METHOD OF CONSTRUCTING A MULTI-STOREY BUILDING USING PREFABRICATED MODULAR PANELS
A method of constructing a multi-storey building entails using prefabricated modular wall panels and floor panels. The prefabricated wall panels have a frame that includes studs, rebar and an upright channel into which concrete is poured and cured to form a concrete column (or a hybrid steel-and-concrete column). Prefabricated floor panels have a frame that includes joists, sheathing and a trench-like track that forms a trough for receiving concrete that cures in the trough to create a concrete beam (or a hybrid steel-and-concrete beam). This novel method is extremely efficient for constructing multi-storey buildings, substantially reducing both construction costs and construction time.
This is the first application filed for the present technology.
TECHNICAL FIELDThe present technology relates generally to building construction and, in particular, to the construction of buildings using prefabricated components.
BACKGROUNDCast-in-place concrete (CIPC) is commonly used to construct both low-rise and high-rise buildings. This technique requires concrete forms to be installed and then removed after the concrete is poured and cured. This is both time-consuming and expensive, thus increasing the overall construction time and construction cost for a given building.
In addition, it is typical practice for the formwork, steel reinforcement and the fabrication of concrete elements to be done by one trade and the infilling between the columns with steel studs and exterior sheathing, along with the interior demising partition, done by another trade. The same holds true for low-rise structural steel construction with open web joists and concrete slabs, which are erected by one trade, followed by infilling of exterior curtain and interior demising partitions by another trade. Because both of these methods involve using multiple trades, coordination can become problematic, i.e. there is more room for error when more than one trade is responsible for interrelated tasks. This in turn can lead to construction delays and a higher overall construction cost.
Furthermore, in cold-weather climates, typical construction techniques can be problematic. For example, extensive tarping is often required to keep the interior of the unfinished building warm and dry.
From the foregoing, it is apparent that the prior-art construction techniques need to be improved. Accordingly, there remains a need in the construction industry for a more efficient technique for constructing a building.
SUMMARYIn general, the present technology provides an innovative method of constructing a multi-storey building by using prefabricated modular wall panels and prefabricated modular floor panels. The novel prefabricated wall panels have a frame that includes studs and an upright channel into which concrete is poured and cured to form a concrete column (or a hybrid steel-and-concrete column). Similarly, the novel prefabricated floor panels have a frame that includes joists, sheathing and a trench-like track that forms a trough for receiving concrete that cures in the trough to create a concrete beam (or a hybrid steel-and-concrete beam).
Thus, a main aspect of the present technology is a method of constructing a building, the method involving steps of preparing a construction site by pouring a floor slab with upright rebar positioned to align with load-bearing concrete columns that are to be poured, erecting an assembly of modular prefabricated wall panels by connecting the wall panels to define one or more walls of the building, the wall panels comprising a frame having a plurality of substantially vertical members, a subset of the plurality of substantially vertical members being closed channels, laying modular prefabricated floor panels onto a top end of the assembly of modular prefabricated wall panels, the floor panels comprising a frame having a plurality of horizontally arranged joists and a sheathing mounted onto the frame, each of the floor panels further comprising a trench-like track that acts as a trough for receiving rebar and concrete, and pouring concrete into the troughs in the floor panels for flowing into the channels, the concrete curing in the troughs to form horizontal concrete beams and curing in the channels to form concrete columns. This completes the walls and load-bearing columns. A roof can then be added for a simple one-storey building. However, the main utility of this invention lies in building multi-storey buildings. Thus, in the context of the construction a multi-storey building, the method would further comprise steps of erecting wall panels and laying modular prefabricated floor panels onto a top end of the assembly of modular prefabricated wall panels, the floor panels comprising a frame having a plurality of horizontally arranged joists and a sheathing mounted onto the frame, each of the floor panels further comprising a trench-like track that acts as a trough for receiving rebar and concrete. The method would also furthermore comprise laying reinforcing rods horizontally over the floor panels and then pouring concrete over the reinforcing rods and into the troughs in the floor panels, the concrete curing to form horizontal concrete beams that are aligned with and supported from below by the load-bearing rebar and concrete columns.
