint
Kind Code:
A1


Abstract:
There is provided a monolithic pour joint interposed between adjacent concrete slabs disposed on a substrate. The pour joint comprises a plurality of elongate forms interconnected with splices. Each one of the forms has a substantially planar, vertical panel with upper and lower edges and opposing ends respectively defining a form width and a form length. The forms are arranged such that the form lengths are generally aligned end to end. The lower edge of the vertical panel has a base flange extending generally laterally therefrom. A plurality of stakes are disposed in transverse relation to the form width and are secured to a side of the vertical panel at spaced intervals to fixedly maintain the forms in relation to the substrate. The pour joint may include a plurality of dowel holes extending through the vertical panel such that a dowel placement system may be installed in the pour joint.



Inventors:
Shaw, Lee A. (Newport Beach, CA, US)
Shaw, Ronald D. (Corona Del Mar, CA, US)
Application Number:
10/638809
Publication Date:
02/17/2005
Filing Date:
08/13/2003
Assignee:
SHAW LEE A.
SHAW RONALD D.
Primary Class:
International Classes:
E01C11/14; (IPC1-7): E01C11/14
View Patent Images:
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Primary Examiner:
ADDIE, RAYMOND W
Attorney, Agent or Firm:
Kit M. Stetina, Esq. (Aliso Viejo, CA, US)
Claims:
1. A monolithic pour joint interposed between adjacent concrete slabs disposed on a substrate, the pour joint comprising: an elongate form having a planar, vertical panel with upper and lower edges and opposing ends respectively defining a form width and a form length, the lower edge having a base flange extending generally laterally therefrom; and a plurality of elongate stakes disposed in transverse relation to the form width and secured to a side of the vertical panel opposite that from which the base flange extends, the stakes being disposed at spaced intervals along the form length; wherein the stakes are configured to fixedly maintain the form in relation to the substrate.

2. The pour joint of claim 1 further comprising a plurality of dowel holes extending through the vertical panel.

3. The pour joint of claim 1 further comprising: a plurality of splices configured to be complementary to the form; and a plurality of the forms being arranged such that the form lengths are generally aligned end to end; wherein each one of the splices is secured to and interconnects adjacent ones of the forms at the lower edges thereof.

4. The pour joint of claim 1 wherein the splices are secured to the vertical panel with mechanical fasteners.

5. The pour joint of claim 1 wherein the stakes are secured to the vertical panel with mechanical fasteners.

6. The pour joint of claim 1 wherein the upper edge includes a folded-over portion extending downwardly therefrom.

7. The pour joint of claim 1 further comprising a layer of resilient joint filler disposed along a side of the vertical panel.

8. The pour joint of claim 7 wherein the joint filler is fabricated from foam material.

9. The pour joint of claim 1 further comprising an elongate edge cap extending along the upper edge.

10. The pour joint of claim 9 wherein the edge cap is fabricated from plastic material.

11. A monolithic pour joint interposed between adjacent concrete slabs, the pour joint comprising: an elongate form having a planar, vertical panel with upper and lower edges and opposing ends respectively defining a form width and a form length, the upper edge having an upper flange of inverted generally U-shaped cross-section including a horizontal section extending laterally from the upper edge and terminating in a downwardly extending vertical section that is spaced apart from the vertical panel; and a plurality of elongate stakes disposed in transverse relation to the form width and secured to a side of the vertical panel opposite that from which the base flange extends, the stakes being disposed at spaced intervals along the form length, each one of the stakes having a stake body with upper and lower ends; wherein the upper flange is configured to receive the upper end of the stake body such that the stakes may support the form in relation to the substrate.

12. The pour joint of claim 11 wherein the upper flange is configured to be resiliently flexible and is spaced away from the vertical panel such that the upper flange may grippingly engage the upper end of the stake body.

13. The pour joint of claim 11 wherein each of the stakes includes at least one stake clip of generally U-shaped cross-section extending from the stake body, the stake clip being configured to receive the lower edge of the form.

14. The pour joint of claim 13 wherein the stake clip is configured to be resiliently flexible such that the stake clip may grippingly engage the lower edge.

15. The pour joint of claim 11 further comprising a plurality of dowel holes extending through the vertical panel.

16. The pour joint of claim 11 further comprising: a plurality of splices configured to be complementary to the form; and a plurality of the forms being arranged such that the form lengths are generally aligned end to end; wherein each one of the splices is secured to and interconnects adjacent ones of the forms at the lower edges thereof.

17. The pour joint of claim 16 wherein the splices are secured to the vertical panel with mechanical fasteners.

18. The pour joint of claim 11 further comprising a layer of resilient joint filler disposed along a side of the vertical panel.

