US3855375A

US3855375A - Floor building system

Info

Publication number: US3855375A
Application number: US00343551A
Authority: US
Inventors: J Boux
Original assignee: General Concrete of Canada Ltd
Current assignee: General Concrete of Canada Ltd
Priority date: 1973-03-21
Filing date: 1973-03-21
Publication date: 1974-12-17
Anticipated expiration: 1991-12-17

Abstract

A floor building system for the construction of a composite floor including prestressed slab portions and poured concrete portions includes forms utilizing the slabs for support instead of floor-to-ceiling shores. Particularly, brackets which fit into opposing grooves on adjoining slabs and are releasable therefrom are used.

Description

' limited States Patent [191 Boux [ Dec. 17, 1974 1 FLOOR BUILDING SYSTEM [75] Inventor: Joseph F. Boux, Burlington,

Ontario, Canada [73] Assignee: General Concrete of Canada Limited, Hamilton, Ontario, Canada [22] Filed: Mar. 21, 1973 [2]] App]. No.: 343,55]

[52] U .S. Cl 264/35, 249/l9, 249/25,

[51] Int. Cl. E04b 1/16 [58] Field of Search 264/35, 261, 334; 249/19, 249/23, 25, 28, 30, 219 R [56] References Cited UNlTED STATES PATENTS 3,628,765 12/1971 Sanders 249/19 1,790,135 l/l931 Cuthbertson 249/25 1,836,197 12/1931 Soule i 249/25 3,693,929 9/1972 Martin 249/25 Primary ExaminerR0bert F. White Assistant Examiner-Thomas P. Pavelko Attorney, Agent, or Firm-Sim & McBurney [57] ABSTRACT A floor building system for the construction of a composite floor including prestressed slabportions and poured concrete portions includes forms utilizing the slabs for support instead of floor-to-ceiling shores. Particularly, brackets which fit into opposing grooves on adjoining slabs and are releasable therefrom are used.

4 Claims, 5 Drawing Figures PATENTEI] DEC I 7 I974 sum 1'0; 2

POSITION SLABS AT DESIRED SPACED-APART LOCATIONS POUR CONCRETE INTO CHANNELS BUILD PREPRESSED SLABS FROM PREFORMED BLOCKS LOCATE FORMS IN TEMPORARY FIXED POSITION DEFINEDBY SLABS AND FORMS BETWEEN PAIRS OF SLABS ALLOW CONCRETE TO CURE FIG 1 PATENTEI] DEB! 71974 sum 2 u; 2

1 FLOOR BUILDING SYSTEM FIELD OF INVENTION The present invention relates to a building system, more particularly to a concrete floor building system.

BACKGROUND TO THE INVENTION A number of floor building systems for multi-storey building structures are known and a number of these involve the use of a combination of prestressed concrete slabs and poured concrete. A form is positioned across the gap between the slabs to define with the slabs a channel into which the concrete may be poured. The form generally is supported from below by shores bearing on the floor of the next lower storey, which must be maintained in place until the concrete cures, generally about 7 or more days.

In building a muiti-storey structure, the presence of these floor-to-ceiling shores hampers the finishing of the area in which the shores are located and it is necessary, in most instances, to await the completion of the curing of the poured concrete. and removal of the shores and forms before finishing work canbe carried out in the lower, storey.

A second type of form is permanently incorporated into the structure, as specifically described in US. Pat. No. 2,102,447. Such forms usually are made of wood, which, while one of the cheapest material available, nevertheless is costly as it is not reusable and additionally represents a fire hazard.

A further type of floor building system which may be used is that described in U.S. Pat. No. 3,283,457, and known commercially as the CELDEX (Trademark) system, involving the use of a plurality of prestressed slabs which are interlocked one with another to provide a floor which is completely formed of side-by-side posi tioned and locked slabs. While this system does afford the advantage that a poured concrete cure period involving shores or in place forms is not required, nevertheless the system is considerably more expensive than the combination of pre-stressed slabs with poured concrete infill.