For completion of the second floor, the method would further comprise steps of erecting a third-storey assembly of modular prefabricated wall panels on top of the floor panels, the wall panels having closed channels and then pouring concrete into the troughs which enable concrete to flow into the closed channels through an open top end of each of the closed channels. The concrete cures in the troughs and closed channels to form second-storey load-bearing concrete beams and columns within the floor and wall panels of the second storey. The second-storey horizontal concrete beams are aligned with and supported from below by the concrete columns.
In like fashion, to complete yet a further floor, the method would further involve installing another set of wall and floor panels and then pouring concrete over the floor, into the troughs and into the channels, the concrete curing in the troughs and channels to form horizontal concrete beams and vertical columns. The beams are aligned with and supported from below by the load-bearing concrete columns.
To build further floors, this process can be repeated. In other words, for building further floors, the method would further involve steps of erecting wall panels, laying floor panels, placing rebar, pouring concrete beams and columns within the troughs and channels in the floor and walls panels.
Another main aspect of the present invention is a modular prefabricated wall panel for use in constructing a building. The wall panel has a frame having a plurality of spaced-apart vertically arranged studs and a vertically arranged closed channel within which concrete can be poured and cured. This wall panel also has a sheet of exterior cladding attached to one side of the frame.
Yet another main aspect of the present invention is a modular prefabricated floor panel for use in constructing a building. The floor panel has a pair of spaced-apart frames, each frame comprising a plurality of spaced-apart horizontally arranged joists and a sheathing attached to each frame. This floor panel also has a trench-like track connected to each of the pair of spaced-apart frames panels to thereby define a trough between the frames for receiving rebar and concrete.
By implementing the method outlined above and the wall and floor panels introduced above, it is possible to construct a novel multi-storey building, which thus represents another main aspect of this invention. This novel multi-storey building has a plurality of modular prefabricated wall panels assembled together to form the walls of the building, the wall panels comprising upright channels into which rebar is placed and concrete is poured and cured to form hybrid steel-and-concrete load-bearing columns. This multi-storey building also has a plurality of modular prefabricated floor panels assembled together to form the floors of the building, the floor panels comprising horizontal troughs into which concrete is poured and cured to form hybrid steel-and-concrete horizontal beams.
In one main implementation of this technology, the concrete columns are aligned with and supported by the concrete beams of the storey immediately below while the concrete beams are, in turn, aligned with and supported by the concrete columns of the storey immediately below.
This innovative construction method is highly efficient, thus reducing construction time and construction cost when building multi-storey buildings.
The details and particulars of these aspects of the technology will now be described below, by way of example, with reference to the attached drawings.
Further features and advantages of the present technology will become apparent from the following detailed description, taken in combination with the appended drawings, in which:
FIGS. 21A-21E-3 are various elevation views of the multi-storey building;
It will be noted that throughout the appended drawings, like features are identified by like reference numerals.
DETAILED DESCRIPTIONIn general, the present technology provides an innovative method of constructing a multi-storey building by using prefabricated modular wall panels and prefabricated modular floor panels. The novel prefabricated wall panels have a frame that includes studs and an upright channel into which concrete is poured and cured to form a concrete column (or a hybrid steel-and-concrete column). Similarly, the novel prefabricated floor panels have a frame that includes joists, sheathing and a trench-like track that forms a trough for receiving concrete that cures in the trough to create a concrete beam (or a hybrid steel-and-concrete beam). These panels are prefabricated before being delivered to the construction site. They are assembled into walls (both exterior and interior) and floors. Concrete is poured into the channels of the wall panels to produce load-bearing concrete columns. Similarly, concrete is poured into troughs in the floor panels to form concrete beams.
