Prefabricated concrete floor structure

Abstract

A precast concrete floor panel having stems molded in a mold with stem mold cavities and a deck. The deck can be formed in the same mold that includes the stem mold cavities or the concrete for the deck can be poured and cured on-site after the stems have been removed from the mold. The mold can include mold segments made from an insulating material that can remain attached to the stems to insulate the finished floor panel.

Claims

1. A method for forming at least a portion of a precast insulated concrete floor panel having a deck and a plurality of spaced-apart stems extending along the length of the floor panel from the deck, the method comprising the steps of: cutting a plurality of stem mold segments from a larger block of expanded polystyrene foam insulation, the multiple stem mold segments being cut from the same block of foam insulation, the stem mold segments being cut in an interlocking pattern from the block of foam insulation, each stem mold segment having a generally “U” shaped cross section having a pair of spaced-apart legs and a web between the legs, the interlocking pattern being formed by the legs of two stem mold segments being cut from between the legs of a third stem mold segment; providing a mold, the mold comprising the plurality of elongate stem mold segments extending parallel with one another on respective longitudinal axes in a length direction and being spaced apart laterally adjacent one another in a width direction perpendicular to the length direction, each pair of adjacent stem mold segments having outer surfaces adjacent to one another that define a space therebetween having the shape of the stem to be formed between the pair of adjacent stem mold segments, each mold segment being an integral one-piece foam insulation member formed without seams or joints that extend in the length direction; and pouring concrete into the spaces between the stem mold segments.

2. The method of claim 1 wherein each pair of adjacent mold segments are connected together by a rigid member closing a side of the space defined by the adjacent stem mold segments.

3. The method of claim 1 wherein a top end of the each space between adjacent pairs of stem mold segments receives the cement poured into the space, the method further comprising the steps of: pouring the concrete to the top end of each space and not above the top end; and allowing the concrete in the spaces to harden to form rigid stems without pouring additional concrete in the spaces, thereby forming a partially completed floor panel without a deck.

4. The method of claim 3 comprising the steps of: transporting the partially completed floor panel from a first location to a second location; and pouring concrete for a deck on the partially completed floor panel at the second location.

5. The method of claim 1 wherein the mold defines a pair of cavities for forming end blocks, the plurality of stem mold segments comprise a respective set of adjacent pairs of stem mold segments associated with each cavity that face each cavity with the spaces between the adjacent pairs of stem mold segments opening into each cavity.

6. The method of claim 1 comprising the step of continuously pouring concrete into the spaces between the stem mold segments to form the stems of the floor panel and pouring concrete over the stem mold segments to form the deck of the floor panel.

7. The method of claim 1 wherein more than one stem mold segment extends on each longitudinal axis.

Description

BRIEF SUMMARY OF THE DRAWINGS

(1) FIG. 1 is a plan view of the top of a precast concrete floor intended to be manufactured off-site.

(2) FIG. 2 is a cross-sectional view of the floor shown in FIG. 1 taken along line 2-2 of FIG. 1.

(3) FIG. 3 illustrates two of the precast concrete floors shown in FIG. 1 connected side-by-side.

(4) FIG. 4 shows a cutting pattern for cutting the stem mold segments shown in FIG. 2 from a foam block.

(5) FIGS. 5 and 6 illustrate cutting patterns for cutting other embodiments of stem mold segments.

(6) FIG. 7 is a plan view of the top of a precast concrete floor without a deck and intended to be manufactured off-site but completed on-site.

(7) FIG. 8 is a cross-sectional view of the floor shown in FIG. 7 taken along line 8-8 of FIG. 7.

(8) FIG. 9 illustrates two of the precast concrete floors shown in FIG. 7 connected side-by-side.

(9) FIG. 10 is a cross-sectional view similar to FIG. 8 of a portion of an alternative embodiment precast concrete floor without a deck and intended to be manufactured off-site but completed on-site.

(10) FIGS. 11 and 12 are top and end views respectively view of a precast concrete floor with a relatively thicker flange and without end blocks.

