Description

APPARATUS FOR HOLDING A WIRE-TYPE FORMWORK

AND METHOD FOR CONSTRUCTING A CONCRETE

STRUCTURE USING THE SAME

Technical Field

[1] The present invention relates to an apparatus for holding a wire-type formwork and a method for constructing a concrete structure using the same, and more particularly to an apparatus for holding a wire-type formwork and a method for constructing a concrete structure using the same, which can keep a distance between the formworks without bending and cutting of reinforcing bars when the concrete structure is constructed, thereby making it possible to construct the concrete structure through a single process regardless of the height of the formworks and the thickness of the concrete.

[2]

Background Art

[3] Generally, in the construction of buildings and the civil engineering, the most common method for forming various posts, walls and the like is to pour and cure concrete in a formwork formed to have a desired shape. In the method, a formwork is used as the frame.

[4] As shown in FIG. 1, a pair of formworks 1 and 2 is set up to correspond to the thickness of a concrete structure 10, for example, a retaining wall, etc., and then restraining bars 11 are arranged between the formworks 1 and 2. Next, concrete 12 is poured and cured between the formworks 1 and 2, so that the concrete structure 10, like the retaining wall, is constructed.

[5] As described above, the pair of formworks, in which concrete 12 is poured, should have a distance kept therebetween within a desired dimension until the completion of curing concrete. An apparatus 20 for holding wire-type formworks is used for keeping the distance between the formworks.

[6] A conventional formwork holding apparatus uses various kinds of tie bolts and distance keeping members.

[7] As shown in FIG. 2, the formwork holding apparatus 20 according to the conventional art includes a tie bolt 21, a separated thread rock bolt (referred to as a sepa- bolt) 22 used as the distance keeping member, and a cone nut 23, which are used for holding the formworks 1 and 2. The cone nuts 23, screw-assembled with both ends of the sepa-bolt 22, are allowed to support the inner surfaces of the formworks 1 and 2, and then the tie bolt 21 extends through the formworks 1 and 2 from the outside of the

formworks 1 and 2 so as to be screw-coupled with the cone nuts 3. Next, washers are mounted on one end of the tie bolts 21, and then wing nuts 24 are screw-coupled with the tie bolts 21. As a result, the formworks 1 and 2 are secured by the wing nuts 24 screw-coupled with the tie bolts 21 while having the distance kept therebetween.

[8] In the conventional formwork holding apparatus, there exists inconvenience in which the cone nuts 23 should be removed. In order to solve the above-mentioned problem, a formwork holding apparatus has been proposed, which need not use cone nuts.

[9] However, a formwork holding apparatus according to a conventional art has the following problem. When sepa-bolts 22 are installed between the formworks 1 and 2, the sepa-bolts 22 interfere with reinforcing bars 11 arranged in the formworks 1 and 2. Since the sepa-bolt 22 has not flexibility but rigidity, the reinforcing bars 11 must be bent or cut as marked by a circle in FIG. 1. In other words, since it is difficult to install the sepa-bolts easily, a worker must pay much attention to the installation of the sepa- bolts 22 in order to avoid interference of sepa-bolts 22 with the reinforcing bars 11. Further, in a case where the sepa-blots 22 interfere with the reinforcing bars 11, the reinforcing bars 11 should be bent or cut. Therefore, it is extremely difficult and inconvenient to install the sepa-bolts. The number and arrangement of reinforcing bars 11 are designed in advance in order to construct a concrete structure 10 like a retaining wall, etc. according to structural mechanics. When the reinforcing bars 11 are bent and cut because of the interference of the sepa-bolts 22, the structural rigidity of the concrete structure 10, like the retaining wall, is deteriorated and causes disruption of the concrete structure 10.

[10] During construction of the concrete structural, the formworks can endure side pressure of the concrete somewhat as the formworks 1 and 2 are supported by means of the sepa-bolts 22. On the other hand, when a retaining wall, a box, and a bridge having a height of about 4m are constructed, distance between the formworks having a height greater than 4m may not be maintained. Therefore, the concrete structure cannot be constructed at one time, but at two or more times. As shown in FIG. 3, a formwork half the height of concrete structure is set up, and then concrete is poured in the formwork so as to construct the first concrete structure 10a (SlO). Next, a pair of formworks is set up on the first concrete structure 10a, and then concrete is poured in the formworks so as to construct the second concrete structure 10b. Hence, concrete structure having full height can be achieved.