These load-bearing columns and beams are thus formed only in the walls (either exterior walls or interior demising partition walls) and in the floors, thus minimally interfering with the architectural layout of the floor plans. Because all columns are within the walls, there are no “orphaned” columns inconveniently placed on the resulting floor plan. In contrast, when constructing a building with prior-art formwork methods (Cast in Place concrete and structural steel construction with open joists), columns are placed strategically throughout all floors which take up valuable floor space. This present invention reduces column sizes and places them within the 6″ (or other size) stud wall cavity, and thus eliminates all columns within the floor space. The columns can be placed within the partitions, for example roughly every 6½′ and are reduced in size to, for example, 6″×6″ or 6″×12″ (or other appropriate sizes), thereby maintaining the structural integrity of the building. There are thus more columns that are spaced closer together than in a typical (prior-art) building, thus allowing the building to withstand just as much weight, if not more than a standard building.
Furthermore, no removable concrete forms are required using this novel construction method, which thereby greatly reduces time, cost and complexity.
Moreover, since the troughs (which can be, for example, steel tracks) remain with the cured concrete, the result is a hybrid steel-and-concrete beam, which has excellent load-bearing capability. Likewise, since the channels (which can be, for example, steel box-beam channels) also remain with the cured concrete, the resulting structure is a hybrid steel-and-concrete column, which also has excellent load-bearing capability.
The present invention will now be described in greater detail with reference to the embodiments illustrated in the attached figures.
In one embodiment, the method involves (as depicted in
The wall and floor panels can be prefabricated prior to being delivered to the construction site. The panels are engineered/designed to specifications that are specific to the building/dwelling to be constructed, as depicted in step 9 in
In one embodiment, the method involves (as depicted in
In one embodiment, the method involves (as depicted in
As depicted in the flowchart in
Additional storeys of the multi-storey building can be built by repeating the foregoing steps of erecting wall panels, pouring concrete columns within the channels in the walls panels, laying floor panels atop the wall panels, laying reinforcing rods horizontally, and pouring concrete over the reinforcing rods and into the horizontal troughs to form concrete beams that are supported by the concrete columns which in turn support the concrete beams of the floor above.
In one embodiment, the frames of the floor panels are spaced apart by a predetermined distance defining an elongated gap into which is placed a trench-like track that acts as the horizontal trough for receiving concrete which, when cured, forms each concrete beam. In one particular embodiment, the predetermined distance defining the gap between the frames is equal to a depth of the joists.
FIGS. 21A-21E-3 are various elevation views of the multi-storey building. These views show how windows are placed in the building (in between the adjacent columns, as described above).
The frames of the wall and floor panels presented in the foregoing disclosure can be constructed of steel or any other suitable metal or composite material. Preferably, but not necessarily, the studs and joists can be made using steel tracks, e.g. commercially available 18 gauge (or 16 gauge) galvanized C-channel or U-channel steel tracks. Similarly, the troughs and box channels can also be made using steel tracks, e.g. 18 gauge or 16 gauge galvanized steel tracks, although other materials or steel of another gauge can be substituted. For the sake of illustration only, an example exterior wall panels can be constructed of 6″×18 gauge C-channel, 1-1×3″-18 ga L-angle, 1-1″×1″-18 ga L-angle which are used for the bottoms of the panels, one being smaller to enable concrete to flow over it, 6″×18 ga steel studs with various flanges (1¼, 1⅝ depending on load design), 6″×6″ galvanized columns, 1½″ stiffeners, 5½″ bridging clips (18 ga), wafer head-self drilling framing screw fasteners 7/16, exterior DensGlass® sheathing or equivalent (½″ or ⅝″), 8″ by 16 gauge track. Once shop drawings for each wall and floor panel assembly have been engineered, materials are ordered for all the variously sized components of both the wall and floor panels. Wall panel jigs are constructed for the assembly of various panels. Firstly, both top and bottom tracks are installed in the jig. Then, 6″ studs are placed at 16″ on center (o.c.) or 24″ o.c. Once the track and studs are installed in the panel, columns are placed within the wall cavity at various locations and are designed to align with the floor assembly beams. Then, 1½″ stiffeners with bridging clips are added at the midpoints of the panels with clips fastened at each stud to increase the rigidity of the panel. Once the fastening of the upper and lower track is complete, the panel is turned over to fasten the track and studs on both the top and bottom of the other side. Then, 6″×6″ column holes are cut into the 6″ track at the column locations. This allows the upper floor concrete to flow down into the channels to form the concrete columns. An 8″ C-channel is installed perpendicular to the studs on a horizontal plane fastened the top of the 6″ track. This will give support to the upper exterior wall panels and form for the concrete on the perimeter beam. The DensGlass® or gypsum will then be installed on the exterior of the wall panel. The exterior (perimeter) wall panel is thus complete. Windows and door opening(s) should be framed within the wall panels between the concrete column forms, as needed.
