PRE-ASSEMBLY SPIRAL STIRRUP

Abstract

The present invention relates to prefabricated shear reinforcement that is built in the interior of a slab around a column, more specifically to prefabricated shear reinforcement that is capable of having a plurality of bottom and top main bars whose one end extending into a column and a spiral stirrup bent continuously to form a plurality of rectangular shapes surrounding the bottom and top main bars, thereby having excellent fabrication, constructability, and space utilization, providing economical advantages, minimizing labors needed on a construction site, and reducing a period of construction.

Claims

1. Prefabricated shear reinforcement, which is built in the interior of a slab (1) around a column (2), comprising: a plurality of bottom main bars (4) located on the bottom of the interior of the slab (1) in such a way as to allow one end to extend to the interior of the column (2); a plurality of top main bars (5) located on the top of the interior of the slab (1) in a parallel relation with the plurality of bottom main bars (4) in such a way as to allow one end to extend to the interior of the column (2); and a spiral stirrup (6) bent continuously to form a plurality of rectangular shapes to surround the plurality of bottom main bars (4) and the plurality of top main bars (5).

2. The prefabricated shear reinforcement according to claim 1, wherein the spiral stirrup (6) consists of a plurality of planar constraint portions (61) bent to surround the bottom and top main bars (4 and 5) on the same plane perpendicular to the bottom and top main bars (4 and 5) and connection portions (62) each connecting the neighboring planar constraint portions (61) to one another.

3. The prefabricated shear reinforcement according to claim 2, wherein four top main bars (5) and four bottom main bars (4) are provided, and a pair of spiral stirrups (6) is provided, so that each planar constraint portion (61) surrounds the two top main bars (5) and the two bottom main bars (4).

4. The prefabricated shear reinforcement according to claim 2, wherein three top main bars (5) and three bottom main bars (4) are provided, and each planar constraint portion of the spiral stirrup is bent to surround the four top and bottom main bars (5 and 4) located on both outermost sides thereof and the remaining one top main bar (5) and the remaining one bottom main bar (4) located on the central portion thereof, sequentially.

5. The prefabricated shear reinforcement according to claim 2, wherein four top main bars (5) and four bottom main bars (4) are provided, and each planar constraint portion (61) of the spiral stirrup (6) is bent to the shapes of two rectangles whose central portions overlapping each other.

6. The prefabricated shear reinforcement according to claim 1, further comprising a pair of braces (60) coupled to both side surfaces thereof, respectively, in such a way as to cross each other in a diagonal direction.

7. The prefabricated shear reinforcement according to claim 1, wherein the bottom main bars (4) are coupled to a fixing plate (7) to which the end portions of the bottom main bars (4) of the prefabricated shear reinforcement in the opposite side to the column (2) are coupled.

8. The prefabricated shear reinforcement according to claim 1, further comprising a spacer (8) located adjustable in height on the undersides of the neighboring bottom main bars (4).

9. The prefabricated shear reinforcement according to claim 8, wherein the spacer (8) has a roller (83) adapted to move the prefabricated shear reinforcement.

10. The prefabricated shear reinforcement according to claim 9, wherein the spacer (8) comprises a support (81) consisting of a horizontal connection portion (811) transversing the neighboring bottom main bars (4), a first vertical portion (812) bent vertically downward from one end of the horizontal connection portion (811), a horizontal support portion (813) bent vertically from the other end of the horizontal connection portion (811) in parallel with the bottom main bars (4), and a second vertical portion (814) bent vertically downward from the outside end portion of the horizontal support portion (813), a leveler (82) coupled adjustable in height to the underside of any one of the first vertical portion (812) and the second vertical portion (814) of the support (81), and the roller (83) detachably coupled to the underside of the other of the first vertical portion (812) and the second vertical portion (814).

Description

DESCRIPTION OF DRAWINGS

[0032] FIG. 1 is a perspective view showing prefabricated shear reinforcement according to the present invention.

[0033] FIG. 2 is a perspective view showing the prefabricated shear reinforcement built in four directions around a column.

