Vertical vibrating screed

This invention discloses a method of building concrete walls, columns and other vertical or sloped structures using a vertically oriented vibrating screed and utilization of the thixotropic properties of wet concrete. The vertical screed is a simple, inexpensive and highly flexible apparatus that may be used for a wide variety of applications that involve the applying of cementicious material in the construction of a vertical structure. By using highly thixotropic concrete, the vertical screed is able to place concrete and other cementicious materials in a vertical plane much like concrete is placed with vibrating screeds in the horizontal plane. The vertical screed's applications range from applying a thin cementicious coating to placing concrete in a vertical plane to construct a wall or column. The various configurations of the vertical screed range from a small hand held device to a much larger mechanically controlled apparatus.

BACKGROUND OF THE INVENTION

Prior Art

U.S. Patent Application Publications

This invention discloses a method of casting concrete walls, columns and other vertical or sloped structures using a vertically oriented vibrating screed and utilization of the thixotropic properties of wet concrete. The vertical screed is a simple, inexpensive and highly flexible apparatus that may be used for a wide variety of applications and may be either a hand held or mechanically controlled device. By using a highly thixotropic cementicious material such as concrete, the vertical screed is able to place concrete and other cementicious materials in a vertical plane much like concrete is placed with vibrating screeds in the horizontal plane.

Vibratory screeds are well known in the art for spreading wet concrete in horizontal casting applications such as roads, sidewalks and floor slabs. These screeds are simple devices that have a vibrator attached to a metal plate or tube and are moved horizontally to spread, level and consolidate the wet concrete placed ahead of their forward movement. These screeds are inexpensive, easy to use and come in a variety of sizes and features. However, such a simple vibrating screed does not exist for casting concrete vertically to build a vertical structure.

Walls and other vertical concrete structures have been built with cast-in-place concrete either by using forms, into which wet concrete is cast, or by shotcrete—the spraying a concrete mix against a form backboard. In the case of forms, the wet concrete is placed, vibrated and left to set or harden inside the forms. In some forming systems the forms permanently remain in place while in other systems the forms are removed at some point after the concrete has sufficiently hardened. In those systems where the forms are removed, some are removed after a day or two while in other systems the forms are moved in a matter of minutes which is a process known as slip forming. In most slip forming processes and in the shotcrete process the finished concrete is exposed well before it reaches its final set.

In the slip forming process forms are moved by being “slipped” along the freshly placed concrete and thereby exposing the concrete within a matter of minutes or hours after being cast. This may be done in either a horizontal or a vertical movement and the prior art discloses either one or the other but not the flexibility to switch from a horizontal to vertical movement as may be desirable from application to application. In addition, the slip form prior art are also highly inflexible apart from casting a specific type of wall within limited dimensions and shapes. For example an apparatus capable of casting a tapered road barrier wall is incapable of casting a tall and thin building wall.

There is no prior art that is capable of casting a wide variety of vertical structures ranging from thin walls to thick columns and irregular shapes. There is no prior art that can vary the thickness of the cementicious material applied to these structures and ranging from a thin coating to a reinforced concrete thickness of 24″ or more. Moreover there is no slip form prior art flexible enough to cast composite structures such as insulated concrete walls and that can also be used to apply concrete to thin shelled, ferrocement structures. Nor is there any prior art slip forming apparatuses with the flexibility to cast from only one-side or from multiple sides or in a sloped position in order to cast vertical walls, columns and sloped roofs.

The prior art slip forming systems for casting building walls are large, expensive and cumbersome forming machines or systems with a multitude of jacks or winches. Most of the prior art requires two or more forms that must be used in unison and further require either applying pressure to the concrete, utilizing accelerators for rapid hardening or keeping the forms in place for a short period of time to allow the concrete to set. In addition, the prior art that discloses slip forms for road barrier walls depend, primarily upon casting short and stocky or taller tapered walls and it is the wall's profile that enables the wet concrete to retain its shape as the slip form passes by.

None of the prior art discloses a reliance upon the thixotropic properties of no-slump concrete as a basis to the concrete retaining its shape as the slip form passes by. And none of the prior art can be downsized to an inexpensive hand held apparatus that can perform the same functions as a much larger mechanically operated apparatus.