For interior demising wall panels, the following methodology can be used: firstly, top track and bottom angles are installed in the jig. Then, 6″ studs are placed at 16″ o.c. or 24″ o.c. inside the track and angles. Once that is completed, 6″×6″ columns are placed at various locations within wall assembly and are designed to align with floor assembly beams. Then, 1½″ stiffeners are added at the midpoint of the panels with clips fastened at each stud to increase the rigidity of the panel. Once the fastening of the upper and lower track is complete, the panel is then turned over to fasten the track and stud on both the top and bottom of the other side. 2″-18 ga galvanized flat stock cross bracing is fastened to the track/studs and columns. Then, 6″ by 6″ column holes are cut out of the 6″ track at the column locations. This will allow upper floor concrete to flow down into the channel and form the column.
For floor panels, the following materials can be used: 8″ track—18 ga galvanized, 6″ joist—18 ga galvanized, 1⅛″ or 1⅝ flange, 1½ 18 ga galvanized U-channel, ½″ fire treated plywood sheathing, 7/16 wafer head self-drilling galvanized screws. In terms of methodology, a jig is assembled on a working table for the various sizes of panels to be fabricated. The joists are fastened back to back continuously with 7/16 screws. They are then placed within the jig at a spacing of 16 o.c. or 18 o.c. and fastened with 8″ track on both ends. Then the two outer studs are turned inwardly, thus creating a flat surface around the perimeter. The surface will then be the form work for the concrete beam of each panel on each side. The plywood is installed perpendicular to studs, covering the complete panel. Stiffeners are added at various locations as required. All floor and walls panels are loaded on a flat bed in a progressive manner and shipped to site. Site preparation requires a floor slab in place with rebar for the columns and plumbing to be installed. The floor slab has to be designed to support the structure.
Installation and assembly of wall panels proceeds as follows: The assembly of the wall panels for the first storey walls and the floor panels for the first storey ceiling (second-storey floor) are repeated in the same fashion for the upper floors.
Exterior wall and interior wall panels are offloaded and placed on the floor slab in their respective locations. 45-degree interior cross-bracing is added as temporary bracing to support the panels. Wall plumbness is checked as walls are secured with cross-bracing. Panels are then fastened to the slab and leveled. Floor panels are then shipped on a flat bed to the site and offloaded. Each floor panel is placed on top of the wall panels in its respective location while maintaining a gap between each panel that is approximately 6″ to 8″. This gap can be filled with an 8″ track which will then be fastened on each side of the panel that will act as a form once the concrete is poured. Each beam has been designed to line up with the columns in the wall panels. Floor panels are then fastened with screws to the top of the wall panels. This is only a temporary means to hold them together—once the concrete is poured and cured the structure will hold together by itself. Once the floor system has been secured, cross-bracing is removed and shoring is placed at the underside of the complete floor system, as engineered. See, for example, the shoring plan depicted in
For the purposes of this specification, the term “prefabricated” means that the panel or other component in question has been fabricated prior to being transported to the construction site. It should be understood that while it is preferable to prefabricate the complete panels prior to transporting them to the job site, it is not essential that this be done, since it is also possible to assemble some of the components of the panels in situ, i.e. at the job site.