[H]

Disclosure of Invention

Technical Problem

[12] However, according to the conventional construction method of the concrete structure, as the concrete is poured at two or more times, curing time is longer than that of a process in which the concrete is poured at one time, so that it takes much time to construct the concrete structure. In the consideration of structural aspect, it is a concern that the configuration of the first and second concrete structures 10a and 10b may be weak and disrupted. Further, since a discontinued portion 10c is generated between the first and second concrete structures 10a and 10b, there is a disadvantage of having a poor appearance.

[13]

Technical Solution

[14] Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide an apparatus for holding wire-type formworks and a method for constructing a concrete structure, which can keep, during construction of a concrete structure, the arrangement of reinforcing bars based on the initial design specification while preventing the concrete structure from expanding due to side pressure of the concrete structure.

[15] It is another object of the present invention to provide a method for constructing a concrete structure using an apparatus for holding wire-type formworks, which can keep a distance between a pair of formworks regardless of the height and thickness of the concrete structure, thereby making it possible to construct the concrete structure in a pouring process.

[16]

Advantageous Effects

[17] In the apparatus for holding wire-type formworks and the method for constructing a concrete structure using the same according to the present invention, wires supporting inner and outer formworks have flexibility. The wires pass by the reinforcing bars due to their flexibility even though the reinforcing bars, arranged depending on a design specification for the concrete structure, interfere with the wires. Therefore, it is unnecessary to bend or cut the reinforcing bars. Further, since the arrangement of the reinforcing bars is deviated from the initial design specification, it is possible to maintain the strength of the concrete structure. As a result, disruption of the concrete structure caused by faulty work can be prevented. In addition, it is possible to omit the unnecessary process of bending or cutting the reinforcing bars.

[18] On the other hand, distance between inner and outer formworks can be maintained regardless of the height of a concrete structure. In the case of a tall concrete structure, the concrete structure can be constructed by pouring concrete at one time instead of pouring the concrete at two times. Hence, time for pouring the concrete can be sig-

nificantly reduced. Further, since there is no discontinuous portion in the concrete structure, it is possible to improve the appearance of the concrete structure. [19]

Brief Description of the Drawings

[20] The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[21] FIG. 1 is a sectional view showing a concrete structure according to the conventional art;

[22] FIG. 2 is an enlarged view showing an apparatus for holding a formwork according to the conventional art;

[23] FIG. 3 is a view illustrating a process for constructing a concrete structure according to the conventional art;

[24] FIG. 4 is a perspective view showing an apparatus for holding a wire-type formwork according to the first embodiment of the present invention;

[25] FIG. 5 is a view illustrating installation of the apparatus for holding the wire-type formwork according to the first embodiment of the present invention;

[26] FIG. 6 is a perspective view showing an apparatus for holding a wire-type formwork according to the second embodiment of the present invention;

[27] FIG. 7 is an exploded perspective view showing an apparatus for holding a wire- type formwork according to the third embodiment of the present invention;

[28] FIG. 8 is a view illustrating installation of the apparatus for holding the wire-type formwork according to the third embodiment of the present invention; and

[29] FIG. 9 is a view illustrating a process for constructing a concrete structure using an apparatus for holding a wire-type formwork according to the present invention.

[30]

Best Mode for Carrying Out the Invention

[31] Hereinafter, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[32] In the apparatus for holding a wire-type formwork according to the present invention, a wire extends through a pair of formworks and keeps a distance between the pair of formworks using tensile force.

[33] The method for constructing a concrete structure using the apparatus for holding the wire-type formwork according to the present invention includes the steps of installing one formwork, fixing one end of the wire, arranging reinforcing bars, installing the other formwork, fixing the other end of wire, stretching the wire, and pouring concrete.

Mode for the Invention

[35] Embodiment 1

[36] As shown in FIGS. 4 and 5, the apparatus 100 for holding a wire-type formwork according to the present embodiment includes a flexible wire having one end fixed to the first formwork 1 and the other end supported by the second formwork, the wire extending between the first and second formworks 1 and 2, and stretching means 120 for stretching the wire 110 so as to keep a distance between the first and second formworks 1 and 2.

[37] First, a plurality of traverse members 3 and vertical members 4 is installed on the outer surface of the formworks 1 and 2 in order to reinforce the strength of the formworks 1 and 2. For example, the traverse members 3 may include rods or pipes, and the vertical members 4 may have a pair of U section shape steels 4a and 4b and a traverse connection member 4c connecting the U section shape steels 4a and 4b, respectively.