19. The pour joint of claim 18 wherein the joint filler is fabricated from foam material.

20. The pour joint of claim 11 further comprising an elongate edge cap extending along the upper edge.

21. The pour joint of claim 20 wherein the edge cap is fabricated from plastic material.

22. A monolithic pour joint interposed between adjacent concrete slabs disposed on a substrate, the pour joint comprising: an elongate form having a planar, vertical panel with upper and lower edges and opposing ends respectively defining a form width and a form length, the vertical panel having a plurality of dowel holes extending therethrough; a plurality of elongate stakes disposed in transverse relation to the form width and secured to a side of the vertical panel at spaced intervals along the form length and being configured to fixedly maintain the form in relation to the substrate; at least one sleeve mounted through one of the dowel holes and extending laterally outwardly from the vertical panel and into one of the concrete slabs; an elongate, tubular dowel-receiving sheath sized and configured to be insertable into and joinable to the sleeve; and an elongate dowel rod extending laterally across the pour joint and being freely slidable within the sheath embedded within one of the concrete slabs and fixedly captured within the adjacent one of the concrete slabs.

23. The monolithic pour joint of claim 22 wherein the lower edge has a base flange extending generally laterally therefrom.

24. The monolithic pour joint of claim 22 wherein: the sleeve includes a sleeve flange disposed on an end thereof and having at least one dimple disposed on an exterior of the sleeve; the sleeve flange extending laterally outwardly from the sleeve and being configured for mounting the sleeve to the vertical panel; the dimple being disposed in spaced relation to the sleeve flange and being positioned such that the vertical panel is capturable between the sleeve flange and the dimple.

25. The monolithic pour joint of claim 24 wherein the sleeve flange includes fastener holes spaced therearound, the fastener holes being sized and configured to permit the passage of a fastener therethrough for attachment of the sleeve to the vertical panel.

26. The monolithic pour joint of claim 22 wherein the sleeve includes a plurality of dimples disposed in spaced relation around the exterior of the sleeve, each one of the dimples having a wedge-shaped configuration.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

(Not Applicable)

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

(Not Applicable)

BACKGROUND OF THE INVENTION

The present invention relates generally to concrete forming equipment and, more particularly, to a uniquely configured monolithic pour joint specifically adapted to prevent shear cracking of adjacently disposed concrete slabs. The pour joints are configured to facilitate the placement of dowel rods within adjacent concrete slabs.

During construction of concrete pavement such as for sidewalks, driveways, roads and flooring in buildings, cracks may occur due to uncontrolled shrinkage or contraction of the concrete. Such cracks are the result of a slight decrease in the overall volume of the concrete as water is lost from the concrete mixture during curing. Typical contraction rates for concrete are about one-sixteenth of an inch for every ten feet of length. Thus, large cracks may develop in concrete where the overall length of the pavement is fairly large. In addition, the cracks may continue to develop months after the concrete is poured due to induced stresses in the concrete.

One of the most effective ways of controlling the location and direction of the cracks is to include longitudinal control joints or contraction joints in the concrete. Contraction joints are typically comprised of forms having substantially vertical panels that are positioned above the ground or subgrade and held in place utilizing stakes that are driven into the subgrade at spaced intervals. The forms act to subdivide or partition the concrete into multiple sections or slabs that allow the concrete to crack in straight lines along the contraction joint. By including contraction joints, the slabs may move freely away from the contraction joint during concrete shrinkage and thus prevent random cracking elsewhere.

In one system of concrete construction, forms are installed above the subgrade to create a checkerboard pattern of slabs. A first batch of wet concrete mixture is poured into alternating slabs of the checkerboard pattern. After curing, forms may be removed and the remaining slabs in the checkerboard pattern are poured from a second batch of concrete. Although effective in providing longitudinal contraction joints to prevent random cracking, the checkerboard system of concrete pavement construction is both labor intensive and time consuming due to the need to remove the forms and due to the waiting period between the curing of the first batch and the pouring of the second batch of concrete.

In another system of concrete construction known as monolithic pour technique, the pour joints are installed above the subgrade in the checkerboard pattern. However, all of the slabs of the checkerboard pattern are poured in a single pour thereby reducing pour time as well as increasing labor productivity. An upper edge of the forms then serves as a screed rail for striking off or screeding the surface of the concrete so that the desired finish or texture may be applied to the surface before the concrete cures. The pour joints, comprised of vertically disposed forms, remain embedded in the concrete and provide a parting plane from which the slabs may move freely away during curing. The pour joints additionally allowing for horizontal displacement of the slabs caused by thermal expansion and contraction of the slabs during normal everyday use.