(11) FIG. 13 is an end view of a portion of a form for casting the precast floor shown in FIG. 11.

(12) FIGS. 14-16 illustrate a top plan view, cross-sectional view, and an enlarged view of a portion of a prior art precast concrete floor.

DETAILED DESCRIPTION

(13) FIGS. 1 and 2 illustrate a precast concrete floor panel 10. The precast floor panel 10 includes a monolithic concrete slab 12 that was poured and cured in a mold 14 formed in part from mold segments described below. The mold segments are cut from EPS (expanded polystyrene) foam blocks. The foam block mold segments remain attached to the concrete slab 12 after the slab 12 has solidified in the mold.

(14) The concrete slab 12 is generally rectangular-shaped and includes a reinforced top flange or deck 16 that defines a flat floor extending the width and length of the floor panel 10 along lateral sides 18 and longitudinal sides 20. End blocks 22, 24 on the bottom of the deck 16 extend the width of the floor panel 10. Four parallel, spaced-apart stems 26 are also on the bottom of the deck 16 and extend along the length of the floor panel 10, connecting together the end blocks 22, 24. The outermost stems 26 are spaced inwardly from the sides 20 of the deck 16.

(15) The illustrated deck 16 has a thickness of one inch. The concrete forming the deck, blocks and stems can be reinforced or pre-stressed with reinforcement bars, reinforcement wires, wire mesh, fibers, or the like (not shown) embedded in the soft concrete or mixed into the concrete prior to pouring as is known in the concrete construction art. An optional light-weight, non-structural leveling coat can be applied to the top of the deck 16.

(16) The stems 26 extend away from the bottom deck surface 28 and extend along the span of the slab 12. The illustrated stems 26 extend along respective longitudinal axes and are spaced apart laterally from one another on two-foot centers, each stem 26 having a preferred width of between two inches and fifteen inches, and extend from the deck bottom surface 28 a distance of between six inches and sixteen inches.

(17) The insulation mold 14 is constructed in part from a number of stem mold segments 30 realized as like stem mold segments 30a and like stem mold segments 30b. The stem mold segments 30 are arranged to extend along respective longitudinal axes parallel with the stem axes and are also arranged to be spaced apart laterally. The stem mold segments 30 are sandwiched between the end blocks and extend the full length of the stems 26, and are spaced apart from one another without foam seams or foam joints that extend along the stems. The pairs of stem mold segments 30 partially define longitudinal mold cavities 32 for the stems 26. The bottoms of the mold cavities 32 are closed by closing members 34 that extend between adjacent pairs of the stem mold segments 30.

(18) The end surfaces of the stem mold segments 30 that face the end blocks also form part of the insulation mold 14 that defines cavities to receive and hold the cement forming the end blocks. The illustrated closing members 34 are rigid members glued or otherwise mechanically fastened to the adjacent stem mold segments 30. The illustrated closing members 34 are plywood sheets. A wall stud (not shown) similar to the wall stud 248 shown in FIG. 10 may be fixed to the bottom side of each closing member 34 for attachment of drywall or other finishing materials, or the closing member 34 can be used directly as an attachment member.

(19) The stem mold segments 30 are integral, homogeneous, one-piece members cut from pre-manufactured blocks of EPS form insulation. The illustrated mold segments 30 are cut from nine-foot long blocks of insulation that have a three foot by two foot rectangular cross section. If the panel 10 to be formed in the mold is less than about nine feet long, then a single stem mold segment 30 can extend the entire longitudinal axis of the mold between the end blocks. If the panel 10 to be formed in the mold is longer than about nine feet long, two or more mold segments 30 can be placed end-to-end along each axis to span the required length of the mold 14 between the end blocks.

(20) The illustrated stems 26 extend away from the deck bottom surface 28 by are about 11 inches and are about two inches thick.

(21) The stem mold segments 30 include like stem mold segments 30a that are each placed between adjacent pairs of mold segments and like end stem mold segments 30b that are each placed adjacent to a single stem mold segment 30.

