WO1999018302A1

WO1999018302A1 - Connector and boot seal assembly for an insulated wall and method for making the building panel

Info

Publication number: WO1999018302A1
Application number: PCT/US1998/020963
Authority: WO
Inventors: Robert T. Long, Sr.
Original assignee: Composite Technologies Corporation
Priority date: 1997-10-07
Filing date: 1998-10-06
Publication date: 1999-04-15
Also published as: AU9684498A

Abstract

An insulated building panel includes first and second spaced apart layers of concrete (12, 14) having a layer of insulating material (16) sandwiched therebetween. Extending through the insulative layer are a plurality of connectors (20) having their opposite ends (28, 30) protruding into the two concrete layers (12, 14) and having their central portions (26) extending through the insulating material (16). A boot seal (22) is positioned on at least the first end portion (28) of the connector (20) for sealing engagement with the insulation layer (16), thereby creating a vapor barrier to prevent and inhibit migration of moisture through the insulation layer (16). The opposite ends (28, 30) of the connectors (20) each include a holding surface (38) facing at least partially toward the central insulative layer (16) and holding the concrete layers against movement away from the insulative layer (16).

Description

TITLE: CONNECTOR AND BOOT SEAL ASSEMBLY FOR

AN INSULATED WALL AND METHOD FOR MAKING THE BUILDING PANEL

BACKGROUND OF THE INVENTION

This invention relates to a connector assembly for a composite insulated building panel and method for making the panel.

Insulated walls have been constructed in the prior art utilizing first and second concrete layers having an insulated layer sandwiched therebetween. Connectors or ties have been provided for extending through the concrete layers and the central insulating layer to connect them together. Since the connectors extend through the insulating layer, potential vapor leaks may be created, particularly if wall installation is not done properly. Thus, moisture could possibly pass through the insulation layer and form undesirable condensation or frost on the cool side of the wall.

Also, when such multi-layer wall panels are used in environments having large temperature variations between the internal and outside wall surfaces, such as freezers or coolers, there must be allowance for thermal expansion and contraction. For example, in a freezer, the inside temperature may be -40°F while the outside temperature is 100°F, with such outside temperature varying substantially over the course of a day. Thus, there is a need for the outer concrete layer or facia to be supported by the connectors so as to allow for thermal expansion and contraction while preventing the bowing and cracking of the outer concrete layer.

Therefore, a primary objective of the present invention is to provide an improved connector assembly for a composite insulated building panel and an improved method for making the panel.

A further objective of the present invention is the provision of an improved insulated wall having a vapor seal around each connector to prevent vapor leaks through the insulative layer. A further objective of the present invention is the provision of a boot seal on each connector in a composite wall structure.

A further objective of the present invention is the provision of an insulated wall and method for making same which involves simple construction techniques, and which is efficient in operation, and which allows for large temperature differentials across the wall thickness while preventing cracking and thermally induced bowing.

SUMMARY OF THE INVENTION The foregoing objectives are achieved by an insulated building panel having first and second spaced apart layers of concrete with a layer of insulating material sandwiched therebetween. A plurality of elongated shear connectors of a material with low thermal conductivity extend through the layer of insulating material so that their opposite ends protrude into the layers of concrete. Each connector includes a central body portion and opposite end portions. The opposite end portions of the shear connectors each have a holding surface defined by segments of varying dimension which face at least partially towards the insulating layer and which engage the first and second layers of concrete respectively to hold the first and second concrete layers against movement away from the insulating material. A boot seal positioned on one end portion of the connector and in sealing engagement with the insulation layer provides a vapor barrier to prevent or inhibit migration of moisture along the connector and through the insulation layer.

The method for making the composite wall involves taking the above described shear connectors and inserting the shear connectors through the layer of insulating material to a position wherein the first and second end portions of the connectors protrude outwardly from the opposite sides of the layer of insulation, and the central portion of the shear connectors are within the layer of insulation. A boot seal is then pushed over the first end portion of each connector until the boot sealingly engages the insulation layer. Ribs on the connector retain the boot in position. Next the first layer of concrete is poured and the layer of insulation material is placed on top of the poured layer before the concrete cures and hardens. The first ends of the shear connectors are pressed downwardly into the first layer of concrete so that the insulative layer abuts against the concrete. Next a second layer of concrete is poured over the upper surface of the insulation material so as to embed the other ends of the connectors in the second layer of concrete. When completed, and when the concrete has hardened, the holding surfaces of the opposite end portions of the shear connectors will hold the first and second concrete layers against movement away from the layer of insulating material.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a perspective view of a first embodiment of one of the connectors of the present invention.

Figure 2 is a view of the boot seal of the present invention. Figure 3 is a partial sectional view showing the connector and boot seal assembly in a wall.

Figure 4 is a sectional view of the connector of Figure 1 taken along lines 4-4 of Figure 1.

Figure 5 is a perspective view of the first end portion. Figure 6 is a sectional view of the connector of Figure 5 taken along lines 6-6 of Figure 5.

