Abstract:
A prefabricated form assembly for making a concrete floor is disclosed. The form comprises an elongated form plate having a front for forming and retaining a flowable concrete material before it sets, anchor elements extending from the back face of the form plate, and being destined to be embedded into the concrete floor; and an L-shaped lintel having a back wall connected to the front face of the form plate and a bearing wall for supporting a masonry wall. Advantageously the construction of a concrete floor adapted to structurally retain a masonry wall using prefabricated form assemblies according to the invention no more requires the use of different groups of workers from different building trades as in the prior art, only one group of workers is required.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention pertains to the general field of building construction, building components and methods of construction and is particularly directed to an adjustable structural lintel assembly used for making and connecting a concrete floor with external walls, and a construction method using the same. 
       BACKGROUND OF THE INVENTION 
       [0002]    Brick, stone and concrete structures are used extensively in the construction or building of residential, industrial, commercial, agricultural and other applications. Indeed, many structures are built from wood, brick, stone, concrete or a combination of these materials or similar materials because of their many advantages including strength, durability, temperature and sound insulation, fire resistance, general attractiveness and ease of maintenance. 
         [0003]    Gravity forces acting on the facing material of a given structure can be transferred to major structural elements of the building, for example, beams, columns, concrete floor slabs or the like using steel rods and shapes attached with mechanical and/or welded connections to the structural elements. As is well known, it is necessary and required by some building codes when building a brick or a stone structure to provide support therefor in some instances. For examples, it is necessary and required by some building codes to provide support for such facing materials over openings in the building structure and when the facing material stands over a given height such as over more than one floor level. 
         [0004]    The support for the facing material is typically provided by so-called lintels. Such conventional lintels are typically in the form of a substantially, horizontally disposed architectural member that is employed to span an opening in a building such as a window or a door or across a given width of a facing for carrying the load created by the facing. The lintels used in modern buildings of cement blocks, bricks, types of masonry construction have traditionally been fabricated of elongated heavy gauge angle iron. Lintels are generally made of steel or concrete because these materials are durable and inexpensive. The lintel is typically nailed, bolted or otherwise secured to the header forming the top of the opening or to a concrete floor slab. It may additionally be simply supported at each end by the brick or concrete just below the header outside the opening. One or more courses of brick are then placed on the lintel and are secured thereto typically using mortar. The lintel supports the weight of all the bricks or stones thereabove. 
         [0005]    Structural lintels refer to the lintels that are typically used for supporting bricks, stones or the like used as facing material spanning from one floor level to the next. Typically, such structural lintels are secured to corresponding beams or slabs of concrete or the like used as flooring material by bearing having corresponding studs embedded within the concrete slab or beam. 
         [0006]    The conventional method of securing a structural lintel to a concrete floor involves initially nailing or otherwise securing the bearing plate to the form used for moulding the concrete slab or beam. The bearing plate with its corresponding anchoring stud hence typically extends into the mould of the concrete slab or beam. 
         [0007]    The concrete or similar material is then poured into the form and allowed to cure. Once the concrete has sufficiently cured, the forms forming the mould are removed leaving the bearing plate anchored to the now-cured concrete beam or slab with their corresponding studs embedded in the cured concrete. 
         [0008]    This part of the job is typically performed by concrete/form workers part of conventional construction teams. 
         [0009]    Once the forms are removed from the cured concrete slab or beam, another group of workers, typically referred to as steel workers such as structural steel installers must gain access to the location in order to perform the next building steps. The steel installers must then secure lintel spacers and the structural lintels themselves to the bearing plate. 
         [0010]    Typically, the steel installers initially weld spacing tubes on the exterior surface of the bearing plates prior to welding the structural lintels to their corresponding spacing tubes. Alternatively, the spacing tubes and structural lintels are pre-assembled in an outside location such as an assembly shop or the like and brought in an assembled configuration to the construction site where they are welded as a single unit to the bearing plate. 