[0034] FIGS. 3 to 6 are perspective views showing a process of constructing the prefabricated shear reinforcement according to the present invention.

[0035] FIG. 7 is a perspective view showing a spiral stirrup according to the present invention.

[0036] FIG. 8 shows the prefabricated shear reinforcement in which two modules each surrounding four main bars are arranged parallel to each other.

[0037] FIG. 9 shows the prefabricated shear reinforcement surrounding six main bars.

[0038] FIG. 10 is a perspective view showing a spiral stirrup of FIG. 9.

[0039] FIG. 11 shows the prefabricated shear reinforcement surrounding eight main bars.

[0040] FIG. 12 is a perspective view showing a spiral stirrup of FIG. 11.

[0041] FIG. 13 is a perspective view showing a state where lift bars are connected to the prefabricated shear reinforcement.

[0042] FIG. 14 is a perspective view showing a coupling relation between both side prefabricated shear reinforcement through fixing plates.

[0043] FIG. 15 is a perspective view showing a coupled state between both side prefabricated shear reinforcement in FIG. 14.

[0044] FIG. 16 is a perspective view showing the fixing plate having incised coupling holes.

[0045] FIG. 17 is a perspective view showing a state where the bottom main bars are coupled to each other through the fixing plate.

[0046] FIG. 18 is a perspective view showing a spacer.

[0047] FIG. 19 is a perspective view showing a coupling relation between the spacer and the bottom main bars.

[0048] FIGS. 20 and 21 are perspective views showing the spacer having a foldable and removable roller.

BEST MODE FOR INVENTION

[0049] To accomplish the above-mentioned objects, there is provided prefabricated shear reinforcement according to the present invention, which is built in the interior of a slab around a column, including: a plurality of bottom main bars located on the bottom of the interior of the slab in such a way as to allow one end to extend to the interior of the column; a plurality of top main bars located on the top of the interior of the slab in a parallel relation with the plurality of bottom main bars in such a way as to allow one end to extend to the interior of the column; and a spiral stirrup bent continuously to form a plurality of rectangular shapes in such a way as to surround the plurality of bottom main bars and the plurality of top main bars.

Mode for Invention

[0050] Hereinafter, the present invention will be explained in detail with reference to the attached drawing.

[0051] FIG. 1 is a perspective view showing prefabricated shear reinforcement according to the present invention, FIG. 2 is a perspective view showing the prefabricated shear reinforcement built in four directions around a column, and FIGS. 3 to 6 are perspective views showing a process of constructing the prefabricated shear reinforcement according to the present invention.

[0052] As shown in FIGS. 1 and 2, prefabricated shear reinforcement 3 according to the present invention is built in the interior of a slab 1 around a column 2 and includes: a plurality of bottom main bars 4 located on the bottom of the interior of the slab 1 in such a way as to allow one end to extend to the interior of the column 2; a plurality of top main bars 5 located on the top of the interior of the slab 1 in a parallel relation with the plurality of bottom main bars 4 in such a way as to allow one end to extend to the interior of the column 2; and a spiral stirrup 6 bent continuously to form a plurality of rectangular shapes in such a way as to surround the plurality of bottom main bars 4 and the plurality of top main bars 5.

[0053] The present invention relates to such prefabricated shear reinforcement that is economical in fabrication and constructability, excellent in space utilization, minimizes the labors needed on a construction site, and reduces a period of construction.

[0054] The prefabricated shear reinforcement 3 according to the present invention is buriedly built around the column 2 constructed on top of the slab 1 made of reinforced concrete.

[0055] The slab 1 is a foundation slab or slab.

[0056] The prefabricated shear reinforcement 3 includes the plurality of bottom main bars 4, the plurality of top main bars 5, and the spiral stirrup 6 for surrounding the plurality of bottom main bars 4 and the plurality of top main bars 5.

[0057] Four prefabricated shear reinforcement 3 are built in four directions around the column 2 so that they are arranged in the form of + (See FIG. 2).