Unfortunately, vertical displacement of adjacent slabs may also occur at a joint due to settling or swelling of the substrate below the slab or as a result of vertical loads created by vehicular traffic passing over the slabs. The vehicular traffic as well as the settling or swelling of the subgrade may create a height differential between adjacent slabs. Such height differential may result in an unwanted step or fault in a concrete sidewalk or roadway or in flooring of a building creating a pedestrian or vehicular hazard. Furthermore, such a step may allow for the imposition of increased stresses on the corner of the concrete slab at the joint resulting in degradation and spalling of the slab. In order to limit relative vertical displacement of adjacent slabs such that steps are prevented from forming at the joints, a form of vertical load transfer between the slabs is necessary.

One system for limiting relative vertical displacement and for transferring loads between slabs is provided by key joints. In key joint systems, the form is configured to impart a tongue and groove shape to respective ones of adjacent slabs. Typically preformed of steel, such a key joint imparts the tongue and groove shape to adjacent slabs in order to allow for contraction and expansion of the adjacent slabs while limiting the relative vertical displacement thereof due to vertical load transfer between the tongue and groove. The tongue of one slab is configured to mechanically interact with the mating groove of an adjacent slab in order to provide reactive shear forces across the joint when a vertical load is place on one of the slabs. In this manner, the top surfaces of the adjacent slabs are maintained at the same level despite swelling or settling of the subgrade underneath either one of the slabs. Additionally, edge stresses of each of the slabs are minimized such that chipping and spalling of the slab corners may be reduced.

Although the key joint presents several advantages regarding its effectiveness in transferring loads between adjacent slabs, key joints also possess certain deficiencies that detract from their overall utility. Perhaps the most significant of these deficiencies is that the tongue of the key joint may shear off under certain loading conditions. Furthermore, the face of the key joint may spall or crack above or below the groove under load. The location of the shearing or spalling is dependent on whether the load is applied on the tongue side of the joint or the groove side of the joint. If the vertical load is applied on the tongue side, the failure will occur at the bottom portion of the groove. Conversely, if the vertical load is applied on the groove side of the joint, the failure will occur near the upper surface of the slab upon which the load is applied.

Shear failure of the tongue and groove may also occur due to opening of the key joint as a result of shrinkage of the concrete slab. As the key joint opens up over time, the groove side may become unsupported as the tongue moves away. Vertical loading of this unsupported concrete causes cracking and spalling parallel to the joint. Such cracking and spalling may occur rapidly if hard-wheeled traffic such as forklifts are moving across the joint. Another deficiency associated with key joint systems is related to the size, configuration and vertical placement of the tongue and groove within the key joint. If excessively large key joints are formed in adjacent slabs or if the tongue and groove are biased toward an upper surface of the slabs instead of being placed at a more preferable midheight location, spalls may occur at the key joint. Such spalls occurring from this type of deficiency typically run the entire length of the longitudinal key joint and are difficult to repair.

Furthermore, key joints suffer from an additional deficiency in that slip dowel systems may not be compatible for use with preformed metallic key joint forms due to interference thereof with a flanged base member of the slip dowel system. Slip dowels are typically configured as smooth steel dowel rods that are placed within edge portions of adjacent concrete slabs in such a manner that the concrete slabs may slide freely along the slip dowels thereby permitting expansion and contraction of the slabs while simultaneously maintaining the slabs in a common plane and thus prevent unevenness or steps from forming at the joint. Because slip dowels are typically located near the midheight of a contraction joint, the tongue and groove of the metal form may interfere with the installation of the flanged base member of the slip dowel system.

As can be seen, there exists a need in the art for a joint system capable of minimizing relative vertical displacement of adjacent concrete slabs caused by settling or swelling of the subgrade or by vertical loads that may be imposed by vehicular traffic. Furthermore, there exists a need for a joint system capable of resisting shear failures at respective faces of adjacent concrete slabs. Finally, there exists a need for a joint system that is compatible with slip dowel systems such that slip dowels may be placed within adjacent concrete slabs to aid in maintaining the slabs in a common plane.

BRIEF SUMMARY OF THE INVENTION

The present invention specifically addresses and alleviates the above-referenced deficiencies associated with contraction joints of the prior art. More particularly, the present invention is an improved, monolithic pour joint that is specifically adapted to prevent shear cracking of adjacently disposed concrete slabs while accommodating slip dowel systems for aiding in the placement of slips dowels within edge portions of adjacent concrete slabs.

