WO2006004357A1

WO2006004357A1 - Concrete-structure constructing system manufactured by pre-fabricating and method therof

Info

Publication number: WO2006004357A1
Application number: PCT/KR2005/002093
Authority: WO
Inventors: Bum-Jun Kim; Yeon-Jin Kim
Original assignee: Bum-Jun Kim; Yeon-Jin Kim
Priority date: 2004-07-02
Filing date: 2005-07-01
Publication date: 2006-01-12
Also published as: KR100731593B1; KR20070036807A

Abstract

Provided are a construction concrete-structure constructing system pre-fabricated at the plant, not at the construction site, which removes the inconveniences of arrangement of steel reinforcing, installation of plates and setup and removal of supports to support the plates, and a constructing method using the same. Since construction is carried out using the pre-fabricated steel reinforcing assembly and standardized mold, period of construction can be reduced significantly. Besides safety and high quality, economic advantages of construction period reduction and cost saving can be attained by this new-concept constructing method.

Description

CONCRETE-STRUCTURE CONSTRUCTING SYSTEM MANUFACTURED BY PRE-FAERICATING AND METHOD THEROF

Technical Field The present invention relates to a concrete-structure constructing system manufactured by pre-fabricating and a constructing method using the same, particularly to a concrete-structure constructing system manufacture by pre-fabricating at the plant, not at the construction site, which removes the inconveniences of arrangement of steel reinforcing, installation of plates and setup and removal of supports to support the plates, and a constructing method using the same. Since construction is carried out using me pre-fabricated steel reinforcing assembly and standardized mold, period of construction can be reduced significantly. Besides safety and high quality, economic advantages of construction period reduction and cost saving can be attained by this new-concept constructing method,

Background Art

In general, structuring of steel reinforcing concrete is a process of manufacturing a structure with concrete and reinforcing. Molding fluid concrete in a frame and arranging steel reinforcing are the typical processes in structuring of steel reinforcing concrete. The subsequent process of removing the mold after the curing of concrete greatly affects safety and economy of the work.

FIG. 1 shows underflooring member (300) and girder member (301) used in the conventional structure construction. FIG. 2 shows separator (302), form tie (303) and spacer (304) used in the conventional structure construction. The separator (302) separates steel reinforcing from plates. The form tie (303) prevents the plates from being widened, outward. And, the spacer (304) maintains spacing between the plates. In the conventional structure construction, a lot of molding members including molds (made of such polywoods as plate), girths, girder members, underflooring members, .supports and form ties are required, along with the process of joining these members.

Also, with regard to steel reinforcing, such members as spacers for maintaining spacing between plates and separators for maintaining spacing between steel reinforcing members are required. In addition, electricity and facility line installations are also accompanied at the construction site. Most of these works are done by a lot of personnel, Accordingly, the conventional construction method is greatly affected by weather and is disadvantageous in process management, safety management, quality control, etc. because it evolves a lot of workers. To reduce construction period, more workers have to be committed, which further aggravates the situation.

In an effort to minimize on-site works in the conventional construction, PC construction, system form, steel reinforcement deck, etc. were proposed. However, none of these suggestions could satisfy all the requirements of mass production, construction convenience, economy, and so forth.

In PC construction, major members of steel-reinforced concrete structure, such as posts, girders, slab and walls are fabricated at the plant and taken to the construction site as concrete curing is finished, The major work at the site is assembly of each member. However, this method costs very much and excessive weight makes transfer, lifting and secure joining difficult.

In some large-scale constructions, system forms, or pre-fabricated molds, are used. But, since the system forms are mainly made of steel, they are heavy, expensive and less likely to cope with modification. Besides, they require additional steel reinforcing workings.

Limited to slab, there is pre-fabricated plant product which is produced by welding steel reinforcing truss in a disposable mold of a given dimension. It is called the steel reinforcement deck. However, this slab member requires some site workings, including opening and steel reinforcing. Also, use of the expensive disposable mold increases construction cost. Besides, it is difficult to find out defects such as cracking, water leakage, etc. after concrete curing.

Despite these efforts to reduce on-site workings, the uniqueness of steel reinforcing concrete structures poses problems and a variety of proposals are difficult to be applied.