SUMMARY OF INVENTION In accordance with the present invention there is provided a floor building system utilizing a combination of prestressed slabs and poured concrete infill, in which both of the aforementioned disadvantages are overcome. The floor building system of the present invention utilizes retractable and reusable forms, (i.e., ones which are positioned between the slabs only during pouring and curing of the concrete infill), which do not utilize conventional shores. In the method of the present invention, one or more forms are positioned between an adjacent pair of prestressed slabs to define with the slabs a pourable concrete receiving channel. The forms are temporarily supported from below by means releasably secured between the slabs. The concrete is poured into the channel to the desired depth, and after the concrete is cured, the support means for the form is released from securement to the slabs and the forms are removed.

In this way, it is possible to utilize retractable and reusable forms and hence avoid the undesirability of permanent forms and, additionally, utilize such forms without conventional floor-to-ceiling shores, and

hence a completely open area is available on the storey level below that in which the floor is being built.

Any desired form of prestressed slab may be used. Preferably, the slab is formed from a plurality of individual concrete blocks.

Any convenient support means releasably secured to the slabs may be utilized. Typically, an elongated groove is formed in each facing side wall of each adjacent pair of slabs. The groove is located below the intended level of the form during the use of the latter. These grooves generally are provided by alignment of pre-formed individual grooves in both side faces of the individual blocks from which the slabs are constructed.

A supporting element is extended between and is releasably positioned in the opposed grooves of the adjacent slabs. Thesupporting element engages at least part of the underside of the form to provide a support from below for the form and hence for the poured infill during cure. Atleast two of such elements are utilized for each form, the number utilized for each form dependtail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 represents a block representation of the method steps involved in the building system of the present invention;

FIG. 2 represents a perspectiveview of one embodiment of a floor built in accordance with the present invention during different phases of the operation;

FIG. 3 is a sectional view of a floor during a further phase of the operation;

FIG. 4 is a perspective view of a releasable supporting device for use in the present invention; and

FIG. 5 is a close-up perspective view of a finished ceiling and floor structure constructed in accordance with the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS In the method of the present invention, a floor is built by a sequential'operation, outlined schematically in FIG. 1. The first step involves the formation of prestressed slabs. The slabs may be formed in any convenient manner, typically using the CELDEX (Trademark) method. The Celdex slabs are formed, as is more particularly described in U.S. Pat. No. 3,283,457 from a plurality of specially constructed concrete blocks, each having centrally located apertures or holes which, when aligned, define a longitudinally-extending, cablereceiving passage. One or more lengths of cable are passed through the passage from end to end of the block row and then tensioned to place the row of blocks under compression. Usually, each of the blocks additionally is provided with laterally-spaced opposed holes which, when the blocks are aligned, define laterally-spaced longitudinally-extending opposed passages in which reinforcing members such as steel rods are placed. Thereafter the cable-containing passage and the reinforcing member-containing passages are filled with grout which is allowed to set while the cable is maintained under tension.

The individual blocks which are combined to provide the prestressed slabs require modification for use in the present invention, and such modifications may be made by appropriate modifications to the mold forming the blocks. Such modifications relate to the side faces of the blocks which will provide longitudinally extending side faces of the slabs.

A groove extending laterally of each side face is provided, aligning with like grooves of other blocks of the slab to define a continuous groove extending longitudinally of each side of the individual slabs. The purpose of this groove will become more apparent hereinafter. The grooves usually are provided in the lower part of the block. Further, a shoulder may be provided extending laterally of each side face in the upper part thereof. The shoulders align with like shoulders of adjacent blocks to define a continuous shoulder along each side of the slab.

The slabs may be of any convenient depth and width, typically a depth about 8 inches with a width of about 24 inches. The length of the slabs depends on the distance between the walls of the structure, the strength of the slab, which in turn is dependent on its depth,

width and the nature and type of reinforcement used, and the loading requirements of the finished floor.

After formation, the slabs are positioned at the desired locations, generally parallel to each other, spaced apart across the width of the floor and supported at their ends by upright walls. The slabs are spaced-apart any desired distance commensurate with loading and economy requirements. In a typical system, the slabs are spaced apart from each other a distance equal to their width, and, therefore, in the case where the slabs have an approximately 24 inch width, a similar 24inch space is provided between adjacent slabs.

