Abstract:
A wall may be formed by a method comprising providing an extrusion platform having a plurality of perforations extending through a surface of the extrusion platform, and extruding a cementitious composite through the perforations of the extrusion platform to grow a plurality of cementitious composite rods each extending from a respective one of the perforations. The method may further comprise allowing the cementitious composite rods to cure to provide the wall.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure generally relates to walls and, more specifically, to walls formed from extruded cementitious composite rods and to methods of fabricating such walls. 
       BACKGROUND 
       [0002]    Cementitious construction materials, which are cement-containing or cement-like materials, are attractive for building and wall construction as such materials possess several advantageous properties. For example, cementitious materials are inherently strong and corrosion resistant. Concrete consists of a mixture of sand, aggregates (e.g., gravel, pebbles, etc.), and a cement paste composed of water and cement which is a binder that hydrates in the presence of water to form a non-water-soluble mineral that holds the aggregate of the concrete together. A concrete material that does not include coarse aggregate but contains only sand is called a mortar. A common type of cement is Portland cement which undergoes a chemical reaction in the presence of water that causes the cement to cure and harden. Specially formulated cementitious composites can be formulated to have higher strength properties and expanded applications compared with traditional Portland cement-based construction materials. For example, certain hybrid polymer/cement composites may be more cohesive and self-supporting than traditional Portland cement-based concretes and mortars. 
         [0003]    Current methods for molding concrete walls involves pouring a slurry of paste and aggregate (or a slurry of cement paste alone) into a water-tight form in the shape of the desired wall. The cementitious material is then permitted to cure and harden by reaction with water, and the form is removed to provide a self-supporting wall. Other methods of fabricating cementitious-based columns involve feeding cementitious material into a vertically-movable form which moves upward and molds the cementitious material into a single column as it cures (see, for example, U.S. Pat. No. 1,894,676). 
         [0004]    While effective, such methods, including the fabrication and use of the water-tight form, may be labor intensive and inefficient. Additional improved methods of fabricating cementitious material-based walls are still wanting. For example, it may be desirable to readily impart strength, ventilation, or even aesthetic properties into cementitious material-based walls using more efficient techniques. The present disclosure addresses these problems. 
       SUMMARY 
       [0005]    In accordance with one aspect of the present disclosure, a wall is disclosed. The wall may be formed by a method comprising providing an extrusion platform having a plurality of perforations extending through a surface of the extrusion platform, and extruding a cementitious composite through the perforations of the extrusion platform to grow a plurality of cementitious composite rods each extending from a respective one of the perforations. The method may further comprise allowing the cementitious composite rods to cure to provide the wall. 
         [0006]    In accordance with another aspect of the present disclosure, a method of forming a wall is disclosed. The method may comprise providing an extrusion platform having a surface with a plurality of perforations extending therethrough, and extruding a cementitious composite through the perforations of the extrusion platform to grow a plurality of cementitious composite rods extending from the extrusion platform. The perforations of the extrusion platform may mold a cross-sectional shape of the cementitious composite rods. The method may further comprise allowing the cementitious composite rods to cure to provide the wall. 
         [0007]    In accordance with another aspect of the present disclosure, a wall is disclosed. The wall may comprise a header or a footer extending along a respective one of a top or a bottom of the wall, wherein the header or the footer has a surface with a plurality of perforations. The wall may further comprise a plurality of cementitious composite rods each extending from and being integral with a respective one of the perforations. 
         [0008]    These and other aspects and features of the present disclosure will be more readily understood when read in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a front view of a wall consisting of cementitious composite rods and a footer, constructed in accordance with the present disclosure. 
           [0010]      FIG. 2  is a front view of a wall similar to  FIG. 2 , but having a header instead of a footer, constructed in accordance with the present disclosure. 
           [0011]      FIG. 3  is a cross-sectional view through the section  3 - 3  of  FIG. 1 , depicting a staggered arrangement of the cementitious composite rods in the wall, constructed in accordance with the present disclosure. 
           [0012]      FIG. 4  is a cross-sectional view similar to  FIG. 3 , but having a filler applied to the outer surfaces of the wall, constructed in accordance with the present disclosure. 
