WO2008069764A1

WO2008069764A1 - Industrialized construction system and method

Info

Publication number: WO2008069764A1
Application number: PCT/SG2007/000418
Authority: WO
Inventors: Bancha Kampanatsanyakorn
Original assignee: Axis Ip Holding Pte Ltd
Priority date: 2006-12-08
Filing date: 2007-12-07
Publication date: 2008-06-12
Also published as: US20100011677A1

Abstract

Problems faced in the residential construction industry include the shortage of skilled manpower which gives rise to problems such as the inconsistencies in construction quality, time delay and cost overrun. This is because most construction work uses on-site wet concreting systems requiring expertise in numerous construction techniques and tasks. Since the progress of most tasks using these construction techniques depends on the progress of another task, most construction projects are difficult to manage. This results in an inefficient construction system that hinders provision of low-cost mass housing. Described according to an embodiment of the invention is an industrialized construction system comprising a roof support structure and a roof frame coupled to and supported by the roof support structure. The construction system further comprises a plurality of wall frames extending from a base. The roof support structure is adapted for being supported by the plurality of wall frames. The roof support structure structurally interposes the roof frame and at least one of the plurality of wall frames for directing weight of the roof frame to substantially along the plane of each of the plurality of walls.

Description

INDUSTRIALIZED CONSTRUCTION SYSTEM AND METHOD

Field Of Invention

The present invention relates generally to a construction system. In particular, the invention relates to a pre-fabricated frame-based construction system for use in constructing residential buildings in an industrialized manner.

Background

Problems faced in the residential construction industry include the shortage of skilled manpower which gives rise to problems such as the inconsistencies in construction quality, time delay and cost overrun. This is because most construction work uses on- site wet concreting systems requiring expertise in numerous construction techniques and tasks. Since the progress of most tasks using these construction techniques depends on the progress of another task, most construction projects are difficult to manage. This results in an inefficient construction system that hinders provision of low-cost mass housing.

To address these problems, a small portion of the construction industry has developed prefabricated construction systems such as a prefabricated framing system, panelization system, and pre-casting concrete. However, these prefabricated systems still have their limitations regarding to designing flexibility as well as difficulties in transportation and installation while using these systems. Moreover, use of conventional construction methods for prefabricating elements of the prefabricated construction system still require a lot of time and work to complete a roofing structure. The steps and skill requirement for erecting trusses and for completing all roofing works still result in low productivity of workers. Consequently, the cost of construction cost is still high.

USPN 6,854,218 describes a panelized construction system which emphasizes on production of standard panels which can be assembled without assistance of an architecture or engineer. However, the structures obtained from the panelized construction system lack aesthetic appeal and structural strength and therefore are used primarily for constructing a building module such as a housing addition. Additionally, panels used in the panelized construction system are of a fixed size and shape which in turn limits the shapes of structures that are constructible.

Thai application no. 105933 describes use of light gauge steel for constructing modular panels. Each of the modular panels is shaped as a wall with the necessary window and door cavities. The modular panels are interconnected using angle bars, or L joints, on upper and lower sides. However, roof trusses are still needed to be constructed using conventional approaches. Once the roof trusses are assembled, a lot of time and work are still needed including the installation of ceilings and electrical wirings. It is difficult to manage the cost when the truss system is used.

As abovementioned, conventional pre-fabricated components, still require a degree of skill in ensuring that the components are properly assembled; for example the assembling of roof trusses still is time consuming. Additionally, the steps required for assembling the components still follow typical construction approaches and are therefore complicated. Handling of the components is also a daunting task due to the weight of the components. Therefore, there is a need for use of appropriate devices or equipment for assembling different components. Skill and accuracy are also required for ensuring that the components are properly inter-configured, for example, with the correct angles and pitches. Furthermore, the assembled structures still require further processing, for example, the installation of electrical wirings. These practices lead to poor project productivity and hence, clearly affirm a need for an improved prefabricated construction system.

Summary In accordance with a first aspect of the invention, there is disclosed a construction system comprising a roof support structure. The roof support structure comprises a first support frame and a second support frame coupled to the first support frame with the second support frame extending substantially perpendicularly to the first support frame and terminating at an edge. The construction system further comprises a roof frame coupled to and extending between the edge of the second support frame and a portion of the periphery of the first support frame, and a plurality of wall frames extending from a base. The roof support structure is adapted for being supported by the plurality of wall frames with the second support frame being substantially perpendicular to at least one of the plurality of wall frames. Each of the first support frame, the second support frame, the roof frame and the plurality of wall frames is planar and pre-fabricated from a plurality of studs. The roof support structure structurally interposes the roof frame and at least one of the plurality of wall frames for directing weight of the roof frame to substantially along the plane of each of the plurality of walls.

