Building floor structure and process for forming same

Abstract

A building floor structure and a process for constructing the building floor structure comprising two or more spaced-apart beams, each beam comprising an upwardly facing support surface on at least one side of the beam; and one or more frameworks positioned between and adjacent two of the two or more spaced-apart beams, each of the one or more frameworks having two side regions, each side region comprising a downwardly facing bearing surface adapted to be received on the upwardly facing support surface of the respective beam.

Claims

1. A building floor structure comprising: a plurality of spaced-apart I-beams, each I-beam supporting a poured concrete surface and having an I-shape cross sectional shape, and each I-beam comprising: a vertically oriented web having a base; and one or more horizontally oriented base flanges connected to and extending across the base of the vertically oriented web and defining an upwardly facing support surface on an upper side of the one or more horizontally oriented base flanges; and a further horizontally oriented top flange connected to a top of the vertically oriented web and defining a downwardly facing surface on an underside of the top flange; at least one framework positioned between and adjacent two of the plurality of spaced-apart I-beams, each of at least one framework having two side regions, each side region comprising a downwardly facing bearing surface adapted to be received on the upwardly facing support surface of each respective I-beam, each of the at least one framework further comprising: a plurality of spaced-apart bearers aligned with the I-beams; a plurality of spaced-apart joists attached to and extending transversely to the bearers; at least one horizontally disposed decking member positioned on top of the plurality of spaced-apart joists; and a volume of concrete of a thickness less than a thickness between the upwardly facing support surface and the downwardly facing surface of two adjacent beams of the plurality of I-beams, the volume of concrete partially encasing a top of the I-beams and substantially filling a volume defined at least by the vertically oriented webs of the beams and the at least one decking member, wherein the volume of concrete covers top surfaces of the I-beams to thereby provide a continuous top surface to the floor structure.

2. A building floor structure as claimed in claim 1, wherein: each framework has a framework bottom surface; and the bearing surface of the side regions defining a plane different from a plane defined by the framework bottom surface.

3. A building floor structure as claimed in claim 2, wherein: the beams have beam bottom surfaces; and each framework bottom surface is located at or below a height of the beam bottom surfaces.

4. A building floor structure as claimed in claim 2, further comprising a plurality of elongate plates corresponding to the plurality of beams, each plate being aligned with and welded to the beam bottom surface and having at least one side extending horizontally beyond a width of the beam to provide the support surface.

5. A building floor structure as claimed in claim 4, wherein: each of the beams has a bottom flange; and each bearer is attached to a respective bottom flange.

6. A building floor structure as claimed in claim 1, wherein each framework further comprises recessed portions defining the bearing surfaces.

7. A building floor structure as claimed in claim 6, wherein: the bearers have bottom surfaces; and the bearing surfaces of each framework are provided by the bottom surfaces of respective ones of the bearers.

8. A building floor structure as claimed in claim 1, further comprising at least one plate attached to each of the bearers.

9. A building floor structure as claimed in claim 1, wherein each beam comprises a plurality of recesses shaped to mechanically key a volume of concrete surrounding the plurality of recesses.

10. A building floor structure as claimed in claim 1, wherein each beam comprises a plurality of lugs shaped to mechanically key a volume of concrete surrounding the plurality of lugs.

11. A building floor structure as claimed in claim 1, wherein each framework has a framework bottom surface, and further comprising at least one ceiling member attached to the framework bottom surface.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

(2) FIG. 1 is a sectional view of a building floor structure in accordance with one of a set of preferred embodiments of the present invention having 200 mm deep intermediate beams;

(3) FIG. 2 is a sectional view of a building floor structure in accordance with a second one of a set of preferred embodiments of the present invention having 200 mm deep intermediate beams;

(4) FIG. 3 is a sectional view of a building floor structure in accordance with a third one of a set of preferred embodiments of the present invention having 200 mm deep intermediate beams;

(5) FIG. 4 is a sectional view of a building floor structure in accordance with a fourth one of a set of preferred embodiments of the present invention having 200 mm deep intermediate beams;

