CONCRETE EXPANSION JOINT INSERT INCLUDING AN EXPANDING SEALANT

Abstract

An illustrative example embodiment of a concrete joint insert includes a body having two end surfaces, two side surfaces, and an upper portion. The upper portion of the body includes a securement feature in the upper portion. A sealant is applied to the securement feature and secured to the upper portion of the body so that the insert and the sealant can be simultaneously installed in a concrete joint. The sealant expands.

Description

BACKGROUND

Concrete has been in widespread use for a variety of surfaces, including roads and walkways. Concrete is a generally porous material and is exposed to changing weather conditions, and expansion or contraction joints between sections or slabs of the concrete accommodate expansion and contraction of the concrete. For discussion purposes, the phrases “expansion joint,” “contraction joint,” or “concrete joint,” within this document should be considered to be interchangeable unless a particular context requires a different understanding.

Many expansion joints include an insert or filler within the space between the sections or slabs of concrete. Traditional joint inserts were made using materials such as wood, paper and asphalt. More recently, recycled rubber expansion joint inserts were introduced.

U.S. Pat. No. 6,616,877 describes a technique for using recycled rubber, such as that available from used vehicle tires, for making concrete expansion joint material. According to the teachings of that document, relatively large sheets of recycled rubber-based material can be cut to a desired size for different installations to accommodate different thicknesses of concrete, for example.

In many installations, after the concrete has cured, at least one individual and often a work crew returns to the jobsite to install a sealant in the expansion joints. The sealant is intended to form a barrier to prevent moisture from entering the expansion joint space. The sealant is often applied with a sprayer or an application gun in fluid form to fill the expansion joint space between the concrete slabs or sections that is not occupied by the expansion joint insert.

Alternatively, sealant is available in a roll or rope form that is installed on top of the expansion joint insert after the concrete has cured. Such sealant may be heated so that it melts sufficiently to seal the upper portion of the expansion joint.

One of the difficulties associated with returning to the jobsite and applying a fluid sealant is that it is possible to get the sealant on the concrete outside of the expansion joint, which leaves the jobsite looking messy and unprofessional. Additionally, the time required for applying such a sealant introduces additional expense. A difficulty associated with the roll or rope form of sealant is that it tends to be difficult to handle, increasing the time required to complete the task of installing the sealant.

Another issue presented by the conventional approach is that a portion of the expansion joint insert material must be removed along the entire length of the expansion joint to create a cavity for receiving the sealant material. This increases the time and labor expense. There is a need for a better way to achieve a sealed expansion joint.

SUMMARY

An illustrative example embodiment of a concrete joint insert includes a body having two end surfaces, two side surfaces, and an upper portion. The upper portion of the body includes a securement feature in the upper portion. A sealant is applied to the securement feature and secured to the upper portion of the body so that the insert and the sealant can be simultaneously installed in a concrete joint. The sealant expands.

Another illustrative example embodiment of a method includes making a concrete expansion joint insert. The method includes establishing a body having two end surfaces, two side surfaces, and an upper portion. The upper portion of the body includes a securement feature in the upper portion. The method includes securing a sealant applied to the securement feature and secured to the upper portion of the body so that the insert and the sealant can be simultaneously installed at the location of an expansion joint and expanding the sealant.

Various features and advantages will become apparent to those skilled in the art from the following detailed description of example embodiments. The drawings that accompany the detailed description can be briefly described as follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a concrete joint including an insert with a sealant on one edge designed according to an embodiment of this invention;

FIG. 2 is a perspective illustration of an example embodiment of a concrete joint insert;

FIG. 3 is an end view of an example embodiment;

FIG. 4 is an end view of another example embodiment;

FIG. 5 schematically illustrates an end view of a first example embodiment insert;

FIG. 6 schematically illustrates an end view of a second example embodiment insert;

FIG. 7 schematically illustrates an end view of a third example embodiment insert;

FIG. 8 schematically illustrates a feature of an example embodiment of an insert in use;

FIG. 9 schematically illustrates a portion of an installation technique;

FIG. 10 of schematically illustrates a device for manufacturing concrete joint inserts according to an example embodiment; and

FIG. 11 schematically illustrates a technique for assembling an insert designed according to an embodiment of this invention.

DETAILED DESCRIPTION

FIG. 1 shows a concrete joint insert 20 within an expansion joint 22 between two sections or slabs of concrete 24 and 26. A sealant 28 is situated on the insert 20 along an upper surface 31 of the expansion joint 22.