In accordance with a second aspect of the invention, there is disclosed a construction method comprising forming a base, extending a plurality of wall frames from the base and attaching and supporting a roof support structure to the plurality of wall frames. The roof support structure comprises a first support frame and a second support frame coupled to the first support frame with the second support frame extending substantially perpendicularly to the first support frame and terminating at an edge. The roof support structure is adapted for being supported by the plurality of wall frames with the second support frame being substantially perpendicular to at least one of the plurality of wall frames. The construction method further comprises coupling of a roof frame to the roof support structure with the roof frame extending between the edge of the second support frame and a portion of the periphery of the first support frame. Each of the first support frame, the second support frame, the roof frame and the plurality of wall frames is planar and pre-fabricated from a plurality of studs. The roof support structure structurally interposes the roof frame and at least one of the plurality of wall frames for directing weight of the roof frame to substantially along the plane of each of the plurality of walls.

In accordance with a third aspect of the invention, there is disclosed a roof system comprising a roof support structure. The roof support structure comprises a first support frame and a second support frame coupled to the first support frame with the second support frame extending substantially perpendicularly to the first support frame and terminating at an edge. The roof system further comprises a roof frame coupled to and extending between the edge of the second support frame and a portion of the periphery of the first support frame. The roof support structure is adapted for being supported on a plurality of wall frames with the second support frame being substantially perpendicular to at least one of the plurality of wall frames. Each of the first support frame, the second support frame and the roof frame is planar and prefabricated from a plurality of studs. The roof support structure structurally interposes the roof frame and at least one of the plurality of wall frames for directing weight of the roof frame to substantially along the plane of each of the plurality of walls.

Brief Description Of The Drawings

An embodiment of the invention is described in detail hereinafter with reference to the drawings, in which:

Fig. 1 shows an industrialized construction system according to an embodiment of the invention;

Fig. 2 shows a roof panel structure of the industrialized construction system of Fig. 1;

Fig. 3 shows a roof support structure 20 of the industrialized construction system of Fig. 1;

Fig. 4 shows wall panel structures of the industrialized construction system of Fig. 1 ;

Fig. 5 shows a floor panel structure of the industrialized construction system of Fig. 1;

Fig. 6 shows a partial cross-section of the wall panel structure of Fig. 4;

Fig. 7 shows process flow diagram of an industrialized construction method for applying the industrialized construction system of Fig. 1; and

Fig. 8a - Fig. 8d shows a roof support structure of a house being constructed using the industrialized construction method of Fig. 7 at different stages of completion. Detailed Description

An industrialized construction system is described hereinafter for addressing the foregoing problems.

For purposes of brevity and clarity, the description of the invention is limited hereinafter to an industrialized construction system. This however does not preclude various embodiments of the invention from other applications that require similar operating performance as an industrialized construction system.

In the detailed description provided hereinafter and illustrations provided in Figs. 1 to 6 of the drawings, like elements are identified with like reference numerals.

An embodiment of the invention, an industrialized construction system 10 is described with reference to the drawings.

With reference to Fig. 1, an industrialized construction system 10 for constructing a house over a foundation 100 according to an embodiment of this invention, comprises one or more of a roof sub-frame 15, a roof support structure 20, a wall frame 30, a floor frame 40 and a stake 110.

Each of the roof sub-frame 15, the roof support structure 20, the wall frame 30 and the floor frame 40 are fabricated from studs arranged along a plane in a pre-determined configuration. The pre-determined configuration is preferably a load-bearing configuration. The studs are preferably C-channels or U-channels (also typically known as C and U profiles respectively) and are preferably made from steel. However, the studs can alternatively be made from wood, thermosetting plastic or alloys. The foundation 100 is preferably an area formed from crushed soil when the house is a temporary structure and where there is a need to speed up the construction of the house. Alternatively, the foundation 100 is formed from concrete when the house is required to be permanent. The stake 110 is preferably for supporting the wall frame 30. However, this depends on the design of the house. Depending on the design of the house, use of the stake 110 may be excluded. The stake 110 is preferably an I-beam with plaster and gypsum sheets cladded thereunto for humidity resistance. Alternatively, the stake 110 is prefabricated from reinforced concrete stake or wood stake.

