JP2022026220A - Form timbering structure - Google Patents

Abstract

To provide a form timbering structure and a form timbering construction method that facilitate construction and can ensure the quality of concrete.SOLUTION: In a form timbering structure 10, a rigid beam 12 for holding a form arranged between main girders 11 supporting the RC deck is supported by a connection metal fitting 20 provided on a web 112 of the main girder 11.SELECTED DRAWING: Figure 2

Description

The present invention relates to a formwork support structure and a method of constructing formwork support when constructing an RC deck.

The formwork support is a temporary structure such as a formwork that supports the cast concrete, and the details of the construction of the RC deck are described in Non-Patent Document 1.
This non-patent document 1 stipulates that the formwork support must have a structure that can ensure sufficient strength and safety, and a mounting diagram as shown in FIG. 6 is described.
In the description of the conventional formwork support mounting diagram shown in FIG. 6, the formwork plywood is fixed by adjusting the height by a receiving beam supported by a hanging bolt attached to the support mounting hanging bracket. It is described as.

Japan Bridge Construction Association, "RC Floor Slab Construction Guide (Revised 3rd Edition)", November 2018, p22-p23

However, in the structure of the formwork support described in Non-Patent Document 1, the hanging metal fittings for mounting the support are buried. Therefore, since the hanging bolts extending from the hanging fittings for mounting the support work protrude from the solidified concrete, holes remain in the concrete after the hanging bolts are removed. Therefore, construction is required to fill the holes. In addition, since the construction is performed after the concrete has solidified, the construction period is long and complicated.
Furthermore, in order to suspend the hanging bolts from the hanging brackets for mounting the support, there is no choice but to place the hanging brackets for mounting the support at the concrete end, so it is required to secure 100 mm as a cover to prevent salt damage, but 20 mm. The fact is that only the degree can be secured.
Therefore, the quality of concrete may not be ensured.

Therefore, an object of the present invention is to provide a formwork support structure and a formwork support method that can facilitate the construction and ensure the quality of concrete.

In the formwork support structure of the present invention, the rigid beam for holding the formwork arranged between the main girders supporting the RC deck was supported by the connecting metal fittings provided on the web of the main girder. It is a feature.

Further, in the construction method of the formwork support of the present invention, the rigid beam for holding the formwork arranged between the main girders supporting the RC deck is supported by the connecting metal fittings provided on the web of the main girder. It is characterized by doing.

According to the present invention, a rigid beam for holding a formwork is connected to and supported by a main girder supporting an RC deck with a connecting metal fitting, so that the hanging metal fitting for supporting support is buried in the RC floor slab. In addition, it is possible to eliminate the need for hanging bolts hanging from the hanging metal fittings for mounting the support.

The connecting metal fitting is fastened to connect the metal fitting body formed in an inverted L shape, a hanging member for suspending the rigid beam, and a mounting metal fitting provided on the web of the main girder. It can be provided with a member.
The metal fitting body is connected to the mounting bracket provided on the web of the main girder by a fastening member, and the rigid beam is suspended from the metal fitting body by the hanging member, so that the rigid beam for holding the formwork becomes the main girder. Can be connected and fixed.

The through holes formed in the top surface and the bottom surface of the rigid beam are formed in the elongated holes along the length direction of the rigid beam, and the mounting bracket is a thick surface along the vertical direction of the web. Is welded and protrudes in the width direction of the RC deck, and the metal fitting body has a main girder side plate portion connected to the mounting bracket by the fastening member and the width from the upper end of the main girder side plate portion. It may be provided with a beam side plate portion for suspending the rigid beam by the suspending member so as to project in a direction orthogonal to the direction.
The plate thickness surface of the main girder side plate is welded along the vertical direction of the web, and the main girder side plate is connected to the mounting bracket protruding in the width direction of the RC deck by a fastening member, and the main girder side plate is connected. Since the beam side plate portion protruding in the direction orthogonal to the width direction from the upper end of the deck suspends the rigid beam by the hanging member, the rigid beam extending in the width direction of the deck is connected to the beam side plate portion by the suspending member. Can be fixed. Further, even if the length of the rigid beam is changed in the length direction of the rigid beam, since the through hole is formed by the elongated hole, the shaft portion of the hanging bolt can be passed through.