[0058] The plurality of bottom main bars 4 are located on the bottom of the interior of the slab 1, and the plurality of top main bars 5 are located on the top of the interior of the slab 1 in a parallel relation with the plurality of bottom main bars 4.

[0059] One end of each bottom main bar 4 and one end of each top main bar 5 extend to the interior of the column 2.

[0060] The bottom main bars 4 and the top main bars 5 simply fix the spiral stirrup 6 in position thereto and further serve as the main bars of the reinforced concrete slab 1.

[0061] To do this, the bottom main bars 4 and the top main bars 5 of one side prefabricated shear reinforcement 3 pass through a position where the column 2 is constructed in such a way as to be thus joined to the bottom main bars 4 and the top main bars 5 of the other side prefabricated shear reinforcement 3.

[0062] Further, the bottom main bars 4 and the top main bars 5 are joined to main bars 11 of the slab 1.

[0063] In this case, the main bars 11, 4, and 5 are joined to one another by means of overlap joining, couplers joining, or the like.

[0064] The spiral stirrup 6 is bent continuously to form a plurality of rectangular shapes in such a way as to surround the bottom main bars 4 and the top main bars 5 on the outsides of the bottom main bars 4 and the top main bars 5.

[0065] One steel wire as the spiral stirrup 6 is bent continuously, which generates no scraps.

[0066] The spiral stirrup 6 is desirably formed of a high-frequency heat-treated steel wire that is made by allowing carbon steel to be subjected to a high frequency heat treatment in such a way as to have a spiral groove on the peripheral surface thereof.

[0067] The high-frequency heat-treated steel wire has excellent yield strength, tensile strength, and elasticity, so that the spiral stirrup 6 is foldable in such a way as to be bent continuously.

[0068] As a result, the spiral stirrup 6 is fabricated in a factory and thus foldedly brought into a construction site. Next, the spiral stirrup 6 is unfolded to a length required on the construction site and joined to the bottom and top main bars 4 and 5, thereby constructing the prefabricated shear reinforcement 3. Accordingly, the prefabricated shear reinforcement 3 minimizes the spiral stirrup 6 in volume, thereby enhancing the efficiencies of delivery and space utilization.

[0069] The prefabricated shear reinforcement 3 is constructed in the following process.

[0070] First, lean concrete 10 is cast on top of the ground, and next, reinforcing bars 21 for the column 2 are built on the lean concrete 10 (See FIG. 3). To arrange the reinforcing bars 21 for the column 2, in this case, a fixing frame 20 consisting of a plurality of vertical bars 201 and a plurality of horizontal bars 202 coupled to one another is built.

[0071] Next, the four prefabricated shear reinforcement 3 are located on the outsides of the reinforcing bars 21 for the column 2 (See FIG. 4). In this case, bar supports may be located on top of the lean concrete 10 to ensure covering depths of the bottom main bars 4 and the spiral stirrup 6 of the prefabricated shear reinforcement 3.

[0072] After that, the top and bottom main bars 11 of the slab 1 are arranged (See FIG. 5), and then, concrete is cast to complete the construction of the slab 1 (See FIG. 6).

[0073] FIG. 7 is a perspective view showing the spiral stirrup.

[0074] As shown in FIG. 7, the spiral stirrup 6 consists of a plurality of planar constraint portions 61 bent to surround the bottom and top main bars 4 and 5 on the same plane perpendicular to the bottom and top main bars 4 and 5 and connection portions 62 for connecting the neighboring planar constraint portions 61 to one another, so that the spiral stirrup 6 is foldable.

[0075] The top main bars 11 of the slab 1 are seated onto top of the prefabricated shear reinforcement 3.

[0076] Further, the spiral stirrup 6 is bent to form a plurality of rectangular shapes in such a way as to extend continuously in longitudinal directions of the bottom and top main bars 4 and 5. If the spiral stirrup 6 is tiltedly bent with respect to the bottom and top main bars 4 and 5, however, the thickness of the slab 1 inevitably increases to ensure covering depths of the top main bars 11 because the top main bars 11 of the slab 1 are seatedly coupled to top of the spiral stirrup 6.