(6) FIG. 5 is a sectional view of a building floor structure in accordance with one of another set of preferred embodiments of the present invention having 250 mm deep intermediate beams;

(7) FIG. 6 is a sectional view of a building floor structure in accordance with a second one of the set of preferred embodiments of the present invention having 250 mm deep intermediate beams;

(8) FIG. 7 is a sectional view of a building floor structure in accordance with a third one of the set of preferred embodiments of the present invention having 250 mm deep intermediate beams;

(9) FIG. 8 is a sectional view of a building floor structure in accordance with a fourth one of the set of preferred embodiments of the present invention having 250 mm deep intermediate beams;

(10) FIG. 9 is a partial plan view of a prefabricated framework including decking elements in accordance with another preferred embodiment of the present invention;

(11) FIG. 10 is a partial plan view of a top flange of a preferred intermediate beam having integral deformations for shear transfer in accordance with another preferred embodiment of the present invention;

(12) FIG. 11 is a partial plan view of a top flange of a preferred intermediate beam having preferred shear studs installed in accordance with another preferred embodiment of the present invention;

(13) FIG. 12 is a partial, detail section view of Section A-A of FIG. 11 showing preferred shear lugs located in pre-punched holes in the top flange of the beam;

(14) FIG. 13 is a partial, schematic plan view of a top flange of a preferred intermediate beam using deformed bars as a shear transfer mechanism in accordance with another preferred embodiment of the present invention;

(15) FIG. 14 is a side view of a dual sheer lug in accordance with another preferred embodiment of the present invention;

(16) FIG. 15 is an end view of the dual sheer lug of FIG. 14; and

(17) FIG. 16 is a section view of a building floor structure in accordance with another preferred embodiment of the present invention shown connected to primary I-beams.

(18) FIG. 17 is a section view of the building floor structure of FIG. 16 shown connected to the primary I-beams.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

(19) It should be noted in the following description that like or the same reference numerals in different embodiments denote the same or similar features.

(20) Referring to FIGS. 1-8, preferred embodiments of a building floor structure, henceforth referred to as floor structure 10, are shown. The floor structure 10 comprises a series of spaced-apart beams, in this case, I-beams 15, plates 20 welded to respective I-beams and a series of frameworks 25 resting on respective plates 20. Each framework 25 comprises two spaced-apart bearers 30 aligned with the I-beams 15 and a series of spaced-apart joists 35 extending transversely and bridging the gap between the bearers 30.

(21) Referring to FIG. 9, the floor structure 10 further comprises a series of horizontally disposed decking panels 37 lying on top of, attached to and traversing the joists 35. The decking panels 37 may overlap or simply abut one another. In this embodiment, the decking panels 37 are fixed to the joists 35 by screws 36. The decking panels 37 run parallel to the bearers 30 and finish on the bearers 30 to ensure formwork closure.

(22) The floor structure 10 also comprises a volume of concrete 38 substantially filling the volume defined by the beams 15, bearers 30, joists 35, decking panels 37 and their edge forms and covering the top surfaces of the I-beams 15 to thereby provide a top surface 39 to the floor structure 10.

(23) Each framework 25 is positioned between and adjacent two of the spaced-apart beams 15. Each framework has a top surface 40 defined as the top surface of the joists 35 and a bottom surface 45 defined as the bottom surface of the joists 35. The framework 25 is designed to have sufficient structural capacity to withstand the construction loading conditions without propping.

(24) Each bearer 30 has a bottom surface and in this embodiment the bottom surface acts as a bearing surface 50 for supporting the respective framework 25. The bearing surface 50 can in various embodiments be above (see FIG. 4) in-line with (see FIG. 3) or below (see FIGS. 1, 2 & 5-8) the bottom surface 45 of the framework 25. The bearers 30 can be attached to the respective I-beams 15. Advantageously, the building floor structure is strengthened by this attachment.

(25) Each plate 20 is aligned with and welded to a bottom surface 55 of a respective beam 15 and extends horizontally beyond the width of the beam. The upper surfaces of the plate 20 provide a first and second support surface 60, 65, respectively, on either side of the respective beam 15. The bearers 30 can either rest on top of or be attached to respective plates 20 for greater strength.