Disclosure of Invention

It is an object of the present invention to significantly reduce construction period by joining plates and steel reinforcing with lattice as if sewn and then laying and curing concrete, thereby enhancing strength of the structure;, and pre- fabricating the steel reinforcing assembly and plates at the plant in order to prevent the plates from being pushed outward after concrete laying and reduce time required for steel reinforcing arrangement and molding. Conventionally, there have been continuous efforts to minimize on-site working personnel in steel reinforcing concrete structure construction. It is because minimizing on-site working personnel is considered essential for efficient process management, safety management, quality control and construction period reduction.

However, such efforts were limited because of the uniqueness of steel reinforcing concrete structures, i.e., excessive molding and steel reinforcing arrangement. Also, the methods proposed to improve the conventional construction method, for example PC construction, system forms and steel reinforcement deck, are impractical because of cost increase, excessive weight, inconvenience of construction, etc.

Pre-fabrication of construction members of the present invention is aimed at minimizing on-site workings, To enable construction by industrial production to succeed, the present invention aims at mass production and transfer of major construction members, ease construction at the site and easy de-molding after concrete curing.

The steel reinforcing assembly of the present invention is made into steel reinforcing truss for plate-type members like slab and walls. Since bending of the lattice constituting the truss and electric resistance welding of the bent lattice to the steel reinforcing can be performed continuously, mass production at the plant becomes possible. The plate-type steel reinforcing truss, which is pre-fabricated in one body with the plates, has such a good strength that it prevents twisting during transfer or lifting. In line-type members, such as poles or girders, three or four outer surfaces of the steel reinforcing assembly are joined with the plates for convenient transfer and lifting. Pre-fabricated members can be designed to minimize volume for the convenience of stockpiling or transfer. Since concrete laying is carried out at the construction site, the members are light, Weight of the members pre-fabricated by the present invention is only about 10 % that of the conventional PC members of the same kind. The pre-fabricated product transferred to the construction site or made into a finished product at an assembly workplace at the construction site requires only a little molding or steel reinforcing arrangement, most of it having been completed. It is assembled using such lifting equipments as tower crane and then concrete laying is carried out.

De-moldiαg after concrete curing is very simple and safe. In addition, damaging of the mold is reduced, so that it can be reused many times.

Hereunder is given a more detailed description of the present invention referring to the attached drawings. The present invention comprises plates capable of holding concrete before curing, a steel reinforcing assembly joined to the plates between them or at the top in order to maintain strength after concrete curing and a joining means, which joins the steel reinforcing assembly and the plates to maintain spacing between them.

The plate can be made of a variety of materials, including polywood and plastics, and may be more than one. In case of slab construction, a sheet of plate is placed horizontally and then the steel reinforcing assembly is put on it. In case of walls, two sheets of plate are set up as opposing each other. Ih case of girders, 3 sheets

of plate are assembled in "U " shape. And, in case of poles, 4 sheets of plate can be assembled, so that the planar shape becomes "□". The steel reinforcing assembly comprises a vertical steel reinforcing, a horizontal steel reinforcing and a lattice. Depending on the construction condition, it may comprise only a vertical steel reinforcing and a horizontal steel reinforcing, without a lattice. The vertical and horizontal steel reinforcings and the lattice are joined by steel wiring, welding, etc. The lattice may have a variety of shape including zigzag, trapezoid, etc. The outer end of the lattice may be exposed outward through the opening of the plate. In case of walls, it may be joined between the two opposing plates, 111 case of slab, it may be joined on top of the plate.

The joining means temporarily fixes the steel reinforcing assembly to the plate, so that concrete may be held inside the plate until it is cured. It may be a bolt and a nut or a pin. In case of using a pin, the bent end of the lattice shall be exposed outward of the opening end of the plate. As another example of the joining means, a joint may be formed at the end of the joining means (see FlG. 16),

Brief Description of the Drawings

FlG. 1 shows underflooring and girder members used in the conventional structure construction.

FIG. 2 shows a separator used in the conventional structure construction.

FIG. 3 is a separational perspective view of a concrete-structure constructing system pre-fabricated according to an embodiment of the present invention.

FIG. 4 shows the assembly of a concrete-structure constructing system pre¬ fabricated according to an embodiment of the present invention.

FIG. 5 shows a concrete-structure constructing system pre-fabricated according to an embodiment of the present invention, with the side wall opened. FIG. 6 is a cross-sectional side view of FIG, 4.

FIG, 7 shows slab construction using a concrete-structure constructing system pre-fabricated according to an embodiment of the present invention.