[0077] Therefore, the spiral stirrup 6 consists of the planar constraint portions 61 bent to the shape of the rectangle on the plane perpendicular to the bottom and top main bars 4 and 5 and the connection portions 62 each for connecting one end of the planar constraint portion 61 to one end of the neighboring planar constraint portion 61 spaced apart from the planar constraint portion 61.

[0078] As a result, the top main bars 11 of the slab 1 are arranged directly on tops of the top main bars 5 of the prefabricated shear reinforcement 3, irrespective of the spiral stirrup 6. That is, the main bars 11 of the slab 1 that are arranged perpendicular to the prefabricated shear reinforcement 3 are kept at constant intervals, while avoiding the interference with the spiral stirrup 6.

[0079] Each planar constraint portion 61 is located perpendicular to the bottom and top main bars 4 and 5 in such a way as to be arranged parallel to the neighboring planar constraint portion 61.

[0080] The planar constraint portions 61 are formed closedly on the same plane in such a way as to constrain concrete therein, thereby exerting excellent concrete constraint effect.

[0081] The connection portions 62 are tilted with respect to the bottom and top main bars 4 and 5 in such a way as to connect the neighboring planar constraint portions 61 spaced apart from one another in the longitudinal directions of the bottom and top main bars 4 and 5 to one another. As a result, the connection portions 62 are desirably located on the undersides of the bottom main bars 4.

[0082] In the drawings, further, the connection portions 62 connect the undersides of the planar constraint portions 61, but in the case of a pile foundation, the connection portions 62 may connect the tops of the planar constraint portions 61 to avoid the interferences with a pile cap extending to the interior of the concrete slab 1 as a foundation slab.

[0083] FIG. 8 shows prefabricated shear reinforcement in which two modules each surrounding four main bars are arranged parallel to each other.

[0084] As shown in FIG. 8, four top main bars 5 and four bottom main bars 4 are provided, and a pair of spiral stirrups 6 is provided to allow each planar constraint portion 61 to surround two top main bars 5 and two bottom main bars 4.

[0085] The number of top main bars 5 and the number of bottom main bars 4 may be determined according to a width of the column 2.

[0086] If four top main bars 5 and four bottom main bars 4 are provided, the spiral stirrups 6 are made to the form of modules each surrounding total four main bars 4 and 5. The modules are spaced apart from each other in a transverse direction in such a way as to be arranged parallel to each other.

[0087] In the same manner as above, if six top main bars 5 and six bottom main bars 4 are provided, three modules are arranged parallel to one another in the transverse direction.

[0088] Like this, the spiral stirrups 6 are provided as several types of modules, and the modules are combined to one another, thereby building the prefabricated shear reinforcement 3.

[0089] FIG. 9 shows prefabricated shear reinforcement surrounding six main bars.

[0090] As shown in FIG. 9, three top main bars 5 and three bottom main bars 4 are provided, and each planar constraint portion 61 of the spiral stirrup 6 is bent to surround the four bottom and top main bars 4 and 5 located on both outermost sides thereof and the remaining one top main bar 5 and the remaining one bottom main bar 4 located on the central portion thereof, sequentially.

[0091] If the three or more top main bars 5 and the three or more bottom main bars 4 are provided, one spiral stirrup 6 is bent continuously to connect all of the top main bars 5 and all of the bottom main bars 4 to one another.

[0092] In detail, if three top main bars 5 and three bottom main bars 4 are provided, the spiral stirrup 6 first surrounds the top main bars 5 and the bottom main bars 4 located on left and right outermost sides thereof, is then bent vertically on the top main bar 5 or the bottom main bar 4 located on the central portion thereof, and finally forms the planar constraint portion 61. As a result, all of the top main bars 5 and all of the bottom main bars 4 are connected to one another through one spiral stirrup 6.