(26) In this embodiment, each I-beam 15 comprises a horizontally oriented top flange, a horizontally orientated bottom flange and a vertically oriented web connecting the center of the top flange to the center of the bottom flange.

(27) Referring to FIG. 4, an embodiment is shown where the bottom surfaces 45 of the frameworks 25 are located below the height of the bottom surfaces 55 of the I-beams 15. This allows ceiling panels (not shown) to be attached directly to the framework 25. This removes the need to suspend a ceiling frame or provide ceiling battens.

(28) The joists 35 can be situated vertically at any position relative to the bearers 30 to achieve the optimum concrete thickness for the required fire resistance loading condition or any other governing design criteria, for example acoustics, and for any ceiling installation requirements. Alternatively, the depth of the joists 35 may be varied to achieve the same optimal concrete thickness.

(29) The floor structure 10 further comprises reinforcing mesh 70 located within the volume of concrete 38. In this embodiment the reinforcing mesh 70 is SL82 but it will be appreciated by the person skilled in the art that any other suitable reinforcing mesh can be used.

(30) The frameworks 25 and decking panels 37 are designed to carry the construction loads associated with wet concrete together with the installers and their equipment without any propping within its span between adjacent beams or supports. When the steel I-beams 15 are designed to be composite, the beam itself can be propped, and this is done with a single prop without additional support material like support beams overhead. This is a much better outcome for site safety than beams and re-useable form boards overhead.

(31) The overall floor thickness is controlled geometrically by the depth of concrete cover over the I-beams 15 and the depth of the beams 15 itself. The depth of concrete cover over the beams 15 is governed by practical limits around reinforcement and crack control. The depth of the I-beams 15 is governed by its span, the floor self-weight, the loading conditions and deflection limits. A framework 25 with decking panels 37 allows the floor self-weight to be reduced without an additional fabrication process on the I-beams 15, such as the installation of composite metal decking support angles on the web, because the bearers 30 can sit on the bottom flange of the I-beams 15.

(32) The framework 25 provides load carrying capacity under normal service conditions removing complication and material from the work decking itself, as required for composite metal decking.

(33) The volume of concrete 38 is designed such that it alone satisfies structural adequacy under fire conditions, thus removing the need to provide separate fire protection to the framework 25 (that is, the framework 25 is redundant under fire conditions).

(34) In this embodiment: 1. The floor structure 10 supports a volume of concrete 38 (i.e. a concrete slab) of thickness between 100 mm and 150 mm. In other embodiments, the thickness can be anywhere up to 1000 mm thick or beyond. 2. The center-to-center spacing 71 of the I-beams 15 is 2400 mm. In other embodiments the center-to-center spacing 71 can be anywhere up to 5000 mm or beyond. 3. The framework width 72 is the same as the spacing 71 of the I-beams 15 less the width 73 of the top flange of the beam, less a clearance for site variation and assembly tolerances, such that the framework 25 can be installed between adjacent I-beams 15 bearing on the plates 20.