           [0013]      FIG. 5  is a cross-sectional view similar to  FIG. 4 , but having the filler applied throughout the gaps between the cementitious composite rods, constructed in accordance with the present disclosure. 
           [0014]      FIG. 6  is a side perspective view of an extrusion platform used to fabricate the wall, constructed in accordance with the present disclosure. 
           [0015]      FIG. 7  is a top view of the extrusion platform of  FIG. 6 , depicting rows of perforations offset from each other in a staggered arrangement, constructed in accordance with the present disclosure. 
           [0016]      FIG. 8  is a partial front view of a bamboo-like wall having cementitious composite rods in the shape of bamboo, constructed in accordance with the present disclosure. 
           [0017]      FIG. 9  is a top view of a perforation of the extrusion platform having internal notches to produce streaks in a cementitious composite rod, constructed in accordance with the present disclosure. 
           [0018]      FIG. 10  is a cross-sectional view of an extrusion platform having an internal manifold leading from an opening of the extrusion platform to the perforations, constructed in accordance with the present disclosure. 
           [0019]      FIG. 11  is a schematic representation of extruding a cementitious composite through the extrusion platform to cause the upward growth of the cementitious composite rods from the extrusion platform, in accordance with a method of the present disclosure. 
           [0020]      FIG. 12  is a schematic representation of using a guide to hold the cementitious composite rods upright, constructed in accordance with a method of the present disclosure. 
           [0021]      FIG. 13  is a schematic representation of extruding the cementitious composite through the extrusion platform to cause the downward growth of the cementitious composite rods from the extrusion platform, in accordance with another method of the present disclosure. 
           [0022]      FIG. 14  is a schematic representation of extruding the cementitious composite through the extrusion platform to cause the upward growth of the cementitious composite rods and the upward movement of the extrusion platform, in accordance with another method of the present disclosure. 
           [0023]      FIG. 15  is a flowchart of a series of steps that may be involved in fabricating the wall, in accordance with a method of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    Referring now to the drawings, and with specific reference to  FIGS. 1-2 , a wall  10  is shown. As used herein, the wall  10  may be a stand-alone wall, a wall that is part of a room or building, or a structural component for various interior and exterior structures such as furniture or entertainment bars. The wall  10  may include a footer  12  along the bottom of the wall  10  ( FIG. 1 ) or a header  14  along the top of the wall  10  ( FIG. 2 ), as well as a plurality of cementitious composite rods  16  extending upwardly from the footer  12  or downwardly from the header  14  along the height (h) of the wall. In particular, the footer  12  or the header  14  of the wall  10  may include a plurality of perforations  18  from which the cement rods  16  extend, and the cementitious composite rods  16  may be integral with the footer  12  or the header  14  (see  FIG. 6 ). As explained in further detail below, the footer  12  or the header  14  of the wall  10  may also function as an extrusion platform  20  through which the cementitious composite rods  16  are extruded. 
         [0025]    The cementitious composite rods  16  may be formed from a cementitious composite that is self-supporting once cured and has similar hardness properties as traditional concrete. As used herein, a cementititious material is a material that contains cement or is cement-like, and a cementitious composite is a composite of a cementitious material. As a non-limiting example, the cementitious composite rods  16  may be formed from a hybrid polymer/cement composite containing a mixture of polymer, cement, and water. The polymer in the hybrid polymer/cement composite may be polyvinyl alcohol, although many other types of polymers may certainly be used. The hybrid polymer/cement composite may be a macro-defect free (MDF) cement that is substantially free of large voids or defects and is much less brittle than traditional mortars or concretes. As is understood in the art, a macro-defect free (MDF) cement is a special class of cementitious composites which rely on a polymeric processing aid to give a millable, high-viscosity material that hardens through a combination of ionic cross-linking of the polymer and cementitious reactions. In particular, the hybrid polymer/cement composite may be more cohesive than traditional Portland cement, such that the cementitious composite rods  16  formed therefrom may maintain an upright position during extrusion and after curing. However, the cementitious composite rods  16  may be formed from other types of extrudable and self-supporting materials as well such as, but not limited to, quick-curing acrylics or other suitable organic materials. 
