Patent Application
20130014458
The present application concerns embodiments of a concrete wall structure, such as for use as a retaining wall or free-standing wall.
There are two main types of retaining walls: (i) retaining walls constructed from courses of pre-cast concrete blocks and (ii) monolithic concrete retaining walls. The construction of monolithic concrete retaining walls typically involves custom fabricating concrete forms from lumber at the job site. In such construction, steel reinforcing rods are placed in the forms, and concrete is poured into the form. After the concrete cures, the forms must be removed, cleaned, and transported back to storage. As can be appreciated, this process is time-consuming and typically requires skilled workers to construct the forms. Moreover, constructing concrete forms for concave or convex curved walls significantly increases the complexity and labor costs for the job. Furthermore, the weather and the elements can have a significant impact in conventional wall construction, especially in rainy climates such as the Pacific Northwest. For example, excavation and form building for walls it is particularly difficult, and sometimes not feasible, during especially rainy months.
Accordingly, there is a strong need for new and improved techniques for constructing monolithic concrete walls.
The present disclosure concerns embodiments of a wall structure that is formed from one or more permanent wall forms (or formworks). The wall forms can be prefabricated at a factory or shop in a controlled environment and then shipped to the job site. Construction of the wall structure at the job site generally entails positioning the wall forms at the desired location for the wall structure and then filling the wall forms with concrete. When the concrete cures, the wall forms are not removed and become a permanent part of the wall structure. Because the wall forms can be manufactured in a controlled environment (e.g., a factory), they can be made for a fraction of the cost of what it would take a skilled laborer to construct custom formwork at a jobsite using conventional techniques. A 50-foot monolithic concrete retaining wall constructed using conventional forms typically would require 4-5 days of onsite labor for excavation, constructing forms and pouring concrete. Comparatively, a similar retaining wall constructed using the prefabricated forms of the invention would require less than a day of onsite labor to construct the wall. Not only are labor costs reduced, onsite construction is much less affected by the weather. Moreover, because the forms become a permanent part of the wall, the additional steps of removing, cleaning, and transporting forms are completely eliminated.
In particular embodiments, the wall form comprises a permanent footing form and a permanent panel form mounted on the footing form. The footing form supports the panel form in an upright position and is typically positioned in a trench that extends along the base of the wall. The panel form can comprise first and second panel members that are interconnected by a plurality of vertical studs positioned between the panel members. A plurality of internal cavities for receiving concrete are formed between the panel members and adjacent pairs of studs. The studs desirably are formed with a plurality of large openings or apertures that allow concrete to flow between cavities of the panel form, thereby forming a unified, monolithic concrete structure when the concrete cures. Moreover, any number of wall forms can be placed end-to-end to achieve a wall of any predetermined length. When poured, the concrete can flow between adjacent wall forms. In this manner, the entire wall, although constructed from multiple, individual forms, is a unified, monolithic concrete structure comparable in strength to a concrete wall formed from a conventional removable form having a single cavity.
In certain embodiments, the panel members can comprise perforated metal sheets, such as conventional expanded metal sheets. The size of the openings in the panel members are selected to allow concrete to seep outwardly onto the outer surface of the panel members. This concrete can be troweled over to form a thin layer of concrete on the outer surfaces of the panel members. The panel members, which can be partially or completed embedded within the concrete, serve as reinforcing members to reinforce and strengthen the wall. Moreover, the external layers of concrete can be troweled as desired to provide a desired finish for the exposed surface(s) of the wall. If desired, the external layer of concrete can also serve as a useful surface for applying a decorative outer layer to the wall. For example, the external layers of concrete can be painted; or alternatively, any of various building elements, such as pre-cast blocks or bricks, or a veneer layer, can be mounted on the external layers of concrete.