(35) The floor structure 10 offers a number of advantages, including: 1. The use of a framework 25 creates a void between the bottom flanges of the I-beams 15 and the decking panels 37 (underside of the concrete) and this reduces concrete volume in the structure saving cost in concrete, reinforcing steel and saving consequential cost associated with lightening the structure and footings. In other words, the framework 25 uses less concrete than laying decking panels on the bottom flanges of I-beams. 2. Advantageously, the overall depth of the floor structure 10 from the top surface of the concrete to the underside of the I-beams 15 is less than using composite metal decking fixed to the top flanges of the I-beams 15. 3. The frameworks 25 can be prefabricated and located in position on-site. This reduces on-site labor requirements and increases the speed of construction on-site. 4. The frameworks 25, when adapted to support the weight of concrete and loading before the concrete has set, do not require a temporary support structure underneath. Consequently, the risk of injury or death can be reduced. 5. In embodiments where the bottom surface 45 of the framework 25 is above the bearing surface 50, the amount of concrete required to create a composite floor will be less, if the framework bottom surface 45 is below the bearing surface 50, battens with a smaller cross-section can be used and if the framework bottom surface 45 is below the bottom surface 55 of the I-beams 15, the ceiling panels can be attached directly to the framework 25. 6. Advantageously, the joists 35 can be attached to the bearers 30 at a height offset to reduce the cross-sectional requirement of the joists 35. 7. The volume of concrete 38 surrounding the top of the I-beams 35 creates a better interlock between the I-beams 35 and the volume of concrete 38 thereby providing greater strength and rigidity. 8. Encasement of the I-beam 15, either in part or in full, in concrete, completely filling the space between the flanges of the I-beam 15 offers a number of advantages, including: a. It stabilizes the I-beam 15 to increase its structural capacity. b. It creates a shear key to keep the volume of concrete 38 bonded to the I-beam 15, that is, the concrete cover over the top of the I-beam 15 prevents it from buckling up (delaminating) under load. c. It protects the beam from loss of structural integrity from temperature increase in fire scenarios. d. It reduces the amount of or obviates the need for additional fire protection treatment, such as sprays, required due to the low exposed surface area to mass ratio used to determine coating thickness. 9. The I-beams 15 are laterally and torsionally restrained by the concrete block encasing it, improving the dynamic response of the floor 10 (e.g. reducing vibration).

(36) Referring to FIGS. 10-16, the I-beams 15 preferably have a mechanism for transferring shear at the top flange to facilitate composite action with the volume of concrete 38.

(37) Referring to FIG. 10, a profile taking the form of a castellated top flange 41 of one of the I-beams 15 is shown. This arrangement provides a greater level of interlock between the I-beams 15 and the volume of concrete 38. This may be formed by cutting from the side edges of the top flange of the I-beams 15. Alternatively, spaced blocks may be welded to the top flange.

(38) Referring to FIGS. 11 & 12, another embodiment is shown where the I-beams 15 each comprise a plurality of recesses 75 and the building floor structure 10 further comprises a plurality of corresponding shear lugs 80 for placement in the recesses 75 during the construction process. The top surface 39 of the floor structure 10 covers and surrounds the shear lugs 80. The shear lugs 80 provide a greater level of interlock between the I-beams 15 and the volume of concrete 38. The shear lugs 80 are flat and are preferably round or square in plan view. The lugs 80 can have a greater width than height and do not need to be flanged at the top as is the case with conventional shear lugs. They can also be effectively installed off-site prior to delivery, again taking labor away from the construction site. In this embodiment, the shear lugs 80 have a slight interference fit affected by ridges 95 to secure the shear lugs 80 in the recesses 75. It has already been discussed that the encasement of the beam 15 creates a shear key, so it is not necessary to have flanged tops on the shear lugs 80.

(39) Referring to FIG. 13, another embodiment is shown and comprises a series of cogged deformed bars 85 fillet welded to the top flange of the I-beam 15. In this embodiment, the required shear force is achieved through anchorage in the concrete. This can be done off-site.

(40) Referring to FIG. 14, an alternative to the sheer lugs 80 of FIG. 12 is shown, being dual sheer lugs 90. The dual sheer lugs 90 provide greater sheer resistance when compared to the single sheer lugs 80.

(41) FIG. 15 is an end view of the dual sheer lug of FIG. 14; and

(42) In the embodiments of FIGS. 10-14, the building floor structure 10 is strengthened by the greater level of interlock between the I-beams 15 and the volume of concrete 38 and it is less likely that cracks in the volume of concrete will form.

(43) Alternatively, the top flange may include spaced deformations. The deformations are best made in the plane of the flange to reduce the depth (cover) of concrete over the top of the flange. The deformations are typically notches cut from and/or blocks welded to the edge of the flange.

(44) It is advantageous to utilize composite action in steel beam/concrete slab floor construction as about 25% greater spans can be achieved for the same steel section in configurations.