FIG, 8 shows simultaneous construction of walls and slab using a concrete- structure constructing system pre-fabricated according to an embodiment of the present invention.

FIG. 9 shows construction of poles using a concrete-structure constructing system pre-fabricated according to an embodiment of the present invention.

FIG. 10 shows a concrete-structure constructing system for walls according to another embodiment of the present invention,

FIG. 11 shows a concrete-structure constructing system for slab according to another embodiment of the present invention.

FIG. 12 shows a concrete-structure constructing system for poles according to another embodiment of the present invention. FIG. 13 is an enlarged view of a joining means of the present invention.

FIG. 14 illustrates an example of simultaneous construction of walls and slab.

FIG. 15 shows construction of a beam according to another embodiment of the present invention.

FIG. 16 shows a joint formed by a joining means. <Symbols used in the drawmgs> , .

10, 20: plates 30, 30a: lattice

34; pin as joining means

200: bolt and nut as joining means

60; water duct 61 : power line

Best Mode for Carrjάng Out the Invention

Hereunder is given a detailed description of a preferred embodiment of the present invention,

FIG. 3 is a separational perspective view of a concrete-structure constructing system pre-fabricated according to an embodiment of the present invention. FIG. 4 shows the assembly of a concrete-structure constructing system pre-fabricated according to an embodiment of the present invention. FIG. 5 shows a concrete- structure constructing system pre-fabricated according to an embodiment of the present invention, with Hie side wall opened. And, FIG. 6 is a cross-sectional side view of FlG. 4. Walls, slab and posts can be constructed using the present invention.

Walls

The system of the present invention for wall construction comprises plates 10, 20 capable of holding concrete before curing,, steel reinforcing assembly 33 assembled with the plates 10, 20 between them to maintain strength after curing of the concrete and a joining means joining the steel reinforcing assembly and the plates, so that spacing between the plates is maintained. Hereunder is given a detailed description of each member.

The plates 10, 20 have a plurality of openings 11, 21. Bent end of lattice 30, which will be described later, crosses the openings 11 of the plate 10 in zigzags and is fixed by pin 34. For the plate, a known NT-structure polywood (concrete mold for slabs) is used. The plate may also be made of polywood, plastics, synthetic materials, etc. , not restricted to the NT-structure polywood.

The steel reinforcing assembly 33 comprises vertical steel reinforcing 31, horizontal steel reinforcing 32 fixed on the vertical steel reinforcing 31 perpendicularly to it and lattice 30 crossing between the vertical and horizontal steel reinforcings and fixed on the horizontal or vertical steel reinforcing, Each of the vertical steel reinforcing 31, the horizontal steel reinforcing 32 and the lattice 30 may be fixed by welding or steel wiring, The lattice 30, which is made of thick steel wire, crosses between the plates in zigzags. The bent, end of the lattice 30 is exposed between the openings H₅ 21 of the plates, where the pin 34 temporarily fixes the lattice 30 to the plates 10, 20. The lattice may have a variety of shape, including " /wv\ "_} "JT-TUT ^» and "ZbTA "_{s no}t restricted to zigzag. Lattice 30a for pole construction has a rubber- ^• band shape.

Assembly is completed by exposing the bent end of the lattice 30 at the openings 11 and inserting the pin, 34. The assembly is performed at a separate plant,

Also, as seen in FIG. 6, power line 61 and water duct 60 may be built inside the walls, if required, for convenience of construction. In that case, construction period can be reduced. This is also true of slab and posts to be described later.

Slab

FIG. 7 shows slab construction using a concrete- structure constructing system pre-fabricated according to an embodiment of the present invention. And, FIG. 8 shows simultaneous construction of walls and slab using a concrete-structure constructing system pre-fabricated according to atj, embodiment of the present invention.

After placing one of plates 1O₃ 20 horizontally, main steel reinforcing 35 is fixed to the top and bottom of lattice 30 by welding. Then, the bent end of the lattice 30 is exposed outward through openings 11 of the plate. Next, top and bottom transverse steel reinforcings 36 are fixed by welding, so that they cross the main steel reinforcing 35. Then, pin 34 is inserted to the lattice 30 which exposed outward through the openings

11.