The pour joint is comprised of at least one elongate form or a plurality of forms arranged in end-to-end alignment with a splice interconnecting the forms and a plurality of elongate stakes secured to a side of the forms to fixedly maintain or support the forms above the substrate. Each of the elongate forms includes a substantially planar, vertical panel having an upper edge and a lower edge to define a form width and opposing ends that define a form length. The lower edge of the form has a base flange that extends laterally from the vertical panel such that the form defines an L-shaped configuration.

The forms, splices and stakes may be fabricated of metal such as galvanized sheet metal. A plurality of the stakes are secured to the vertical panel and are disposed in transverse relation to the form width at spaced intervals along the form length. Each one of the stakes has a stake body with an upper end and a lower end. The upper end of the stake body is adapted to abut against the vertical panel. The lower end of the stake body may be provided with a point such that the stake may be driven into a substrate of soil.

The splices are configured to interconnect adjacent ones of the forms at the lower edges and may be secured to the vertical panel with mechanical fasteners such as self-tapping screws. The splices may be configured in a shape that is complementary to the form such as in an L-shaped configuration matching the L-shaped configuration of the form. The stakes for supporting the form may also be secured to the vertical panel with self-tapping screws. Additionally, the stakes may be secured to the lower edge of the vertical panel with at least one stake clip that may be integrally formed with and extensible from the stake body such that the form may be rigidly held at a preset height above the substrate.

The pour joint of the present invention is configured to be compatible with dowel placement systems due to the inclusion of dowel holes in the forms and due to the generally planar configuration of the vertical panel. Such dowel placement systems may be provided at spaced intervals in the pour joints as a means of preventing buckling or relative angular or vertical displacement of the slabs. A sleeve of the dowel placement system may be mounted on the form by insertion through the dowel hole. A sleeve flange of the sleeve is abutted against and secured to the planar vertical panel with fasteners. A sheath may be inserted into the sleeve with steel or iron dowel rods being advanced into the sheath prior to the pouring of concrete slabs such that the slabs may slide freely during expansion and contraction of the slabs to maintain the slabs in a common plane and thus prevent unevenness or steps from forming at the pour joint.

A layer of resilient joint filler may be included along a side of the vertical panel. The joint filler may be configured to alternately compress and expand during relative lateral movements of the concrete slabs such as may occur during thermal expansion and contraction. The joint filler prevents the entrapment of stones, debris or other material between the slabs that may otherwise interfere with thermal expansion of the slabs. The joint filler may be fabricated from foam material such as fiber board, closed-cell foam rubber or low density, closed-cell polyethylene foam. An edge cap may also be mounted upon and extend along the upper edge of the form in order to provide protection against water infiltration and particle entrapment within the pour joint. The edge cap may be formed as an extrusion of relatively flexible, elastomeric material such as a plastic material.

BRIEF DESCRIPTION OF THE DRAWINGS

These as well as other features of the present invention will become more apparent upon reference to the drawings wherein:

FIG. 1 is a perspective view of a pour joint of the present invention illustrating a pair of forms arranged in end-to-end alignment with a splice interconnecting the forms;

FIG. 2 is a cross-sectional view of the pour joint taken along line 2-2 of FIG. 1 illustrating an embodiment of the form wherein a base flange extends laterally from a lower edge of a vertical panel of the form and wherein the splice is configured to be complementary to the form;

FIG. 3 is a cross-sectional view of the pour joint illustrating the form wherein a folded-over portion extends downwardly from an upper edge of the vertical panel;

FIG. 4 is a cross-sectional view of the pour joint illustrating the form wherein a U-shaped upper flange extends from the upper edge of the vertical panel with a slip dowel system being installed therein and further illustrating the placement of the pour joint above a subgrade using a stake;

FIG. 5 is an elevational view of the form of FIG. 4 illustrating a dowel hole extending through the vertical panel for receiving the slip dowel system;

FIG. 6 is a cross-sectional view of the pour joint illustrating the form wherein the upper flange in configured to be resiliently flexible such that the upper flange may grippingly engage the upper edge; and

FIG. 7 is an elevational view of the form of FIG. 6 illustrating stake clips secured to the lower edge of the vertical panel.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein the showings are for purposes of illustrating preferred embodiments of the present invention and not for purposes of limiting the same, FIG. 1 illustrates a monolithic pour joint 10 of the present invention wherein the pour joint 10 may be interposed between concrete slabs 12 that are disposed above a subgrade or a substrate 14. The substrate 14 may be soil underlying the slab. Alternatively, the substrate 14 may be a metal decking or other underlying surface adapted to support concrete slabs 12. The pour joint 10 is comprised of at least one elongate form 16 or a plurality of forms 16 arranged in end-to-end alignment with a splice 60 interconnecting the forms 16 and a plurality of elongate stakes 48 secured to a side of the forms 16 to fixedly maintain or support the forms 16 above the substrate 14.