         [0026]    As shown in  FIG. 3 , the wall  10  may have one or more rows  22  of cementitious composite rods  16 . If the wall  10  has two or more rows  22 , the cementitious composite rods  16  in each row  22  may be offset with respect to the rods  16  in an adjacent row to provide a staggered arrangement  24  of the cementitious composite rods  16 . The staggered arrangement  24  of the cementitious composite rods  16  may advantageously assist in blocking the passage of light through the wall  10  so as to maintain privacy and/or a desired internal brightness. It will be understood that the number of the rows  22  of cementitious composite rods  16  in the wall  10  may vary depending various design considerations, such as the desired strength of the wall and degree of insulation. 
         [0027]    In some arrangements, the wall  10  may be ventilated due to gaps  26  between the cementitious composite rods  16  which may permit the passage of air therethrough. Such ventilation properties may be beneficial, for example, in certain hotter climates where indoor cooling systems are not available. Alternatively, the wall  10  may be non-ventilated such that the passage of wind or air through the wall  10  is obstructed as shown in  FIGS. 4-5 . To obstruct the passage of air through the wall  10 , a filler  28  may be applied to the gaps  26 . As one possibility, the filler  28  may be applied to one or both of the outer surfaces  30  of the wall  10  as shown in  FIG. 4 . Alternatively, the filler  28  may be distributed throughout the wall to fill all of the gaps  26  between the cementitious composite rods  16 , as shown in  FIG. 5 , or through certain sections of the wall  10 . Suitable fillers for this purpose include plaster or other suitable materials that harden. In other alternative arrangements, the cementitious composite rods  16  may be densely packed in the wall  10  such that a filler is not necessary to obstruct the passage of air therethrough. 
         [0028]    Referring now to  FIGS. 6-7 , the extrusion platform  20 , which ultimately provides the footer  12  or the header  14  of the wall  10 , is shown in more detail. Although shown as a box-like structure, it will be understood that in practice the extrusion platform  20  may have any shape (such as curved shapes) suitable to support the design of the wall  10 . In general, the extrusion platform  20  may have a surface  32  that includes a plurality of perforations  18  configured to mold each of the cementitious composite rods  16  into a desired cross-sectional shape as a cementitious composite, in the form of a dough, is extruded through the platform  20  (see further details below). Depending on the design of the wall  10 , the perforations  18  may have identical shapes and dimensions or they may have shapes and dimensions that deviate from one another. 
         [0029]    In order to mold the cross-sectional shapes of the cementitious composite rods  16 , the perforations  18  may have shapes and dimensions that mirror the desired cross-sectional shapes and dimensions of the cementitious composite rods  16 . For example, to produce cementitious composite rods having a circular or ovular cross-sectional shape, the perforations  18  of the platform  20  may be circular or ovular. However, the perforations  18  may have a number of alternative shapes to afford desired functional or aesthetic properties to the final wall  10 . As one non-limiting example, it may be desirable to provide a tiki hut-like wall having cementitious composite rods  16  with random angles and/or streaks that resemble bamboo (see  FIG. 8 ). To introduce streaks into the cementitious composite rods  16 , the perforations  18  may include one or more internally- (or externally-) extending notches  34  (see  FIG. 9 ). In addition, the cementitious composite dough may include one or more dyes to introduce a desired color into the cementitious composite rods  16 , such as a tan or green color if the cementitious composite rods  16  are intended to have a bamboo-like appearance. 
         [0030]    The extrusion platform  20  may further include one or more rows  36  of perforations  18  (see  FIG. 7 ). For example, to mold the staggered arrangement  24  of the cementitious composite rods  16 , the platform  20  may have two or more rows  36  of perforations  18  in which the perforations  18  in a given row  36  are offset with respect to the perforations  18  in an adjacent row  36  to produce a staggered arrangement  38 . The staggered arrangement  38  of the perforations  18  may correspond to and minor the staggered arrangement  24  of the cementitious composite rods  16  in the wall  10 . It will be understood, however, that the number or rows and the distribution of the perforations  18  in practice may vary depending on a number of design considerations. 