For the purposes of this specification, “sheathing” means a structural covering, usually boards, plywood, or other sheet material that is placed over studding, rafters, etc. In this case, the sheathing is placed on top of the assembly of frames to support the rebar can be placed and the concrete that is poured to form the floor of the next storey. The sheathing can be plywood treated with a fire-resistant preservative or any other suitable covering. It should be understood that it is preferable to attach the sheathing before transporting the panels to the job site, but this is not necessary.
This novel technology can be applied to efficiently construct multi-storey buildings. While this technology is primarily intended for low-rise multi-storey buildings such as, for example, buildings have six floors or less, the technology can be applied in theory to the construction of a high-rise building as well, provided that the structure is engineered to withstands the loads involved.
This novel technology provides a number of substantial advantages over the prior art. For example, this novel technology reduces construction time and construction cost by doing away with removable concrete forms and eliminating the coordination problems associated with employing different trades to complete the framing and cladding. Since the panels are lightweight, mobile cranes can lift the panels from a flatbed truck (without requiring a tower crane, which is far more expensive and time-consuming). This novel construction method also eliminates the forming contractor and all the structures are engineered in house, reducing on-site engineering costs. Since only one trade is responsible for the entire framework and all partitions, quality control is improved (fewer mistakes are likely to be made by only a single trade). Furthermore, this technique allows other trades (e.g. electricians, plumbers) to proceed on the lower levels while the construction on the upper levels may continue, again reducing construction time substantially.
This technique furthermore is easy to implement. The panels are quickly and easily attached to one another using fasteners. A mobile crane can easily lift the panels from a flatbed truck and with the guiding hand of a couple workers easily position the panels at the right place on the building. Due to the repetitive nature of the assembly process, workers will quickly become adept at assembling the panels and pouring the columns and beams, thus improving efficiency.
This novel technique furthermore reduces waste (compared to prior-art construction techniques) and is thus environmentally friendly.
Since the prefab panels already have exterior cladding, there is no need to tarp the building (during bad weather). Alternatively, a first (intermediate) cladding can be pre-installed and a finished (final) cladding can be added on site, which also is efficient. Moreover, the floor space is optimized since the columns are intelligently located within exterior and interior walls. Since the columns are small, i.e. no thicker than a stud, they perfectly fit within the wall space.
This new technology has been described in terms of specific implementations and configurations which are intended to be exemplary only. The scope of the exclusive right sought by the Applicant is therefore intended to be limited solely by the appended claims.
Claims
1. A method of constructing a building, the method comprising steps of:
- preparing a construction site by pouring a floor slab with upright rebar positioned to align with load-bearing concrete columns that are to be poured;
- erecting an assembly of modular prefabricated wall panels by connecting the wall panels to define one or more walls of the building, the wall panels comprising a frame having a plurality of substantially vertical members, a subset of the plurality of substantially vertical members being closed channels;
- laying modular prefabricated floor panels onto a top end of the assembly of modular prefabricated wall panels, the floor panels comprising a frame having a plurality of horizontally arranged joists and a sheathing mounted onto the frame, each of the floor panels further comprising a trench-like track that acts as a trough for receiving concrete; and
- pouring concrete into the troughs in the floor panels for flowing into the channels, the concrete curing in the troughs to form horizontal concrete beams and curing in the channels to form concrete columns.
2. The method as claimed in claim 1 further comprising a step of adding rebar prior to pouring concrete.
3. The method as claimed in claim 1 wherein the concrete beams are aligned with and supported from below by the load-bearing concrete columns.
4. The method as claimed in claim 1 wherein the steps of erecting the wall panels and laying the floor panels comprises erecting two storeys of modular prefabricated wall panels and two floors of floor panels before pouring the concrete.