FIG. 2 illustrates an example embodiment of a concrete joint insert 20 including sealant 28 on a body 21 of the insert 20 before it is delivered to a jobsite or installed in an expansion or contraction joint. In this example, the body 21 of the insert 20 has longitudinal edges 30 and 32 that extend between end surfaces 34 of the body 21. Side surfaces 36 are between the longitudinal edges 30 and 32 and between the end surfaces 34. Only one of the side surfaces 36 is shown in the illustration of FIG. 2.

The body 21 of the insert 20 of FIG. 2 has a width W, a thickness T, and a finished length L. The length L and thickness T correspond to dimensions of the longitudinal edges 30 and 32, respectively. The sealant 28 in this example has the same length L and thickness T. The thickness T and width W correspond to dimensions of the end surfaces 34. The width W and length L correspond to dimensions of the side surfaces 36.

In some examples, the width W varies between two inches and twelve inches. Many concrete installations include slabs that have a thickness on the order of 3.5 inches, 4 inches or 6 inches. The width W is selected to correspond to the thickness of the concrete in such examples.

The thickness T may vary between 0.25 inch and 1 inch. Many expansion joints have a gap size of approximately one-half inch, and the insert 20 will have a thickness T of one-half inch for such installations.

The body 21 of the insert 20 may include various materials. In some examples, the body 21 of the insert 20 includes recycled rubber, while in other embodiments, the body 21 of the insert 20 includes one of wood fibers impregnated with asphalt, asphalt with minerals such as sand added between two layers of tar paper, recycled newspaper bonded under pressure and containing wax, recycled vinyl, cork, rebounded rubber, or neoprene and wood strips.

FIG. 3 is an end view of the embodiment shown in FIG. 2. The sealant 28 is situated along the longitudinal edge 30 with the sealant 28 exposed. In this example, during application, the material of the sealant 28 adheres to the longitudinal edge 30 without requiring any additional adhesive. The material of the sealant 28 is sufficiently tacky for the sealant 28 to remain in place on the longitudinal edge 30.

One example sealant 28 has a material composition like that of a commercially available concrete joint and crack filler material sold by Dalton Industries under the tradename CRACKSTIX™.

In some embodiments, the sealant 28 includes a material that has a hardness sufficient for retaining an established shape in ambient temperature conditions. In some embodiments, the sealant 28 material is capable of retaining a desired shape in temperatures up to approximately 160° F. The sealant 28 holds its established shape throughout shipping, handling, and installation. Even though such materials may be melted by applying heat, in some embodiments, after being melted, the material cures and has a hardness that is at least the same as used for maintaining the shape prior to installation. In some embodiments, curing the sealant 28 by applying heat when the sealant 28 has been installed results in a greater hardness at the installation site compared to the hardness of the sealant 28 during shipping and handling, for example. When the concrete cures, it shrinks slightly, pulling away and leaving a gap nearest to the current expansion joints. The sealant 28 is used to accommodate for the gap. The sealant 28 expands with heat, air, and water. In one example, the sealant 28 is an expanding foam.

When the concrete cures, it shrinks slightly, pulling away and leaving a gap nearest to the current expansion joints. The sealant 28 expands with heat, air, and water. In one example, the sealant 28 is an expanding foam.

In some examples, the adhesive material will have an exterior tackiness. The embodiment of FIG. 4 includes a cap or cover 40 over the sealant 28 to avoid adhesion during handling or storage. In one example, the cover 40 is a thin layer or film of plastic material that may be melted with the adhesive when the insert 20 is in place between slabs of concrete 24 and 26. Some polymer films used as the cap or cover 40 will eventually disappear after being exposed to outdoor weather conditions. For example, the cap or cover 40 may dissipate, disintegrate, evaporate or melt over time. Given this description, those skilled in the art will be able to select an appropriate material to prevent undesired adhesion between the sealant 28 and any object or surface that contacts the sealant 28 before installation. The cover 40 material is durable enough to protect against adhesion during production, packaging, storage, and transport to a job site while allowing for eventual, desired exposure of the sealant 28.

In some example embodiments as shown in FIG. 4, the sealant 28 holds an established shape in ambient conditions. For example, the sealant 28 establishes a relatively stiff, flat surface along the top of the insert 20.

The examples of FIGS. 5 to 7 include a securement feature to which the sealant 28 is applied and secured to an upper portion of a body. The sealant 28 expands and self-levels.