The prior art slip forms that are based upon a one-sided forming system either require the cementicious material to sufficiently hardened before the forms are moved or uses the shotcrete process. The shotcrete process of placing concrete uses air pressure and a gun or nozzle to impinge wet concrete in thin layers against a vertical form/backstop with successive layers built-up to the desired thickness. The thin layers and air pressure dissipates most of the hydrostatic pressure that is ordinarily created with vertical stacking of wet concrete. The result is minimal sagging and the ability to hand trowel it to a smooth, vertical surface within minutes after the final layer has been applied. Shotcrete is a more expensive system due to the material waste caused by the rebounding sprayed concrete, safety precautions related to a spraying operation and the hand labor required to work the sprayed concrete into an acceptable finish.

While there is no prior art of vertical vibrating screeds, there are vibrating trowels that are used to finish either vertically or horizontally placed concrete. The vibrating trowels do not place the concrete or vibrate the full depth of the concrete, but rather vibrate the surface area to produce a better finish and appearance.

SUMMARY OF INVENTION

The present invention is a simple, low cost and highly flexible alternative to slip forms and shotcrete. It can be used to cast any type, size and shape of solid or composite vertical or sloped concrete structure. In its most simplified design, the present invention is a small, inexpensive handheld vibrating screed that places, consolidates, shapes and finishes concrete or other cementicious material in a vertical manner so as to construct building walls or to apply a thin coating to a wall or other vertically oriented structure. In its more elaborate design, the present invention does these same activities, although in a larger and highly mechanized apparatus. Such a large mechanical device can place hundreds of square feet of area per hour to build walls, columns and other vertical structures or place concrete on roofs, embankments and other sloped structures.

The present invention is able to screed concrete vertically while being vibrated because it utilizes the thixotropy of low-slump concrete. Thixotropy is a material property that describes a material as being in a solid state when at rest and becoming liquefied while being agitated. Thixotropy is a property of freshly mixed zero-slump, no-slump or low-slump concrete in that this type of concrete is in a solid state, similar to moist, clumpy dirt, when at rest and becomes liquefied when vibrated. Therefore, concrete and other cementicious materials with a zero-slump, no-slump or low-slump are said to be highly thixotropic. Relative to the present invention, this material property enables the no-slump or low slump concrete to be consolidated, spread, shaped and molded in a liquefied state through vibration by the screed and then to immediately revert to a solid state once the vibration ceases as the moving screed passes by. When in a solid state, the no-slump, concrete exerts no hydrostatic pressure which enables it to hold its shape while other wet concrete is being stacked vertically above it, no matter what the wall height or thickness.

An important aspect of this invention is that it is the only concrete placing machine that enables concrete to be inexpensively placed in a vertical plane much like concrete is inexpensively placed in a horizontal plane. In both applications, a vibrating screed liquefies, consolidates, spreads and levels the fresh concrete against a stay-in-place or removable form. The primary difference is at the concrete used in the vertical application must have a high degree of thixotropic behavior that is found in low or no-slump concrete whereas the concrete used in horizontal castings typically uses a much higher slump of concrete. This difference in the concrete slump requires certain modifications to the vibration to ensure the no-slump concrete is adequately consolidated, shaped and finished.

In one embodiment of this invention, the vibrating screed is vertically oriented and is used to place highly thixotropic concrete, in a vertical plane to cast walls, columns and other vertical structures in a wide variety of thicknesses, shapes and sizes.

In another embodiment of this invention the vertical screed is a simple, inexpensive and highly flexible apparatus that can be configured for use as either a small hand held device or a larger, mechanically operated apparatus capable of placing several hundred square feet of area per hour.

In another embodiment of this invention, the vertical screed may be mounted on tracks or a mechanical arm and used to stabilize and move the screed in a vertical, horizontal or diagonal direction.

In another embodiment of this invention, sensors and other mechanical or manual means are used to guide the vertical screed in a predetermined path and apply the appropriate thickness of material needed for a particular application.

In another embodiment of this invention the vertical screed is used to place concrete to cast a sloped structure such as a sloped roof or embankment.

In another embodiment of this invention, the vertical screed has a degree of flexibility that it can be used to place concrete on one side of a vertical structure such as a composite wall or on multiple sides of a vertical structure such as a column.

In another embodiment of this invention a mesh is used to support the cementicious material and the use of several layers of wire mesh enables the construction of thin walled ferrocement structures by using this invention.

In another embodiment of this invention additives may be added prior to or during the placement of the cementicious material to achieve a variety of desired effects.

Other objects, advantages and features of my invention will be self evident to those skilled in the art as more thoroughly described below.