(45) FIG. 16 is a section view of a building floor structure in accordance with another preferred embodiment shown connected to primary I-beams 100. The I-beams 15 connect to the major structural elements of the building—a wall or in this case to the primary I-beams 100. In this case, the connection type is a cleat 105 welded to the vertical web of the primary I-beam 100, to which a respective I-beams 15 is bolted through its web. They are arranged so that the top surfaces of the beams 15, 100 are in the same plane.

(46) FIG. 17 is a side view of the building floor structure 10 of FIG. 16. The building floor structure 10 further comprises a blocking angle 110, fixed to the end joists 115 and connecting to respective primary I-beams 100, and a U-shape blocking section 120 fitted between the end joists 115 and the primary I-beams 100 under the top flange of the primary I-beams 100.

(47) In other embodiments of the invention: 1. Each framework further comprises recessed portions defining the bearing surfaces. 2. Each of the beams further comprises an elongate, laterally extending beam flange aligned with the beam on both sides of the beam, the support surfaces being provided by the upper surfaces of the beam flanges. 3. The bottom flange of each I-beam is wider than the top flange and the support surfaces are provided by an upper surface of the bottom flange on each side of the vertically oriented web. This allows the frameworks to be more easily positioned on the I-beams. The pre-assembled frameworks are lowered into position where the bearers sit with adequate bearing on the outside edge of the bottom flange of the I-beams. This is advantageous since, in terms of fire design, it is important to have concrete encasing as much of the beam as possible. This floor structure design keeps the bulk of the bottom flange in direct contact with concrete for better heat dissipation. 4. The reinforcement rods can be replaced by a reinforcement grid, mesh or any other suitable engineering reinforcement arrangement or material. 5. The I-beams and/or plates and/or bearers and/or joists are steel sections. 6. The bearer may be a C-section open towards the I-beam's web or a boxed section with holes facing towards the beam's web to allow the remaining edges of the bottom flange of the I-beam to be protected by concrete. 7. The decking panels are panels of wave, rectangular or trapezoidal corrugated steel, aluminum or plastic sheet, or longitudinally-joined steel or aluminum roofing strip material or timber boards or sheeting such as plywood. 8. The bearers are cold rolled-hollow-sections. 9. The joists are cold rolled-hollow-sections. 10. The bearers, beams, plates and joists are made from wood, steel, aluminum, plastic, composite (e.g. concrete composite) or any other suitable engineering material. 11. The beams may actually be a top portion of a wall of a building. 12. The decking panels may be fixed to the joists by rivets, nails or an adhesive.

(48) In another embodiment of the invention, a process for constructing a building floor structure 10 is provided, comprising the numbered steps below. 1. Providing a plurality of prefabricated frameworks 25 assembled with decking panels 37. 2. Locating each of the frameworks 25, between two adjacent I-beams 15, such that the bearing surfaces 50 rest on respective support surfaces 60, 65. 3. Pouring concrete into and above a volume defined by the beams 15 and the one or more frameworks 25 such that the volume of concrete 38 covers the top surfaces of the beams 15; and 4. Screeding the concrete flat.

(49) Advantageously, this process for constructing a building floor structure 10 uses less concrete than laying decking panels on the bottom flange of an I-beam 15.

(50) Advantageously, the overall depth of the floor structure 10 from the top surface of the concrete to the underside of the I-beams 15 is less than using composite metal decking fixed to the top flanges of the I-beams 15.

(51) Advantageously, the frameworks 25 can be prefabricated and located in position on-site. This reduces on-site labor requirements and increases the speed of construction on-site.

(52) Advantageously, the frameworks 25, when adapted to support the weight of concrete and loading before the concrete has set, do not require a temporary support structure underneath. Consequently, the risk of injury or death can be reduced.

(53) Preferably, the framework 25 and decking panels 37 are pre-assembled before being transported to site ready for placement by installation team. Placement of the prefabricated framework 25 can be done manually when its size is manageable and weight is considered acceptable for lifting and handling. However, the fastest and most cost efficient method will be to install large deck assemblies of multiple frameworks 25 using a crane and that also satisfies a primary objective which is to reduce the number of installers on site to, in turn, reduce safety management risks.