         [0011]    Regardless of whether the spacing tubes and bearing plates are welded sequentially or as a pre-assembled unit to the bearing plate, the welding of the spacing tubes to the bearing plates is typically considered to be a tedious, time-consuming, costly and potentially hazardous process. One of the reasons why the mounting of the structural lintels and their associated spacing tubes is considered physical relates to the fact that the outer surface of the bearing plates on which the spacing tubes are to be welded often needs to be prepared or modified prior to the welding of the spacing tubes on the bearing plates. Indeed, when the moulding forms are removed from the cured or hardened concrete, the outer surface of the concrete in contact with the forms often does not present a perfectly aligned and smooth surface. Variables such as the positioning of the moulding forms, the type of structure or anchor used for maintaining the forms aligned during pouring and curing of the concrete, the type of concrete used, the conditions during curing of the concrete and other variables cooperate in varying degrees to imperfections to the outer surface of the concrete slab or beam and in the relative positioning of the outer surface of the bearing plate relative to the adjacent outer surface of the concrete beam or slab. 
         [0012]    For example, the bearing plates may be slightly misaligned or out of register with the outer surface of the concrete slab or beam so that at least a portion of the outer surface of the bearing plates often is either embedded too deeply relative to the outer surface of the concrete slab or beam, or sticks out too far therefrom. Sometimes, the imperfections in the outer surface of the concrete slab or beam are such that such imperfections in themselves cause interference to the welding of the spacing tubes to the outer surface of the bearing plate. 
         [0013]    Regardless of the reason, on site modifications often need to be performed on either the concrete slab or beam or the bearing plates prior to welding of the spacing tubes to the outer surface of the bearing plates. For example, the bearing plates may need to be cut using a torch or additional levelling components may need to be welded or otherwise secured to the bearing plates. Such on-site modifications require that specialized and skilled workmen spend a considerable amount of time. The delays caused by the need for a correction of imperfections in the alignment of the outer surface of the bearing plates relative to the outer surface of the concrete slab or beam sometimes slow down other steps in the overall construction of a building. Also, the required on-site modifications are sometimes of the type that may be potentially hazardous such as in situations wherein a torch is required for cutting through a portion of a bearing plate or the like. 
         [0014]    Accordingly, there exists a need for an improved method and device for building a concrete floor and anchoring structural lintels thereto. 
       SUMMARY OF THE INVENTION 
       [0015]    An object of the present invention is to provide a form assembly suitable for making a concrete floor and that satisfies the above-mentioned need. In accordance with the present invention, that object is achieved with a prefabricated form assembly comprising an elongated form plate having a front and a back face, for forming and retaining a flowable concrete material before it sets and a substantially L-shaped lintel having a back wall secured to the front face of the form plate and a bearing wall for supporting a masonry wall. The assembly further comprises at least one anchor element destined to be embedded into the concrete floor and which extends from the back face of the form plate. 
         [0016]    By prefabricated, it is meant an assembly manufactured in advance in factory, especially in standard sections that can be easily shipped and used directly on the site of construction. The assembly can be used for example in the construction of a building or section of a building, more specifically for making a concrete floor able to structurally support a masonry wall. 
         [0017]    As for conventional forms made of wood and used for moulding a concrete slab, the elongated form plate has a horizontal length adapted to span the length of the floor to be built. It is used and assembled with other elongated form plates to form a mould for the flowable concrete material. The vertical width of the form plate is preferably identical to the widths of the adjacent plates, and superior or equal to the final desired width of the concrete floor to build. 
         [0018]    Two elongated form plate may also be preassembled to form corners such as inside or outside corners. 
         [0019]    The present invention is also directed to a method for making a concrete floor comprising the following steps of: 
         [0020]    a) providing a plurality of prefabricated form assemblies as just defined in above; 
         [0021]    b) installing a temporary supporting floor and assembling the form plates of the prefabricated form assemblies to form a mould, the anchor element(s) of the prefabricated form assemblies extending into the mould; 
         [0022]    c) pouring a flowable concrete material into the mould; 
         [0023]    d) letting the flowable concrete material to set; and 
         [0024]    e) removing temporary supporting floor. 
         [0025]    It has to be understood that the number and size of each prefabricated form assembly provided in step a) of the above method, depends on the size and shape of the final mould to assemble, and thus to the final concrete floor to build. As aforesaid, each assembly is manufactured in advance, especially in standard sections that can be easily shipped and assembled on the site of construction to form the desired moulds. 