Posts

FIG. 9 shows construction of poles using a concrete-structure constructing system pre-fabricated according to an embodiment of the present invention. The system of the present invention for post construction comprises a plurality of vertical steel reϊnforcmgs 31 fixed vertically, a plurality of plates 10 surrounding the vertical steel reinforcing and opposing one another, lattice 30a crossing between the opposing plates 10 and fixed to the vertical steel reinforcings 31, thereby fixing the vertical steel reinforcings with the plates 10, and pin 34 inserted to the lattice, which is exposed outward through openings of the plates 10, For posts, the lattice 30a also plays a role of horizontal steel reinforcing.

Hereunder is given a specific description of construction according to an embodiment of the present invention. The construction system of the present invention is pre-fabricated along with the mold at a plant near to the construction site. At the construction site, each wall, post and slab is placed at the right position and then concrete is laid.

For wall construction, a pre-fabricated concrete-structure system for wall construction (see FIG. 2) is transferred to the construction site. It is placed at the right position and concrete is laid inside plates 10, 20. After the concrete is cured, pin 34 is removed and the plates 10, 20 are separated from the concrete.

Slab can be constructed alone or along with walls. When slab and walls are constructed together (see HG. S), a concrete-structure system for wall construction (FIG. 4) and a concrete-structure system for slab construction (FIG. 5) are purchased or pre- fabricated at a plant. The concrete-structure system for wall construction is placed at the right position and the concrete-structure system for slab construction is placed on top of me concrete-structure system for wall construction, Then, concrete is laid from the top, so that it is filled in the walls and slab. After the concrete is cured, pin 34 is removed and plates 10, 20 are separated from the concrete. For post construction, a concrete-structure system for post construction (FIG. 7) is purchased or pre-fabricated at a plant. The concrete-structure system for post construction, is placed at the right position and concrete is laid from the top. After the concrete is cured, pin 34 is removed and plate 10 is separated from the concrete, FIG. 10 to FIG. 13 show another embodiment of the present invention, FIG.

10 shows a concrete-structure constructing system for walls according to another embodiment of the present invention. Walls

As another embodiment of the present invention, the system of the present Invention comprises plates 10, 20 capable of holding concrete before curing, a steel reinforcing assembly joined to the plates 10, 20 between them in order to maintain strength after concrete curing and a joining means 200, which joins the steel reinforcing assembly and the plates 10, 20 to maintain spacing between them. Hereunder is given a detailed description of each member. The plates 10, 20 have a plurality of openings 11, 21, For the plate, a known

NT-structure polywood (concrete mold for slabs) is used. The plate may also be made of polywood, plastics, synthetic materials etc., not restricted to the NT-structure polywood,

The steel reinforcing assembly 33, which is placed between the plates, comprises vertical steel reinforcing 31, horizontal steel reinforcing 32 fixed on the vertical steel reinforcing 31 perpendicularly to it and lattice 30 crossing between the vertical and horizontal steel reinforcings and fixed on the horizontal or vertical steel reinforcing. Each of the vertical steel reinforcing 31, the horizontal steel reinforcing 32 and the lattice 30 may be fixed by welding or steel wiring. The lattice 30 is made of thick steel wire. The lattice may have a zigzag shape, but may have a variety of other shape, including not restricted to zigzag.

The joining means 200 comprises nuts 201 fixed horizontally or vertically on the lattice 30 of the steel reinforcing assembly 33 or on the vertical steel reinforcing 31 and bolts 202 joined with the nuts 201 crossing the plate 10, as seen, in FIG. 11. On top of the bolt 202 is washer 203 preventing the plate 10 from being separated.

Although not depicted in the drawing, power line 61 and water duct 60 may be built inside the walls, if required, for convenience of construction and construction period reduction, as in FIG. 4. The outer diameter of the nuts 201 is about 2-3 mm, for example, larger than the inner diameter of the openings formed on the plate. The nuts

201 of the joining means 200 maintain the spacing between the steel reinforcing assembly 33 and the plates 10, 20. Because the outer diameter of the nuts 201 is larger man the inner diameter of the openings, the nuts are inserted forcibly, thereby keeping concrete from infiltrating between the nuts 201 and the openings of the plates, Consequently, the plates 10, 20 can be easily separated after concrete curing.