[0093] If five top main bars 5 and five bottom main bars 4 are provided, a module having two rows of top main bars 5 and two rows of bottom main bars 4, as shown in FIG. 8, is combined with a module having three rows of top main bars 5 and three rows of bottom main bars 4, thereby building the prefabricated shear reinforcement 3.

[0094] In this case, the top main bars 5 and the bottom main bars 4 are called a first row of top or bottom main bar, a second row of top or bottom main bars, and the like from the left side to the right side. Therefore, the top main bars 5 and the bottom main bars 4 in FIG. 8 have total four rows, and the top main bars 5 and the bottom main bars 4 in FIG. 9 have three rows.

[0095] FIG. 11 shows prefabricated shear reinforcement surrounding eight main bars, and FIG. 12 is a perspective view showing a spiral stirrup of FIG. 11.

[0096] As shown in FIGS. 11 and 12, four top main bars 5 and four bottom main bars 4 are provided, and a planar constraint portion 61 of the spiral stirrup 6 is bent to the shapes of two rectangles whose central portions overlapping each other.

[0097] In the case where the four top main bars 5 and the four bottom main bars 4 are provided, the spiral stirrup 6 is bent to the shapes of two rectangles overlapping each other.

[0098] In detail, the spiral stirrup 6 is bent to the shape of a rectangle surrounding first and third rows of bottom and top main bars 4 and 5 and then bent continuously to the shape of a rectangle surrounding second and fourth rows of bottom and top main bars 4 and 5.

[0099] The spiral stirrup 6 allows concrete to be more effectively constrained in the rectangular portion of the center in which the two rectangles overlap each other, thereby increasing the strength and ductility of the prefabricated shear reinforcement.

[0100] In this case, a module having two rows of bottom and top main bars 4 and 5 is combined freely with a module having three rows of bottom and top main bars 4 and 5 or a module having four rows of bottom and top main bars 4 and 5, thereby building the prefabricated shear reinforcement 3 having the various row combination of the bottom and top main bars 4 and 5.

[0101] FIG. 13 is a perspective view showing a state where lift bars are connected to the prefabricated shear reinforcement.

[0102] As shown in FIGS. 1 and 13, a pair of braces 60 crossing each other in a diagonal direction is coupled to both side surfaces of the prefabricated shear reinforcement 3, respectively.

[0103] The conventional prefabricated reinforcing bar assembly may be deformed on connection positions with lift bars during lifting. To avoid such a problem, reinforcing bars or steel wires are fixed in position by means of welding.

[0104] However, welding requires a lot of fabrication time. Besides, the welding is carried out in a factory, and therefore, after the prefabricated assembly is produced as a complete product in the factory, it is brought into the construction site. In this case, the prefabricated assembly is bulky in volume, thereby lowering delivery and space utilization efficiencies.

[0105] According to the present invention, however, one pair of braces 60 is coupled to both side surfaces of the prefabricated shear reinforcement 3, respectively, so that the braces 60 reinforce the prefabricated shear reinforcement 3 in the form of X-bracing.

[0106] Reinforcing bars, steel wires, steel bars, etc. may be used as the braces 60, and the braces 60 are fixed to the outer or inner surface of the spiral stirrup 6 through tying wires.

[0107] Accordingly, the spiral stirrup 6 is just tied with the bottom and top main bars 4 and 5 through the tying wires, without being welded therewith, which allows the prefabricated shear reinforcement 3 to be stably kept in shape during lifting, so that the prefabricated shear reinforcement 3 can be built, without any welding.

[0108] As such welding is not needed, in some cases, the spiral stirrup 6 and the bottom and top main bars 4 and 5 are carried out of the factory, without any prefabrication, and then brought into the construction site, so that they can be coupled simply to one another through the tying wires.

[0109] If a high-frequency heat-treated steel wire easily foldable is used as the spiral stirrup 6, further, it is foldedly bent in a factory, and next, it can be brought into the construction site. This optimizes delivery conveniences and space utilization.