Fig. 2 shows the roof sub-frame 15 according to the embodiment of this invention.

According to Fig. 2, preferably pieces of the roof sub-frame 15 are inter-coupled for forming a roof frame 47. The roof sub-frame 15 is prefabricated prior to being transported to the site whereat the house is constructed to reduce the number of workers needed and tools required by each worker for constructing the roof frame 47.

Pieces of the roof sub-frame 15 are inter-coupled by screw fastening or A. C arc welding. One or more of the wall frame 30 supports the completed roof frame 47. The roof frame 47 is subsequently laid over with a roof.

Referring to Fig. 2, the roof sub-frame 15 is constructed from the studs arranged to form a lattice for enabling load bearing and to facilitate attachment of roof tiles thereto. The use of the studs for constructing the roof sub-frame 15 also allows the shape of the roof sub-frame 15 to be varied to suit the design of the house.

Fig. 3 shows the roof support structure 20 according to the embodiment of this invention.

According to Fig. 3, the roof support structure 20 comprises a horizontal frame 52 and a vertical frame 54. The vertical frame 54 is disposed substantially perpendicular to the horizontal frame 52 for supporting the weight of the roof sub-frame 15 and roof tiles supported thereon (not show)

The studs for the roof support structure 20 are preferably made from wrought iron, C- channels or U-channels interconnected by A. C. arc welding or screw fastening.

The horizontal frame 52 of the roof support structure 20 is preferably pre-fabricated with a smooth surface layer, for example a flat gypsum board, extending over the studs for forming the ceiling of the house. This enables electrical lighting systems, such as fluorescence bulb and down light, and electrical wiring and conduits to be installed in the horizontal frame 52 during pre-fabrication thereof. This substantially speeds up on-site construction of the house. Fig. 4 shows a prefabricated wall frame 30 formed from an arrangement of studs.

Referring to Fig. 4, the studs of the wall frame 30 are preferably pre-fabricated from wrought iron C-channels, U-channels or a combination thereof. The studs of the wall frame 30 are arranged for forming window openings 56 and door openings 58 to enable windows and doors respectively to be attached in place during pre-fabrication. This reduces complication during on-site construction of matching right windows and doors to the right window openings 56 and door openings 58.

Referring to Fig. 5, the floor frame 40 is constructed from wrought iron C-channels and U-channels. A template structure 60 is preferably used as a shape and structural reference during prefabrication of the floor frame 40. The floor frame 40 is paved with a floor layer 62 for supporting up to a pre-determined load thereon. The floor frame 40 is usable as flooring for the ground level or other levels of the house. Should the floor frame 40 be used as the flooring of the second or a higher level of the house, a ceiling layer (not shown) is paved across the underside of the floor frame 40 below the floor layer 62.

The floor layer 62 is preferably formed from 19mm gypsum board while the ceiling layer is preferably formed from 9mm gypsum board. Additionally, a concrete layer embedded with a wire mesh is formed over the floor layer 62.

With the concrete layer being 4cm in thickness, the floor frame 40 is able to withstand a load of 1,500kg with a deflection of 2.50 mm.

Fig. 6 shows a partial cross-sectional view of the wall frame 30 being clad with sheet material for forming an external wall 64 and an internal wall 66. An air gap 68 formed between the external wall 64 and the internal wall 66 functions as a thermal insulator. This allows the wall frame 30 to provide thermal insulation even in a hot climate while providing a strong, hard and preferably cement block-like feel.

Preferably, a wire mesh layer 70 disposed over the external wall 64. The wire mesh layer 70 is plastered over with a cement layer 72. This wire mesh layer 70 holds the cement layer 72 in place over the external wall 64. The internal wall 66 is preferably a 12 mm gypsum board while the external wall 64 is preferably a 9 mm gypsum board. The air gap 68 preferably extends 7.5 cm from the internal wall 66 to the external wall 64. The cement layer 72 is preferably 2 cm thick. These allow the wall frame 30 to achieve a heat resistance (R) of 0.466 and a thermal conductivity (U) of 2.14 W/m-c (watt per square meter. Celsius).

In addition to improved thermal insulation, fiber glass insulator or cellulose can be inserted into the air gap 68 to enable the wall frame 30 to achieve a total heat resistance (R) of 2.813 and a thermal conductivity (U) of 0.36 W/m-c (watt per square meter. Celsius). Noise insulation is also increased thereby.

