SUPPORTS

Field

[0001] The present disclosure relates to a lattice of hollow bodies and, in particular, to a lattice of hollow bodies for use in the construction of reinforced concrete slabs, such as floor slabs.

Background

[0002] United States Patent No. 5,396,747 which issued on March 14, 1995, to Breuning et al. discloses plane, hollow, reinforced concrete floor slabs having a two-dimensional structure and a method for their production. Floor slabs produced by this technique will vary widely and with considerable profit replace conventional floor structures. The technique makes it possible to provide higher strength and stiffness, with less volume of materials, greater flexibility, better economy, or an arbitrary combination of these gains. The technique makes it possible to create a total balance between bending forces, shear forces and stiffness (deformations) so that all design conditions can be fully optimized at the same time. The technique presents a distinct minimized construction characterized by the ability to place concrete exactly where it yields maximum strength capacity. The technique offers material and cost savings compared with conventional compact two-way reinforced slab structures and is suitable for both in-situ works and for prefabrication. [0003] International Patent Application Number PCT/CA2019/050148 discloses a structure where a plurality of hollow bodies are connected together in a lattice like arrangement and are embedded in a concrete slab. SUMMARY

[0004] In one embodiment, there is provided an apparatus for use in forming a concrete slab. The apparatus comprises a lattice of hollow bodies, wherein each of the hollow bodies is coupled to at least one adjacent other of the hollow bodies and wherein each of the hollow bodies has at least one outwardly extending support projection for supporting at least one reinforcement member.

[0005] The hollow bodies may be aligned in a two-dimensional array comprising rows and columns perpendicular to each other.

[0006] The lattice may include a top portion comprised of a two-dimensional array of semi-spherical top portions and a bottom portion comprised of a corresponding two-dimensional array of semi-spherical bottom portions. The top and bottom portions of the lattice may be connected together to form the array of hollow bodies.

[0007] The top semi-spherical portions of the hollow bodies may have respective top surfaces and at least one of the at least one outwardly extending support projection may extend outwardly from at least one of the top surfaces.

[0008] The at least one outwardly extending support projection may include a plurality of generally triangular shaped projections.

[0009] The generally triangular shaped projections may have concave surfaces for supporting the at least one reinforcement member. [0010] The generally triangular shaped projections may be positioned on the hollow bodies to define at least one of rows and columns of support surfaces on the lattice to support the at least one reinforcement member on the lattice.

[0011] The generally triangular shaped projections on each hollow body of the array may include four generally triangular shaped projections spaced apart from each other by 90 degrees about a center axis of the hollow body.

[0012] The at least one outwardly extending support projection may include connectors extending between adjacent hollow bodies.

[0013] The connectors may be integrally formed with the hollow bodies. [0014] The connectors may have a U-shape.

[0015] The connectors may be connected between adjacent the semi-spherical bottom portions of the hollow bodies.

[0016] The connectors may be oriented and positioned to support the at least one reinforcement member between adjacent semi-spherical bottom portions of the hollow bodies.

[0017] The at least one outwardly extending support projection may include one or more legs extending from the bottom semi-spherical portions of the hollow bodies and terminating in connectors having surfaces generally in a common plane. [0018] The one or more legs and connectors may form a generally half U- shaped structure. [0019] The rows and columns of hollow bodies of the lattice include outer rows and columns and at least one of the outer rows and outer columns of the hollow bodies may have legs terminating in connectors for connecting the at least one of the outer rows and outer columns of the hollow bodies of the lattice to corresponding connectors on legs extending from semi-spherical bottom portions of hollow bodies of at least one of an outer row and outer column of an adjacent similar lattice, for connecting the lattice and the adjacent lattice together.

[0020] The connectors may have respective top surfaces for supporting the at least one reinforcement member. [0021] The semi-spherical top portions and the semi-spherical bottom portions may be respective shells.

[0022] The semi-spherical top portions and the semi-spherical bottom portions may have first complementary connectors on the shells for connecting the semi- spherical top portions and corresponding the semi-spherical bottom portions together to form the lattice.