The joining means 200 may be made of steel or plastics. The joining means

200 may have joint 204 at the end, as in FIG. 16. In that case, it is made of plastics, so that when the plate is pulled from one side after concrete curing, the plate can be separated as the washer 203 is broken, The washer may be wedged or nailed for exterior working. The same is true of slab and posts to be described below,

Slab

FIG. 11 shows a concrete-structure constructing system for slab according to another embodiment of the present invention. Plate 10 is placed horizontally and lattice 30 is aligned on the plate 10. Main steel reinforcings 35 are fixed up and down of the lattice 30 and transverse steel reinforcings 36 aie fixed, so that they cross the main steel reinforcings 35 perpendicularly. Then, nuts 201 of joining means 200 outside of the main steel reinforcings 35 are fixed by welding, Assembly is completed by tightening up bolts 202 a$ they penetrated the openings of the plate. Posts

FIG. 12 shows a concrete-structure constructing system for poles according to another embodiment of the present invention. It shows a concrete-structure system for post construction. The system comprises a plurality of vertical steel reinforcings 31 fixed vertically, a plurality of plates 10 surrounding the vertical steel reinforcings 31 vertically and opposing one another, lattice 30a joining the opposing vertical steel reinforcings 31 between the opposing plates 10 and joining means 200 fixed to the vertical steel reinforcings 31 and joining them to the plate 10 as it penetrates the plate 10 from, outside. Lattice 30a has a rubber-band shape.

Hereunder is given a detailed description of another preferred embodiment of the present invention.

The construction system is also pre-fabricated at a plant near to the construction site along with the mold. At the construction site, the system is placed at each position of walls, posts and slab and then concrete is laid.

For wall construction, a concrete-structure system for wall construction (FIG. S) is purchased and transferred to the construction site. The system is placed at the right position and concrete is laid inside plates 10, 20. It takes about 24 hours for the concrete to be cured. After curing, bolts 202 are removed and the plates 10, 20 are separated from the concrete,

Slab can be constructed alone or along with walls. When slab and walls are constructed together (see FIG. 14), a concrete-structure system far wall construction (FlG. 8) and a concrete-structure system for slab construction (FIG. 11) are purchased or pre-fabricated at a plant. The concrete-structure system for wall construction is placed at the right position and the concrete-structure system for slab construction is placed on top of the concrete-structure system for wall construction. Then, concrete is laid from the top, so that it is filled in the walls and slab. After the concrete is cured, bolts 202 are removed and plates 10, 20 are separated from the concrete.

For post construction, a concrete-structure system for post construction (FIG.

12) is purchased or pre-fabricated at a plant, The concrete-structure system for post construction is placed at the right position and concrete is laid from the top. After the concrete is cured, bolts 202 of joining means 200 are removed from outside and plate 10 is separated from the concrete,

The present invention is not limited to the above-described embodiments. Of course, it can be applied to a variety of girders, including T-girder and cantilever, and civil engineering structures,

FIG. 15 shows construction of a beam according to another embodiment of the present invention. In FIG. 15, "A" is the system for post construction of FIG. 12. "B" is the girder. The post and the girder are joined by rib 70.

Industrial Applicability

The pre-fabricated system of the present invention is transferred to the construction site after molding and steel reinforcing arrangement are finished and can be easily set up using such lifting equipments as tower crane. This means that the molding and steel reinforcing works, which account for most of the on-site works in the conventional construction, can be performed at a plant or an assembly workshop at the construction site. Minimizing on-site works means nύαimization of working personnel, which leads to maximization of personnel management and safety management.

The material of pre-fabricated system of the present invention is produced according to the standard using specialty machinery, including lattice bending machine, electric resistance welding machine, polywood cutter, etc., and joining members. Consequently, joining of the steel reinforcing assembly and the plate minimizes required members and related working. The present invention makes spacer for maintaining spacing between the steel reinforcing and the plate, separator for maintaining spacing between the steel reinforoings, form tie for maintaining spacing between the plates, etc. unnecessary, which are directly related with quality or life cycle of the structure.