Each of the forms 16 includes a substantially planar, vertical panel 18 having an upper edge 20 and a lower edge 22 to define a form 16 width. Each of the forms 16 also has opposing ends 24 that define a form 16 length. In one embodiment of the form 16 shown in FIGS. 1 and 2, the lower edge 22 of the form 16 has a base flange 26 that extends laterally from the vertical panel 18 such that the form 16 defines an L-shaped configuration. However, the form 16 may be configured in any number of alternative configurations wherein an upper flange 30 or a folded-over portion 28 extends from the upper edge 20 of the vertical panel 18, as will be described in greater detail below.

The forms 16, splices 60 and stakes 48 may be fabricated of metal such as sheet metal. The sheet metal may be a steel sheet material. A galvanized coating on the steel sheet may be included in order to provide maximum protection of the metal from exposure to concrete which may other wise result in corrosion. Other coatings for the sheet metal are contemplated and may include powder coating and epoxy coating. In addition, the forms 16, splices 60 and stakes 48 may be fabricated of fiber glass, carbon fiber, Kevlar, or a polymeric material such as plastic or any combination thereof. However, it is contemplated that the forms 16, splices 60 and stakes 48 may be fabricated from any number of alternative materials.

A plurality of the stakes 48 may be secured to the vertical panel 18 in order to support the forms 16 at a preset height above the substrate 14. The stakes 48 are disposed in transverse relation to the form 16 width and are secured to a side of the vertical panel 18 at spaced intervals along the form 16 length. The spacing of the stakes 48 along the form 16 length may be adjusted based on a number of factors including the condition of the underlying soil and the thickness of the slabs 12. Each one of the stakes 48 has a stake body 50 with an upper end 52 and a lower end 54. The upper end 52 of the stake body 50 may be adapted to abut against the vertical panel 18 as shown in FIG. 1. The lower end 54 of the stake body 50 may be provided with a point such that the stake 48 may be readily driven into the ground. Alternatively, the lower end 54 of the stake body 50 may be configured with a clip such that the stake 48 may be secured to a metal decking substrate 14 as was earlier mentioned.

It is contemplated that the pour joint 10 may be comprised of only a single one of the forms 16 with at least one stake 48 or a pair of the stakes 48 being secured to the vertical panel 18 adjacent to the ends 24 of the form 16 in order to support the form 16 above the substrate 14. However, the forms 16 may be arranged in a manner similar to that shown in FIG. 1 wherein the form 16 lengths are aligned in end 24 to end 24 arrangement such that respective ones of the ends 24 are disposed in abutting contact wherein a plurality of the splices 60 are attached to respective ones of the ends 24 of the forms 16. Such splices 60 are configured to interconnect adjacent ones of the forms 16 at the lower edges 22 thereof in a manner similar to that shown in FIG. 2.

The splices 60 may be secured to the vertical panel 18 with mechanical fasteners 62 extending through the splice 60 and into the vertical panel 18 of the form 16 and/or into the base flange 26 of the form 16. The mechanical fasteners 62 may be self-tapping screws or sheet metal screws as is shown in FIGS. 1, 2 and 3. Any number of mechanical fasteners 62 may be used to secure the adjacent form 16 lengths together such that axial and lateral loads may be transferred across adjacent ones of the forms 16 by the splice 60. Such axial and lateral loads may be imposed on the pour joint 10 during assembly of the form 16 as well as during pouring of the concrete. In addition, such axial and lateral loads may be imposed by traffic passing over the pour joint 10 after the concrete cures. The splices 60 may be configured in a shape that is complementary to the form 16. As is shown in FIG. 2 the splice 60 may be formed in an L-shaped configuration matching the L-shaped configuration of the form 16 in order to facilitate the attachment of the splice 60 thereto. However, it is recognized herein that the splice 60 may be configured in any number of alternate configurations such as in a generally planar configuration in order to facilitate the attachment of the splice 60 to the vertical panel 18 at any height between the upper edge 20 and the lower edge.