[38] The wires 110 are made of a flexible material, which can cross reinforcing bars 11 without bending or cutting the reinforcing bars even though they interfere with the reinforcing bars 11 arranged in a concrete structure such as a retaining wall. The wires 110 are fixed to the first formwork 1 by means of wire fixing members 130. Each wire fixing member 130 may be a rod or plate and has a wire fixing groove 131 formed therein. Latching jaws 131a having different diameters are formed in the wire fixing groove 131. Hence, one end of each wire 110 is knotted and latched by the wire latching jaw 131a.

[39] The wire stretching means 120 is provided with a base frame 121 welded to the vertical member 4, a wire winder 122 rotatably mounted on the base frame 121 and winding the other end of the wire 110 so as to stretch the wire 110, and a stopper 123 for holding the wire winder 122 on which the wire is wound.

[40] The base frame 121 is provided with a plate shaped vertical fixing member 121a, a traverse member 121b attached to the vertical fixing member 121a, and side walls 121c and 121d formed at both sides of the traverse member 121b.

[41] The wire winder 122 has a cylindrical shape and is disposed between both sidewalls

121c and 12 Id. The wire winder 122 has both ends rotatably connected to the sidewalls 121c and 121d and a wire linker 122a, such as a hexagon head bolt 122b, which is connected to the wire winder 122 by means of tools, for example, a wrench. In the state that the wire is fixed to the wire linker 122a, the wire 110 is wound on the wire winder 122 and stretched when the wire winder 122 rotates. The wire linker 122a may be bent in the form of a letter "L" so that one end of the wire is connected to the wire linker 122a.

[42] The stopper 123 includes a ratchet wheel mounted on one end of the wire winder

122 (extending through the sidewall 121c of the base frame 121) and a ratchet 123b restraining the rotation of the ratchet wheel 123a.

[43] In the apparatus for holding the wire-type formwork according to the present embodiment, since the wire 110 is flexible, the wire 110 can pass by the reinforcing bars 11 although the reinforcing bars 11 arranged in the concrete structure are not cut or bent.

[44] Embodiment 2

[45] As shown in FIG. 6, according to the present embodiment, the wire winder 122 is disposed between two U section shape steels 4a and 4b of the vertical member 4 without the use of a separate base frame, both ends of which are connected to the two U section shape steels 4a and 4b, respectively, so that the wire winder 122 rotates. The stopper 123 is installed on the U section shape steel 4b. The principle of operation of the stopper 123 is the same as the stopper as described above with relation to the embodiment 1. According to the present embodiment, since the separate base frame is not used, it is possible to reduce the manufacturing cost. Further, the process of coupling the wire winder 122 to the vertical member 4 using a separate base frame can be omitted.

[46] Embodiment 3

[47] In the apparatus for holding a wire-type formwork according to the present embodiment, wire stretching means 120 is selectively installed on a desired position of the vertical member 4. In the concrete structure 10 such as a restraining wall, side pressure increases from a lower portion to an upper portion when the concrete is poured. Thus, the wires 110 are densely arranged at the lower portion rather than the upper portion of the concrete structure. Further, distance between the wires 110 may be changed depending on the height and thickness of the concrete structure 10. If lots of wire stretching means 120 are fixedly installed on the vertical member 4 as described with relation to the embodiments 1 and 2, some wire stretching means 120 may not be used and the some wires 110 may not be installed at desired positions, respectively. The present embodiment can solve the above-mentioned disadvantages.

[48] As shown in FIGS. 7 and 8, in the apparatus for holding the wire-type formwork according to the present embodiment, a plurality of winder mounting holes 4d is formed in the U section shape steels 4a and 4b of the vertical member 4. The winder 122 is selectively and separately mounted in one of the winder mounting holes 4d. The winder 122 generally has a cylindrical shape with a step portion 122c formed adjacent to one end thereof to have a diameter smaller than the residual portion thereof. The step portion 122c is inserted into the U section shape steel 4B so that the winder 122 rigidly extends between the U section shape steels 4a and 4b. The winder 122 is

mounted between the U section shape steels 4a and 4b in such a manner that one end of the wire winder 122 extends through the U section shape steel 4a of the vertical member 4 and is inserted into the U section shape steel 4b. Then, a fixing pin 124 is inserted into a pin hole 122d formed in one end of the wire winder 122. As a result, the winder 122 is rotatably fixed to the vertical member 4. The fixing pin 124 and the pin hole 122d are not limited to the shapes shown in drawings, and thus may have any shape if they can fix the wire winder 122 to the vertical member 122.