[0023] The semi-spherical top portions and the semi-spherical bottom portions may have axially projecting internal projections having second complementary connectors that engage when the semi-spherical top portions and the corresponding semi-spherical bottom portions are connected together to form the lattice, whereby the axially projecting projections of corresponding semi-spherical top portions and the semi-spherical bottom portions form support posts inside respective hollow bodies when the semi-spherical top portions and the semi- spherical bottom portions may be connected together.

[0024] In another embodiment, there is provided a concrete slab comprising the apparatus described above, at least one reinforcement member on the at least one outwardly extending support projection of the apparatus, and concrete encasing the apparatus and the at least one reinforcement member, whereby the hollow bodies define voids in the concrete and spaces between the hollow bodies are occupied by concrete. At least one of a space between the lattice and a top surface of the concrete, a space between the lattice and a bottom surface of the concrete and the one of the spaces between the hollow bodies is occupied by the at least one reinforcement member.

[0025] The at least one reinforcement member may include a reinforcing bar.

[0026] In another embodiment, there is provided a method of making a concrete slab. The method involves placing the lattice described above within the bounds of a concrete form, positioning at least one reinforcement member within the bounds of the concrete form and on a least one of the at least one outwardly extending support projection such that the at least one reinforcement member is at least one of between adjacent hollow bodies or above the hollow bodies. The method also involves placing concrete into the form to encompass the lattice of hollow bodies and the at least one reinforcement member, and curing the concrete to bind the apparatus, the at least one reinforcement member and the concrete into a unitary solid mass.

[0027] In another embodiment, there is provided a concrete slab made according to the method above.

[0028] The concrete slab may be a floor slab or a wall slab. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The concepts described herein will be more readily understood from the following description, with reference to the accompanying drawings, in which: [0030] Figure 1 is a top, front isometric view of a lattice of hollow bodies for use in the construction of reinforced concrete slabs;

[0031] Figure 2 is a bottom, rear isometric view of the lattice of Figure 1;

[0032] Figure 3 is a top plan view thereof;

[0033] Figure 4 is a bottom plan view thereof; [0034] Figure 5 is a side elevational view thereof;

[0035] Figure 6 is an end view thereof;

[0036] Figure 7 is an isometric view of an assembly comprising six of the lattices of Figure 1.

[0037] Figure 8 is an isometric view of the lattice of Figure 1 positioned adjacent to another, similar lattice;

[0038] Figure 9 is an isometric view of an assembly comprising the lattices of Figure 8; [0039] Figure 10 is an exploded top, front isometric view of the lattice of Figure

1;

[0040] Figure 11 is a top, front isometric view of the bottom portion of the lattice;

[0041] Figure 12 is a fragmented perspective view of a bottom portion of one hollow body at a lower left corner of the lattice;

[0042] Figure 13 is a bottom, front isometric view of a top portion of the lattice, shown upside down;

[0043] Figure 14 is a fragmentary, isometric view of the lattice with a side of one of the hollow bodies cut away to show an interior thereof when the top and bottom portion of the lattice are connected together;

[0044] Figure 15 is a is a perspective view of a top portion of one hollow body of the lattice;

[0045] Figure 16 is a side, front isometric view of the lattice of Figure 1 with reinforcement members mounted thereon; [0046] Figure 17 is a side elevational view thereof;

[0047] Figure 18 is a flow chart of the method of making a floor slab using the lattice of Figure 1 and reinforcement members; and

[0048] Figure 19 is a front, top isometric view of a floor slab having the lattice of Figure 1 and reinforcement members embedded in concrete, the slab being shown partly in section and mounted within a concrete form shown in fragment.

DETAILED DESCRIPTION [0049] Figures 1 and 2 are, respectively, a top, front isometric view and a bottom, rear isometric view of an apparatus for use in forming a concrete slab. Figures 3 and 4 are, respectively, top and bottom plan views of the apparatus.