The stakes 48 for supporting the form 16 may be attached to the vertical panel 18 with mechanical fasteners 62, as can be seen in FIGS. 2 and 3. Such mechanical fasteners 62 may include self-tapping screws that may be screwed through the upper end 52 of the stake 48 and into the vertical panel 18 in order to eliminate the need for pre-drilling of the stake 48 and the form 16. Alternatively, the stakes 48 may be secured to the vertical panel 18 with bolts, rivets, by wiring the stake 48 to the form 16 or by the use of a stake clip 56. The stake clip 56 may be integrally formed with and extensible from the stake body 50, as is shown in FIGS. 4 and 6 and as will be described in greater detail below. Alternatively, the stake clip 56 may be a separate component (not shown) that may be mounted on the stake body 50 and secured to the lower edge 22 of the vertical panel 18. Regardless of the specific manner with which the stake clip 56 is mounted, it is contemplated that the stakes 48 may be secured to the form 16 by any number of means such that the form 16 may be rigidly held at a preset height above the substrate 14.

Referring now to FIGS. 1 and 4, the pour joint 10 of the present invention is advantageously configured to be compatible with available dowel placement systems 36 due to the inclusion of dowel holes 64 in the forms 16. Dowel placement systems 36 are typically provided at spaced intervals in pour joints 10 as a means of preventing buckling or relative angular or vertical displacement of the slabs 12. Each one of the dowel holes 64 allows for the installation of the dowel placement system 36 which is further facilitated by the generally planar configuration of the vertical panel 18. As can be seen in FIG. 4, each one of the dowel placement systems 36 may be comprised of an elongate, tubular dowel-receiving sheath 42 that is insertable into a sleeve 38.

The sleeve 38 is mounted on the form 16 by insertion through the dowel hole 64. The sleeve 38 may include a sleeve flange 40 that is abutted against and secured to the planar vertical panel 18 of the form 16. As is shown in FIG. 4, a plurality of dimples 44, each of which may have a wedge-shaped configuration, are spaced around the sleeve 38 and are configured such that forcing of the dimples 44 through the dowel hole 64 results in the capture of the vertical panel 18 between the sleeve flange 40 and the dimples 44, thus maintaining the sleeve 38 in rigid attachment to the form 16. The sheath 42 is then inserted into the sleeve 38 such that the sleeve 38 supports the sheath 42 on the form 16.

Steel or iron reinforcing bars or dowel rods 46 may then be advanced into the sheath 42 prior to the pouring of concrete slabs 12 such that the slabs 12 may slide freely during expansion and contraction of the slabs 12. The dowel placement systems 36 maintain the slabs 12 in a common plane and thus prevent unevenness or steps from forming at the pour joint 10. As is shown in FIGS. 1 and 4, the dowel holes 64 are typically located near the midheight of the form 16 such that the sleeve flange 40 of the dowel placement system 36 may be secured to the vertical panel 18. The sleeve flange 40 may include fastener holes that are sized to permit the passage of a fastener through the sleeve flange 40 in order to facilitate the rigid attachment of the sleeve 38 to the vertical panel 18 subsequent to the insertion of the dowel rod 46 into the sheath.

The dowel holes 64 may be sized and configured to be complementary to the sleeve 38 of the dowel placement system 36 and may be disposed at spaced intervals along the form 16 length depending on the loading conditions that may be imposed upon the slabs 12 and also depending upon the stability of the underlying substrate 14. The longitudinal spacing of the dowel holes 64 may be such that dowel holes 64 are provided at regularly spaced intervals such as at six-inch spacings along the form 16 length. The dowel placement systems 36 may be installed along the pour joint 10 at wider spacings wherein some of the dowel holes 64 between the dowel placement systems 36 are unused.

As is shown in FIGS. 1 and 4, the dowel holes 64 may be located at the approximate midheight of the vertical panels 18. However, the dowel holes 64 may be located at any other vertical location of the vertical panel 18 such that the sleeve flange 40 may be readily secured to the vertical panel 18. Although illustrated in FIG. 1 as through-holes, the dowel holes 64 may alternatively be formed in the vertical panel 18 as “knockouts”. Such knockouts are generally configured as circular perforations partially formed through the vertical panel 18 leaving an uncut portion that allows a tab to remain with the form 16 if the tab is bent outwardly away from the vertical panel 18. By forming the dowel holes 64 in this manner, unused ones of the knockouts may be bent outwardly at an angle such that they may anchor the form 16 in the concrete slab 12 to prevent floating or rising of the form 16 in the concrete during pouring and after curing.

Referring now to FIG. 3, the form 16 may be configured such that the upper edge 20 of the vertical panel 18 includes the folded-over portion 28 extending downwardly therefrom. The folded-over portion 28 may be disposed in generally abutting contact with the vertical panel 18 along the form 16 length. The folded-over portion 28 may be configured such that it increases the structural rigidity or stiffness of the form 16 in order to ensure straighter sections of the forms 16 and to resist longitudinal bending of the form 16 during a first pour of wet concrete on one side of the pour joint 10. Advantageously, the folded-over portion 28 may also prevent personal injury or property damage that may otherwise result during contact with an exposed rough edge of the form 16 at the upper edge 20. Furthermore, such folded-over portion 28 may serve as a guide rail for use with a screed for striking off and leveling of the slabs 12 using a pair of the pour joints 10 so as to smooth off the top surface of freshly poured concrete prior to curing.