         [0026]    Any sort of temporary supporting floor used in the art of building construction may be used in step b) of the above mentioned method. The supporting floor is generally supported itself by the foundations of the building or by pre-built beams, girders or supporting walls. The supporting floor is generally made of strong wood such as plywood. 
         [0027]    Flowable concrete material encompasses any kind of building material produced from a mixture of stone, gravel, sand, pebble or slag with water and/or a binding material that can harden to form a hard, strong construction material gravel; including but not limited to ordinary concrete, reinforced concrete or pre-stressed concrete. 
         [0028]    By anchor element, it is meant any type of device used to structurally secure the plate once the concrete is set and that remains in place or maintains its position so that the plate is strong enough to bear the weight of the masonry wall. The anchor element may have the form of a rod or a stick having one of its free ends substantially bent, the other end being secured to the form plate. The invention is not limited to this specific shape of an anchor element. 
         [0029]    By masonry wall it has to be understood any stonework or brickwork or any sort of wall made, for example, of stones, bricks, breezeblocks, cinderblocks, or pre-formed concrete or wood panels. 
         [0030]    Advantages of the present invention include that the proposed method and device allows for the securing or anchoring of structural lintels to concrete slabs or beams through a set of relatively quick, ergonomic and unhazardous steps, thanks mainly to the fact that no more welding process is required in place the lintel arrives on the site of construction already secured to the form plate. 
         [0031]    Another advantage is the fact that the construction of a concrete floor adapted to structurally retain a masonry wall no more requires the use of two different groups of workers from different building trades as in the prior art discussed above. 
         [0032]    The proposed method and device is thus more economical, less time-consuming and less dangerous than the conventional methods and devices detailed above used for anchoring structural lintels to concrete slabs or beams. 
         [0033]    According to a preferred aspect of the invention, the prefabricated form assembly may further comprise at least one spacing element interconnecting the lintel to the form plate, thereby leaving a gap between the form plate and the lintel. The presence of this gap may be used for example for covering the inside surface of the masonry wall with an insulated material. 
         [0034]    According to another preferred aspect of the invention, the prefabricated form assembly has its lintel vertically movable with respect to its form plate for levelling the lintel before building up the masonry wall. In a case where a spacing element interconnects the lintel to the form plate, the lintel is vertically movable with respect to the spacing element, the spacing element being itself fixed, for example by welding, to the form plate. 
         [0035]    A further advantage of using the prefabricated form assembly and method of the present invention resides in the fact that there is no more need for performing steps in order to ensure that the outer surface of conventional form plates be in register or proper alignment with a corresponding adjacent outer surface of the concrete slab or beam into which the form plates and their corresponding anchoring elements are embedded. Accordingly, and as mentioned above the anchoring of the prefabricated form assembly may be performed by a single class of building trades, namely concrete/form workers and/or masonry workers without requiring steel workers for performing tedious, time-consuming and potentially dangerous torching and welding for the correction of imperfections. 
         [0036]    The invention and its advantages will be better understood upon reading the following description made with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0037]      FIG. 1  is a general perspective view of a prefabricated form assembly according to a preferred embodiment of the invention showing a concrete slab that has been poured and a masonry wall under construction. 
           [0038]      FIG. 2  is an exploded perspective view of a prefabricated form assembly according to another preferred embodiment of the invention. 
           [0039]      FIG. 3  is a cross-sectional side view of the prefabricated form assembly of  FIG. 2  in use, and showing a just poured concrete slab supported by a temporary supporting floor. 
           [0040]      FIG. 4  is a top view of the prefabricated form assembly illustrated in  FIG. 3 . 
           [0041]      FIG. 5  is a cross-sectional side view of a prefabricated form assembly according to a further preferred embodiment of the invention which includes an adjustment bar, the assembly being shown in use with a just poured concrete slab supported by a temporary supporting floor. 
           [0042]      FIG. 6  is a top view of the prefabricated form assembly of  FIG. 5 . 
