Patent Application
20160177585
This invention relates generally to the field of concrete depression form systems and methods utilized to create a poured concrete slab having a first upper surface and a depressed second upper surface, the second upper surface being lower than the first upper surface.
In the construction of multi-floor apartment buildings, commercial buildings and the like, it is often desired to provide upper floors with peripheral exterior concrete slabs, such as decks or walkways, which are exposed to the elements. To prevent rain water from flowing into the interior of the building, it is customary to construct the exterior portion of the slab with a depressed or lower upper surface relative to the interior floor portion of the slab, such that the vertical wall or shoulder resulting from the difference in height between the interior slab portion upper surface and the exterior slab portion upper surface acts as a water stop or dam.
Both the primary interior concrete slab portion and the depressed exterior concrete slab portion in such a construction may be poured simultaneously by utilizing a horizontally extending, elongated depression rail or scrim that is mounted on individual spaced supports placed upon the bottom form surface, the bottom form often comprising plywood panels which are removed after the concrete cures. The upper edge of the rail is positioned at the desired height for the upper surface of the interior concrete slab portion. The lower edge of the rail is positioned at the desired height for the upper surface of the depressed exterior slab portion, such that the height of the rail determines the height of the water stop wall. When the concrete is poured it first flows under the rail to create the exterior depressed slab portion. The depression rail then impedes additional flow while the pour continues so as to fill in the interior slab portion to the desired height.
The most common technique utilized in this method has not changed in many years. It is typical to use wooden boards, such as 2×4′s, as rails mounted upon wooden, plastic or metal supports. This technique is very labor intensive and requires experienced workers to provide a proper set-up prior to the concrete pour. Wooden supports must be removed from the slab prior to complete hardening, with the resulting wells in the slab having to be filled in later. Typical designs for plastic or metal supports usually require post-curing processes, such as cutting or grinding, to remove exposed portions of the supports. It is also known to utilize sacrificial or consumable rails and supports where both remain embedded within the concrete slab, such as shown in U.S. Pat. No. 4,466,222 to Mitchell.
It is an object of this invention to provide a concrete depression form system and method that provides for easier installation than known systems, wherein the rail is readily removable from sacrificial support towers after the concrete has sufficiently cured, leaving a slab having an elevated interior slab surface and a depressed or lower exterior slab surface, the support towers being structured such that concrete flow is only minimally impeded and such that no portion of the support towers extends outward from the slab surfaces, securement of the support towers to the base is readily accomplished, and wherein post-curing processing of the support towers is not required. It is a further object to provide such a system and method possessing other advantages over known systems and methods, as will be apparent from the following disclosure.
The invention is in general a concrete depression form system and method comprising a removable, horizontally disposed, elongated guide rail or screed member releasably mounted onto a plurality of discrete support towers. The system enables creation of a multi-level slab from a single pour, the upper edge of the rail member determining the surface height of the elevated slab portion relative to the base and the lower edge of the rail member determining the surface height of the depressed or lower slab portion relative to the base. Various cross-sectional configurations may be utilized for the rail member, such as for example a square profile bar, a flat bar, an L-shaped angle iron bar or other bar shapes. The rail member may be straight, angled or curved. Various fasteners may be utilized to releasably mount the rail member to the support towers.
The support towers are preferably formed of folded sheet metal or rigid plastic, but may also be formed of connected wire or rod members. The upper portion of a support tower defines a shoulder to which the rail member is temporarily secured during the slab pouring operation. The support towers may be height-adjustable.
To create the multi-level flooring slab, the support towers are positioned and preferably affixed onto the bottom member, such as a plywood base, of a concrete form assembly. The rail members are mounted and secured to the support towers at the proper height, the rail members being bent or angled as required to produce the proper shape for the finished slab. The concrete is poured on the high side of the support towers so as to flow beneath the rail members, and the slab is then further processed in known manner to create a multi-level slab with a depressed surface and an elevated surface. The slab is then allowed to adequately cure such that flow no longer occurs, at which time the rail members are removed, leaving the support towers embedded in the concrete slab with no protruding exposure above the cured slab on either the high or low side. After full curing the form bottom member beneath the concrete slab is removed.