DETAILED DESCRIPTION ACCORDING TO THE EMBODIMENTS OF THE PRESENT INVENTION

The present invention discloses a method of casting concrete walls, columns and other vertical structures or sloped structures such as roofs, by use of a vertically oriented screed and utilization of the thixotropic properties of wet concrete. Freshly mixed concrete and other cementicious materials that have a zero-slump, no-slump or low-slump all contain a high degree of thixotropy and are thereby highly thixotropic. Throughout the following detailed description the term low-slump concrete shall include zero-slump and no-slump concrete and shall also refer to other highly thixotropic cementicious materials. In addition, the term vertical shall include anything sloped so that a vertical structure includes a sloped structure such as a sloped roof and vertically oriented includes a slope.

FIG. 1shows the vertical screed10placing low-slump concrete11into a vertically oriented casting area26bordered by a vertically oriented screed face15of the vertical screed10on the open side and a vertically oriented form12positioned a predetermined space apart from the vertical screed10on the opposite side. The concrete11is cast into a hopper14that is generally above the screed face15and is used to feed concrete11into the casting area26. The hopper14has one or more openings to receive the concrete11and one or more openings to feed the concrete11into the casting area26. The hopper14may also have one or more movable sides not shown) to enable an adjustable width to accommodate different pass widths.

As the vertical screed10is moved, the concrete11falls from the hopper14into the casting area26and against the form12that provides a backstop, and fills the casting area26between the screed face15and the form12. Once the low-slump concrete11is in the casting area26, it is vibrated by a vibrator20attached to the backside of the screed face15as a means for liquefying, consolidating and spreading the concrete11to fill the casting area26between the screed face15and the form12.

The vertical screed10, with its screed face15and vibrator20acts to liquefy, consolidate and spread the low-slump concrete11against the form12and around the steel reinforcement19to produce a solid concrete structure with an outside face17of a concrete wall18. Immediately below the vertical screed10is a slip-form16that extends and finishes the forming function of the screed face15. The slip form16is in the same plane as the screed face15and does not vibrate or has minimal vibrations so as to allow the recently cast low-slump concrete11to revert to its solid state while retaining the shape produced by the screed face15. The slip form16provides the concrete11a transition from its liquefied state, as caused by the intense vibrations on the concrete11produced by the screed face15, to its exposed, unsupported and finished solid state. The slip form16also provides the desired finish to the outside face17and may be directly or indirectly attached to the vertical screed10or it may be a separate device that trails the vertical screed10.

One embodiment of the invention is to utilize the thixotropic properties of low-slump concrete. Thixotropy is a material property that describes a material that is in a solid state when at rest and a liquid state while being agitated. The thixotropic property of freshly mixed low-slump concrete is such that it is in a solid state after mixing, liquefies during vibration and immediately reverts back to a solid state when the vibration ceases. Specifically, upon mixing and during placement, the low-slump concrete is similar to moist clumpy dirt and, as it is vibrated by the screed, it is liquefied into a cookie dough-like material that flows and fills the contained space. When vibration ceases, the concrete immediately reverts back to its solid state, which is now a consolidated, shaped and solid structure. In addition, the low-slump concrete exerts little or no hydrostatic pressure when in its solid state which enables it to hold its post-vibration shape despite additional wet concrete stacked on top of it. Additives may be added to the concrete and/or heat, pressure or other mechanical means may by used by the vertical screed10or form12to induce an even faster set time.

FIG. 2shows a hand held configuration of the invention which is a vertical screed10consisting of a generally rectangular, flat surfaced screed face15positioned perpendicular to the ground and parallel to the face of the wall or column to be cast with cementicious material. The screed face15has a vibrator20or similar mechanical device attached to it's backside so that it will vibrate or otherwise cause motions to the screed face15that can be transmitted to the concrete11as it comes into contact with the screed face15. The vibrator20may be any type of mechanical device that vibrates, tamps, packs, rolls, spins, oscillates, compresses or otherwise provides a means for liquefying, consolidating and spreading the concrete11as it comes into contact with the screed face15.

In one embodiment the means for liquefying, consolidating and spreading the concrete is caused by directional vibrations extending from the screed face15into the adjacent concrete11and continuing through the concrete11until reaching the form12against which the concrete11is vibrated. The concrete11cast into the casting area26is vibrated to liquefy, consolidate and spread only within the casting area26. There are a variety of directional vibrators that may be attached to the screed face15and are well known in the art.

