Patent Abstract:
A fastener is disclosed having a an extension portion configured to be inserted into a first construction material such as foam, and having a stirrup portion configured to retain portion of a second construction material, such as rebar at a distance from the first construction material. A third construction material such as concrete can then be inserted (poured) in contact with the first construction material and surrounding the second construction material such that the second construction material is not directly in contact with the first construction material.

Full Description:
BACKGROUND OF THE DISCLOSURE 
       [0001]    Foam concrete structures are utilized in various capacities ranging from concrete stairs, drive ways, ramps, floating docks, precast walls, abutments, retaining walls with lightweight fill load distribution slabs, roadways and applications for concrete foam systems such as Geofoam™ and other applications for concrete foam structures. In general, a foam concrete structure has a central region comprised of foam material which may be expanded polystyrene (EPS) or extruded polystyrene (XEPS) with a perimeter portion of concrete therearound. Oftentimes, a tensile strength member such as rebar is positioned within the concrete. At present time, rebar, which is comprised of steel or other iron-based compositions, is a primary form of enhancing the strength of concrete to reinforce concrete structures. In general, concrete is very poor in tension, and having an insert therein, for example a metallic member such as a longitudinally extending piece of rebar, significantly enhances the strength of the concrete structure. 
         [0002]    Now in the case of having a concrete block with a foam center portion, when a bending moment is placed upon the structure, there is a compressive force at its greatest magnitude in one portion of the block structure, whereas the opposing portion has a tensile stress imposed thereon. The concrete is used to encapsulate or provide a protective shell, for example: floatation, geofoam, floor systems, ICF&#39;s, poured-in-place and pre-cast concrete systems. The foam portion functions as floatation, lightweight fill, or insulation. Of course, the center portion has a shear force acting as welt pursuant to basic beam theory. Therefore, having a properly spaced tensile member such as rebar positioned in the foam concrete structure is important for properly positioning the rebar in the concrete to absorb the tensile stress placed thereon. 
         [0003]    The prior art has failed to present a system, apparatus and method for properly positioning and orienting rebar at a proper depth within the outer concrete perimeter region. In some forms the rebar is positioned during a construction state in vertically and inverted orientated positions as well as a regular horizontal position. Therefore, in one form, having an apparatus to orientate the rebar in various orientations with respect to the flux field of gravity is desirable for constructing and forming a concrete/foam structure. 
         [0004]    Further, having a proper anchoring system to attach to the foam material allows for proper positioning of the rebar holding unit. In one form, having a properly sized and dimensioned base portion allows for a sufficient amount of stability, without requiring excessive force to penetrate the foam to be mounted during production. These steps may be carried out in a manufacturing facility, or on a job site. 
       SUMMARY OF THE DISCLOSURE 
       [0005]    The structure in one form described in this disclosure is a holding member having an extension portion, a base portion, and a stirrup portion. The extension portion is configured to be inserted into a rigid construction material such as a block of foam. The extension portion in one form comprises a plurality of base members with barbs which extend radially outward from the longitudinal axis of the extension portion. These barb members are constructed to add rigidity to the structure, and assist in proper positioning within the rigid construction material. These barb members are especially helpful in preventing rotational and longitudinal movement of the holding member in relation to the foam. In one form, a plurality of barb members extend from the barb members to further maintain the position of the extension within the first construction material. The extension portion may be directly coupled to or formed with the stirrup portion, or an intermediate base portion may be provided between the two. This base portion can provide a stop which will limit the depth to which the extension member can be inserted into the foam. All three elements may also be formed as a unitary structure, say of a polymer or metal. 
         [0006]    In one form, after inserting the extension portion of the structure into the rigid construction material, a portion of an elongate construction material, such as a length of rebar, is coupled to the stirrup portion of the structure to hold the rebar a specified distance from the rigid construction material. After the rebar is positioned within the stirrup, another construction material such as concrete can be disposed in contact with the first construction material and substantially surrounding the second construction material. This will substantially encapsulate the construction materials and form a protective shell with the rebar adding support to the concrete (second material). 