The hanging member is formed of a hanging bolt and a nut screwed to the threaded portion of the hanging bolt, and the shaft portion of the hanging bolt is formed in a through hole formed in the beam side plate portion. The shaft portion of the hanging bolt is passed through the through holes formed in the top and bottom surfaces of the rigid beam, and the nut is screwed to the threaded portion of the hanging bolt. Can be.
The shaft of the hanging bolt is passed through the through hole formed in the beam side plate, and the shaft of the hanging bolt is passed through the through holes formed in the top and bottom of the rigid beam to suspend. By screwing the nut to the threaded portion of the bolt, the rigid beam can be suspended from the beam side plate portion.

The shaft portion of the hanging bolt may be formed to have a length such that a gap is formed between the beam side plate portion and the rigid beam.
If the shaft of the hanging bolt is formed to a length that creates a gap between the beam side plate and the rigid beam, change the position of the nut to be screwed to the threaded part of the hanging bolt. By determining the lower end position of the rigid beam, the height position of the rigid beam can be adjusted.

According to the present invention, it is possible to eliminate the need for the hanging metal fittings for mounting the support work buried in the RC deck and the hanging bolts hanging from the hanging metal fittings for mounting the support work, so that the construction can be facilitated. , The quality of concrete can be ensured.

It is an overall view for demonstrating the formwork support structure which concerns on embodiment of this invention. It is a partially enlarged view of the formwork support structure shown in FIG. It is a figure for demonstrating the connecting metal fitting of the formwork support structure shown in FIG. 2, and is a figure for demonstrating the positional relationship between the mounting metal fitting formed on the web of a main girder, and the connecting metal fitting. It is a figure for demonstrating the connecting metal fitting of the formwork support structure shown in FIG. 2, and is the figure which looked at the state which the rigid beam was connected to the connecting metal fitting, from the length direction of the floor slab. It is a figure for demonstrating the connecting metal fitting of the formwork support structure shown in FIG. 2, and is the figure which looked at the state which the rigid beam was connected to the connecting metal fitting, from the width direction of the floor slab. It is a figure which shows the conventional formwork support structure, and is the figure for demonstrating the construction method of the conventional formwork support.

The formwork support structure according to the embodiment of the present invention will be described with reference to the drawings.
The formwork support structure 10 shown in FIG. 1 is used for RC slab construction of bridges and highways using five main girder plate girders.

In the formwork support structure 10, a rigid beam 12 for holding the formwork is arranged between the main girders 11. A joist 13 is arranged on the rigid beam 12. Formwork plywood 15 is arranged on the rigid beam 12 on the main girder 11 side and on the joist 13 via the crosspiece 14.
As shown in FIG. 2, an adjusting material may be arranged on the crosspiece 14 on the rigid beam 12 on the main girder 11 side with the formwork plywood 15 as shown in FIG.

By locating the upper flange 111 of the main girder 11 between the formwork plywood 15, the formwork plywood 15 and the upper flange 111 are connected, and the reinforcing bars and concrete for forming the RC deck S are supported. To.

The rigid beam 12 is connected to and supported by the main girder 11 by the connecting metal fitting 20 connected to the main girder 11. Here, the connecting metal fitting 20 will be described with reference to FIGS. 3 to 5.
As shown in FIGS. 3 to 5, the mounting bracket 113 is fixed to the web 112 of the main girder 11 by welding along the vertical direction F1 of the web 112, so that the mounting bracket 113 is RC. It protrudes toward F2 in the width direction of the deck.
The mounting bracket 113 is formed with two through holes 113a for fastening members in columns. The mounting bracket 113 is formed of a rectangular plate material. The connecting metal fitting 20 is connected to the mounting metal fitting 113.

The connecting metal fitting 20 is for connecting the metal fitting body 21 formed in an inverted L shape, a hanging member 22 that hangs from the metal fitting body 21 to suspend the rigid beam 12, and the metal fitting body 21 to the mounting metal fitting 113. It is provided with the fastening member 23 of the above.
The metal fitting body 21 is formed by a main girder side plate portion 211 and a beam side plate portion 212.

The main girder side plate portion 211 is formed of a rectangular plate member and is arranged along the vertical direction. In the main girder side plate portion 211, through holes 211a having the same spacing and diameter as the through holes 113a for the fastening member formed in the mounting bracket 113 are formed at two places.
The beam side plate portion 212 is also formed of a rectangular plate member, and protrudes from the upper end of the main girder side plate portion 211 in a direction orthogonal to the width direction F2 (RC floor slab length direction F3). The beam side plate portion 212 is formed with a through hole 212a for passing the suspending member 22 at one place.

The hanging member 22 includes a hanging bolt 221 and a nut 222 screwed to the threaded portion of the hanging bolt 221, a square washer 223 inserted into the head side of the hanging bolt 221 and a nut 222. It is formed by a round washer 224 inserted on the side.
The shaft portion of the hanging bolt 221 is formed to have a length such that a gap is formed between the beam side plate portion 212 and the rigid beam 12.