In one representative embodiment, a wall structure comprises a permanent footing form configured to receive a cementitious fill material to form the footing of the wall structure, the footing form comprising first and second longitudinally extending side portions and a plurality of transverse cross-members extending between and interconnecting the side portions. The wall structure also comprises a permanent panel form mounted to the cross-members of the footing form, the panel form comprising first and second opposing panel members, and a plurality of spaced-apart, upright studs disposed between and interconnecting the panel members such that a plurality of cavities are defined by the panel members and adjacent pairs of studs for receiving the fill material. The footing form and the panel form collectively form a permanent, pre-fabricated wall form that becomes a permanent part of the wall structure when the footing form and the panel form are filled with the fill material.
In another representative embodiment, a wall structure comprises first and second opposing panel members, wherein at least one of the panel members comprises a perforated metal panel. A plurality of spaced-apart, upright studs are disposed between and interconnect the panel members such that a plurality of cavities are defined by the panel members and adjacent pairs of studs. A cementitious fill material is disposed in the cavities and forms a solidified wall structure, wherein the metal panel is at least partially embedded in the fill material so as to reinforce one face of the wall structure.
In another representative embodiment, a wall structure comprises a permanent footing form configured to receive a cementitious fill material to form the footing of the wall structure. The wall structure also comprises a permanent panel form mounted to the footing form, the panel form comprising first and second opposing panel members, and a plurality of spaced-apart, upright studs disposed between and interconnecting the panel members such that a plurality of cavities are defined by the panel members and adjacent pairs of studs for receiving the fill material. The footing form and the panel form collectively form a permanent wall form that becomes a permanent part of the wall structure when the footing form and the panel form are filled with the fill material. The panel members desirably are curved along a length of the wall structure to form a curved wall having a convex and/or concave shape.
The foregoing and other features and advantages of the invention will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
As used herein, the singular forms “a,” “an,” and “the” refer to one or more than one, unless the context clearly dictates otherwise.
As used herein, the term “includes” means “comprises.” For example, a device that includes or comprises A and B contains A and B but may optionally contain C or other components other than A and B. A device that includes or comprises A or B may contain A or B or A and B, and optionally one or more other components such as C.
Referring first to
The wall form 10 generally comprises a base portion 12 and an upright panel portion 14 that is supported by and extends upwardly from the base portion 12. As further described below, the base portion 12 desirably is installed in a trench that extends along the length of the wall structure while the panel portion 14 extends upwardly from the trench. When filled with concrete, the wall form 10 forms a strong, permanent monolithic concrete structure. As best shown in
A significant advantage of the wall form 10 is that it can be entirely pre-manufactured in a controlled environment away from the jobsite (e.g., at a factory or shop), and then shipped to the jobsite, installed at the desired location, and filled with concrete, thereby significantly reducing labor and installation costs compared with a conventionally poured concrete wall.
Referring also to
The studs 18 within the interior of the panel form (spaced from the opposing ends of the panel form) can be formed with a plurality of apertures, or openings, 26 that are large enough to allow concrete, when poured into the wall structure, to flow through the studs and become evenly distributed throughout the interior of the panel form 14. Thus, once cured, the concrete forms a single, unified or monolithic structure that extends the length of the panel form, with the concrete within adjacent cavities 50 being interconnected with one another. The apertures 26 can also be used to position one or more horizontally disposed reinforcing members 28 (e.g., steel rebar) that can extend the length of the panel form through the apertures 26. Alternatively, the studs can be formed with an additional set of relatively smaller openings (smaller than apertures 26) for positioning the rebar. The studs 18 at the ends of the panel form can be formed without apertures 26 so as to contain the concrete within the wall form as the concrete is poured into the cavities 50. Alternatively, one or both panel members 20 can have end portions that cover the ends of the panel form. The end portions can be formed by bending one or both panel members 90 degrees at the ends of the panel form. Alternatively, a separate piece of material can be secured at each end of the panel form to cover the studs at each end.