         [0007]    In one form, the barb members previously discussed also have a plurality of barb-like extensions which are configured to keep the structure from pulling out of the rigid construction. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  shows a side view taken along a first transverse axis of the rebar holding member; 
           [0009]      FIG. 2  shows another side view taken along a first transverse axis; 
           [0010]      FIG. 3  is looking longitudinally rearward along the support portion of the rebar holding member; 
           [0011]      FIG. 4  is taken from a longitudinally forward vantage point looking at the extension portion of the rebar holding member; 
           [0012]      FIG. 5  is a progressive view of a method of manufacture of a foam concrete block structure; 
           [0013]      FIG. 6  shows a rebar positioned in a stirrup region of the rebar holding member which is embedded in the foam; 
           [0014]      FIG. 7  shows a completed foam concrete structure with concrete in the outer perimeter region having a foam center region. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0015]    As shown in  FIG. 7 , there is an environmental view of a foam concrete structure  20 . In general, the foam concrete structure  20  comprises a foam material  22  and a concrete perimeter  24 . Further comprising the foam concrete structure  20  are tensile stress members such as rebars and rebar holding members  28 . Further, in one form of manufacture, an outer mold member  30  can be utilized to hold the concrete  24  in its position while in an uncured state. This outer mold member  30  can either be a part of the veneer of the structure, or be removed from the concrete perimeter  24  once the concrete cures or otherwise is sufficiently rigid to hold its stationary form. 
         [0016]    Therefore, it can be appreciated that the tensile stress member  26 , which is most commonly rebar at the time of this writing, is positioned at a substantially center region  32  within the concrete perimeter  24 . This positioning allows the rebar  26  to engage the surrounding concrete so as to transfer force thereto, so when for example the particular concrete perimeter wall section  34  is in tension, these tensile stresses are transferred to the rebar  26  properly, whereas the concrete aggregate itself is in general very poor at handling tension, and of course very strong in compressing as is well-known pursuant to conventional material science theory. 
         [0017]    Therefore, as described in detail herein, the rebar holding member  28  provides utility in properly positioning the rebar during the production and manufacture of the foam concrete structure  20 . Various attributes of one form of a rebar holding member will be described herein in detail with the understanding that other forms could be utilized without departing from the spirit and scope of the Applicant&#39;s broad concept. 
         [0018]    In another embodiment, a section of tubing can be utilized instead of the tensile stress member  26 . This would not only add rigidity to the material but would also add a channel for applying fluids, gases, or serve as a conduit for electrical or communication service. For example, once the structure is completed, hot water could be provided through the tubing which would heat the structure adjacent the tubing. 
         [0019]    Referring now to  FIG. 1 , there is shown a side profile view of the rebar holding member  28 . To aid in the general description, the axes system  10  is provided where axis  12  indicates the longitudinal forward direction. Referring ahead now to  FIG. 4 , there is shown a first transverse axis  14  and a second transverse axis  16 . In general, the axes  14  and  16  extend radially outward from the longitudinal center axis  12 ″. In one form these axes are orthogonal to one another, but of course the general directions of the structures related to these axes need not be orthogonal. 
         [0020]    Referring now to  FIG. 1 , it can be appreciated that in general the rebar holding member  28  has an extension portion  36  and a support portion  38 . Interposed between the extension portion  36  and the support portion  38  is a base portion  40  which in one form is a transverse extending planar member configured to be positioned adjacent to the outer surface  96  of the foam center  22  described herein with reference to  FIG. 5 . 
         [0021]    In general, the extension portion  36  is configured to be positioned in the foam material  22  in a manner as shown in  FIG. 5 . The foam material in one form may be expanded polystyrene (EPS) or extruded polystyrene (XEPS). By way of background, one form of a foam concrete structure is a concrete dock where the interior portion is comprised of foam material. The perimeter portion can be between 1 and 3 inches of concrete or more. Rebar being placed in this perimeter region, as shown in  FIG. 6  and  FIG. 7 , greatly enhances the structural integrity of the foam concrete structure  20  (see  FIG. 7 ). 