While the entire screed face15vibrates, the vibrations may be stronger at some locations and less or even minimal in others. For example, the vibrations at the bottom of the screed face15may be minimal so as to facilitate the transition of the concrete from the screed face15to the trailing slip form16or the slip form16may be a non-vibrating or minimally vibrating area of the screed face15.

In addition the vibrations at the top of the screed face15may have a different amplitude or frequency than the vibrations at the bottom of the screed face15. This could be accomplished by having vertically stacked directional vibrators attached to the screed face15(not shown) A frame25as shown inFIG. 2may be used to hold the hopper14, screed face15and slip form16together while providing a means for minimizing or eliminating the vibrations to the hopper14and/or slip form16. The minimally or non-vibrating slip form16provides a transition of the vibrated concrete immediately above to the formless concrete immediately below.

FIG. 2also shows the edge barrier23which extends perpendicular from the edge of the screed face15and slip form16a set distance toward the form12. The edge barrier23provides a side form against which the concrete11is vibrated so as to facilitate better consolidation and complete spreading of the concrete along the edge of the pass.

Also shown inFIG. 2is the vibrator20attached to a frame25that is attached to the back side of the screed face15such that the vibrations extend through the frame25to the screed face15. In the hand held configuration, the handle21is used as a means for supporting and guiding the vertical screed10, in a predetermined direction and a predetermined distance from the form12. An optional laser or other positioning sensor24may be attached to the frame25and used to as a means for guiding or otherwise assist in achieving both a proper concrete thickness and constructing a straight and plumb or some other type of shaped concrete structure.

FIG. 3is the backside of one configuration of the vertical screed10and shows two vibrators20that are attached to the frame25of the vertical screed10. One or more vibrators20are necessary for each vertical screed10.FIG. 4shows the front of the vertical screed10and the screed face15with the slip form16at the bottom. In this configuration the hopper14is open to the top, to receive concrete11and also open to the front to allow the concrete11to be gravity fed as a means for casting the concrete into the casting area26between the vertical screed10and the form12.

Also shown inFIGS. 3 and 4is the seam form22that is an extension of the screed face15and the slip form16beyond one side of the hopper14. This lateral extension consolidates the concrete from the present pass with the adjoining concrete from the previous pass and thereby provides a means for eliminating seams between the two adjacent screed passes to produce a monolithic structure. As the vertical screed10makes a successive pass, the seam form22overlaps the edge of the concrete11placed in the previous pass to vibrate, consolidate and slip form the still plastic concrete with and into the fresh concrete being placed in the present pass and thereby eliminate any seam between the two passes. When the seam form22is used, it extends the screed face15laterally which causes the casting area26to be enlarged.

In another configuration of this invention one or more variable speed vibrators may be used to increase the flexibility of the invention. For example one vibrator of a multi-vibrator screed may be set to produce a high amplitude and/or frequency to vibrate a deeper area of a wall while an adjacent vibrator may be set with lower amplitude and/or frequency to vibrate a much thinner adjacent wall section. In addition, the seam form22, edge barrier23, hopper14and slip form16may be disconnected from the vertical screed10to provide it with greater flexibility to place and finish the concrete. For example the vertical screed10, after disconnecting some or all of the above parts, may be used as a vibrating trowel to work the surface area of the vertical structure or fill concrete into small voids.

The screed face15may have a flat, concave or convex surface or it may have a moving object built into it so as to shape the concrete11as the screed face15passes by. The screed face15may also be three dimensional with curved or rectangular shapes as shown inFIGS. 5A to 5C. InFIG. 5Aa rectangular protrusion30is shown on the outside face17of the wall18as created by the vertical screed10.FIG. 5Bshows a curved protrusion31andFIG. 5Cshows a rectangular indentation32both created by the screed face15on the outside face17of the wall18. The screed may also provide any type of finished surface including smooth, textured or rough depending upon at least a portion of the screed face15and the trailing slip form16.

To cast a wall, column or similar vertical structure, a vertically oriented backstop is positioned on one side of the casting area26. The backstop is a surface against which the concrete is cast and vibrated or otherwise liquefied, consolidated and spread by the vertical screed10and its vertically oriented screed face15positioned opposite the backstop, on the other side of the casting area26. The backstop may be a form12and may be either a stay-in-place or a removable type. For example inFIGS. 6 and 7, the form12is an insulation board13that will remain in place and permanently bond to the concrete11to produce a composite insulated concrete wall18. In other applications the form12may be conventional removable forms well known to the art and adapted to function as one-sided forms.