Figure 7 is a perspective view of the first end portion.

Figure 8 is a sectional view of the connector of Figure 7 taken along lines 8-8 of Figure 7. Figure 9 is a perspective view of the first end portion.

Figure 10 is a sectional view of the connector of Figure 9 taken along lines 10-10 of Figure 9.

Figure 11 is a sectional view taken along lines 11-11 of Figure 3. DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to the drawings, the numeral 10 generally designates a wall made according to the present invention. The multi-layered wall 10 includes a first concrete layer 12 and a second concrete layer 14 which have an insulating layer 16 sandwiched therebetween. The insulative layer 16 may be formed from one or more sheets of insulation board commonly used in the construction industry. Its thickness may vary as desired, but preferably it is of a rigid material so that it will hold its own shape.

Extending through the insulation board 16 are a plurality of connectors 20. A boot seal 22 is mounted on each of the connectors.

Each connector 20 includes a central portion 26, a first end portion 28, and a second end portion 30. In the embodiment shown in Figures 1 and 4, the connector 20 has a star shape in cross section. The alternative embodiment connector 20A of Figures 5 and 6 has an X shape in cross section. The connector embodiment 20B of Figures 7 and 8 has a figure 8 or butterfly wing cross section, as does the connector 20C shown in Figures 9 and 10. These shapes provide projections with increased surface areas which dissipate heat from the molding process. Thus, connectors with greater cross-sectional areas and therefore tensile strengths can be manufactured. The connectors 20, 20A, 20B and 20C all function identically with respect to the boot seal 22.

The boot seal 22 is generally conical in shape before being positioned on a connector 20. The boot seal 22 includes a planar outer flange 32, a conical portion 33, and a planar inner flange 34 having an aperture 35 therein. The boot seal 22 is preferably made of an elastomeric rubber or, more generally, an elastomeric material so as to be flexible and resilient.

A plurality of ribs or ridges 36 are provided on the connector 20 on the central portion 26 adjacent the first end portion 28. The diameter of the connector 20 varies along the ribs 36. However, the smallest diameter portion of the ribs 36 is larger than the diameter of the hole 35 in the boot seal 22. Thus, when the boot seal 22 is mounted over the first end portion 28 of the connector 20 and onto the ribs 36, a water tight seal is provided between the connector ribs 36 and the boot seal 22. The central portion 26 of the connector 20 also includes a plurality of ridges 37 which provide a mechanical interlock with the insulation layer 16. The ridges 37 also provide a secondary moisture seal to inhibit migration of vapor and moisture along the central portion 26 of the connector 20.

Holding surfaces 38 are formed on the end portion 28 and face at least partially toward the central portion 26 of each of the connectors 20, 20A, 20B and 20C. The holding surfaces 38 are defined by the varying dimension of the end portion 28 from the terminal end to the central portion 26. The holding surfaces 38 are shown on the drawings to be at an acute angle to the longitudinal axis of the connector 20, but they could also be at larger angles, up to 90°. It is important, however, that the surfaces 38 face at least partially toward the central portion 26 so that they can engage concrete in the concrete layer 12 and hold the concrete layer to the insulative layer as will be described hereafter. The second end portion 30 also includes similar holding surfaces 40 defined by the varying dimension of the end portion 30 to the central portion 26. These surfaces 40 engage in layer 14. A flange 42 is attached to the connector 20 and is positioned between the second end portion 30 and the central portion 26. While the flange 42 is preferred for use with the connector 20, it is possible to use the connector 20 without having any flange 42 thereon. The method of construction using the connectors 20, 20A, 20B and 20C is the same. Therefore, the following description will reference connector 20, and apply equally for connectors 20A, 20B and 20C.

First, a form is made for the first and second concrete layers 12 and 14 and concrete layer 12 is poured into the form. A plurality of connectors 20 are inserted through the insulation board which has pre-drilled or thermally formed holes for receiving the connectors. When using connectors having the flange 42, the connector is inserted until the flange 42 abuts against the insulation board 16 as shown in Figure 3. In this position, the second end portions 30 are protruding from one side of the insulation board 16, and the first end portions 28 are protruding out the opposite side of the board 16. A boot seal 22 is then placed over the first end of each connector 20 and forced into retentive engagement with the ribs 36. Preferably, a tool with a hollow tubular tip is used to push the boot seal 22 into position on the connector 20 such that the boot is collapsed accordion-style. As the boot seal 22 is placed onto the connector 20, the conical portion 33 of the boot seal is deformed or pushed inwardly such that the inner flange 34 sealingly engages the surface of the insulation layer 16. The outer flange 32 of the boot seal 22 also sealingly engages the surface of the insulation layer 16. Thus, the boot seal 22 is placed under residual compression, or compression with a resulting friction seal between the boot 22 and the insulation layer 16. This friction seal serves as a vapor barrier or seal to prevent and inhibit the migration of moisture along the connector 20 and through the insulation layer 16.