           [0043]      FIG. 7  is an exploded perspective view of the prefabricated form assembly illustrated in  FIG. 6 . 
           [0044]      FIG. 8  is a side view of the prefabricated form assembly according to a still preferred embodiment of the invention which comprises and adjustment bar. 
           [0045]      FIG. 9  is a top view of the form assembly of  FIG. 1  without the masonry wall. 
           [0046]      FIG. 10  is a top view of two prefabricated form assemblies assembled to make an outside corner. 
           [0047]      FIG. 11  is a top view of two prefabricated form assemblies assembled to make an inside corner. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0048]    In the following description, similar features in the drawings have been given similar reference numerals and in order to lighten the figures, some elements are not referred to in some figures if they were already identified in a preceding figure. 
         [0049]    Also, in order to ease the reading of following description, it will always be considered that the concrete floor described is built upon a pre-existing inferior level of a building. In other word, the concrete floor described corresponds to at least the second level of a building. However it has to be understood that the object and method of the invention may be used for the construction of each floor of the building in construction. 
         [0050]    As aforesaid, and referring to  FIG. 1 , the present invention concerns a prefabricated form assembly  10  adapted to both built a concrete floor  2  and a masonry wall  4  structurally retained by the concrete floor  2 . The assembly  10  is manufactured in advance, especially in standard sections that can be easily shipped and assembled on the site of construction. 
         [0051]    Referring to any of  FIGS. 1 to 9 , the prefabricated form assembly  10  comprises an elongated form plate  12  for forming the concrete floor  2  or slab ; The elongated form plate  12  is generally made of a metallic strong and rigid material which cannot be pulled out of shape under pressure. It is configured and sized so as to be able to withstand structural stresses imparted thereon. Typically, although by no means exclusively, the form plate  12  is made out of steel and has a thickness in the range of 3 to 4 millimeters. It is adapted to act as a mould or a form for limiting the flow of concrete prior to the latter being solidified or cured. 
         [0052]    Still referring to  FIGS. 1 to 9 , the form assembly  10  further comprises a substantially L-shaped lintel  20  used for building and supporting the masonry wall  4 . The lintel  20  has a back wall  22  secured to the front face  18  of the form plate  12  and a bearing wall  24  for supporting the masonry wall  4 . The lintel  20  could be directly secured to the form plate  12 , for example by welding, bolting or by using any other securing means known in the construction field or, as shown in the drawings, the lintel  20  could be indirectly secured to the form plate  12  by using at least one spacing elements  30  interconnecting the lintel  20  and the form plate  12 , and thereby leaving a gap  31  between the form plate  12  and the lintel  20 . This gap  31  may be used, for example, to insert between the masonry wall  4  and an inside wall (not illustrated) various construction or structural elements and/or insulation materials. The inside wall is generally made of plaster wall such as Gyproc® or the like well known in the art, maintained by joists placed and fixed inside the gap. The spacing elements  30  will be described in more details further below. 
         [0053]    The lintel  20  is made of a material which cannot be pulled out of shape under the pressure exerted by the masonry wall. For example, the lintel may be made of steel, iron, or other metallic material generally used in this field. The length of the lintel  20  generally conformed to the length of the form plate  12 . However, there could be situations where the lintel&#39;s length may be smaller or larger than the plate&#39;s length. For example, when two prefabricated form assemblies  10  are used for making an outside corner, as shown in  FIG. 10  or an inside corner as shown in  FIG. 11 , the length of the lintel has to be respectively larger and shorter than the length of the plate 
         [0054]    The spacing elements  30  may have different configurations and shapes, not limited to the ones illustrated in the enclosed Figures. However, for the purpose of lightness and economy, each of the spacing elements  20  has a substantially U-shaped cross-section, such as the one illustrated on  FIG. 2 . It could also be a substantially square-shaped hollow tube such as the one illustrated on  FIG. 1  and commonly referred as HSS tubes. However, the U-shape form has the advantage of facilitating the assemblage of the different components of the prefabricated assembly  10 . 
         [0055]    Turning to  FIG. 2 , each of the U-shaped spacing elements  30  comprises a base wall  32  facing the back wall  22  of a lintel  20  and two lateral walls  34  secured to the front face  18  of the form plate  12 . The base wall  32  is also provided with at least one screw-receiving hole  36  for receiving an adjustable fastener  40  as will be described further below. 