As explain in greater detail below, multiple wall forms 10 can be placed end-to-end to form a longer wall structure. In such cases, the studs 18 at the ends of each panel form (except at the ends of the overall wall structure) can be formed with apertures 26 to allow concrete to flow from a cavity 50 of one panel form 14 to flow into a cavity 50 of another panel form 14.
One or both of the panel members 20 desirably comprise perforated sheets of material formed with a plurality of openings, or apertures, sized to permit a limited amount of concrete to flow outwardly through the panel members. In the illustrated embodiment, for example, the panel members 20 comprise sheets of expanded metal, which can be made of any various suitable metals or metal alloys, such as steel, galvanized steel, stainless steel, aluminum, copper, etc. As used herein, “expanded metal” refers to metal sheets that are formed by cutting or otherwise forming series of slits in a sheet of metal and expanding the sheet to form a plurality of apertures, as commonly known in the art. Expanded metal of any of various mesh sizes can be used. In particular embodiments, for example, the panel members comprise ½ inch, #13 type expanded metal.
The expanded metal panel members 20 can serve several purposes. Explaining further, the expanded metal sheets serve as the formwork at the front and back of the panel portion 14 to shape the concrete as it is poured into the panel form 14. Due to the presence of the openings in the expanded metal, a limited amount concrete can seep through the openings in the expanded metal. The concrete on the outside of the expanded metal can be troweled over to form a thin layer of concrete covering the entire exposed face(s) of the wall (both faces can be troweled for a fence structure while only one face need be troweled for a retaining wall). Advantageously, this gives the appearance of a conventionally poured concrete wall, but requires significantly less labor to construct than a conventionally poured concrete wall. Another advantage of the expanded metal is that it becomes embedded within the faces of the panel portion 14, thereby further reinforcing the wall structure.
As shown in
In alternative embodiments, instead of expanded metal, the panel members can comprise perforated metal sheets having a plurality of holes punched or otherwise cut in the metal. In still other embodiments, other types of perforated or non-perforated materials can be used to form the panel members, such as various types of sheathing boards used in construction. The panel members can be made of metal, metal alloys, wood, polymers, composite materials, or combinations thereof. Without limitation, some examples of sheathing boards that can be used include plywood, cement board, oriented strand board, sheet metal etc.
The panel members 20 can be mounted to the studs using any of various suitable techniques or mechanisms. For example, as best shown in
Referring to
The side portions 38 and the end portions 40 in the illustrated configuration are formed from sections of Form-A-Drain™ footing material (available from Certainteed Corporation, Valley Forge, Pa.), which is a four-sided, elongated plastic channel. Alternatively, these components can be formed from various other types of building materials, such as elongated channel (metal or plastic channel) having C- or U-shaped cross sections. For example, the sides and ends of the base form can be formed from metal studs having the same configuration as the studs 18. The adjacent ends of the side portions and end portions can be secured to each other with L-shaped couplers 46 at the corners of the base portion 12.
The panel form 14 can be supported directly on the cross-members 42 as shown. As best shown in
As noted above, the wall form 10 can be pre-manufactured and shipped to a jobsite in the form shown in
In an alternative embodiment, the base form 12 and the panel form 14 can be transported to a job site as separate components and connected to each other during installation at the job site. In another embodiment, although less desirable, the various components for making each of the base form and the panel form (e.g., studs 18, panel members 20, etc.) can be provided as a kit, which can be assembled at a job site.
In particular embodiments, the wall structure 8 can be provided without a base form 12. For example, in one implementation, the panel form 14 can be mounted on a conventional concrete footing or pad (or multiple concrete footings spaced along the length of the wall). In another implementation, the wall structure 8 can be installed without any footing structure, such as by installing a portion of the panel form 14 below ground. For example, walls that are not subject to significant external loads, such as relatively short landscaping walls, need not include any footing structure and can be installed with a lower portion of the panel form below grade.