[0050] The apparatus comprises a lattice 100 of hollow bodies, wherein each of the hollow bodies is coupled to at least one adjacent other of the hollow bodies and wherein each of the hollow bodies has at least one outwardly extending support portion for supporting at least one reinforcement member, such as a reinforcing bar, also known as a rebar.

[0051] In the embodiment shown, there are eight hollow bodies 102, 104, 106, 108, 110, 112, 114 and 116. Each of the hollow bodies is coupled to at least one adjacent one of the hollow bodies by two integral connectors. For example, referring to Figure 5, a first hollow body 102 is coupled to an adjacent second hollow body 104 by a top integral connector 118 and a bottom U-shaped integral connector 120. Referring to Figure 6, the second hollow body 104 is likewise coupled to a third hollow body 108 in a similar manner. [0052] Referring back to Figures 1 and 2, the hollow bodies are linearly aligned in a two-dimensional rectangular array in this example. For example, hollow bodies 102, 106, 110 and 114 are linearly aligned in a column along a straight line 122, while hollow bodies 104, 108, 112 and 116 are linearly aligned in a column along a straight line 124 in this example. As described thus far, the lattice 100 is generally similar to the first embodiment of the lattice described in my earlier International Patent Application Number PCT/CA2019/050148. [0053] In Figures 1 to 6, the lattice 100 is a lattice of two columns by four rows of generally spherical hollow bodies, the rows and columns being perpendicular to each other. However, in other examples, the lattice 100 may be any suitable shape, configuration, and number of hollow bodies. A typical lattice structure for normal usage would typically have many more spherical bodies than illustrated in Figures 1 to 6 and could include a rectangular array of 48 hollow bodies as seen at 400 in Figure 7, for example, or could be formed from a plurality of lattices of the type shown in Figures 1-6 connected together as shown by lattices 100 and 300 in Figures 8 and 9.

[0054] Referring now to Figure 10, the lattice 100 in this embodiment has a top portion 126b comprised of a two-dimensional array of semi-spherical top portions and a bottom portion 126a comprised of a corresponding two-dimensional array of semi-spherical bottom portions. The top and bottom portions 126a and 126b may be connected together to form the array of hollow bodies.

[0055] The lattice 100 in this embodiment is made of a thermoplastic material and is manufactured by injection moulding the first or bottom portion 126a of the lattice 100, and injection moulding the second or top portion 126b of the lattice 100. The injection molding may be done with various materials such as polyethylene, polypropylene, recycled materials, and fillers (up to 80%, for example). Injection molding may be done at temperatures between 160 degrees Celsius and 280 degrees Celsius. However other materials and methods of manufacture could be used for other embodiments.

[0056] For an 8-inch thick slab the hollow bodies may have a diameter of about 5 inches, for example, to provide for at least 1-inch of concrete on top of the hollow bodies and at least 1-inch of concrete beneath the hollow bodies to engage with the rebars supported by the hollow bodies. For a 10-inch thick concrete slab the hollow bodies may have a diameter of about 7 inches, for example. Bottom portion

Referring to Figure 11, the first or bottom portion 126a of the lattice 100 is shown in greater detail and includes an integral unit comprised of a two-dimensional rectangular array of semi-spherical bottom portions 128, 130, 132, etc., connected together by the U-shaped integral connectors 120. The U-shaped integral connectors 120 are positioned to extend between hollow bodies of the lattice and are thus located in positions angularly spaced apart by 90 degrees on each bottom portion to connect to adjacent bottom portions in an adjacent row and in an adjacent column, as seen in Figure 4. [0057] The at least one outwardly extending support projection may include one or more legs extending from the bottom semi-spherical portions of the hollow bodies and terminating in connectors having surfaces generally in a common plane. For example, all of the bottom portions on the right side of the lattice, along line 122 for example, have right side legs 220 that extend downwardly, outwardly and perpendicular to the line 122, as shown in Figure 10. Similarly, all of the bottom portions on the left side of the lattice along line 124 for example, have left side legs 221 that extend downwardly, outwardly and perpendicular to the line 124. The left side legs 221 and right-side legs 220 are terminated in respective connectors. For example, each of the left side legs 221 is terminated in a respective female connector 222 and each of the right-side legs 220 is terminated in a respective male connector 224 complementary to and engageable with a corresponding female connector 222 on a leg of a bottom portion of a hollow body of a column-adjacent similar lattice such as lattice 300 shown in Figures 8 and 9. This enables lattice 100 and similar lattice 300 to be connected together side-by- side.