The hand held configuration of the vertical screed10is shown inFIGS. 6 and 7as making a second vertical pass up the wall18.FIG. 6is a section side view of a wall being cast with the vertical screed andFIG. 7is a front view ofFIG. 6. InFIG. 7the first vertical pass33has been made up the entire height of the wall18and a second, successive vertical pass is in progress with the vertical screed10placing the fresh concrete11adjacent to the first pass33. As can be seen inFIG. 7the unfinished edge34from the first pass33is being joined together with the concrete11of the second pass by the seam form22that vibrates, consolidates and slip forms the concrete from both passes. In a like manner, if the screed moves horizontally, a successive horizontal pass is consolidated and finished with the top edge of the prior horizontal pass to produce a seamless monolithic wall slab.

FIGS. 6 and 7also show the concrete reinforcement19which may be welded wire fabric or steel rebar, although any type of reinforcement, including fibers, may be used. Concrete11may be fed into the hopper14or in front of the vertical screed10by any means that can move low slump concrete11including a scope, bucket, auger, conveyor and a pump. In addition, the concrete may be spread inside the hopper14to achieve a more even distribution by any means including manually, with an auger or with some other mechanical spreading device.

The vertical screed10may be used vertically as shown inFIGS. 6 and 7from the bottom up with a single pass to complete a section of the wall. The vertical screed10may be used to dispose a single layer of the cementicious material or it may be used to place multiple layers of the same or different cementicious material in one or more passes. The screed may also be used with different screed faces15or trailing slip forms16to produce different cementicious surface finishes. The vertical screed10may also be used to cast straight, curved or tapered profiles of almost any thickness and can accommodate any type of cementicious reinforcement material.

As a means for supporting and guiding the vertical screed10in a predetermined direction while maintaining a predetermined distance from the from12, it may be hand held or it may be mechanically supported and guided by one or more tracks or other mechanical means including cables, mechanical arms, cylinders and platforms.FIG. 8shows a vertical track51to which the vertical screed10is attached. In this configuration there are two tracks51, one on either side of the vertical screed10which slides up and down the tracks51by manually guiding the handle21. Also shown inFIG. 8the tracks51may have a means for attaching to the foundation or slab53at the bottom and at the top to a form40through mounts54. These secured mounts54or other means for attaching the tracks51at the top and the bottom of the concrete structure will ensure a straight and rigid support to the tracks51on which the vertical screed10is guided.

FIG. 9shows another configuration of this invention whereby a four-legged vertical track51is used to support and guide the vertical screed10. A top support frame48, a bottom support frame49and a screed frame25are all mounted on two pairs of tracks51, a pair one each side of the vertical screed10. The vertical screed10assembly slides up and down the vertical tracks51.

The vertical screed must be guided in terms of both its direction and in maintaining a predetermined distance between the vertical screed and the form. The means for supporting and/or guiding the vertical screed in this manner may be done manually or mechanically with tracks or a mechanical arm and may include the use of a sensor24as shown inFIG. 2, a string line, visually and the use of a depth meter.

FIG. 10shows another configuration of this invention with a much larger vertical screed10positioned by being attached to vertical support frames. InFIG. 10, the top support frame48and the bottom support frame49hold the tracks51together at the top and bottom while the frame25enable the vertical screed10to be mounted upon the tracks51for vertical movement. The tracks51may be of any size and shape and of any material that supports the frame25, vertical screed10and hopper14, either combined or separate, as it is guided in a predetermined direction along the tracks51using various means including manually, winches, cylinders, screw, cogs, crank or other means known to the art. For example an electric winch may be used to pull the vertical screed10and hopper14up one or more round pole tracks51. The track drive mechanism may be powered by any number of means known to the art or operated manually.

In another configuration, the vertical screed10and hopper14may be mounted on one or more tracks51and intermittently repositioned to place the concrete11. For example, instead of placing concrete11in a continuous directional movement, the vertical screed10and hopper14may be held in a predetermined location while the concrete11is placed and once that location is fully placed, then the vertical screed10and hopper14are repositioned to the next location for concrete placement and repeating the process.