5. The method as claimed in claim 4 further comprising building additional storeys of the building by repeating the steps of erecting wall panels, laying floor panels, pouring concrete beams and columns within the troughs and channels in the wall and floor panels.
6. The method as claimed in claim 1 wherein the frame of each wall panel is prefabricated by:
- fastening a plurality of spaced-apart, vertically arranged studs and a vertically arranged box channel to top and bottom tracks, the top track having a hole in the track above the box channel to thereby enable concrete to flow through the hole in the top track into the box channel; and
- fastening cross-bracing and stiffeners to the studs and box channel.
7. The method as claimed in claim 6 wherein each wall panel is prefabricated by attaching an exterior wall sheathing to one side of the frame.
8. The method as claimed in claim 1 wherein the frames of the floor panels are spaced apart by a predetermined distance defining an elongated gap into which is placed a trench-like track that acts as the horizontal trough for receiving concrete which, when cured, forms each concrete beam.
9. The method as claimed in claim 8 wherein the predetermined distance defining the gap between the frames is equal to a depth of the joists.
10. The method as claimed in claim 1 further comprising steps of:
- temporarily bracing the wall panels;
- checking that the wall panels are plumb; and
- fastening the wall panels to the floor slab.
11. The method as claimed in claim 1 further comprising steps of:
- fastening floor panels to a top portion of the wall panels;
- removing bracing from the wall panels; and
- shoring an underside of the floor panels.
12. A modular prefabricated wall panel for use in constructing a building, the wall panel comprising:
- a frame having a plurality of spaced-apart vertically arranged studs and a vertically arranged closed channel within which concrete can be poured and cured; and
- a sheet of exterior sheathing attached to one side of the frame.
13. The modular prefabricated wall panel as claimed in claim 12 further comprising top and bottom tracks connected to the studs and channel, the top track having holes aligned with a top of the channel to permit poured concrete to flow into the channel.
14. The modular prefabricated wall panel as claimed in claim 12 comprising two channels for receiving concrete to form respective load-bearing columns, the two channels being spaced apart to permit an aperture for a window to be disposed between the channels.
15. A modular prefabricated floor panel for use in constructing a building, the floor panel comprising:
- a pair of spaced-apart frames, each frame comprising a plurality of spaced-apart horizontally arranged joists and a sheathing attached to each frame; and
- a trench-like track connected to each of the pair of spaced-apart frames panels to thereby define a trough between the frames for receiving concrete.
16. The modular prefabricated floor panel as claimed in claim 15 wherein the frame comprises:
- a plurality of joists connected back to back with fasteners;
- top and bottom tracks connected to the top and bottom sides of the joists; and
- a sheathing mounted to the top track or to one or more of the plurality of joists.
17. The modular prefabricated floor panel as claimed in claim 15 further comprising stiffeners interconnecting adjacent joists.
18. A multi-storey building comprising:
- a plurality of modular prefabricated wall panels assembled together to form the walls of the building, the wall panels comprising upright channels into which concrete is poured and cured to form hybrid steel-and-concrete load-bearing columns; and
- a plurality of modular prefabricated floor panels assembled together to form the floors of the building, the floor panels comprising horizontal troughs into which concrete is poured and cured to form hybrid steel-and-concrete horizontal beams.
19. The multi-storey building as claimed in claim 18 wherein the columns of each upper floor are aligned with and are supported by the beams of the floor immediately below.
20. The multi-storey building as claimed in claim 19 wherein the beams of each upper floor are aligned with and are supported by the columns of the floor immediately below.
Type: Application
Filed: Sep 5, 2008
Publication Date: Mar 11, 2010
Inventor: Bernard M. NORMAND (Ottawa)
Application Number: 12/205,496
International Classification: E04H 1/00 (20060101); E04B 1/30 (20060101); E04C 3/294 (20060101);