[0058] Similarly, referring to Figure 2, all of the bottom portions in the top row of the lattice, perpendicular to lines 122 and 124, have top row legs 225 that extend downwardly, outwardly and parallel to the lines 122 and 124. Referring back to Figure 10, all of the bottom portions on the bottom row of the lattice have bottom row legs 223 that extend downwardly, outwardly and parallel to the lines 122 and 124. The top row legs and bottom row legs 223 are also terminated in respective connectors. For example, the top row legs 225 are terminated in female connectors 222 and the bottom row legs 223 are terminated in male connectors 224 complementary to and engageable with corresponding female connectors on corresponding legs of a bottom portion of a hollow body of a row-adjacent similar lattice. This enables lattice 100 and a similar row-adjacent lattice to be connected together end-to-end.

[0059] Referring to Figures 11 and 12, the bottom portion 130 of hollow body 104 is shown and includes a semi-spherical hollow shell 131 having a hollow interior 134 and a central, hollow, cylindrical projection 136 having a circular opening 138 in a distal end 140 thereof. A radially outwardly axially extending central leg 142 having an axis coincident with the cylindrical projection 136 and having an end 145 that extends below the shell 131 and is operable to rest on a support surface 147. The support surface 147 may be a layer of construction aggregate material, for example.

[0060] The U-shaped integrally formed connectors 120 are shown in fragment in Figure 12 and extend downwardly and radially outwardly from the exterior surface of the shell 131 and are spaced apart angularly by 90 degrees and in positions aligned with the rows and columns of the lattice 100. The connectors 120 have fins 420 that extend downwardly and have bottom surfaces 421 that rest on the surface 147. Referring back to Figure 10, the U-shaped integrally formed connectors 120 have bight portions 219 that are directly over respective fins, to help the bight portions support a portion of rebar received therein when the apparatus is used. [0061] Referring back to Figure 12, the bottom portion 130 also has a left side leg 221 and a bottom row leg 223, terminated in female and male connectors 222 and 224 respectively. The left side leg 221 is slightly curved into a half-U shape as it terminates in the female connector 222. The female connector 222 comprises an enlarged portion 227 having a rectangular receptacle 229 with a top surface 230, a floor 231 and a wall 233 defining an opening 235. A cruciform fin 237 extends below the floor 231 to rest on the surface 147 and support the enlarged portion 227. The left side leg 221 and enlarged portion 227 are dimensioned such that the top surface 230 is approximately in a same plane as lower surfaces 241 of the bight portions 219 of the U-shaped integrally formed connectors 120.

[0062] The bottom row leg 223 is also slightly curved into a half-U shape as it terminates in the male connector 224. The male connector 224 includes a rectangular-sectioned distal portion 249 of the bottom row leg, terminated in a solid rectangular portion 251 dimensioned and oriented complementary to the receptacle 229 of the female connector 222 so as to be fully received in such a receptacle of an adjacent top row leg on a bottom portion of a top row hollow body of a similar adjacent lattice. The solid rectangular portion 251 has a top surface 253 that lies in generally the same plane as the top surface 230 of the female receptacle 222, so that when the male connector 224 is received in a female connector 222, the top surface 253 of the solid rectangular portion 251 and the top surface 230 of the female connector 224 are flush. When the male and female connectors 224 and 222 are engaged, each of them provides a respective half U- shape to form a full U-shaped rebar support between the lattice 100 and an adjacent similar lattice as seen at 255 in Figure 9. As such, one or more legs and connectors on each hollow body may form a generally half U-shaped structure, which, when the connectors are coupled to an adjacent leg and connector of an adjacent hollow body form a full U-shaped structure having a bight portion for receiving and hold a rebar. In general, the rows and columns of hollow bodies of the lattice include outer rows and columns and at least one of the outer rows and outer columns of the hollow bodies may have legs terminating in connectors for connecting the at least one of the outer rows and outer columns of the hollow bodies of the lattice to corresponding connectors on legs extending from semi- spherical bottom portions of hollow bodies of at least one of an outer row and outer column of an adjacent similar lattice for connecting the lattice and the adjacent lattice together to form a lattice system.