The vertical screed10apparatus may also have horizontal tracks52as shown inFIG. 10with one or more horizontal tracks52at the base and the top of the structure being cast. The top and bottom support frames48and49respectively, may be mounted on the horizontal tracks52to enable fast and accurate horizontal repositioning to support and guide the vertical screed10and frame25to facilitate the next concrete placement pass. Once a vertical pass is completed, the support frames48and49are unlocked from the horizontal tracks52, and the supporting frames48and49along with the vertical screed10and screed frame25, are slid on the horizontal tracks52to the new position, at which location the support frames48and49are locked or otherwise secured to the track52to support and guide the next pass of the vertical screed10.

To obtain finished and well compacted corners or edges, top forms40and edge forms41may be placed at the outside and top corners or edges and at the window, door and other openings.FIG. 10shows a top form40and the edge form41. These optional forms act as a barrier against which the concrete11is compacted by the vertical screed10to produce straight, plumb and finished corners and edges.

The present invention may also be used in a configuration that has a slip form or a second vibrating screed as the backstop instead of the form12.FIG. 11shows two sets of tracks51A and51B positioned on either side of a wall18. The tracks51A and51B both have top support frames48A and48B and bottom support frames49A and49B respectfully. The vertical screed10and hopper14are attached to a frame25A which is mounted on tracks51A to support and guide vertical movement of the vertical screed10. In this configuration a second slip form58is attached to frame25B which is mounted on tracks51B. This second slip form58and frame25B replaces the form12that was used inFIG. 9and moves vertically in unison with the vertical screed10and frame25A. The concrete11is cast into the casting area26which is bordered by the screed face15on one side and the second slip form58on the opposite side. The concrete11is liquefied, consolidated and spread by the vertical screed10as frames25A and25B move vertically upward and each side of the wall18is respectively finished by the slip form16on one side and the second slip form58on the other side.

Frames25A and25B may be moved separately or together and manually or mechanically with winches, cylinders, screw, cogs, crank or other means know to the art. For example a single hoist may be used to raise both sides or separate hoists may be used to raise each side. In addition, the two tracks51A and51B and their respective support frames may be connected at the top or sides or they may be totally separated as may be desirable in certain situations.

In addition to being a second slip form58, the backstop of this invention may also be any apparatus that affects the concrete from the second side of the vertical structure. For example the backstop may provide heat to speed the concrete setup and curing or a packing mechanism that packs the concrete from one side while it is vibrated from the other side of the wall or column.

FIG. 12shows another configuration where a second vertical screed10B is used as the backstop. InFIG. 12, the first screed frame25A has a vertical screed10A, a hopper14A and a slip form16A attached and a second and opposite screed frame25B has a screed10B and a slip form16B attached and may also have an optional hopper attached (not shown). The two screed frames25A and25B are mounted on their respective tracks51A and51B such that the two vertical screeds10A and10B are positioned with their respective screed faces15A and15B facing each other and bordering the casting area26into which concrete11is cast. In this configuration, the concrete11is fed into the hopper14A from which it is cast into the casting area26between the two vertical screeds10A and10B and the concrete11is liquefied, consolidated and spread by the vibration motions from both sides. This configuration permits much thicker concrete walls, columns and other vertical structures since the vibrations from each vertical screed need only to affect about half of the concrete11and from only one side of the structure.

The hopper14A is also optional and as an alternative the concrete11could be cast directly into the casting area26between the two vibrating screeds10A and10B. The purpose of the hopper14A is to cast the concrete11into the casting area26and in some applications the width of the casting area may be sufficiently large to eliminate the need for a hopper.

FIG. 13shows a finished wall18fromFIG. 12with the vertical tracks51A and51B and their respective support frames and vertical screeds moved away from the concrete wall18. Another embodiment of this invention is that the vertical screed has significant flexibility in both the type of vertical structures it can construct and how the vertical structures are cast. For example, the vertical screed can be positioned on one side of the wall only with some type of insulating foam board13positioned on the second side to cast a composite insulated wall as shown inFIG. 1. The vertical screed can also be positioned on two or more sides of a wall or column with the sides all connected to one another to cast a solid concrete structure. Finally, the vertical screed can be positioned independently of the other side(s) with each side positioned separate and apart from the other such as in high walls or columns where the rebar makes it impractical to connect the vertical screed or slip form sides. WhileFIG. 13shows the two tracks51A and51B separate and apart, the tracks and respective frames could also be connected to each other at the top or sides.