The industrialized construction system 10 is preferably applied using an industrialized construction method 200. In a step 202 of the industrialized construction method 200 as shown in Fig. 7, multiple pieces of each of the roof sub-frame 15, the horizontal frame 52 and the vertical frame 54 of the roof support structure 20, the wall frame 30, the stake 110 and the floor frame 40 are prefabricated off-site prior to being transported on-site.

In a step 204, the foundation 100 is formed. Step 204 can occur either subsequent to or concurrently with step 202 due to the separate localities used for performing these two steps. This is one example where completion status of one step is not dependent on completion status of another step of the industrialized construction method 200.

Next in a step 206, the wall frames 30 are installed over the foundation 100. When required, the stakes 110 are also installed in step 206. The floor frames 40 are then installed in a step 208 should the house have a second level. The floor frames 40 are coupled to the wall frames 30 for being supported thereby. Next in a step 210, the wall frames 30 are installed over the floor frames 40 for forming the walls of the second level of the house.

Next in a step 212, the roof support structure 20 is attached to the wall frames 30 by screw fastening or A. C. arc welding with the wall frames 30 supporting the roof support structure 20. Subsequently in a step 214, the roof sub-frames 15 are attached to the roof support structure 20 for forming the roof frame 47. Figs. 8a-8d illustrates an example of the roof structure 20 of a house constructed using the industrialized construction method of Fig. 7 at different stages of completion. Additionally, Figs. 8b and 8c show preferred use of gable structures 200 disposed between the roof support structure 20 and the roof frame 47. Fig. 8d shows the roof frame 47 being covered with roof finishing material 202.

As the roof frame 47 is disposed at an incline, the weight of the roof frame 47 creates forces directed transverse the plane of the wall frame 30. The roof support structure 20 functions as a structural interposer between the roof frame 47 and the wall frame 30. The roof support structure 20 redirects transverse forces contributed by the weight of the roof frame 47 to along the plane of the wall frames 30. This substantially prevents lateral flexure of the wall frames 30 which may occur when the roof sub-frame 15 are directly connected thereto. Additionally, assembly of the roof support structure 20 and the roof frame 47 to the wall frames 30 is also structurally and procedurally simplified. As assembly of the roof support structure 20 only requires very simple assembly steps, the need for different tradesmen with different skill-sets is substantially eliminated. This coupled with the reduced number of assembly steps required leads to improved project efficiency.

During the steps 206 to 214, the floor layer 62, the ceiling layer, the external wall layer 64, the internal wall layer 66, the wire mesh layer 70 and the cement layer 72 can be applied to already installed components of the industrialized construction system 10. Subsequently in a step 216, the house is finished by installation of preferably internal walls, window-door frames and stairs, and by the application of paint thereto. The necessary conduits, electrical wirings and electrical points pre- installed into the components of the industrialized construction system 10 during prefabrication, further facilitate reduction in the construction duration.

According to the aspect of the invention as mentioned, the industrialized construction system 10 is an appropriate system for constructing prefabricated houses as different types of work can occur substantially concurrently to reduce time and the size of manpower required. On-site material wastage and construction cost are also reduced without sacrificing required strength, durability and aesthetic appeal of the houses.

In the foregoing manner, an industrialized construction system and an industrialized construction method are described according to one embodiments of the invention for addressing the foregoing disadvantages of conventional approaches. Although only one embodiment of the invention is disclosed, it will be apparent to one skilled in the art in view of this disclosure that numerous changes and/or modification can be made without departing from the scope and spirit of the invention.

Claims

1. A construction system comprising: a roof support structure comprising: a first support frame; and a second support frame coupled to the first support frame, the second support frame extending substantially perpendicularly to the first support frame and terminating at an edge, a roof frame coupled to and extending between the edge of the second support frame and a portion of the periphery of the first support frame; and a plurality of wall frames extending from a base, the roof support structure adapted for being supported by the plurality of wall frames with the second support frame being substantially perpendicular to at least one of the plurality of wall frames, wherein each of the first support frame, the second support frame, the roof frame and the plurality of wall frames is planar and pre-fabricated from a plurality of studs, wherein the roof support structure structurally interposes the roof frame and at least one of the plurality of wall frames for directing weight of the roof frame to substantially along the plane of each of the plurality of walls.