(22) Each illustrated stem mold segment 30a is about 21 inches wide and about 11 inches deep. The mold segment 30a is a generally “U” or “C” shaped member and includes spaced apart legs joined together by a web 38. The legs 36 are each about 5 inches wide. The web 38 is about 3 inches thick.

(23) The outside surfaces of the legs 36 define respective sides of the mold cavities 32 located on either side of the mold segment 30a. The upper surface of the web 38 defines the bottom of the deck 16 that spans between the two adjacent mold cavities 32. Having a cutout portion in the stem mold segment 30a between the legs 36 to define the interior of the “U” or “C” shape reduces the weight of the stem mold segment 30a. The cutout portion also enables more efficient utilization of the foam block supplying the mold segments 30a as will be explained in greater detail below.

(24) Each stem mold segment 30b is generally rectangular in cross-section and sized to extend between an adjacent stem 26 and a longitudinal side 20 of the deck 16.

(25) FIG. 3 illustrates two like floor panels 10 connected side-by-side by metal slab connectors 40. The stem mold segments 30b do not extend beyond the deck 16 and enable the floor panels 10 to be spaced closely to one another. The connection of the two floor panels 10 is otherwise conventional and so will not be discussed in further detail.

(26) FIG. 4 illustrates a periodic tiling pattern used to cut stem mold segments 30a from an EPS foam block 42. FIG. 4 illustrates the tiling pattern on a rectangular cross-section of the block 42. Except for stem mold segments 30a that adjoin an outer face of the block, all outer surfaces of a stem mold segment 30a are surfaces cut from the block 40. The illustrated tiling pattern has two tiling rows 44, 46 of interlocking stem mold segments 30a extending across the width of the block 42 and the rows 44, 46 repeating across the height of the block 42. The stem mold segments 30a in a row 44 are offset columnwise by one-half the segment width from the pair of facing stem mold segments 30a in the adjacent row 46.

(27) The cutout portion removed from a stem mold segment 30a between the legs of the “U” in a tiling row 44 or tiling row 46 is used in forming a leg 36 of each facing stem mold segment 30a in the other row 46 or row 44. This interlocking pattern enables cutouts to be formed in the stem mold segments 30a for weight saving without substantial waste of foam insulation. In embodiments portions of the block 42 not used in the stem mold segments 30a can be used to form stem mold segments 30b or other parts of the mold 14 to further eliminate waste.

(28) FIGS. 5 and 6 illustrate similar tiling patterns for cutting other embodiments of stem mold segments 30a from an EPS foam block 42 using interlocking tiling rows 44, 46.

(29) FIGS. 7 and 8 illustrate a pre-cast, concrete floor panel or slab 110 that was poured and cured in a mold formed in part from the mold segments 30a previously described. The mold segments 30a remain attached to the cured concrete.

(30) The floor panel 110 is formed with end blocks 122 and 124 like the end blocks 22, 24 and stems 126 like the stems 26. In the illustrated embodiment the outer stems 126 are placed on the longitudinal sides 20 of the floor panel 110. This enables all the stem mold segments to be mold segments 30a as can be best seen in FIG. 8.

(31) The slab or floor panel 110 is initially constructed without the equivalent top sheet or deck 16 of the floor panel 10. The deck is intended to be constructed off-site, that is, the cement for the deck is poured and cured later after the floor panel 110 shown in FIGS. 7 and 8 is completed. The mold 114 includes the mold segments 30a that remain attached to the end blocks 122, 124 and the stems 126 and partially define the later formed deck.

(32) It has been found that having the end blocks 122, 124 and the stems 126 form a unitary structure provides sufficient rigidity and strength for transportation of the floor panel 110 to a job site. By not forming the deck, the weight of the floor panel 110 is significantly reduced and a truck can transport more of the more of the partially completed floor panels to the job site.

(33) A temporary mold form made of plywood or timber that defines the outer perimeter of the deck is formed on-site for pouring the deck.