Top Portion

[0063] Referring to Figure 13, the second or top portion 126b of the lattice 100 is shown upside down and is substantially similar in structure to the first portion 126a of the lattice 100 seen in Figure 11. The top portion 126b, comprises an array of semi-spherical top portions each having the form of a shell and connected together by the top integral connectors 118 which are straight connectors connecting adjacent semi-spherical top portions of the second portion 126b of the lattice 100. For example, the top integral connector 118 connects top portion 144 of the hollow body 102 to top portion 146 of hollow body 104.

[0064] The semi-spherical top portions and the semi-spherical bottom portions may have axially projecting internal projections having second complementary connectors that engage when the semi-spherical top portions and the corresponding semi-spherical bottom portions are connected together to form the lattice, whereby the axially projecting projections of corresponding the semi- spherical top portions and the semi-spherical bottom portions form support posts inside respective hollow bodies when the semi-spherical top portions and the semi- spherical bottom portions may be connected together.

[0065] For example, the top half of each of the spherical portions has a semi spherical, hollow interior 148 and a central, hollow, cylindrical projection 150 having a circular opening 152 in a distal end 154 thereof. The cylindrical projection dimensioned and configured to fit tightly within the corresponding circular opening 138 of the cylindrical projection 136 shown in Figure 12 of the corresponding one of the bottom portion (such as 130) of the hollow bodies when the top portions and bottom portions are fitted together into the configuration shown in Figures 1 and 2.

[0066] Referring to Figure 14, when fitted together, cylindrical projections 150 and 136 of each hollow body 102 may, for example, form vertical post-like internal supports 151 which act as internal supports for respective hollow bodies.

[0067] The semi-spherical top portions and the semi-spherical bottom portions have first complementary connectors on the shells for connecting the semi- spherical top portions and corresponding semi-spherical bottom portions together to form the lattice.

[0068] For example, referring to Figures 10, 11, 12, 13 and 14, the first portion 126a of the lattice 100 and the second portion 126b of the lattice 100 are connected together to form the overall lattice 100. The first portion 126a of the lattice 100 and the second portion 126b of the lattice 100 are connected together by bottom clasp fasteners 156 and top clasp fasteners 158, although they may be additionally or alternatively heat sealed together or sealed together with an adhesive or other means. In the embodiment shown there are four equally angularly spaced apart bottom clasp fasteners on each of the bottom portions and four corresponding equally angularly spaced apart top clasp fasteners on each of the top portions to secure the first and second portions 126a and 126b together to form the hollow bodies and the lattice 100.

[0069] Referring back to Figure 1, in this embodiment, each of the hollow bodies, for example hollow body 106, has a plurality of outwardly extending generally triangular support projections which, in this example, are integrally formed on a top portion 188 thereof to project outwardly from a top outer surface 198 of the top portion. Not all of the hollow bodies need to have these support projections and where and when to provide such projections will depend on how may rebars are desired to be supported by the lattice as will become apparent from the discussion below.