2. The construction system as in claim 1, the base being concrete foundation.

3. The construction system as in claim 1, the base being pre-fabricated from a plurality of studs and comprising: first and second base layers formed over opposing sides of the base for containing at least a portion of the plurality of studs of the base therebetween.

4. The construction system as in claim 3, at least one of the first base layer and the second base layer comprising: a wire mesh; and a cement layer formed over the wire mesh.

5. The construction system as in claim 3, each of the first base layer and the second base layer being one of gypsum board, cement-fiber plate and sheet material.

6. The construction system as in claim 1, each of the plurality of wall frame comprising first and second wall layers formed over opposing sides thereof for containing at least a portion of the plurality of studs of the each of the plurality of wall frame therebetween.

7. The construction system as in claim 6, at least one of the first wall layer and the second wall layer comprising: a wire mesh; and a cement layer formed over the wire mesh.

8. The construction system as in claim 6, each of the first wall layer and the second wall layer being one of gypsum board, cement-fiber plate and sheet material.

9. The construction system as in claim 6, at least one of the plurality of wall frames comprising: at least one electrical conduit extending between the first and second wall layers and at least one of an electrical socket and a electrical switch formed in the first wall layer.

10. The construction system as in claim 1, the first support frame comprising: a panel extending over one side of the support frame; and a lighting connectors extending along the support frame.

11. A construction method comprising: forming a base; extending a plurality of wall frames from the base; attaching and supporting a roof support structure to the plurality of wall frames, the roof support structure comprising: a first support frame; and a second support frame coupled to the first support frame, the second support frame extending substantially perpendicularly to the first support frame and terminating at an edge, the roof support structure adapted for being supported by the plurality of wall frames with the second support frame being substantially perpendicular to at least one of the plurality of wall frames, and coupling a roof frame to the roof support structure, the roof frame extending between the edge of the second support frame and a portion of the periphery of the first support frame, wherein each of the first support frame, the second support frame, the roof frame and the plurality of wall frames is planar and pre-fabricated from a plurality of studs, wherein the roof support structure structurally interposes the roof frame and at least one of the plurality of wall frames for directing weight of the roof frame to substantially along the plane of each of the plurality of walls.

12. The construction method as in claim 1 1, wherein forming the base comprises: forming the base from concrete foundation.

13. The construction method as in claim 11, wherein forming the base comprises: pre-fabricating the base from a plurality of studs; and forming first and second base layers over opposing sides of the base for containing at least a portion of the plurality of studs of the base therebetween.

14. The construction method as in claim 13, wherein at least one of the first base layer and the second base layer comprising: a wire mesh; and a cement layer formed over the wire mesh.

15. The construction method as in claim 13, wherein each of the first base layer and the second base layer being one of gypsum board, cement-fiber plate and sheet material.

16. The construction method as in claim 11, wherein each of the plurality of wall frame comprising first and second wall layers formed over opposing sides thereof for containing at least a portion of the plurality of studs of the each of the plurality of wall frame therebetween.

17. The construction method as in claim 16, wherein at least one of the first wall layer and the second wall layer comprising: a wire mesh; and a cement layer formed over the wire mesh.

18. The construction method as in claim 16, wherein each of the first wall layer and the second wall layer being one of gypsum board, cement-fiber plate and sheet material.

19. The construction method as in claim 16, wherein at least one of the plurality of wall frames comprising: at least one electrical conduit extending between the first and second wall layers and at least one of an electrical socket and a electrical switch formed in the first wall layer.

20. The construction method as in claim 11 , wherein the first support frame comprising: a panel extending over one side of the support frame; and a lighting connectors extending along the support frame.

21. A roof system comprising: a roof support structure comprising: a first support frame; and a second support frame coupled to the first support frame, the second support frame extending substantially perpendicularly to the first support frame and terminating at an edge; and a roof frame coupled to and extending between the edge of the second support frame and a portion of the periphery of the first support frame; the roof support structure adapted for being supported on a plurality of wall frames with the second support frame being substantially perpendicular to at least one of the plurality of wall frames, wherein each of the first support frame, the second support frame and the roof frame is planar and pre-fabricated from a plurality of studs, wherein the roof support structure structurally interposes the roof frame and at least one of the plurality of wall frames for directing weight of the roof frame to substantially along the plane of each of the plurality of walls.

22. The roof system as in claim 21, the roof frame forming an incline with at least one of the plurality of wall frames.