         [0031]    Referring back to  FIG. 6 , the extrusion platform  20  may also include one or more openings  40  through which a cementitious composite dough is pumped or otherwise pushed into the platform  20  for extrusion. The opening  40  may be provided on one or both sides  42  of the platform  20  and/or a bottom  44  of the platform  20  as needed to provide suitable flow dynamics of the cementitious composite through the platform. In one arrangement, the extrusion platform  20  may be internally hollow to allow the cementitious composite dough to fill the platform  20  and extrude through the perforations  18 . Alternatively, the extrusion platform  20  may include an internal manifold  46  with a plurality of connected internal channels  47  that guide the cementitious composite from the opening(s)  40  to each of the perforations  18 , as shown in  FIG. 10 . The dimensions, diameters, and curvature of the each of the internal channels  47  of the manifold  46  may be varied to optimize the flow dynamics of the cementitious composite and provide uniform flow rates to each of the perforations  18  and equivalent rod growth rates. In particular, the channels  47  that are farther from the inlet  40  and have longer flow lengths may have wider diameters, whereas the channels that are closer to the inlet  40  and have shorter flow lengths may have narrower diameters such that the flow rates through each of the channels  47  are about the same. For example, as shown in  FIG. 10 , the two inside channels  47  that are closer to the inlet  40  have narrower diameters, and the two outside channels that are further from the inlet  40  have wider channels  47 . However, the diameters of the exits of each of the channels  47  near the perforations  18  may be about the same, as shown. It will be understood, however, that the number of channels  47  in the manifold  46 , their relative diameters, as well as the relative angles therebetween may, of course, vary depending on such factors as the number and location of the inlets/openings  40 , the number and location of the perforations  18 , and the desired flow dynamics. 
         [0032]    Turning now to  FIG. 11 , one possible approach to produce the wall  10  is shown. In this approach, the extrusion platform  20  may be placed on a support structure  48  with the perforations  18  facing upward and away from the support structure  48 . As used herein, the support structure  48  may be the ground or any other support structure capable of supporting the weight of the wall  10 . One or more hoses  50  (or other suitable structures such as tubes, etc.) may be connected to the opening(s)  40  of the extrusion platform  20  to permit a cementitious composite dough to be pumped or pushed into the platform  20  while the platform  20  remains fixed in position on the support structure  48 . The cementitious composite dough may then extrude through the perforations  18  to allow an upward growth  52  of the cementitious composite rods  16  from the extrusion platform  20  while the perforations  18  mold the cross-sectional shape of the cementitious composite rods  16 . The cementitious composite rods  16  may continue the upward growth  52  until reaching a desired wall height, after which the cementitious composite rods  16  may be permitted to cure and harden. As explained above, due to the cohesive properties of the cementitious composite dough, the cementitious composite rods  16  may be sufficiently self-supporting to maintain an upright position as the cementitious composite rods  16  are extruded through the platform  20 . However, in some circumstances, one or more guides  54  may be optionally positioned against the growing rods  16  to prevent the rods from buckling and assist in holding the rods vertically upright (see  FIG. 12 ). The guides  54  may take the form of a brace or a block that leans against the growing rods  16  to hold them upright, although other types of guides may certainly be used. In any event, once the extrusion and curing is complete, the extrusion platform  20  may be left in position to provide the footer  12  for the wall  10 , as shown in  FIG. 1 . 
         [0033]    As an alternative approach to produce the wall  10 , the extrusion platform  20  may be suspended at a fixed position above the support structure  48  at a desired wall height, such as with a stilts, with the perforations  18  facing downward and toward the support structure  48  (see  FIG. 13 ). The cementitious composite dough may be pumped or otherwise pushed though the platform  20  with the hose  50  or another suitable structure. When the cementitious composite rods  16  are extruded through the platform  20 , downward growth  56  of the cementitious composite rods  16  from the platform  20  toward the support structure  48  may occur. In this way, gravity may advantageously assist the downward growth  56  of the cementitious composite rods  16  and assist in maintaining the rods  16  in a vertically upright position, such that a guide may not be needed. Once the cementitious composite rods  16  have cured, the extrusion platform  20  may be left in place on top of the cementitious composite rods  16  as the header  14  for the wall  10 , as shown in  FIG. 2 . 