[0070] Referring to Figures 1 and 15, in the embodiment shown, the top portion 188 has four projections 190, 192, 194 and 196 spaced at 90-degree intervals about the center axis of the hollow body and project upwardly and radially outwardly from the top outer surface 198. Each of the projections, for example projection 194, includes a concave edge 200 where it emerges from the top outer surface 198 and a concave edge 202 adjacent a vertex 204 of the projection. The concave edges 202 face upwardly to hold reinforcement bars when the lattice 100 is positioned for use, as will be described below. The concave edges 202, nicely hold round reinforcement bars, but it will be appreciated that the concave edges could be replaced with other surfaces that facilitate holding one or more reinforcing components having other cross-sections shapes in position on the top of the lattice 100

[0071] In this particular example, there are four generally triangular projections which are arranged 90° apart about a center axis of the hollow bodies, on the top outer surfaces (198) of each of the hollow bodies. The triangular support projections 190, 192, 194 and 196 may receive and support on their concave edges 202, one or more reinforcement bars, or other types of reinforcement members, and are thus also referred to herein as support projections or reinforcement bar supports. [0072] Referring back to Figure 1, in the embodiment shown corresponding projections on adjacent hollow bodies are row and column aligned. For example, projections 190 and 192 on hollow body 106 are column-wise linearly aligned respectively with similar projections 190 and 192 on row-adjacent hollow body 110, parallel to lines 122 and 124 in a first direction. Likewise, projection 194 of hollow body 106 is linearly aligned with projection 194 of column-adjacent hollow body 108 in a second direction perpendicular to lines 122 and 124. Since the hollow bodies are arranged in linearly aligned rows and columns in the lattice, the support projections on adjacent hollow bodies are also linearly aligned in rows and columns. As such, the generally triangular shaped projections may be positioned on the hollow bodies to define at least one of rows and columns of support surfaces on the lattice to support at least one reinforcement member on the lattice 100. Alternatively, the top surface of each hollow body may have less than four or more than four projections, depending on how many rebars are desired to be held by the lattice. For example, the top surfaces of a row or column of hollow bodies may each have only one projection for holding a portion of a rebar.

Reinforcement [0073] Referring to Figures 12, 16 and 17, the lattice 100 may be used to manufacture a reinforced concrete slab by forming a system wherein the lattice 100 is positioned between a first or upper reinforcement bar layer 162a and a second or lower reinforcement bar layer 162b of a reinforcement assembly, and pouring concrete over the lattice and first and second reinforcement bar layers 162a and 162b.

[0074] In this example the first reinforcement bar layer 162a includes a plurality of criss-crossing steel reinforcement bars, for example, a first plurality of steel reinforcement bars 166, 168, 170, and 172 is supported in a first sub-layer by the triangular projections 190 and 192 on the hollow bodies and a second plurality of steel reinforcement bars 174, 176, 178, and 180, is supported in a second sub layer on steel reinforcement bars 166, 168, 170, and 172. The steel reinforcement bars 174, 176, 178, and 180 may be held in place on the reinforcement bars 166, 168, 170, and 172 by using heavy duty twist wires (not shown) known in the art for tying rebar together. The first reinforcement bar layer 162a is thus supported by the triangular projections 190 and 192 on the hollow bodies.

[0075] Alternatively, the bars 174-180 could rest on other triangular projections. For example, bar 178 could be supported by linearly aligned projections 194 and 196 on column-adjacent hollow bodies. In this case the reinforcement bars 166- 172 would rest on top of bars 174-180. As such, a plurality of parallel, straight reinforcement bars are receivable on the lattice 100 to be supported by the lattice 100 [0076] The second reinforcement layer 162b is comprised of a third plurality of parallel reinforcement bars, for example, bars 182, 184, and 186 that are supported between the columns of hollow bodies in the lattice, on the U-shaped connectors 120 or on the male and/or female connectors 222 and 224 on the left and/or right side legs 220 and 221 respectively and any adjacent left and/or right side legs 220 and 221 respectively of a corresponding adjacent lattice.