Another embodiment of this invention is its high degree of flexibility in casting a variety of types, sizes and shapes of vertical structures. In addition to straight walls, columns of all shapes and sizes can be cast from the vertical screed of this invention. For example, one or more vertical screeds10may be positioned on one or more sides of a column with or without forms12set opposite or between the screeds. When done without forms12, the vertical screeds10opposite one another provide another means for providing the backstop.FIG. 14is a top view of a round column55being cast with a single vertical screed10that has eight vibrators20surrounding the column55. The vertical screed10and the vibrators20are supported and guided by a support frame50which travels up the vertical tracks51. The support frame50is anchored at the bottom (not shown) to secure the frame and screed in alignment. The invention may also be used to cast unusually shaped columns such as octagons, crosses, etc., whereby the shape of the screed face(s)15determines the shape of the column or other vertical or sloped structure.

FIG. 15shows a top view of the vertical screed10used to cast a rectangular shaped column55. In this configuration two vertical screeds10A and10B are positioned opposite each other and two second slip forms58A and58B are also positioned opposite each other to comprise the four sides of the rectangular column55. As the support frame50moves up the vertical tracks51the concrete (not shown) is vibrated, liquefied, consolidated and spread and a finished rectangular column emerges from the bottom as the vertical screed10moves upward.

In all of the above configurations, the concrete vibration was caused by a vibrating screed that is well known in the art as an external vibrator. In another configuration of the invention, the concrete vibrations are caused by an internal vibrator which is also well known in the art.FIG. 16Ashows an internal vibrator56attached to the hopper14that is above a slip form16. InFIG. 16B, concrete11is deposited between slip form16and a second slip form58and the internal vibrator56liquefies, consolidates and spreads the concrete between the slip form16and the second slip form58. As the slip forms travels upward, the exposed finished concrete wall18emerges from below.

The internal vibrators56may be mounted anywhere on the vertical screed10or support frame or on another mechanical apparatus or they may be manually held and used to consolidate the concrete or otherwise work in concert with the slip forms which acts to shape and texture the concrete in this configuration.

In another configuration of the invention, a cylinder57is situated above the concrete and used to deposit, consolidate and spread the concrete11. The cylinder57may simply spin or it may also vibrate or otherwise agitate the concrete. The cylinder57may also have protrusions that extend into the concrete (not shown).FIG. 17shows a configuration of a cylinder57located between slip form16and second slip form58and a means by which the cylinder57spreads and consolidates the concrete11.

There are any number of additives that can be used with the concrete and the invention. For example, the additives can be used to lubricate the concrete, as a water reducer or to induce a fast set. The additives may also be added to the concrete mix or injected, sprayed or otherwise applied to the concrete at any time prior to, during or after the vertical screed has placed the concrete.

The vertical screed may be designed such that it performs more than one function as it passes by the concrete. For example the top section of the screed may provide the vibration stage whereby the concrete is liquefied and consolidated. The lower part of the vertical screed or an attachment thereto may provide a second stage such as a mechanical device that packs the concrete and a third part of the screed may act as a slip-form to shape the concrete. Other functions that may be used with the vertical screed include: mixing concrete, placing additives, heating or dehydration and applying concrete finishes.

In another configuration of this invention, wire or plastic mesh or similar materials may be used to support the wet concrete in its vertical position while curing or to construct ferrocement structures.FIG. 18shows the wire mesh60attached to the rebar steel reinforcement19by a means for attachment61A that restrains the mesh60and prevents it from moving away from the rebar steel reinforcement19. Also shown inFIG. 18is the mesh60attached to the insulation board13by a means for attachment61B that extends through the insulation board13to which a clip62is attached to prevent the means for attachment61B from being pulled out.

FIG. 19shows a front view ofFIG. 18with the addition of the vertical screed10and concrete11that has been placed by the vertical screed10. InFIG. 19the mesh60has a means for being secured to the rebar19, or the form12and/or the top form and the bottom foundation or other rigid object (not shown). For example mesh60may be attached by a means for attachment to the rebar19and/or the form12such that the mesh60is secured away from the form12and near the front face of the wall18to be cast. As the vertical screed10makes it's pass, concrete11is fed from the hopper14through the opening in the mesh60to fill the casting area26between the form12and the vertical screed10and the concrete11is liquefied, consolidated and spread embedding the mesh60. As the vertical screed10passes by and only the concrete and the embedded mesh60remain, the mesh60acts to support the concrete11in its final vertical position. The inclusion of the mesh60will allow for a higher slump of concrete or provide concrete support and/or reinforcement as may be desired in a particular application.