[0110] Furthermore, the spiral stirrup 6 is tied with the bottom and top main bars 4 and 5 through the tying wires, without any welding, and therefore, the prefabricated shear reinforcement 3 can handle various construction site situations easily.

[0111] FIG. 14 is a perspective view showing a coupling relation between both side prefabricated shear reinforcement through fixing plates, and FIG. 15 is a perspective view showing a coupled state between both side prefabricated shear reinforcement of FIG. 14. FIG. 16 is a perspective view showing the fixing plate having incised coupling holes, and FIG. 17 is a perspective view showing a state where the bottom main bars are coupled to each other through the fixing plate.

[0112] As shown in FIGS. 14 and 15, the bottom main bars 4 are coupled to a fixing plate 7 to which the bottom main bars 4 of the prefabricated shear reinforcement 3 in the opposite side to the column 2 are coupled.

[0113] The bottom and top main bars 4 and 5 serve as structural materials so that they pass through the column 2 and are thus joined to the bottom and top main bars 4 and 5 of the opposite side prefabricated shear reinforcement 3.

[0114] If the bottom and top main bars 4 and 5 are overlappingly joined with one another, the joined bottom and top main bars 4 and 5 are fixed to one another through tying wires so that they are not varied in position during concrete casting.

[0115] The tying of the top mina bars 5 with the tying wires is relatively easy because a worker easily moves closer to the top main bars 5, but the tying of the bottom main bars 4 with the tying wires is not easy because of interferences with the reinforcing bars 21 for the column 2 or the fixing frame 20.

[0116] To solve such a problem, the fixing plate 7 is coupled to the bottom main bars 4, and next, the end portions of the opposite side bottom main bars 4 are coupled to the fixing plate 7, thereby avoiding separate tying on a construction site.

[0117] The fixing plate 7 is located on the outsides of the reinforcing bars 21 for the column 2.

[0118] If the fixing frame 20 is built to arrange the reinforcing bars 21 for the column 2, the fixing plate 7 is fixedly brought into close contact with the outer surfaces of the vertical bars 201 of the fixing frame 20 (See FIG. 15).

[0119] As shown in FIGS. 14 to 17, the fixing plate 7 has coupling holes 71 through which the bottom main bars 4 and 4 of the prefabricated shear reinforcement 3 opposing to each other are insertedly coupled to one another.

[0120] Each coupling hole 71 is a long hole extending in a horizontal direction of the fixing plate 7. The bottom main bar 4 of one side prefabricated shear reinforcement 3 is inserted into one side of each coupling hole 71, and next, the bottom main bar 4 of the opposite side prefabricated shear reinforcement 3 is inserted into the remaining portion of each coupling hole 71.

[0121] If it is desired to insert the bottom main bars 4 into the coupling holes 71, the bottom main bars 4 are inserted into the coupling holes 71, while the opposite site prefabricated shear reinforcement 3 is moving in the longitudinal directions of the bottom main bars 4. In this case, if a gap of each coupling hole 71 is not big, it is hard to insert the bottom main bars 4 into the coupling holes 71.

[0122] Therefore, as shown in FIGS. 16 and 17, each coupling hole 71 is incised to the shape of L with a vertical portion and a horizontal portion on the fixing plate 7 in such a way as to be open on top thereof, so that after the opposite side prefabricated shear reinforcement 3 is built in place, the bottom main bars 4 enter the coupling holes 71 above the fixing plate 7 by means of the elasticity thereof and are thus inserted into the coupling holes 71.

[0123] In detail, one side prefabricated shear reinforcement 3 is pre-coupled to the fixing plate 7 to allow the bottom main bars 4 to be inserted into the horizontal portions of the coupling holes 71.

[0124] In the state where one side prefabricated shear reinforcement 3 is built, the bottom main bars 4 of the other side prefabricated shear reinforcement 3, that is, the opposite side prefabricated shear reinforcement 3 enter the vertical portions of the coupling holes 71, move inside the horizontal portions of the coupling holes 71, and are finally coupled to the fixing plate 7 (See FIG. 17).