In alternative language, the invention is described as a method of forming a poured concrete slab comprising an interior elevated slab portion having a first upper surface and an exterior depressed slab portion having a depressed second surface lower than said first upper surface, said method comprising the steps of providing a plurality of sacrificial support towers and positioning said support towers on a bottom form member; providing an elongated rail member, said rail member comprising an upper edge, a lower edge and an interior side, and attaching said rail member to said support towers such that no portion of said support towers extends above said upper edge of said rail member; pouring uncured concrete onto the bottom form member such that a portion of said uncured concrete flows under said lower edge of said rail member and around said support towers to form said depressed slab portion, the depressed second upper surface being even with said lower edge of said rail member; continuing to pour said uncured concrete such that said uncured concrete contacts said interior side of said rail member to form said elevated slab portion such that said first upper surface is even with the upper edge of said rail member; allowing said uncured concrete to cure such that no further flow occurs and wherein said support towers are embedded within the poured concrete slab; and removing said rail member from said support, wherein no portion of said support towers extends above said first upper surface or said depressed second surface of the poured concrete slab. Furthermore, the steps wherein said step of providing said support towers comprises providing support towers that are height adjustable, and further adjusting said support towers to a predetermined height; wherein said step of providing said support towers comprises providing support towers comprising a first notch and a second notch, and wherein said step of positioning said support towers comprises orienting said support towers such that said step of attaching said rail member to said support towers comprises positioning said rail member in either said first notch or said second notch; further comprising the step of providing a positioning line on the bottom form member, and wherein said step of positioning said support towers comprises aligning said support towers in spaced relation along said positioning line such that said interior side of said rail member is aligned with said positioning line; wherein said step of providing said support towers comprises providing support towers comprising alignment members, and wherein said step of positioning said support towers comprises aligning said alignment members along said positioning line such that said interior side of said rail member is aligned with said positioning line; further comprising the step of using said upper edge of said rail member to grade said uncured concrete prior to removal of said rail member; wherein said step of attaching said rail member is performed by securing plastic ties around said rail member; wherein said step of providing support towers comprises providing support towers having integral fixation stakes, and wherein said step of positioning said support towers comprising inserting said fixation stakes into the bottom form member; wherein said step of providing support towers comprises providing support towers formed of rods, each of said support towers comprising a pair of elongated rod members having foot segments, vertical segments, horizontal cross members connecting said pair of elongated rod members, and at least one rail support extension extending beyond one of said elongated rod members and adapted to receive said rail member; and/or wherein said step of providing support towers comprises providing support towers each comprising a thin in cross-section base, a thin in cross-section body, a top edge and at least one notch adapted to receive said rail member.
Alternatively still, the invention is described as a concrete depression form system comprising in combination a plurality of support towers adapted to receive a rail member removably positioned thereon, said rail member having an upper edge and an interior side, such that no portion of said support towers extends above said upper edge of said rail member when said rail member is positioned on said support towers; and rail securement members attaching said rail member to said support towers; whereby said rail member is removable from said support towers after concrete has been poured to form a concrete slab comprising an interior elevated slab portion and an exterior depressed slab portion. Furthermore, wherein said support towers comprise visual alignment members adapted to be aligned with a positioning line placed on a bottom form member prior to pouring said concrete such that said interior side of said rail member is properly positioned; wherein said support towers further comprise integral fixation spikes for affixing said support towers to a bottom form member; wherein said support towers are formed of rods, each of said support towers comprising a pair of elongated rod members having foot segments, vertical segments, horizontal cross members connecting said pair of elongated rod members, and at least one rail support extension extending beyond one of said elongated rod members and adapted to receive said rail member; wherein said support towers comprise two rail support extensions adapted to receive said rail member; wherein said foot segments comprise visual alignment members adapted to be aligned with a positioning line placed on a bottom form member prior to pouring said concrete such that said interior side of said rail member is properly positioned; wherein said support towers each comprise a thin in cross-section base, a thin in cross-section body, a top edge and at least one notch adapted to receive said rail member; wherein said support towers each comprise two notches adapted to receive said rail member; wherein said base comprises visual alignment members adapted to be aligned with a positioning line placed on a bottom form member prior to pouring said concrete such that said interior side of said rail member is properly positioned; and/or further comprising a thin in cross-section extension plate connected to each said support tower, said extension plate comprising at least one notch adapted to receive said rail member such that the height of said rail member is adjustable.
With reference to the drawings, the invention in various embodiments will be described in detail with regard to the best mode and preferred embodiments. In a broad sense, the invention is a concrete depression form system and the method of using such system to create a poured, multi-level, unitary, concrete slab having an elevated or upper surface and a depressed or lower surface, the junction between the elevated surface and the depressed surface defining a water stop wall to prevent intrusion of water onto the elevated surface. Typically, the depressed surface is an exterior surface exposed to the elements, such as a deck or walkway, separated from an interior elevated surface, such as a floor. In general, the system comprises a plurality of discrete support towers which releasably or removably retain an elongated, horizontally disposed, guide rail or screed member having an upper edge and a lower edge. Multiple rail members will be utilized in end-to-end manner when needed. With the support towers and rail members properly positioned and secured onto the bottom form member, concrete is poured on the interior side of the rail member, which then flows beneath the rail member to create the depressed portion of the slab. The height of the lower edge of the rail member above the bottom form member determines the height of the depressed portion. As the concrete pour continues, the rail member impedes flow of the concrete such that the concrete on the interior side of the rail member rises to create the elevated portion of the slab. The upper edge of the rail member is used as a screed guide for finishing the concrete surface in known manner. Upon curing, the rail members are removed.