         [0022]    Therefore, it can be appreciated that the extension portion  36  must provide a reasonably stable platform when inserted within the foam. As shown in  FIGS. 1 and 2 , there are first and second base portions  46  and  48 . In one form these base portions are orthogonal to one another as shown in  FIG. 4 , but of course need not be orthogonal to one another. As shown in  FIGS. 1 and 2 , each of the first and second base portions  46  and  48  comprise a plurality of barb members. As shown in  FIG. 2 , the plurality of barb members  50  generally comprise, in one form, three barb members  50   a ,  50   b  and  50   c . In one form the barb members are of a similar radial width from a center longitudinal axis  12 ′ as shown at  50   a  and  50   b , and in another form the barb members reduce in their radial width extension, such as where the barb  50   c  is shorter than the barb  50   b . In general, the barbs provide a transverse extension where in particular the plurality of barbs  50  extend in the first transverse direction  14  as shown in  FIG. 4 , and provide a locking-like action when extended within the foam material. 
         [0023]    Now referring to  FIG. 1 , it can be appreciated that the plurality of barb members  52  are shown, and more specifically in one form there are three sets of barb members  52   a ,  52   b  and  52   c . In one form, the plurality of barb members  52  can have (as shown in  FIG. 2 ) a perimeter flange  54  which basically extends slightly outward from the surfaces  56  and  58  of the second base member  48 . Present analysis indicates that this perimeter flange extension provides extra gripping of the foam material when inserted therein. Further, it can be appreciated that the barb members have a leading surface  60 , which is configured to engage the foam material when thrust therein. As shown in  FIG. 1 , the trailing surface  62  is provided which is configured to engage the foam material to maintain the extension portion  36  mounted firmly in the core foam structure  22  (see  FIG. 7 ). 
         [0024]    With the foregoing description in place with regard to the extension portion  36 , there will now be a discussion of the support portion (otherwise referred to as a stirrup portion)  38  with initial reference to  FIG. 1 . As shown in  FIG. 1 , in one form the support portion  38  is comprised of a base region  70 . The base region  70  in one form can be comprised of base extensions  72  and  74 . Positioned in the longitudinally rearward region of the support portion is a support  74  which comprises first and second arms  76  and  78 . The first and second arms comprise an interior surface  80 , which is configured to hold a tension member, such as a rebar  26  as shown in  FIG. 5 . In general, the interior surface can have a longitudinally outward region  82  which encompasses the cylindrical rebar member  26  so as to lock it in place therein. Further provided in the support  74  are the radially inward extension/fins  84  as shown in  FIG. 1  and  FIG. 3  within the stirrup  80 . In general, the radially inward extension is configured to have a width  86  which is such that the stresses placed thereon when a rebar member is placed in the radially inward extensions plastically deform and mesh to the rebar to further lock the rebar in place. This deformation is particularly advantageous because it prevents the rebar from repositioning or otherwise slipping along the longitudinal axis of the rebar, such as if the rebar is positioned in a more vertically oriented manner. Therefore, the width  86  would be somewhat less than the width  88  is shown in  FIG. 3 , depending upon the material used. Using a plastic injected molded unitary piece to construct the rebar holding member  28 , a desirable plastic may have a durometer rating between 50 and 100 made from nylon, polyethylene, or other suitable material. 
         [0025]    As further shown in  FIG. 5 , in one form the first and second legs  76  and  78  each comprise an inward slanting surface  90  and  92 . The surface of course facilitates positioning the outer surface  27  of the rebar member  26  into the central chamber region  94  of the support portion  38 . Still referring to  FIG. 5 , the base portion  40  generally comprises a base surface  94  positioned in a longitudinally forward direction, which is configured to engage the outer surface  96  of the full material  22 . 