The pre-fabricated system of the present invention is very light for its volume. It can be fabricated into large volume as the plate and the steel reinforcing assembly made into one body has good strength. For linear construction members like posts or girders, it may be fabricated into multi-story or span type. For planar construction members like slab or walls, a large-scale plate of multi-story, post or girder type can be fabricated. Such large-scale pre-fabricated systems will significantly reduce construction period. Since the pre-fabricated system of the present invention has good strength, molding installation and required members related with it can be significantly reduced compared with the conventional construction. Since spacer, separator, form tie, etc., which were manually operated in the conventional construction, are not necessary, the present invention is advantageou s in quality improvement and cost reduction. As steel reinforcing, which was just thought of as a component of steel reinforcing concrete in the conventional construction, is formed into a steel reinforcing assembly, such items as girder, underflooring, supporting post, vertical and horizontal batten boards, etc. become unnecessary, thereby reducing cost. Material and type of the joining means of the present invention, for joining the plate with the steel reinforcing assembly are determined depending upon productivity, easiness of de-molding and use of concrete surface after de-molding. The joining means is produced massively as nuts are welded from outside of the steel reinforcing assembly at a given interval. The nuts are anti-corrosion coated and play the role of the conventional spacer since they have a neck thickness similar to the coating thickness of the external steel reinforcing. Joining is performed by contacting the cut or punched side of the plate with the nuts and tightening bolts. Separation of the plate after concrete curing can be easily done by unscrewing the bolts. Also, since the plate is hardly damaged after de-molding, it can be reused for many times. Since the nuts are exposed on the outer surface of the de-molded concrete, insertion is unnecessary. Conventionally, insertion of ceiling, outer wall, etc. requited many personnel and was the cause of damage to the structure.

As described above, the present invention provides a new-concept system offering optimum safety requirement, quality control, construction period reduction and economic advantage, which are recently the urgent requirements of the construction sites.

In the present invention, the nuts 201 of the joining means 200 maintain the spacing between the steel reinforcing assembly and the plate. Since the nuts 201 have an outer diameter larger than the inner diameter of the openings, the nuts are inserted forcibly, thereby keeping concrete from infiltrating between the nuts 201 and the openings of the plates. Consequently, the plate can be easily separated after concrete curing.

Claims

1. A concrete-structure constructing system comprising plate(s) capable of holding concrete before curing and a steel reinforcing assembly joined at the top of the plate(s) or between the plates and maintaining strength after curing of the concrete, Wherein after the steel reinforcing assembly and the plate(s) are joined and the concrete is cured, the ρlate(s) and the steel reinforcing assembly are pre-assembled at a site other than the construction site using a joining means, so that the plate(s) can be easily separated from the cured concrete, and the resultant pre-fabricated system is transferred to the construction site and then concrete is laid.

2. The concrete-structure constructing system of claim 1, wherein the steel reinforcing assembly comprises at least two of a vertical steel reinforcing fixed vertically, a horizontal steel reinforcing fixed horizontally perpendicularly to the vertical steel reinforcing and a lattice crossing the vertical steel reinforcing or the horizontal steel reinforcing in zigzags.

3. The concrete-structure constructing system of claim 2, wherein the bent end of the lattice is exposed to outside of openings of the opposing pair of plates and a pin is inserted into the exposed lattice as joining means,

4. The concrete-structure constructing system of claim 3, wherein the lattice has a shape selected from the group consisting

5. The concrete-structure constructing system of claim I, wherein the joining means comprises nuts fixed to the steel reinforcing assembly and bolts locked with the nuts penetrating the plate(s), outer diameter of tlie nuts being larger than, inner diameter of the openings of the plate(s) to which the nuts are inserted, so that the spacing between the plate(s) and the steel reinforcing assembly is maintained by the nuts.

6. The concrete-structure constructing system of claim 5, wherein a washer is formed on the nuts to prevent the plate(s) from being separated.

7. The concrete-structure constructing system of claim 1, wherein the joining means has a washer at one end and a joint at the other end and is made of plastics,

S. The concrete-structure constructing system of claim 1_> wherein the plate(s) has openings and is made of polywood or plastics,

9. The concrete-structure constructing system of claim 1, wherein power line and water duct are installed in the steel reinforcing assembly.

10. A constructing method using a concrete-structure constructing system manufactured by pre-fabricating comprising the steps of pre-fabricating a concrete- structure constructing system having ρlate(s) capable of holding concrete before curing at a plant, placing each pre-fabricated system for post, girder, slab and wall construction at the right position at the construction site, laying concrete at the top of between the plate(s) and separating the plate(s) after the concrete is cured.

11. The constructing method of claim 10, wherein the pre-fabricated system comprises plate(s) capable of holding concrete before curing, a steel reinforcing assembly joined at the top of the plate(s) or between the plates and maintaining strength after curing of the concrete and a joining means temporarily fixing the steel reinforcing assembly and the plate(s), so that the plate(s) can be easily separated from the concrete after curing.