         [0056]    Anchor elements  50  (not visible on  FIG. 1 ) extending from the back face  16  of the form plate  12  and destined to be embedded into the concrete floor  2  are also provided with the assembly  10  for structurally retaining the masonry wall  4  to the building  50 . In the embodiments illustrated in  FIGS. 1  or  2 , there is one anchor element associated with each spacing element  30  whereas two anchor elements  50  are associated with each spacing element  30  in the embodiments shown in  FIGS. 5 to 7 . The anchor element  50  may have a rod-shaped portion  52  having one of its free end  54  substantially bent, the other end (hereinafter referred as to the second end  56 ) being directly or indirectly secured to the form plate  12 . In the embodiments shown in  FIGS. 1  or  2 , the rod-shaped portion  52  of the anchor element  50  is crossing the form plate  12  and its second end  56  is welded to the base wall  32  of a respective spacing element  30 . In the case of the embodiments shown in  FIGS. 5 to 7 , the rod-shaped portion  52  of each of the two anchor elements  50  is also crossing the form plate  12  but in that case the part of the rod-shaped portion  52  extending on the front side of the form plate  12  is welded to the outer face of a corresponding lateral wall  34  of the spacing element  30 . 
         [0057]    It is worth mentioning that the size and shape of the anchor element  50  used hereby in the present invention is not limited to the size and shape illustrated on the Figures and described in the present description. Any size and shape could be use as long as it can structurally secure the form plate  12  and the lintel  20  once the concrete has set so that the form plate  12  be strong enough to bear the weight of the masonry wall  4 . 
         [0058]    Another interesting feature of the preferred embodiments illustrated is the fact that they are designed so that the lintel  20  can be moved vertically with respect to the form plate  12 , thereby allowing the masonry wall  4  to be easily levelled. Indeed, and as can be appreciated by referring for example to  FIG. 2 , the back wall  22  of the lintel  20  may be provided along its length with at least one vertical slot  26 . Each slot is adapted to receive the adjustable fastener  40  connecting the back wall  22  to a respective one of the spacing elements  30 . In the absence of spacing elements  30  (not illustrated), the vertical slot  26  would allow the lintel  20  to be movable with respect to the form plate  12 . Otherwise, the lintel  20  is movable with respect to the spacing element  30  fixed to the front face  18  of the form plate  12 . The level or horizontality of the lintel  20  may be adjusted by loosening/tightening the adjustable fastener  40 . As illustrated on  FIG. 2 , each of the adjustable fastener  40  interconnecting the lintel  20  and the spacing element  30  (or the form plate  12 ) may comprise a bolt  42  having a threaded shank  44  inserted through the vertical slot  26  of the lintel  20  and the screw receiving hole  36  of the spacing element  30 . The bolt  42  has a head  46  abutting the back wall  22  of the lintel  30 . A nut  48  is mounted on the free end of the threaded shank  41 , whereby the level of the lintel  20  is adjustable by loosening/tightening the bolt  42 . Preferably, the nut  48  is fixed to the base wall  32  of the spacing element  30  in order to facilitate the screwing of the bolt  42 . 
         [0059]    According to another preferred embodiment of the invention, such as the ones illustrated on  FIG. 1  or  8 , each of the adjustable fasteners  40  may be embodied by each of the anchor elements  50 . In that case, the rod-shaped portion  52  of the anchor element  50  crosses together the form plate  12 , the spacing element  30  and the vertical slot  26  in the lintel  20  and it has a threaded end  58  jutting out of the back wall  22  of the lintel  20 . A nut  59  mounted to that threaded end  58  is used to loosen/tighten the lintel  20  for levelling the masonry wall. 
         [0060]    Referring to  FIGS. 3 to 6 , shim plates  60  may also be used for facilitating alignment of the lintel  20 . Typically, the shim plates  60  are provided with a shim plate slot for facilitating their insertion, for example, between the HSS tube and the lintel vertical segment (back wall  22 ) by merely sliding the shim plate  60  there between with the shim plate slot receiving a corresponding rod- shaped portion  52  of the anchor component  50 . 