FIG. 5 illustrates another example insert 82 including a body 84 and the sealant 28. In one example, the sealant 28 is extruded as a structural foam. A groove 88 that is the securement feature. An upper surface 86 of the body 84 of the insert 82 includes the groove 88 that extends downwardly. In one example, a cross-section of the groove 88 is tear dropped shaped. However, the groove 88 can have any shape. As described, a structural sealant 28 is extruded on the upper surface 86 of the body 84 of the insert 82 and enters the groove 88. The application of heat, water, or UV lights causes the sealant 28 to expand outwardly on the side surfaces 90 of the body 84 and self-levels on the upper surface 86 of the body 84 to have a concave shape, taking the shape shown in dashed lines. By extruding the structural foam of the sealant 28 that expands while self-leveling, the expansion joint seal against concrete is improved. Less expansion leveling product can be used because its volume is increased during foaming process. As the sealant 28 expands, the expansion joint becomes tighter in the gap, improving the sealant 28.

FIG. 6 illustrates another example insert 92 including a body 94 having an upper surface 96. A reduced width portion 98 is the securement feature. A portion of a side surface 100 of the body 94 extending from the upper surface 96 of the insert 92 includes the reduced width portion 98. The structural sealant 28 is extruded on the upper surface 96 on the insert 92 and enters the reduced width portion 98. The application of heat, water, or UV lights causes the sealant 28 to expand outwardly from the reduced width portion 98 of the side surfaces 100 and downwardly on the upper surface 96 of the body 94 and self-level on the upper surface 96 of the body 94 to have a concave shape, taking the shape shown in dashed lines. By extruding the structural foam of the sealant 28 that expands while self-leveling, the expansion joints seal against concrete is improved. Less expansion leveling product can be used because its volume is increased during foaming process. As the sealant 28 expands, the expansion joint becomes tighter in the gap, improving sealant 28.

FIG. 7 illustrates another example insert 102 including a body 104 having side surfaces 106 and an upper surface 110. A passage 108 is the securement feature. The passage 108 extends from the side surfaces 106 near the upper surface 110. A structural sealant 26 is extruded into the passage 108. When exposed to water, the sealant 28 expands outwardly from the passage 108 to take the shape shown in dashed lines to cover a portion of the side surfaces 106 of the body 104. As the sealant 28 expands and self-levels, the expansion joint becomes tighter in the gap, improving expansion joint over time.

One example use is schematically represented in FIG. 8 where a screed tool 44 is pulled along the top surface of the concrete during installation to establish a level, finished surface on the concrete. The sealant 28, when covered or uncovered with the cap or cover 40, provides a rigid guide surface along which an individual may pull or push the screed tool 44. In this example, the sealant 28 facilitates achieving a desired finish surface on the concrete that is installed with the insert 20 in place during installation.

FIG. 9 schematically illustrates a heat source 50, such as a torch, for heating the adhesive 28 when the insert 20 is in the expansion joint 22 between the slabs of concrete 24 and 26 after the concrete has cured. Heating the adhesive 28 causes the adhesive to at least partially melt and seal off the top portion of the expansion joint 22 above the body of the insert 20. With embodiments of this invention, concrete installers may place the expansion joint inserts 20 within expansion joints with the adhesive 28 already secured to the body of the insert 20. The final sealing of the expansion joint 22 is simpler because all that is required after the concrete has cured is for an individual to heat the sealant 28 to at least partially melt it for sealing off the top portion of the expansion joint.

In some embodiments of this invention, the insert 20 is cut from a larger sheet to achieve the desired width W while in others, the width W and thickness T are established during a molding process, depending on the material chosen from those mentioned above.

FIG. 10 schematically illustrates a device 60 useful for manufacturing the body 21 of the inserts 20 having width W and thickness T dimensions that are preset to correspond to the dimensions desired for installation. In other words, the device 60 provides elongated strips of insert 20 material instead of generating or yielding a sheet of material that is subsequently cut into strips.

The device 60 includes an extruder 62 for extruding material, such as recycled rubber, into a manifold 64 that distributes the extruded material into individual channels 66. The material flows through the channels 66 in the direction shown by the arrow 68. The channels 66 in this example have an adjustable dimension to achieve different width W dimensions of the body 21 of the inserts 20.

One side 70 of each channel 66 is adjustable relative to an opposite side of the channel 66 as schematically shown by the arrow 72. The side 70 of each channel 66 may be adjusted from a smaller width W dimension to a larger width W dimension as schematically shown in phantom at 74. The adjustable feature of the channels 66 allows for making different sized inserts without requiring a completely separate die channel and without requiring complex changes to the device 60.

The device 60 includes the ability to provide the sealant 28 along at least one of the longitudinal edges of the body 21 of the insert 20 produced by the device 60. In the illustrated example, another extruder 76 extrudes sealant 28 material into a manifold 78 that distributes the sealant 28 material along secondary channels 80 that are situated along one of the longitudinal edges of the channels 66. Such an arrangement allows for coextruding two materials so that at least one longitudinal edge of the molded insert 20 has the sealant 28 in place on the longitudinal edge.