As used herein, the terms “external”, “exterior” or the like shall refer to the side or direction from the elevated slab portion toward the depressed slab portion, i.e., toward the exterior of the building, while the terms “internal”, “interior” or the like shall refer to the side or direction from the depressed slab portion toward the elevated slab portion, i.e., toward the interior of the building. The term “horizontal” or the like shall refer to the plane or direction that is coplanar to the top of the slab or the bottom form member, while the term “vertical” or the like shall refer to the upward direction generally but not necessarily perpendicular to the horizontal direction.
The embodiments described and shown in the drawings are meant to be illustrative of the invention and are not meant to be limiting.
At least one, but preferably a pair of rail support extension 16 extend outwardly to the exterior of one of the elongated rod members 11, the rail support members 16 preferably being formed by a pair of uppermost cross members 12 that have a greater length than the distance separating the two elongated rod members 11. The rail support extensions 16 are disposed on the vertical segments 13 a short distance below the horizontal upper segment 15 of one of the rail support members 11, such that the combination of the rail support extensions 16, the portions of the vertical segments 13 extending above the rail support extensions 16 and the horizontal upper segment 15 creates a receiving shoulder to retain a rail member 30, which preferably comprises a tubular, square profile, i.e., one having a square cross-sectional profile. Other configurations for rail member 30 may also be utilized, such as but not limited to a flat bar or L-shaped angle iron. The rail support extensions 16 extend a sufficient distance underneath the rail member 30 to maintain the rail member 30 on the receiving shoulder, which may be less or more than the width of the rail member 30. The rail member 30 is preferably affixed to the wire frame support tower 10 by rail securement members 17, such as wire members, plastic ties or the like. Rail securement members 17 are chosen such that they are easily cut or removed after the slab 40 has sufficiently cured to allow for removal of the rail member 30 from the wire frame support tower 10.
For larger depressions, i.e., where a significantly taller water stop wall 45 is desired, a sacrificial or consumable extension bracket member 20 is utilized, as shown in
In typical practice the support towers 10 are properly aligned and positioned using a positioning line 82, such as a chalk line, that is applied to the upper surface of the bottom form member 50, the chalk line 82 being applied to the bottom form member 50 where the water stop wall 45 is to be formed. As seen in
An alternative embodiment for the plate support tower 60 is shown in
In typical practice the plate support towers 60 are properly aligned and positioned using a positioning line 82, such as a chalk line, that is applied to the upper surface of the bottom form member 50, the chalk line 82 being applied to the bottom form member 50 where the water stop wall 45 is to be formed. As seen in
Still another embodiment of plate support tower 60 is shown in
A representative example of the method for using the concrete depression form system to form a slab with a depressed external portion on an upper level floor in a building is shown in
The rail members 30 are mounted and fastened so as to extend between multiple support towers 10 or 60, the height of the support towers 10 or 60 having been selected so as to properly position the rail member 30 height-wise for the elevated slab upper surface 44 and the depressed slab upper surface 43, which is determined by the upper edges 32 and the lower edges 31 of the rail members 30, respectively. Concrete is then poured into the interior and allowed to flow outward underneath the rail members 30 to fill the main concrete form. When the height of the wet concrete reaches the lower edges 31 of the rail members 30, the concrete flow is impeded by the rail members 30 and the flowing concrete is prevented from continuing onto the depressed slab portion 41. The concrete then builds up on the interior side of the rail members 30 and the flow is stopped when the concrete reaches the upper edges 32 of the rail members 30 and the elevated slab portion 42 is properly filled. The upper edges 32 of the rail members 30 may be used as screed guides to finish the elevated slab upper surface 44. Once the concrete has hardened to the point where gravity flow no longer occurs, the rail members 30 are removed from the support towers 10 or 60 by cutting the rail fasteners 17 or 67 flush with the concrete surfaces, or cutting the rail fasteners 17 and 67 and then pulling them from the concrete prior to full curing. The support towers 10 or 60 are deemed sacrificial or consumable, as they are left embedded in the concrete slab 40. After full curing, the main concrete form members and their supports are removed. Because no portions of the support towers 10 or 60 extend above the depressed slab upper surface 43 or the elevated slab upper surface 44, no subsequent processing of the support tower members 10 or 60 is required.
This method produces a multi-level slab 40 having a depressed slab portion 41 and an elevated slab portion 42 with a vertical water stop wall 45 situated at the junction to prevent water flow from the exterior depressed slab portion 41 to the interior elevated slab portion 42. The height of the water stop wall 45 is determined by the height of the rail members 30. This system and method allow for the formation of a multi-level slab 40 that is more easily and rapidly constructed with less manpower, and results in an accurately dimensioned multi-level slab 40 that requires less post-cure processing.
It is understood that equivalents and substitutions for certain elements and steps set forth above may be obvious to those of skill in the art, and therefore the true scope and definition of the invention is to be as set forth in the following claims.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 62/093,765, filed Dec. 18, 2014, the disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62093765 | Dec 2014 | US |