[0077] Referring back to Figures 2 and 12, since the legs 220 and 221 and enlarged portions 227 are dimensioned such that the top surface 230 of the receptacle 229 is approximately in a same plane as lower surfaces 241 of the bight portions 219 of the U-shaped integrally formed connectors 120, the rebars that are supported by the top surfaces 230 of the female connectors 222 and the top surfaces 253 of the solid rectangular portions 251 and on the surfaces 241 of the bight portions 219 of the U-shaped connectors 120 are disposed in a common plane beneath the hollow bodies. Effectively, the U-shaped connectors are oriented and positioned to support at least one reinforcement member between adjacent to the semi-spherical bottom portions of the hollow bodies. Thus, the at least one outwardly extending support projection may include one or more legs extending from the bottom semi-spherical portions of the hollow bodies and terminating in connectors having surfaces generally in a common plane.

[0078] In an alternative embodiment, the second reinforcement layer 162b may be comprised of a third plurality of parallel reinforcement bars, not shown, that are supported between the rows of hollow bodies in the lattice, on the U-shaped connectors 120 and/or on the male and/or female connectors 222 and 224 on the top and/or bottom row legs 225 and 223 respectively and any adjacent bottom and/or top row legs 223 and 225 respectively of a corresponding adjacent lattice. As a further alternative, the second reinforcement layer 162b may be comprised of the third plurality of parallel reinforcement bars 182, 184, and 186 supported by the U-shaped connectors 120 between the columns as shown, but with an additional, fourth plurality of reinforcement bars (not shown) laying on the third plurality of reinforcement bars, each bar of the fourth plurality laying between two adjacent rows of hollow bodies and extending perpendicularly to the bars of the third plurality to produce a criss-cross grid of reinforcement bars like the criss-cross grid on the top of the hollow bodies, only at a lower level, near the bottoms of the hollow bodies. A concrete slab having this arrangement of reinforcing bars with the previously described first reinforcement layer 162a would thus have two criss cross grids of reinforcement bars disposed in separate vertically spaced apart planes among the lattice of hollow bodies, which would provide greater strength to the slab.

[0079] In general, the first and second reinforcement bar layers 162a and 162b are held in fixed, spaced apart planes respectively, above and below the hollow bodies to accurately locate and maintain the rebars in position when pouring concrete poured over the system.

[0080] Figure 18 is a flow chart showing steps of a method of making the concrete slab 160 shown in Figure 19. Generally, the method involves placing the lattice described above within the bounds of a concrete form, positioning at least one reinforcement member within the bounds of the concrete form and on a least one of the at least one outwardly extending support projection such that the at least one reinforcement member is at least one of between adjacent hollow bodies or above the hollow bodies, placing concrete into the form to encompass the lattice of hollow bodies and the at least one reinforcement member, and curing the concrete to bind the apparatus, the at least one reinforcement member and the concrete into a unitary solid mass.

[0081] More particularly, referring to Figure 18, the method begins at step 232, wherein a lattice of hollow bodies is provided. The lattice may include a single lattice such as shown at 100 in Figure 1 or a lattice system comprising a plurality of any number of lattices 100 connected together as shown in Figure 7, 8 and 9, for example. The plurality of lattices 100 may provided and connected together on-site to form the lattice system or the lattice system may be pre-assembled by connecting a plurality of lattices 100 together, prior to placing the lattice system into a concrete form, a portion of which is shown at 302 in Figure 19.

[0082] At step 234, the lattice or lattice system is placed within the bounds of a concrete form 302, or the lattice system is assembled in the concrete form.