Referring now to FIG. 2, included with the pour joint 10 may be a layer of resilient joint filler 66 disposed along a side of the vertical panel 18. As can be seen, the layer of joint filler 66 has a constant thickness that spans the form 16 width and which may also extend longitudinally along the pour joint 10 across adjacently disposed ones of the form 16 lengths. The joint filler 66 may be configured to alternately compress and expand during movement of the concrete slabs 12 such as may occur during thermal expansion and contraction thereof.

In addition, the joint filler 66 may be configured to prevent the entrapment of stones, debris or other material between the slabs 12 that may otherwise interfere with thermal expansion of the slabs 12. The joint filler 66 may also provide a weather tight seal preventing excess moisture from entering the space between adjacent ones of the slabs 12 which may otherwise lead to freeze-thaw cracking of the concrete slabs 12. Toward this end, the joint filler 66 may be fabricated from foam material such as fiber board, closed-cell foam rubber or low density, closed-cell polyethylene foam. Such foam may be pre-formed at a predetermined thickness that is sized to be complementary to a gap between the slabs 12. The joint filler 66 may include an adhesive layer on one side thereof for facilitating installation to the vertical panel 18.

Referring still to FIG. 2, an elongate expansion joint cap or edge cap 68 may also be included with the pour joint 10 wherein the edge cap 68 may be mounted upon and extend along the upper edge 20 of the form 16 in order to provide protection against water infiltration and particle entrapment within the pour joint 10. The edge cap 68 may be configured with an upper portion having a generally trapezoidal cross-sectional shape with downwardly extending cap legs 70 that are configured to overlap exterior surfaces of the joint filler 66 and vertical panel 18, as is shown in FIG. 2. The trapezoidal cross-sectional shape of the upper portion may reduce the likelihood of spalling at the pour joint 10 edge as the trapezoidal cross-sectional shape may impart a slightly beveled edge to corners of the slabs 12. It is contemplated that the edge cap 68 may be provided in number of alternative cross-sectional shapes such as in a rectangular shape.

Alternatively, for pour joint 10 configurations wherein the joint filler 66 is omitted, the edge cap 68 may be configured to be mounted directly upon the form 16 itself with the cap legs 70 being spaced apart at a width complementary to a thickness of the upper edge 20 of the vertical panel 18. As mentioned above, such upper edge 20 of the vertical panel 18 may include the folded-over portion 28 in which case the cap legs 70 may be spaced apart at a complementary width. The edge cap 68 may be fabricated as an extrusion from a relatively flexible, elastomeric material such as a plastic material. Such plastic material may be polystyrene, vinyl or other material. However, other materials may be used to fabricate the edge cap 68. The edge cap 68 may be bonded to the pour joint 10 with adhesive such as a semi-rigid epoxy adhesive in order to reduce the tendency for cracking of the slabs 12.

Referring now to FIGS. 4 and 5, shown is an alternative embodiment of the pour joint 10 wherein the form 16 is configured to include an upper flange 30 of inverted, generally U-shaped cross-section on the upper edge 20 of the vertical panel 18. As can be seen in FIG. 4, the lower edge 22 of the vertical panel 18 omits the laterally extending base flange 26 of the earlier-described embodiment shown in FIGS. 2 and 3. In the alternative embodiment shown in FIG. 4, the upper flange 30 includes a horizontal section 32 that extends laterally from the upper edge 20 and terminates in a downwardly extending vertical section 34 that is spaced apart from the vertical panel 18. The upper flange 30 may be configured to receive the upper end 52 of the stake body 50 as can be seen in FIG. 5. As was earlier described, the stakes 48 are secured to the side of the vertical panel 18 at spaced intervals along the form 16 length.