(54) A pre-assembled framework 25 including decking panels 37 that is placed by crane takes a significant amount of labor off the construction site. There is no welding or mechanical connecting of individual lost formwork sheets, so the number of people involved in the installation of the floors is significantly reduced, with consequential improvements to both site safety and speed of construction. The frameworks 25 naturally align to the supports, are robust of their own accord, and require just a simple clip to temporarily secure them.

(55) In addition to the benefits of placing large frameworks 25 by crane, further speed of construction improvements will be achieved through improved materials management and handling techniques. Multiple sections of frameworks 25 will be craned to the construction floor area with the capacity to release the first, move to the next location, release the second, and so on. The objective is to maximize the square meter of floor area installed per crane lift. A further advantage of this is in the management of material delivery to the site. A “pack” of floor frameworks 25 is removed from the delivery truck in a single lift within minutes of its arrival and is installed immediately.

(56) One week per floor structure completion times are considered fast for concrete frame structures and this requires the use of post tensioning with high early strength concrete. Steel frame structures can be faster, but tend to be constrained by the speed of floor construction as the composite metal deck frameworks 25 are built in-situ. The present invention takes floor construction off the critical path and speeds of up to 2 days per floor may be realizable.

(57) A pre-assembled framework which is lost formwork can be used as a ceiling support system, either by hangers or by fixing ceiling linings direct to the underside of the joists 35. When suspended ceilings are installed, the suspension rods can be fixed to the joists 35 using self-drilling screws. This is much safer, faster and quieter than drilling into concrete to then install an anchor.

(58) An alternative to the lost frame formwork is a curved decking having sufficient structural integrity spanning between the beams 15.

(59) A further embodiment of the invention includes pre-stressing the beams 15 so as to create a pre-camber and avoid the use of props altogether. This is achieved using cable that runs under spigots connected to preferably each side of the web of the beam 15. In the mid-span the spigots are close to the bottom flange with cable running under, and near the supports the spigots are near the top flange with cable running over, so as tension is applied to the cables, the center of the beam 15 is lifted upwards. This pre-tensioning can also be created by installing a temporary ‘Barrup Truss’ under the beam—a compression strut mid-span with tension cable anchored near the supports—again avoiding the use of a prop.

(60) The filling of the space between the flanges of the I-beam 15 with concrete further allows for a post-tensioned composite steel beam, which is not known. A tension cable and conduit system can be pre-assembled in the intermediate beams, preferably one either side of the web, and provision made in the top flange to pass the cable through to apply tension and block off after concrete cure.

(61) The floor structure 10 further offers alternative ways of managing noise resistance. Because the decking panels 37 do not need to work compositely with the volume of concrete 38, it's possible to place impact resistant and dampening material between the decking panels 37 and the volume of concrete 38. Additionally, the voids between the framework members can be filled or partially filled with noise insulating material.

INTERPRETATION

(62) Embodiments

(63) Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

(64) Similarly it should be appreciated that in the above description of example embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the Detailed Description of Specific Embodiments are hereby expressly incorporated into this Detailed Description of Specific Embodiments, with each claim standing on its own as a separate embodiment of this invention.

(65) Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

(66) Specific Details

(67) In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

(68) Terminology

(69) In describing the preferred embodiment of the invention illustrated in the drawings, specific terminology will be resorted to for the sake of clarity. However, the invention is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes all technical equivalents which operate in a similar manner to accomplish a similar technical purpose. Terms such as “forward”, “rearward”, “radially”, “peripherally”, “upwardly”, “downwardly”, and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.

(70) Comprising and Including

(71) In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

(72) Any one of the terms: including or which includes or that includes as used herein is also an open term that also means including at least the elements/features that follow the term, but not excluding others. Thus, including is synonymous with and means comprising.

(73) Scope of Invention

(74) Thus, while there has been described what are believed to be the preferred embodiments of the invention, those skilled in the art will recognize that other and further modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the scope of the invention.

INDUSTRIAL APPLICABILITY

(75) It is apparent from the above, that the arrangements described are applicable to the construction industry.