FIG. 11 schematically illustrates another technique for making an expansion joint insert 20 according to an embodiment of this invention. In this example, the body 21 of the insert 20 is already established. In some examples, a molding process will form the body 21 having the desired dimensions. In another example, the body 21 of the insert 20 is cut from a larger sheet of material. Regardless of how the body 21 of the insert 20 is established, the adhesive 28 is applied after the body 21 already has its desired dimensions.

In some examples, the adhesive is applied by attaching a rope or bead of adhesive material to the longitudinal edge 30. In other examples, the adhesive is applied using a fluid form of the adhesive and an applicator. In such examples, while the adhesive is fluid, there is enough solidity to it once the material leaves the applicator that the material remains in a desired position relative to the rest of the insert body until the adhesive material cures. Some examples include placing the body 21 of the insert 20 within a molding station and then molding the adhesive material onto the longitudinal edge 30.

In some embodiments, once the sealant 28 material is applied to the selected edge of the insert 20, the sealant 28 is cooled and shaped to a desired configuration. Some examples include using rollers that establish the desired profile or shape of the sealant 28. Once shaped, the sealant 28 is cooled and is ready for the cap or cover 40 to be applied. In one example, a film is draped over the top edge of the sealant 28 and extends down the sides toward the insert body a sufficient length to cover all exposed surfaces of the sealant 28.

Including an adhesive 28 on a longitudinal edge 30 of an expansion joint insert 20 facilitates faster installation and more consistent finished results. The amount of adhesive within each joint is controlled because the adhesive material is already present on the insert 20 before it is installed in an expansion joint between sections of concrete. This avoids misapplication or under-application where insufficient amounts of adhesive are otherwise present in an expansion joint, which may lead to future deterioration of the concrete along that joint. Additionally, having a controlled amount of adhesive within the expansion joint facilitates achieving a more consistent and aesthetically pleasing appearance to the finished concrete installation.

The preceding description is exemplary rather than limiting in nature. Variations and modifications to the disclosed examples may become apparent to those skilled in the art that do not necessarily depart from the essence of this invention. The scope of legal protection given to this invention can only be determined by studying the following claims.

Claims

1. A concrete joint insert comprising a body having two end surfaces, two side surfaces, and an upper portion, wherein the upper portion of the body includes a securement feature in the upper portion; anda sealant applied to the securement feature and secured to the upper portion of the body so that the insert and the sealant can be simultaneously installed in a concrete joint, wherein the sealant expands.

2. The concrete joint insert as recited in claim 1 wherein the sealant self levels.

3. The concrete joint insert as recited in claim 1 wherein the upper portion of the body includes an upper surface, and the securement feature is a groove on the upper surface.

4. The concrete joint insert as recited in claim 2 wherein the groove is tear dropped shaped.

5. The concrete joint insert as recited in claim 1 wherein the securement feature is a reduced width portion on the upper portion of the two side surfaces.

6. The concrete joint insert as recited in claim 1 wherein the securement feature is a passage that passes through the upper portion of the body between the two side surfaces.

7. The concrete joint insert as recited in claim 1 wherein the body comprises rubber.

8. The concrete joint insert as recited in claim 1 wherein the sealant comprises an expanding foam.

9. The concrete joint insert of claim 1, wherein the sealant has a melting temperature at which the sealant will at least partially melt and change from the selected shape to another configuration, and the melting temperature is above 160° F.

10. A method of making a concrete expansion joint insert, the method comprising: establishing a body having two end surfaces, two side surfaces, and an upper portion, wherein the upper portion of the body includes a securement feature in the upper portion;securing a sealant applied to the securement feature and secured to the upper portion of the body so that the insert and the sealant can be simultaneously installed at the location of an expansion joint; andexpanding the sealant.

11. The method as recited in claim 10 wherein the sealant self levels.

12. The method as recited in claim 10 wherein the upper portion of the body includes an upper surface, and the securement feature is a passage on the upper surface.

13. The method as recited in claim 12 wherein the passage is tear dropped shaped.

14. The method as recited in claim 10 wherein the securement feature is a reduced width portion on the upper portion of the two side surfaces.

15. The method as recited in claim 10 wherein the securement feature is a passage that passes through the upper portion of the body between the two side surfaces.

16. The method as recited in claim 10 wherein the body comprises rubber.

17. The method as recited in claim 10 wherein the sealant comprises an expanding foam.

18. The method as recited in claim 10, comprising establishing the body before securing the sealant to the one of the longitudinal edges.

19. The method as recited in claim 10, wherein the sealant has a melting temperature at which the sealant will at least partially melt and change from the selected shape to another configuration, and the melting temperature is above 160° F.