         [0061]    Another interesting feature of the preferred embodiment shown in  FIGS. 5 to 8  is the use of adjustment bars  70  which can be particularly helpful for erecting the masonry wall  4  on a facade of the building provided with window or door openings. For that particular purpose, the form assembly  10  comprises at least one adjustment bar  70  slidable within a respective U-shaped spacing element  30 . The adjustment bar  70  is vertically extending through a hole delimited by the lateral walls  34  and base wall  32  of the spacing element  30 . The adjustment bar  70  further comprises a plurality of fastener-receiving holes placed there along. One or two of these holes  72   a  can be use to secure the lintel  20  to the adjustment bar  70  and the others  72   b  are used to secure the adjustment bar  70  to the spacing element  30 . These latter holes  72   b  can be positioned in front of the screw-receiving hole  36  of the base wall  32  of the spacing element  30  by sliding the bar  70  upwardly or downwardly with respect to the spacing element  30 . Conventional fastener  5  such as a bolt  74  and nut  76  are used to secure the adjustment bar  70  to the spacing element  30  and the lintel  20  to the adjustment bar  70 . For purposes of lightness and cost, the bar  70  is preferably a U-shaped bar. 
         [0062]    Now referring to  FIG. 8 , and supposing that there is a window or door opening in the floor below the concrete slab  3 . If a masonry wall  4  has to be erected over the that opening  1 , the adjustment bars  70  of the form assembly  10  secured to the upper concrete slab  1  are lowered until the lintel  20  extends approximately at the level of the upper edge of the opening so that the construction of the masonry wall  4  can start at that level. The lintel  20  could also be positioned above the concrete floor for supporting, for example, the frame of a window. 
         [0063]    As illustrated on  FIGS. 10 and 11 , two prefabricated form assemblies  10  may be pre-assembled to form prefabricated corners  80 . The corners  80  may be inside ( FIG. 11 ) or outside ( FIG. 10 ) depending on where the anchor elements  30  are placed. The corners  80  may also be suspended or supported by the adjustment bars  70  of the assembly  10 , allowing, for example, windows or doors to be built in the corners  80  of a building. 
         [0064]    The present invention also concerns a method for making a concrete floor  2 . The builder has to select several prefabricated form assemblies  10 , including the corners  80 , in function of the final desired shape of the concrete floor. 
         [0065]    After the installation of a temporary supporting floor  90 , generally made of plywood, the components of the form assembly  10  are assembled together. Concrete is then poured into a form wherein the elongated form plate  12  acts as a stopper for the flow of concrete and hence acts as a mould panel. The form plate  12  is solidly anchored to the slab as the concrete hardens or cures by the direct contact of its back surface with the latter and also, mostly, by the presence of the anchoring elements  50  embedded in the slab  2  and attached to the form plate  12 . Once the concrete material is set, the temporary supporting floor  90  may be removed safely. During the pouring of the concrete and hardening of the latter, the lintel  20  provides support for lateral forces by the concrete on the form plate  12 . 
         [0066]    The set up and installation of the assembly may readily be performed through a set of quick and ergonomic steps by a single class of workmen, typically the concrete/form workers. Alignment of the lintel  20  with respect to a vertical line may be readily performed using the shim plates  60  and its alignment with a horizontal line may be performed thanks to the vertical slots  28  provided therein. The shim plates  60  may be readily put in place by simply loosening the exterior nut and bolt combination, slightly pulling the lintel  20  out and then retightening the exterior nut and bolt combination without requiring that the lintel  20  be pulled out completely from the anchoring element  50 . In order to allow for horizontal alignment the lintel  20  may be lowered or raised to the proper elevation. The vertical and horizontal adjustment may be performed, for example, by the masonry workers once the concrete has hardened prior to the mounting of bricks on the lintel. 
         [0067]    Although preferred embodiments have been described in details, it is worth mentioning that the present invention is not limited to these embodiments and that any modifications to these preferred embodiments within the scope of the present invention is not deemed to alter or change the nature and scope of the invention.