The earlier-described dowel placement system 36 is shown in FIG. 4 as being mounted on the vertical panel 18 of the form 16 at about the midheight of the vertical panel 18 with the sleeve 38 of the dowel placement system 36 being secured to the vertical panel 18 with the sleeve flange 40 abutting thereagainst. The dowel rod 46 can be seen extending axially within the sheath 42 and extending outwardly therefrom on a side of the pour joint 10 opposite the sheath 42 such that the sheath 42 and the dowel rod 46 may be captured within the adjacent ones of the slabs 12 after concrete is poured on both sides of the pour joint 10. Also shown in FIG. 4 is the joint filler 66 which generally spans the form 16 width and which has a cutout for the sleeve flange 40. As was earlier described, the joint filler 66 may be included with the pour joint 10 in order to fill the gap between adjacent ones of the slabs 12 and thereby prevent entrapment of debris in the gap. The above-described edge cap 68 may also be included in the pour joint 10 as shown in FIG. 4 with such edge cap 68 being configured to be complementary to the specific configuration of the pour joint 10. In this regard, the cross-sectional shape and size of the edge cap 68 may be configured to be compatible with the combination of the joint filler 66 and the form 16 or with the form 16 alone.

Referring now to FIGS. 6 and 7, the form 16 may be configured such that the upper flange 30 includes a longitudinal rib 58 formed within the downwardly extending vertical section 34. As shown in FIG. 6, the rib 58 is formed such that the upper end 52 of the stake body 50 may be inserted between the upper flange 30 and the vertical panel 18. Furthermore, the upper flange 30 may be configured to be resiliently flexible and may be spaced away from the vertical panel 18 at the upper edge 20 such that the rib 58 of the upper flange 30 may grippingly engage the upper end 52 of the stake body 50. A lower portion of the upper flange 30 may be folded outwardly at an angle of about 45 degrees such that the upper end 52 of the stake 48 may be easily inserted between the rib 58 and the vertical panel 18.

The stake clip 56 may also be configured in a generally U-shaped cross-section extending from the stake body 50 and configured to receive the form 16. As shown in FIG. 6, a rib 58 may be formed in an upwardly extending portion of the stake clip 56 such that the stake clip 56 may grippingly engage the lower edge 22 of the vertical panel 18, as is shown in FIG. 6. The stake clip 56 may be integrally formed on a side of the stake body 50 or it may be formed on opposite sides of the stake body 50 as is shown in FIGS. 5 and 7. The stake clip 56 may be configured to be resiliently flexible such that rib 58 of the stake clip 56 may grippingly engage the lower edge 22 when the form 16 is placed on the stakes 48 subsequent to driving the stakes 48 into the substrate 14.

Although not shown, the stake clip 56 may be configured as a separate component that is configured to interlock the stake body 50 to the form 16. In such a configuration, the stake clip 56 may be configured to straddle the stake body 50 and engage the lower edge 22 of the vertical panel 18 for restraining the form 16 against the stake 48 during lateral displacement caused by pouring of wet concrete on a side of the pour joint 10. The ribs 58 formed in the upwardly extending portions allow the stake clip 56 to grippingly engage the lower edge 22 of the form 16.

The operation of the pour joint 10 will now be described with reference to FIGS. 1 through 7. The stakes 48 are initially driven into the substrate 14 or attached to the substrate 14 depending on whether the substrate 14 is earthen (e.g., soil) or artificial (e.g., metal decking). The stakes 48 are generally aligned according to the desired location of the pour joint 10. Typically, the stakes 48 are initially installed at opposite ends 24 of a predetermined length (e.g., twenty feet) after which additional stakes 48 are then installed at intermediate positions (e.g., at two-foot intervals). The stakes 48 are typically driven into the substrate 14 at a depth equivalent to a desired height of the pavement or at a desired floor elevation. If an edge cap 68 is to be included with the pour joint 10, the stakes 48 may be driven deeper into the substrate 14 by an amount equivalent to an additional height of the edge cap 68.

The forms 16 are then installed on the stakes 48 with splices 60 interconnected to opposing ends 24 of the forms 16. If separate ones of the stake clips 56 are included, such stake clips 56 are then mounted on the stake body 50 such that the stake clips 56 engage the lower edge 22 of the vertical panel 18. If included, a layer of joint filler 66 may be mounted against a side of the form 16. Edge caps 68 may then be installed along the forms 16. Dowel placement systems 36 may be installed in the forms 16 at a desired spacing. If the dowel holes 64 are configured as knockouts, such knockouts are first bent outwardly or removed such that the sleeves 38 of the respective ones of the dowel placement system 36 may be installed in the dowel holes 64. Sheaths 42 are the attached to the respective ones of the sleeves 38 and the dowels rods 46 are then inserted into the sheaths 42. Wet concrete is then poured over the substrate 14. Prior to curing, the concrete is leveled. A pair of the pour joints 10 may be utilized to screed the top surface of the slabs 12 after which a finish may be applied to the freshly poured concrete.

Additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art. Thus, the particular combination of parts described and illustrated herein is intended to represent only certain embodiments of the present invention, and is not intended to serve as limitations of alternative devices within the spirit and scope of the invention.





 
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