Forms then are positioned between adjacent slabs and supported from below to define poured concrete receiving channels of shallow depth between each adjacent pair of slabs. The forms may be of any convenient length and usually have a transverse width approximately equal to the gap between the slabs, so that poured concrete is substantially prevented from leaking downwardly out of the concrete receiving channel. The forms generally have a length and weight capable of ready handling by a single workman and a plurality of forms generally is required to provide each channel. It is possible, however, to provide a form having a length substantially the same as the gap between the slabs.

The forms may be supported from below in any convenient manner in which the supporting .device is releasably positioned in the opposed grooves in the side faces of the slabs, such as, in the manner described in more detail below with reference to FIGS. 2 to 4 of the accompanying drawings. By utilizing a support device which is engaged in the opposed grooves of the slabs, the use of temporary shores is avoided.

The next step involves pouring concrete into each of the concrete receiving channels. A suitable end barrier, such as an upright skirt on the form, or an end block on the supporting wall, is located at each end of the channels to prevent the concrete from pouring out of the channel. Usually, the channels are filled just to the level of the top of the slabs by the poured concrete. In some instances, the slabs also may be encased in poured concrete resulting in a monolithic concrete floor surface. Steel reinforcement, or any other desired type of reinforcement, may be positioned in the poured concrete. The poured concrete then is left to cure. Since floor-to-ceiling shores are not required in the present invention to support the forms, during the period that the poured concrete is curing, the whole working area below the floor under construction is open and unobstructed by shores and work may be carried out in this area.

At the end of the curing period, the supports for the forms are removed and the forms then are retracted. The resulting floor structure, which is a composite of prestressed slabs and poured concrete sections requires little or no further finishing and is suitable for tiling, wood block laying or carpet laying. The overall loading capacity may be modified over a wide range by use of particular slabs, particular concrete, steel reinforcement of the concrete, and varying widths of these items.

The floor building system of the present invention has particular applicability in multi-storey structures. In such structures the floor of one storey also provides the ceiling of the next lower storey. After removal of the forms, the ceiling may be finished in any convenient manner.

Referring now to FIGS. 2 to 4, there is shown in FIGS. 2 and 3 a floor building system according to the present invention at different phases and described above with reference to FIG. 1. Thus, in FIG. 2 there is seen the cured concrete after removal of the form and the position of form prior to pouring of the concrete. In FIG. 3, the concrete is curing or is cured and the form is still in place. Spaced-apart prestressed slabs 10 are constructed from individual blocks 12', such as in the manner described in US. Pat. No. 3,283,457. The prestressed slabs 10 may be of any'convenient design.

The individual blocks 12 include an opening 14 which is aligned with like openings of other blocks 12 to provide a first longitudinal passage in each slab l0. Stressed cables (not shown) are situated in this first longitudinal passage to prestress the slab 10 and the passage is filled with grouting. Further openings 16 are aligned with like openings of other blocks 12 to provide second and third longitudinal passages in each slab 10. In each of these second and third longitudinal passages is situated reinforcing rods (not shown) of any desired dimension and the passages are filled with grouting. Voids l8 and 20 are provided in each block 12 to lighten its weight and additionally to provide ducting through the slab to receiving service members, such as electricity or phone leads and heating or airconditioning ducts.

Further openings 22 may be provided and these openings are aligned with like openings in other blocks 12 to provide grouting passages through the slabs.

The side faces 24 of the individual blocks 12 each are shaped in particular manner. A shoulder 26 is provided in the side faces 24. An elongated form 28, generally constructed of wood, although any other convenient material may be used, is positioned between adjacent spans to cooperate with the shoulders 26 of the opposed side faces 24 to define a channel 30 into which concrete 32 may be poured.

The form 28 generally is of a length such that it is manageable by a single workman.'Typically in a floor construction a plurality of such forms 28 are positioned effectively to provide a continuous form between the spans along the length thereof. Each remote end of the channel 30 is sealed off in any convenient manner, such as an upright end wall (not shown), whereby the concrete infill 32 is confined in the channel 30 during curing. Reinforcing rods for the concrete may be positioned in the channel 30 prior to pouring same.