[0083] At step 236, reinforcement bars 182, 184, 186 that will form the second reinforcement bar layer 162b seen in Figures 15-17 are placed in bight portions 219 of U-connectors 120 and on the top surfaces 230 and 253, for example, of mating male and female connectors 224 and 222 of column-adjacent hollow bodies of adjacent lattices. The U-shaped connectors 120 and top surfaces 230 and 253 hold the rebars of the second reinforcement bar layer 162b between column- adjacent hollow bodies and generally in a plane beneath the hollow bodies, but above the surface (147 in Figure 12) on which the hollow bodies rest. Alternatively, reinforcement bars 182, 184, 186 may be placed between adjacent rows of hollow bodies (not shown), or an additional layer of reinforcement bars (now shown) may be placed perpendicularly on the reinforcement bars 182, 184, 186, to extend between adjacent rows of hollow bodies to form a lower criss-cross grid of reinforcement bars as the second reinforcement layer 162b. [0084] Also at step 236, reinforcement bars 166-172 that will form the first sub layer of the first reinforcement bar layer 162a are placed on the triangular projections 190 and 192 for example on the top portions of the hollow bodies to generally lie spaced apart and column-aligned in a plane above the hollow bodies. Next, the reinforcement bars 174-180 that will form the second sublayer of the first reinforcement bar layer 162a are placed in spaced-apart relation to one another and perpendicularly to the rebars 166-172 of the first sublayer and are secured to the first sublayer by heavy duty twist ties in a manner known in the art. This places the first reinforcement bar layer 162a on top of the hollow bodies of the lattice.

[0085] Referring to Figure 19, the form 302 within which the lattice system is placed will have a top surface 304 positioned higher than an uppermost surface 306 of the second sublayer of rebars 174-180, preferably about 1-inch above that upper most surface, so that the first reinforcement bar layer 162a is located about 1-inch below the surface 308 of the finished concrete, after the concrete has been placed. [0086] Then, at step 238, wet concrete is poured into the form 302 to encompass the lattice system and the reinforcement bar layers 162a and 162b seen best in Figures 16 and 17. When pouring, the wet concrete is directed into the spaces between the hollow bodies to flow around and under the hollow bodies to surround the second reinforcement bar layer 162b and to fill and build up in areas between the hollow bodies and then to cover the tops of the hollow bodies and engulf the first reinforcement bar layer 162a, until the wet concrete reaches a level commensurate with the top surface 304 of the concrete form 302 about 1- inch above the uppermost surface 306 of the second sublayer of the first reinforcing bar layer 162a.

[0087] At step 240, the concrete is allowed to set, i.e. , become a solid unitary mass, henceforth referred to as the slab, encapsulating the lattice system and the first and second reinforcing bar layers 162a and 162b.

[0088] Finally, at step 242 the form 302 is removed from the slab 160 and the cross-sectional view of the slab shown in Figure 19 reveals the relative positions of the second reinforcing bar layer 162b, the relative positions of the hollow bodies of the lattice 100 and the relative position of the first sublayer of the first reinforcing bar layer 162a contained in the slab.

[0089] Referring to Figure 19, it can be seen that the concrete has engaged and surrounds the reinforcement members of the first and second reinforcing bar layers 162a and 162b, while the hollow bodies of the lattice occupy spaces 310 that would otherwise be occupied by concrete. The hollow bodies of the lattice have held the reinforcement members in suitable positions during the pouring of the wet concrete to locate the first and second reinforcing bar layers in appropriate locations to provide strength to the slab and to cause the concrete to engage with the reinforcement members when the concrete is poured. The hollow bodies also define areas to be occupied by the concrete, i.e., between adjacent hollow bodies and they also define areas that are not to be occupied by concrete i.e., inside the spaces 310 of the hollow bodies thereby providing occupied areas and voids in the concrete and reducing the amount of concrete needed to make the slab, while providing a slab of similar or better strength than a slab formed without use of the hollow bodies. The slab may be used as a floor slab or a wall slab for example, or may form part of a footing to be used as a foundation on which to build a building structure. [0090] Generally, there is provided a concrete slab comprising the apparatus described above, at least one reinforcement member on the at least one outwardly extending support projection of the apparatus and concrete encasing the apparatus and the at least one reinforcement member, whereby the hollow bodies define voids in the concrete and spaces between the hollow bodies are occupied by concrete and at least one of a space between the lattice and a top surface of the concrete, a space between the lattice and a bottom surface of the concrete and the one of the spaces between the hollow bodies is occupied by the at least one reinforcement member. [0091] It will be understood by a person skilled in the art that many of the details provided above are by way of example only and are not intended to limit the scope of this disclosure.