[0125] The top main bars 5 are of course coupled to the fixing plate 7 in consideration of the lengths and intervals of the reinforcing bars 21 for the column 2.

[0126] FIG. 18 is a perspective view showing a spacer, and FIG. 19 is a perspective view showing a coupling relation between the spacer and the bottom main bars.

[0127] As shown in FIG. 19, a spacer 8 is located on the undersides of the neighboring bottom main bars 4 in such a way as to be adjustable in height.

[0128] Since the bottom and top main bars 4 and 5 of the prefabricated shear reinforcement 3 serve as the structural materials, their covering depths have to be ensured.

[0129] To allow the bottom and top main bars 4 and 5 to be joined to one another, after the prefabricated shear reinforcement 3 is located on both sides of the column 2, respectively, installation heights of the prefabricated shear reinforcement 3 are adjusted to be the same as each other.

[0130] If the slab 1 is a foundation slab, however, the smoothness of the lean concrete 10 cast onto the bottom of the foundation slab is poor, and therefore, there is a need to finely adjust the height of the prefabricated shear reinforcement 3 after the prefabricated shear reinforcement 3 has been located on top of the lean concrete 10.

[0131] To do this, the spacers 8 are located on the undersides of the bottom main bars 4 to ensure the covering depth of the prefabricated shear reinforcement 3 and adjustable in height to allow the heights of both side prefabricated shear reinforcement 3 to be the same as one another.

[0132] The covering depths of the undersides of the bottom main bars 4 can be ensured by means of the spacers 8.

[0133] After both side prefabricated shear reinforcement 3 have been built, further, the heights of the spacers 8 are adjusted to allow both side main bars 4 and 5 to be the same in height and then joined to one another.

[0134] As shown in FIG. 18, each spacer 8 has a roller 83 adapted to move the prefabricated shear reinforcement 3.

[0135] The bottom and top main bars 4 and 5 of the prefabricated shear reinforcement 3 extend to the column 2. If the reinforcing bars 21 for the column 2 and the fixing frame 20 are built, accordingly, it is difficult to lift and move the prefabricated shear reinforcement 3 in a vertically downward direction due to the interferences of the reinforcing bars 21 and the fixing frame 20.

[0136] To avoid such a problem, the prefabricated shear reinforcement 3 is located on one side of the column 2, and next, the prefabricated shear reinforcement 3 slides toward the column 2 to allow the bottom and top main bars 4 and 5 to pass through the column 2.

[0137] To do this, each spacer 8 has the roller 83 through which the prefabricated shear reinforcement 3 moves, without any separate lift equipment used by the worker.

[0138] The roller 83 is used only to move the prefabricated shear reinforcement 3, and since the prefabricated shear reinforcement 3 is fixed in position after it has been located in an appropriate place, there is no need to use the roller 83. Therefore, it is desirable that the roller 83 be detachably mounted on the spacer 8.

[0139] FIGS. 20 and 21 are perspective views showing the spacer having a foldable and removable roller.

[0140] As shown in FIGS. 20 and 21, the spacer 8 includes a support 81 consisting of a horizontal connection portion 811 transversing the neighboring bottom main bars 4, a first vertical portion 812 bent vertically downward from one end of the horizontal connection portion 811, a horizontal support portion 813 bent vertically from the other end of the horizontal connection portion 811 in parallel with the bottom main bars 4, and a second vertical portion 814 bent vertically downward from the outside end portion of the horizontal support portion 813, a leveler 82 coupled adjustable in height to the underside of any one of the first vertical portion 812 and the second vertical portion 814 of the support 81, and the roller 83 detachably coupled to the underside of the other of the first vertical portion 812 and the second vertical portion 814.

[0141] The spacer 8 consists of the support 8 coupled to the undersides of the bottom main bars 4 to support the prefabricated shear reinforcement 3 and the leveler 82 and the roller 83 coupled to the undersides of the support 81.