In the embodiment illustrated, the infill concrete 32 completely fills the channel 30 and its upper surface is located in the same plane as the upper surface of the slabs 10. This represents a preferred embodiment of the invention, it being possible to pour concrete in sufficient quantity not only to fill the channels 30 but also to overlie the upper surface of the slabs 10, so that the whole upper surface of the floor when cured is of poured concrete. v

The depth of location of the shoulders 26 from the upper surface of the slabs 10 may vary depending on the load requirements of the floor, the load bearing capacity of the particular concrete and the total depth of the slabs 10.

The side faces 24 of each block 12 also have a lateral groove 34 formed therein and extending substantially parallel to the top face of the slab 10. The lateral grooves 34 of each block 12 are aligned to provide a longitudinal groove extending along each side face of each slab 10. The channel 34 defines with the shoulder 26 a protrusion 36, the protrusion generally having a depth substantially that of the deepest portion of the side edges of the form 28.

A plurality of releasable support members or brackets 38, illustrated more particularly in FIG. 4, is provided to engage and support the forms 28. Each support member 38 includes an'elongated element 40 having a relatively deep dimension 42 in the plane of the member 38 and a relatively narrow dimension 44 in a perpendicular plane. In use when supporting the-form 28, the remote ends 46 and 48 of the element 40 are .received one in each ofthe opposed grooves 34, with the deep dimension extending vertically of the groove and with the narrow dimension supporting the form 28.

The grooves 34 and the

ends

46 and 48 of the element 40 generally are dimensioned so that, when the bracket 38 positioned substantially perpendicular to the horizontal plane of-the slabs 10, the depth of the

ends

46 and 48 substantially fills the distance between the side walls of the grooves 34.

Two arm elements 50 are provided, pivotally secured to the element 40 one adjacent each remote end 46 and r 48 thereof, by pivo pins 52. Each of the arm elements 50 has mounted thereon a flange 54, each of which extends in the direction of the appropriate end of the element 40. The flanges 54 each include a block engaging surface 56, extending in plane perpendicular to the plane of the bracket 38. As seen be seewn in dotted outline, more particularly in FIG. 3, during support of the form 28, the surface 56 of the flange 54 touchingly engages the underside surface of the adjacent block 12. The engagement of the planar surface 56 and the flat bottom surface of the block 12 stabilizes the element 40 ina plane perpendicular to the horizontal plane of the slabs, and prevents rotation of the element 40 about its axis, and in this way the forms 28 are supported.

Each flange 54 is secured to an arm 50 at a location equivalent to substantially the vertical distance from the lower side of the channel 34 to the underside sur-' be readily apparent from this description the manner in which assembly is achieved.

The arms 50 of the support member or bracket 38 are moved towards each other to release the flanges 54 from engagement with the underside of the blocks 12 and hence the solid outline position of FIG. 3 is attained. The element 40 then is rotated on its longitudinal axis by moving the arms 50 towards the form 28 to release the

ends

46 and 48 of the element 40 from fixed engagement with the upper and lower walls of the grooves 34. This motion may loosen the form 28 from the undersurface of the cured concrete infill 32, although in many instances the form 28 needs to be jarred loose. During this motion the element 40 is released from the wedging action of the form 28 and, in those instances where the form remains stuck to the cured concrete and requiresjarring to loosen it, the element 40 is moved out of engagement with the form 28.

The ends 46 and 4 of the element 40 then are removed completely from the grooves 34 by rotation of the support member 38 in its plane. The support member 38 thus is free to be removed. When all of the support members 38 supporting a particular form 28 have been removed, the form 28 then may be removed, leaving a finished all concrete structure.