Moisture migrates from a warm surface to a cooler surface. Therefore, the boot seal 22 is placed adjacent the warm side of the wall 10, which, in freezer and cooler applications is normally the first or outer concrete layer 12. However, in some applications, the external temperatures may be less than the internal temperatures, such that it is desirable to place the boot seal 22 adjacent the inner or second concrete layer 14. It is also conceivable that a pair of boot seals 22 may be used on each end of the connectors 20 so as to prevent moisture transfer in either direction through the insulation layer 16. More particularly, the inner flange 34 of the boot seal 22 is formed with an inside diameter which is smaller than the outside diameter of the ridges 37 of the connector 20. Because the seal 22 is formed from an elastomeric material, it deforms but applies a compressive stress at the seal-connector interface. If a pressure is applied to the seal, a traction stress at the interface will allow the seal to maintain a pressure differential.

The outer flange 32 of the boot seal 22 is forced against the insulation 16 as the boot seal 22 is deformed from its initial conical shape to a flattened configuration, as shown in Figure 11. This induces compressive stress normal to the insulation 16 at the seal-insulation interface. This allows a traction stress which maintains a seal. The insulation board 16 is placed over the concrete layer 12 before the concrete cures or hardens, and the first end portions 28 of the connectors 20 and boot seals 22 are forced downwardly into the concrete layer 12 and become imbedded therein as shown in Figure 3.

Next, the concrete layer 14 is poured into the form above the insulative layer 16 so that it completely surrounds and covers the second end portions 30 of each of the connectors 20.

When the concrete of layers 12 and 14 cure and harden, the layers are held in position against the insulation board 16 by virtue of the holding surfaces 38 and 40 on the connectors 20. It is possible to use the connectors 20 with or without the flange 42, but it is important that the end portions 28, 30 protrude outwardly beyond the opposite sides of the insulative board 16 and into the concrete layers 12, 14.

Because the connectors 20-20C are made of low conducting material such as fiberglass or other plastic material, there is a complete thermal barrier between the two concrete layers 12, 14. This is to be contrasted with many prior art devices which utilize metal connectors capable of providing a thermal conduit between the two concrete layers. The various connectors 20-20C may be used in a variety of patterns or combinations so as to minimize the cracking or bowing of the composite panels in response to temperature changes. It is also understood that the connectors of the present invention can be used in other building panels having a multi-layered insulation sandwich construction. For example, the connectors can be used in a roof panel having an insulation layer sandwiched between layers of concrete.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, these are used in a generic and descriptive sense only and not for purposes of limitation. Changes in the form and the proportion of parts as well as in the substitution of equivalents are contemplated as circumstances may suggest or render expedient without departing from the spirit or scope of the invention as further defined in the following claims.

Claims

What is claimed is:

1. A connector assembly for a wall having first and second spaced apart concrete layers and an insulation layer sandwiched between the concrete layers, the connector assembly comprising: a connector having a central body portion and first and second end portions extending oppositely from the central body portion, the connector being adapted to extend through the insulation layer with the first and second end portions extending outwardly from opposite sides of the insulation layer; a boot seal mountable over one of the first and second end portions for engagement with the insulation layer so as to inhibit migration of moisture along the connector and through the insulation layer.

2. The connector assembly of claim 1 wherein the boot seal is constructed of elastomeric material.

3. The connector assembly of claim 1 wherein the boot seal is deformable.

4. The connector assembly of claim 1 wherein the boot seal includes a hole through which the one end portion of the connector extends and the connector includes at least one rib for retentively engaging the boot seal.

5. The connector assembly of claim 1 wherein the connector end portions have a plurality of projections to provide increased surface area for dissipation of heat during the manufacturing process.

6. A building panel, comprising: first and second spaced apart concrete layers; an insulation layer sandwiched between the concrete layers; a plurality of connectors each extending through the insulation layer and having opposite first and second ends embedded in the first and second concrete layers, respectively; and a plurality of boot seals, each boot seal being sealingly mounted on one end of one of the connectors and being in sealing engagement with the insulation layer to form a vapor barrier around each connector.

7. The building panel of claim 6 wherein each connector has ribs on the one end and each boot seal has a hole therein through which the one end extends such that the boot seal engages one of the ribs for securement on the connector.

8. A method of forming a multi-layered building panel, comprising: pouring a first concrete layer; inserting a connector through an insulation layer and such that opposite first and second end portions of the connector extend outwardly from opposite sides of insulation layer; placing a boot seal over the first end portion of the connector so as to form a moisture barrier around the connector thereby inhibiting passage of moisture through the insulation layer, placing the insulation layer onto the first concrete layer before the first concrete layer hardens such that a first end portion of the connector extends into the first concrete layer; pouring a second concrete layer over the insulation layer so as to embed the second end portion of the connector within the second concrete layer.

9. The method of claim 8 wherein the boot seal is in frictional engagement with the connector and with the insulation layer.

10. The method of claim 8 wherein the boot seal is under tension when mounted on the connector.