[49] At this time, the ratchet wheel 123a of the stopper 123 is mounted on the other end of the wire winder 122, and the ratchet 123b is rotatably attached to a separate support plate 125 and mounted along with the support plate 125 on the U section shape steel 4a. As described above, the wire winder 122 extends through the support plate 125, the U section shape steels 4a and 4b, and a washer 126, and is rotatably fixed by means of the fixing pin 124.

[50] The wire linker 122a may be a rod as mentioned above relating to the first embodiment, or may be a hole perforated in the wire winder 122 as shown in FIGS. 7 and 8.

[51] The wire fixing member 130 may be fixed to the formwork 1 by means of a coupling member such as a bolt, a clamp, and the like which are not shown, or may be kept in a fixed state by the tensile force of the stretching means 120 without the use of a separate coupling member.

[52] Hereinafter, a method of constructing a concrete structure using the apparatus for holding the wire-type formwork according to the present invention will be described with respect to FIG. 9. For convenience, the method of constructing the concrete structure using the apparatus for holding the wire-type formwork according to the third embodiment will be described.

[53] Installation of an inner formwork SlO: an inner formwork 1 is set up in order to construct the concrete structure. At this time, the traverse member 3, the vertical member 4, and the wire fixing member 130 are coupled to the inner formwork 1, and one end of the wire 110 is fixed to the wire fixing member 130.

[54] Arrangement of reinforcing bars S20: a plurality of reinforcing bars 11 is arranged in order to maintain the strength of the concrete structure 10. The arrangement of the reinforcing bars 11 is variable depending on the magnitude and area of the concrete structure 10, and thereby is not particularly limited.

[55] Installation of an outer formwork S30: an outer formwork 2 is set up according to the design for the concrete structure 10. Further, the wire stretching means 120 of the apparatus for holding the wire-type formwork is mounted on the vertical member 4 under structural mechanics according to the design for the concrete structure 10. In particular, as shown in FIGS. 7 and 8, the wire winder 122 and the support plate 125

are assembled with the vertical member 4 in such a manner that the support plate 125 is attached to the vertical member 4 to correspond to the mounting hole 4d, and the wire winder 122 extends through the support plate 125 and the mounting hole 4d of the vertical member 4.

[56] Installation and Stretching of wires S40: when the installation of the inner and outer formworks 1 and 2 and the arrangement of the reinforcing bars 11 have been completed, one end of the wire 110 is fixed to the wire stretching means 120. At this time, in the case where the reinforcing bars 11 are arranged on a pathway of the wires 110, the wire 110 is flexible and end-runs the reinforcing bars 11. Therefore, the wires 110 can be installed without bending and cutting the reinforcing bars 11. After the installation of the wires 110 is completed, the hexagonal head 122b is turned by using tools such as a wrench and the like, and thereby the ratchet wheel 123a rotates along with the hexagonal head 122b, so that the wire 110 is wound on the wire winder 122. As a result, the wire 100 is stretched so as to keep the inner and outer formworks 1 and 2 upright. While the wire is wound on the winder, the ratchet 123b does not restrain the rotation of the ratchet wheel 123a. However, when the ratchet wheel 123a stops its rotation, the ratchet 123b restrains the rotation of the ratchet 123a so as to prevent the wire winder 122 from rotating anymore.

[57] Pouring of concrete S50: when the installations of the formworks 1 and 2 and of a distance maintenance device 100 have been completed, the concrete is poured between the formworks 1 and 2, so that the concrete structure is constructed. While the concrete is poured and cured, side pressure may be applied from the concrete to the formworks, thereby causing the formworks to expand. However, the distance maintenance device 100 maintains the distance between the formworks 1 and 2 and prevents the formworks from expanding. A high concrete structure 10, for example higher than 4 m, can be constructed by pouring the concrete only once.

[58]

Industrial Applicability

[59] The present invention is applied to formworks used for constructing a concrete structure, for example, a building, a road structure and the like. In comparison with the conventional formwork fixing apparatus, the apparatus for holding the formwork can be produced inexpensively. Further, since the method of using the formwork fixing apparatus is easily applicable on the conventional technological level, the method has high industrial applicability. In addition, since new construction and reconstruction of concrete structures are actively executed as the industry has been developed, the present invention greatly will make a pervasive effect on the construction industry.

[60] Although the preferred embodiments of the present invention has been described for

illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. [61]

Sequence Listing

[62] 1,2 : a formwork 3 : a traverse member

[63] 4 : a vertical member 10 : a concrete structure

[64] 100 : a distance maintenence device 110 : a wire

[65] 120 : a stretching means 121 : a base frame

[66] 122 : a wire winder 123 : a stopper

[67] 124 : a fixing pin 125 : a separate support plate