The support member or bracket 38 represents only one manner in which retractable support for the form 28 may be achieved. Any convenient device capable of releasable engagement with the grooves 34 may be employed. The device also must be capable of ready release from engagement with the form 28 after the curing stage. a

As mentioned previously, in many instances; the floor building system of the present invention is utilized in multi-storey buildings, so that the floor of one storey also is the ceiling of the next lower storey. The ceiling associated with the floor built as described above may be finished in any convenient manner, for example, as

illustrated in FIG. 5. As shown in FIG. 5, the gap between the slabs 10 may be bridged by suitable lathing 58 extending in a single or multiple elements along the length of the ceiling and suspended from the concrete infill 32 by suspension rods 60. The lathing 58 may be secured to the slabs 10 by suitable or any convenient Modifications are possible within the scope of the invention.

What I claim is:

l. A method of constructing a floor which comprises positioning a plurality of prestressed concrete slabs having upper, lower and side faces in spaced apart locations, each of said slabs having a longitudinallyextending groove in each side face thereof adjacent the lower face thereof, each said groove defining with said lower face a shoulder, supporting each of said slabs in said spaced-apart locations at each end thereof, positioning at least one removable form between each pair of slabs and above said grooves to define therebetween a shallow elongated channel, for each said at least one form positioning at least two bracket supports in longitudinally spaced-apart positions beneath said form, each of said bracket supports having a beam member contacting said form and two arm members pivotally mounted to said beam member one adjacent each end therof, positioning the ends of said beam member in the opposed grooves of an adjacent pair of slabs, locking the ends of said beam member in said opposed grooves with said arm members depending generally downwardly from said beam member by moving flange elements on each of said arm members into engagement with said lower face of the slabs cooperatively with the ends of the beam member to grip said shoulders thereby temporarily supporting each of said forms from below on an adjacent pair of slabs, pouring concrete into each of said channels at least to the depth thereof to define with the prestressed slabs a substantially flat floor surface, allowing the concrete to cure, moving said flange elements out of said engagement thereby releasing each of said bracket supports from said locked position, removing said ends of said beam members from said grooves, removing said beam members from engagement with said forms thereby releasing said temporary support, and separately removing said forms.

2. The method of claim 1, wherein said concrete is poured into said channels to the depth thereof.

3. The method of claim 1 wherein said beam member has a depth substantially greater than its width, the depth of said beam member at each end thereof being substantially the width of said grooves, each of said flanges has a flat surface extending substantially perpendicular to the plane of said beam member, and said temporary support for each beam is achieved by positioning said at least two bracket supports with said beam member aligned with its depth vertical and said ends extending into said grooves and engaging the walls thereof, the engagement of the flanges with the lower face of said slabs and said gripping thereby maintaining said beam member in said substantially vertical alignment, and said ends are removed from said grooves after release of said bracket supports from said locked position rotating said bracket support about the longitudinal axis of said beam member to release said ends from engagement with the side walls of said grooves and thereafter rotating said bracket support in the plane of said beam member to remove said ends from said grooves.

4. The method of claim 3, wherein reinforcing rods are positioned in said concrete receiving channel.

Claims

1. A method of constructing a floor which comprises positioning a plurality of prestressed concrete slabs having upper, lower and side faces in spaced apart locations, each of said slabs having a longitudinally-extending groove in each side face thereof adjacent the lower face thereof, each said groove defining with said lower face a shoulder, supporting each of said slabs in said spaced-apart locations at each end thereof, positioning at least one removable form between each pair of slabs and above said grooves to define therebetween a shallow elongated channel, for each said at least one form positioning at least two bracket supports in longitudinally spaced-apart positions beneath said form, each of said bracket supports having a beam member contacting said form and two arm members pivotally mounted to said beam member one adjacent each end therof, positioning the ends of said beam member in the opposed grooves of an adjacent pair of slabs, locking the ends of said beam member in said opposed grooves with said arm members depending generally downwardly from said beam member by moving flange elements on each of said arm members into engagement with said lower face of the slabs cooperatively with the ends of the beam member to grip said shoulders thereby temporarily supporting each of said forms from below on an adjacent pair of slabs, pouring concrete into each of said channels at least to the depth thereof to define with the prestressed slabs a substantially flat floor surface, allowing the concrete to cure, moving said flange elements out of said engagement thereby releasing each of said bracket supports from said locked position, removing said ends of said beam members from said grooves, removing said beam members from engagement with said forms thereby releasing said temporary support, and separately removing said forms.