Additionally, the mesh60may be a wire mesh and set in a multitude of layers so as to produce a ferrocement structure when the concrete is applied to it. In this manner, the vertical screed can be used to cast a wire mesh reinforced thin walled concrete structure as is well known in the art.

InFIG. 20is a section side view of an optional side support70that restrains the wet concrete (not shown) in a vertical position between the mesh60and the form12and provides a means for bonding the concrete placed in one pass to the wet concrete placed in a successive pass. The vertical side support70is a mesh60that supports the side of the concrete11during and after placement to prevent it from falling or slumping to the side. FromFIG. 19, as the vertical screed10passes, wet concrete11is vibrated against the concrete11being restrained by the first side support70A which has been partially embedded in concrete11from the prior pass. During that same pass, concrete11is also vibrated against the second side support70B that restrains the concrete11from falling to the adjacent open area. As the vertical screed10makes its successive passes, the new concrete11is pushed against the first side support70A and the exposed concrete from the prior pass that is being restrained by the first side support70A is re-vibrated, liquefied and consolidated with the new concrete.

FIG. 21shows a vertical screed10placing concrete11to cast a reinforced concrete wall18through a horizontal movement. The horizontal tracks52support the two vertical tracks51A and51B which in turn support the top frame48, the bottom frame49and two screed frames25as the vertical screed10places concrete11while moving in a horizontal direction. After each horizontal pass is completed, the screed frames25are moved up vertically so as to reposition the vertical screed for the next horizontal pass.

In this configuration the screed face15is positioned perpendicular to the ground and parallel to the face of the wall or column being cast with the cementicious material. The only difference is that the vertical screed has been rotated 90 degrees to an upright position so as to more efficiently place the concrete when used in a horizontal direction.

The vertical screeds may be configured to be field modified for use in either the vertical direction or in the horizontal direction. When the same vertical screed used in the vertical direction is modified for use in the horizontal direction, the vertical screed and hopper are rotated 90 degrees. This causes the top and one side of the hopper in the vertical direction to change positions when used in the horizontal direction. Therefore, what used to be the open top of the hopper in the vertical direction is now the side of the hopper in the horizontal direction and must be closed to prevent the concrete from falling out of the hopper. Likewise, what was the closed side of hopper in the vertical direction is now the top of the hopper in the horizontal direction and must be opened to allow concrete to be fed into the hopper.

FIG. 21shows the vertical screed10and the attached hopper14rotated 90 degrees and what was the hopper top71is now a side and must be closed so as to contain the concrete fed into the hopper14. In addition, the hopper side72has also been rotated 90 degrees to the top of the hopper and therefore must be opened to allow concrete to be fed into the hopper14. InFIG. 21, the concrete11is being fed into the hopper14through the hopper side72by way of an elephant truck73, which is well known in the art, and constitutes another means for casting concrete into the casting area.

From the above it is apparent that the vertical screed can also be moved in a diagonal direction as the application may require or otherwise may be desirable.

From the description above, a number of advantages of some embodiments of my vertical screed and method of casting vertical structures with a vertical screed become evident:(a) The present invention is a simple, low cost and highly flexible alternative to all other methods of casting concrete.(b) The vertical screed of this invention may be used as a small, inexpensive handheld vibrating screed for use to cast concrete walls.(c) The vertical screed of this invention offers an inexpensive method of casting larger concrete walls, columns and other vertical or sloped structures with a highly mechanized apparatus that can place hundreds of square feet of area per hour.(d) The vertical screed of this invention places concrete in a vertical plane using highly thixotropic concrete, to cast walls, columns and other vertical structures in a wide variety of thicknesses, shapes and sizes.(e) The vertical screed of this invention may be mounted on tracks used to stabilize and move the screed in a vertical and/or horizontal direction.(f) The vertical screed of this invention may be used to place concrete to cast a sloped structure such as a sloped roof or embankment.(g) The vertical screed of this invention may be used to cast on one side of a vertical structure such as a composite wall or it may be used on multiple sides of a vertical structure such as a column.(h) The method of using the vertical screed of this invention may include applying concrete in a vertical plane to several layers of wire mesh which will enable the construction of thin walled ferrocement structures.

Although the description above contains many specifications, these should not be construed as limiting the scope of the embodiments but as merely providing illustrations of some of several embodiments. Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given.