(34) FIG. 9 illustrates two floor panels 110 bolted together side-by-side by a set of bolt fastener assemblies 140. Clearance holes 142 are formed in the facing mold segments 30a for the bolts and nuts, the bolt extending through bolt holes in the facing stems 126.

(35) The floor panel 110 has a pair of outermost stems 126 that are not sandwiched between adjacent pairs of stems and are located along the left and right sides respectively of the panel 110 as viewed in FIG. 8.

(36) FIG. 10 illustrates a left side portion of a slab 144 in which the left-most stem 145 is spaced away from the longitudinal left edge of the slab 144. To provide greater structural support of the slab 144 along the longitudinal edge of the slab 144, the stem 145 includes a relatively thin support flange 146 that is even with and extends from the top of the stem 145 to an outer, flat flange surface 147. The flange surface 147 is flush with and extends along the longitudinal left edge of the slab 144. The flange surface 147 is also flush with an outer facing surface of a stem mold segment 148. The stem mold segment 148 cooperates with a stem mold segment 149 (stem mold segment 149 is like a stem mold segment 30a) in defining a mold cavity for the stem 145 and its flange 146. Interior stems 150 that are located between adjacent pairs of stems are formed using adjacent pairs of stem mold segments 149 as described above for the floor 110. The right-most stem (not shown) is a mirror image of the stem 145 and includes a flange like the flange 146 that extends along the right longitudinal edge of the slab 144. Lumber pieces 151 between adjacent mold segments close the mold between mold segments.

(37) The support flange 146 helps support the deck that is poured on top of the slab 144 as previously described for the slab 110.

(38) FIGS. 11 and 12 show views of a precast concrete floor formed as a monolithic concrete slab 152 that was poured and cured in a mold constructed entirely from, in the illustrated embodiment, one-quarter inch steel plate. There is no insulation attached to the concrete slab 152 when the slab 152 is removed from the mold after solidifying. Insulation can be attached to the concrete slab 152 after removal from the mold if desired.

(39) The slab 152 has a top flange or deck 156 that includes the top surface of the floor. The deck 156 is similar to the deck 16 but is relatively thicker than the deck 16. By thickening the deck 156, it is possible to cast the slab 152 within a steel form or mold without the need for EPS foam forming any part of the mold and without the need for end blocks molded into the slab to support the stems 166. The slab 152 is removed from the mold and is moved during transport using conventional vacuum lifting devices or lifting brackets typically used for lifting steel plate. Vacuum lifters that can be modified for use in lifting and moving the slab 152 are available from, among others, The Caldwell Group, Inc., Rockford, Ill., USA.

(40) The form used for casting the slab 153 may be a reusable form perhaps several hundred feet long for use at a precast plant. The form is, in an embodiment, made from steel plate that is bent as needed to form the desired shape. FIG. 13 illustrates a steel plate bent to form a portion of the mold defining a stem cavity 160 for forming a stem and a deck cavity 162 for forming the deck, the deck cavity opening to each of the stem cavities. The outer stem cavities can define a stem like the stem 145 if the outer stems are spaced from the outer longitudinal edges of the floor slab. In the illustrated embodiment the floor slab is made without end blocks and so the mold defines only stem cavities and a deck cavity.

(41) The mold is used to cast multiple slabs 152 at the same time (in a possible embodiment it is contemplated that ten slabs 152 are formed simultaneously). The slabs 152 would be formed end-to-end along the length of the form, with each slab 152 separated from an adjacent slab by a removable bulkhead placed in the form. The bulkhead is placed along the form as required by the desired length of the slab, enabling slabs of varying length to be formed merely by changing the location of the bulkheads. If desired, members or studs can be placed in the form for attachment to the bottom of the stems.

(42) While one or more embodiments have been disclosed and described in detail, it is understood that this is capable of modification and that the scope of the disclosure is not limited to the precise details set forth but includes modifications obvious to a person of ordinary skill in possession of this disclosure and also such changes and alterations as fall within the purview of the following claims.