         [0026]    To further describe one form of the rebar holding member  28 , the plurality of barbs  50  and  52  as shown in  FIGS. 1 and 2  are arranged such that, for example, the barb  50   a  is offset by approximately 90° and interposed between the barbs  52   a  and  52   b . Present analysis indicates that this transversely offset and interposed relationship provides greater engagement of the surrounding foam material when the extension portion  36  is embedded within the foam  22  as shown in the lower portion of  FIG. 5 . Of course other forms of a barb can be employed and the above description is one form of carrying out the applicant&#39;s concept. 
         [0027]    Analysis upon the overall dimensions of the rebar holding member  20  will now be presented. As shown in  FIGS. 1 and 2 , these dimensions are in one form substantially to scale, and in one form 95% of an actual prototype. Of course the scope of the concept is not limited to the specified dimensions of the figures; however, for purposes of included subject matter, the figures are to scale of one embodiment (plus or minus 20%) as to the actual dimensions and the relative dimensions between portions of the rebar holding member  28  itself. In other words, it has been found that having a length from the most forward location  96  from the base surface  94  of approximately 3 11/16″ provides a desirable combination of stability of the rebar holding member  28  when fully embedded in the foam  22  (see  FIG. 6 ), and ease of force required to position and force the extension portion  36  in the foam. Further, having the first and second base portions  46  and  48  which extend longitudinally provide a sufficient amount of rigidity to hold the rebar and further provide a sufficiently narrow cross-section (see  FIG. 4 ) to fit within the foam material  22 , which as noted above, in one form is EPS. The stirrup can be higher, for example three-six inches (plus or minus say 20% in broader range), such as when utilizing a low distribution slab where the layer of concrete may be a thick layer so the rebar is positioned substantially in a central region thereof. In the broader scope, with a low distribution slab of say twelve inches, the stirrup region can extend vertically six inches or more. Even with the longer stirrup region, it has been found using the EPS foam that having the distance of approximately just under 4 inches (±30% in one form depending on the nature of the foam) provided a desirable combination of stability and ease of force depressing within CPS foam. 
         [0028]    Therefore, as shown in  FIG. 5 , the force vector  100  is applied to the rebar holding member  28 . The force  100  can be by way of an impact force such as a mallet-like member, or directly pushed by one who is constructing a foam concrete structure. When the extension portion  36  is fully inserted or at least substantially inserted within the foam  22 , in one form the base surface  94  is pressed thereagainst and the rebar  26  can be properly positioned within the central chamber region  94 . As shown in  FIG. 6 , a plurality of rebar members  26   a  and  26   b  can be positioned within the various rebar holding members  28 . The support portion  38  is generally arranged to position the rebar a prescribed distance  102  from the outer surface  96  of the foam  22  (EPS in one form), and further positioned a prescribed distance  104  from the interior wall  108  of the outer mold member  30 . 
         [0029]      FIG. 6  illustrates one method of manufacture where some form of outer mold member  30  is utilized in a lower wail or a lateral wall as shown in  FIG. 6 . This outer mold member  30  can be a part of the final structure or removed thereafter. The interior wall  108  positions the un-cured concrete and maintains the desired form of the concrete until the concrete cures. The upper region  110  can additionally be poured and have concrete filled therein as shown  FIG. 7 . Therefore, it can be appreciated that a foam concrete structure  20  can be more readily constructed with a higher degree of confidence of the orientation in position of the rebar contained therein. The rebar may be specified to be positioned in a central region of the overall width of the concrete layer, such as the region indicated at  32  in  FIG. 7 . 
         [0030]    In general, the device can be utilized in various forms, such as concrete sandwich panels, which in one form are poured in place, or alternatively can be pre-cast. Further, the device can be utilized in other forms, such as insulated heated floors, or further, precast concrete joists, decking, floors, or roofs and various compositions thereof. For example, the device could be utilized similar to decking for insulated reinforced concrete floor such as Decklite™ from Benchmark Foam, Inc. and other similar products from other manufactures. 
         [0031]    While the present invention is illustrated by description of several embodiments and while the illustrative embodiments are described in detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the scope of the appended claims will readily appear to those sufficed in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of Applicants&#39; general concept.

Technology Classification (CPC): 4