[0142] The support 81 consists of the horizontal connection portion 811, the first vertical portion 812, the horizontal support portion 813, and the second vertical portion 814.

[0143] The support 81 may be made by bending a reinforcing bar or the like.

[0144] The horizontal connection portion 811 transverses the neighboring bottom main bars 4 and thus supports them. The horizontal connection portion 811 are fixed to the bottom main bars 4 through tying wires or the like.

[0145] The first vertical portion 812 is bent vertically downward from one end of the horizontal connection portion 811.

[0146] The second vertical portion 814 is formed on the other end of the horizontal connection portion 811.

[0147] If the first vertical portion 812 and the second vertical portion 814 are bent vertically downward from both ends of the horizontal connection portion 811, however, the spacer 8 may rotate. To avoid such a rotation, the horizontal connection portion 811 is spaced apart from the second vertical portion 814 in such a way as to be connected to each other by means of the horizontal support portion 813.

[0148] That is, the horizontal support portion 813 is provided parallel to the bottom main bar 4 in the longitudinal directions of the bottom main bar 4 in such a way as to be supported against the bottom main bar 4, thereby preventing the spacer 8 from rotating.

[0149] Even if not shown in the drawings, a horizontal support portion may be provided between the first vertical portion 812 and the horizontal connection portion 811.

[0150] The leveler 82 is coupled to one of the first vertical portion 812 and the second vertical portion 814, and the roller 83 is coupled to the other.

[0151] As shown in FIGS. 18 to 21, there is provided an embodiment in which the leveler 82 is coupled to the underside of the first vertical portion 812 and the roller 83 to the underside of the second vertical portion 814. Hereinafter, an explanation of such an embodiment will be given below.

[0152] The leveler 82 is coupled adjustable in height to the first vertical portion 812. To do this, a screw thread is formed on the outer peripheral surface of the first vertical portion 812 so that the leveler 82 is coupled to the first vertical portion 812.

[0153] The roller 83 is detachably coupled to the second vertical portion 814. To do this, like the leveler 82, a screw thread is formed on the outer peripheral surface of the second vertical portion 814 so that the roller 83 is coupled to the second vertical portion 814.

[0154] If it is desired to move the prefabricated shear reinforcement 3, the leveler 82 rotates to move up, and only the roller 83 is brought into contact with top of the lean concreate 10, so that the prefabricated shear reinforcement 3 moves. After the prefabricated shear reinforcement 3 has been located at the appropriate place, the leveler 82 rotates to move down and thus supports the prefabricated shear reinforcement 3.

[0155] If the prefabricated shear reinforcement 3 is supported against the leveler 82, the roller 83 is detached from the second vertical portion 814.

[0156] In the case where the roller 83 is coupled to the second vertical portion 814, the roller 83 reversely rotates and is thus removed from the second vertical portion 814. In this case, a given spare space is needed between the roller 83 and top of the lean concrete 10.

[0157] To do this, the leveler 82 moves further down to allow the roller 83 to be spaced apart from top of the lean concrete 10, and next, the roller 83 is removed from the second vertical portion 814.

[0158] Further, the roller 83 is foldable, so that if the prefabricated shear reinforcement 3 is supported against the leveler 82, the roller 83 rotates in a horizontal direction and is then folded, and next, the roller 83 reversely rotates and is thus removed from the second vertical portion 814 (See FIGS. 20 and 21).

[0159] The support 81 and the leveler 82 are permanently buried in the concrete of the slab, and the roller 83 is removed from the spacer 8 after the prefabricated shear reinforcement 3 has been built.

INDUSTRIAL APPLICABILITY

[0160] The prefabricated shear reinforcement according to the present invention is configured to have the spiral stirrup fabricated in a factory in such a way as to be bent continuously and thus foldable so that the spiral stirrup extends to a length required on the construction site and is thus coupled to the bottom and top main bars, thereby having excellent fabrication and constructability, minimizing the volume of the spiral stirrup, and enhancing the efficiencies of delivery and space utilization.