         [0034]    As yet another alternative strategy to produce the wall  10 , the extrusion platform  20  may be placed on the support structure  48  with the perforations  18  facing downward toward the support structure  48  so that the upward growth  52  of the cementitious composite rods  16  from the support structure  48  is concurrent with the upward movement of the platform  20  until it reaches a desired wall height (see  FIG. 14 ). The cementitious composite rods  16  may be permitted to cure and harden, and the platform  20  may be left in place on top of the cementitious composite rods  16  as the header  14  for the wall  10 , as shown in  FIG. 2 . It is further noted here that other alternative approaches in which the cementitious composite rods  16  grow horizontally or at an angle with respect to the support structure  48  and/or the extrusion platform  20  are also encompassed within the scope of the present disclosure. 
       INDUSTRIAL APPLICABILITY 
       [0035]    The teachings of the present disclosure may find industrial applicability in a variety of settings such as, but not limited to, building construction and other infrastructure construction applications. The technology disclosed herein provides a wall formed from a plurality of cementitious composite rods that are extruded through an extrusion platform. The extrusion platform may also provide a footer or a header for the wall when the extrusion process is complete. The cementitious composite rods are formed from a self-supporting cementitious composite, such as a hybrid polymer/cement composite, that cures to a hardened state that is similar to traditional concrete. Notably, the cementitious composite rods may be extruded in a range of shapes and colors to provide desired physical properties and/or aesthetic appeal to the final wall product. As one non-limiting example, the wall may have cementitious composite rods with bamboo-like shapes and colors to give the wall a tiki but appearance. 
         [0036]    A series of steps that may be involved in the fabrication of the wall  10  of the present disclosure is shown in  FIG. 15 . Beginning with a first block  60 , the extrusion platform  20  having perforations  18  with shapes, dimensions, and a distribution that match the desired cross-sectional shapes, dimensions, and distribution of the cementitious composite rods  16  may be provided. Depending on the selected approach to grow the cementitious composite rods  16 , the extrusion platform  20  may be positioned on the support structure  48  with the perforations  18  facing upward (block  62 / FIG. 11 ) or downward (block  64 / FIG. 14 ). Alternatively, the extrusion platform  20  may be suspended above the support structure  48  with a suitable supporting device (e.g., stilts, etc.) at a desired wall height with the perforations  18  facing downward (block  66 / FIG. 13 ). Subsequent extrusion of a cementitious composite in the form of a dough through the perforations  18  of the extrusion platform  20  may allow the upward growth  52  ( FIG. 11 ) or the downward growth  56  ( FIGS. 13 and 14 ) of the cementitious composite rods  16  from the platform  20  to a length corresponding to the desired wall height (block  68 ). Optionally, one or more guides  54  may be positioned against the growing rods to further support their vertically upright growth during the block  68  if needed (see  FIG. 12 ). 
         [0037]    Once developed to the desired wall height, the cementitious composite rods  16  may be permitted to cure and harden (block  70 ), and the extrusion platform  20  may be left in position along the bottom or the top of the cementitious composite rods  16  to respectively provide either the footer  12  or the header  14  of the wall  10  (block  72 ). If gaps  26  exist between the cementitious composite rods  16  and a non-ventilated wall is desired, the filler  28  may be applied to the wall to obstruct air flow through the wall according to an optional block  74  (also see  FIGS. 4-5 ). For example, the block  74  may be achieved by applying plaster to the wall  10  using a trowel or other tool, although other types of fillers may certainly be used. 
         [0038]    Accordingly, it can be seen from the above that the wall disclosed herein may be fabricated by a more efficient and less labor intensive method than those used in current systems. In particular, the extrusion platform disclosed herein may be easier to handle and manufacture than large, water-tight concrete wall forms of the prior art. The perforations of the platform also offer the option to readily tailor the shapes and distribution of the cementitious composite rods according to desired wall properties. It is expected that the technology disclosed herein may find wide industrial applicability in a wide range of areas such as, but not limited to, construction, design, and architectural applications.