In other embodiments, the panel form 14 need not be filled with a cementitious fill material or can be only partially filled with a cementitious fill material. In one specific implementation, the panel form 14 can be partially filled with concrete, leaving a cavity at the upper portion of the panel that can be used as a planter box, which can be filled with soil for planting plants. In another implementation, panel form 14 need not have any cementitious fill material and instead can be filled with other types of fill material, such as soil, gravel, etc. For example, relatively short wall structures, such as landscaping walls, can be filled entirely with loose fill material such as soil (in which case it would be desirable to use non-perforated panel members to keep the fill material in the panel form).
The wall structure can include one or more reinforcing bars 28 that can extend through the panel forms 14a, 14b. In certain embodiments, a single reinforcing bar 28 can extend through multiple panel forms 14a, 14b as shown, in which case the reinforcing bar can be installed at the job site so that each form 10a, 10b can be transported to the job site as separate units. In other embodiments, each panel form 14a, 14b can have respective one or more reinforcing bars 28 that do not extend into multiple panel forms. In the latter case, the reinforcing bars 28 can be installed in the forms prior to shipment to the job site. The reinforcing bars can be sized to extend through the studs 18 at the end of the panels such that adjacent ends of reinforcing bars installed in adjacent panel forms can be connected to each other using, for example, rebar ties.
A wall structure can be formed from forms 10a, 10b by placing the forms end-to-end with the footing forms 12a, 12b positioned in a trench extending the length of the wall structure, and then filling the forms with a cementitious material (e.g., concrete) as described above. The studs at the ends of the panel forms within the interior of the wall structure (identified as 18a′ and 18b′) can be formed with apertures 26 (see
It should be noted that any of the materials described herein for forming panel members 106 (or panel members 20) exhibit some degree of flexibility and therefore can be used to form curved walls. For example, the expanded metal panels 20 described above can be bent and secured to studs 18 in a curved configuration, such as shown in
The base form 102 has a slightly different construction from that of base form 12 described above. The base form 102 in the illustrated embodiment comprises two longitudinally extending side portions 108 extending the length of the base form and two end portions 110 extending between respective ends of the side portions 108. The side portions 108 and end portions 110 can be sections of channel material, such as the Form-A-Drain™ material described above. The adjacent ends of the side portions and end portions can be connected by respective L-shape couplers 118.
The base form 102 further comprises a plurality of spaced-apart cross-members 112 that support the panel form 104. Each cross-member 112 extends across the width of the base form and has opposite end portions secured to the upper surface of the side portions 108, such as by welding, screws or other fasteners. The cross-members 112 can be sections of metal channel. In the illustrated embodiment, for example, the cross-members 112 are formed from U-shaped channel having longitudinally extending flanges 116 that support the panel form 104.
As shown in
As further shown in
In the illustrated embodiment, the side portions 108 of the base form 102 are straight and do not track the curvature of the panel form 104. However, this is not a requirement. The side portions 108 can be curved to match the curvature of the panel form 104 along the length of the wall. This can be accomplished by bending the channel material used to form the side portions. A series of slits or grooves can be cut into the channel material at locations spaced along its length to allow the channel material to be bent or curved to the desired shape.
A wall structure can be formed from one or more forms 100 placed end-to-end in a straight or curved line or at 90-degree angles in a desired configuration, and then pouring a cementitious fill material into the form(s) 100 as described above.
The construction of the column form 206 is best shown in
As noted above, the size of the openings of the expanded metal panels can be selected such that a limited amount of concrete can seep out of the openings. The concrete on the outside of the metal panels can be troweled over to form a thin layer of concrete on the outside of the wall structure. Any of various decorative layers can be applied to the exposed layer of concrete. For example,
In view of the many possible embodiments to which the principles of the disclosed invention may be applied, it should be recognized that the illustrated embodiments are only preferred examples of the invention and should not be taken as limiting the scope of the invention. Rather, the scope of the invention is defined by the following claims. We therefore claim as our invention all that comes within the scope and spirit of these claims.