The fastening member 23 includes a bolt 231 formed so as to penetrate the mounting bracket 113 and the main girder side plate portion 211 of the bracket main body 21 so that the threaded portion is exposed, and a nut 232 screwed to the threaded portion of the bolt 231. , A round washer 233 inserted into the head side of the bolt 231 and a square washer 234 inserted into the nut 232 side.

The construction method of the formwork support in the formwork support structure according to the embodiment of the present invention configured as described above will be described with reference to the drawings.
As shown in FIGS. 3 to 5, first, the main girder side plate portion 211 of the metal fitting body 21 of the connecting metal fitting 20 is applied to the mounting bracket 113 arranged on the web 112 of the main girder 11, and the main girder side plate portion 211 penetrates. The position of the hole 211a is aligned with the through hole 113a of the mounting bracket 113.
Next, the shaft portion of the bolt 231 which is the fastening member 23 is passed through the round washer 233, the through hole 211a, the through hole 113a, and the square washer 234, and screwed to the screw portion of the bolt 231 by the nut 232 to form the metal fitting body. 21 is connected to the mounting bracket 113.

Then, the shaft portion of the hanging bolt 221 is passed through the through hole 212a of the beam side plate portion 212 via the square washer 223, and is formed in the vertical direction formed on the top surface 12t and the bottom surface 12b of the end portion of the rigid beam 12. The hole is penetrated from the top surface 12t side to expose the threaded portion of the hanging bolt 221 from the bottom surface 12b. A nut 222 is screwed to the threaded portion of the hanging bolt 221 exposed from the bottom surface 12b via a round washer 224, and the end portion of the rigid beam 12 is connected to the beam side plate portion 212.

The holes (through holes of the top surface 12t and the bottom surface 12b) formed at the end of the rigid beam 12 are formed by the elongated holes along the length direction of the rigid beam 12, and the ends of the rigid beam 12 are also formed. A long hole is also formed in the reinforcing plate 12a arranged in the portion along the length direction, and the beam side plate portion 212 protrudes from the main girder side plate portion 211 toward the length direction F3 of the RC deck. Therefore, even if the length of the rigid beam 12 changes in the length direction of the rigid beam 12 (width direction F2 of the RC deck), the rigid beam 12 is suspended without hitting the beam side plate portion 212. The shaft of the lowering bolt can be passed through.

In this way, the rigid beam 12 can be connected to the main girder 11 by the connecting metal fitting 20. Therefore, the hanging metal fitting for mounting the support work, which is buried in the RC deck as shown in FIG. 6, becomes unnecessary.

In the conventional formwork support construction method shown in FIG. 6, since the support mounting hanging metal fittings are welded and fixed to the flange of the main girder, the strength of the main girder may be affected and the quality may deteriorate. However, in the method of constructing the formwork support according to the present embodiment, since it is not necessary to weld the hanging metal fittings for mounting the support, the quality of the main girder can be maintained.
In addition, by eliminating the need for hanging fittings for mounting support works, it is not necessary to consider fog for preventing salt damage.

Since the hanging bolts hang down from the support mounting hanging metal fittings that are buried in the RC deck, it is necessary to fill the holes after removing the hanging bolts. In the construction method, the hanging metal fittings for mounting the support work are not required, so that the hole filling work is not required.

In addition, since the hanging bolts hanging from the hanging metal fittings for mounting the support work penetrate the formwork plywood, it is necessary to perform processing such as drilling and cutting in the formwork plywood. Plywood becomes industrial waste. However, in the construction method of the formwork support according to the present embodiment, since the hanging bolts hanging from the support mounting hanging metal fittings are not required, the processing work to the formwork plywood is not required, and the formwork is used. Plywood can be reused.

In addition, when concrete is placed to form an RC deck, concrete may leak from the gap between the hanging bolts and the formwork plywood, so coking work with glass putty is required, but this is also a support work. Since there is no need for hanging bolts to hang from the mounting hanging bracket, no coking work is required.

As described above, according to the formwork support structure and the formwork support construction method according to the present embodiment, the end portion of the rigid beam 12 is connected and fixed to the main girder 11 by the connecting metal fitting 20. It facilitates construction and ensures the quality of concrete.

In the connecting bracket 20 shown in FIGS. 3 to 5, the hanging bolt 221 is passed through the through hole 212a (see FIG. 3) of the beam side plate portion 212, and the rigid beam 12 is passed from above to below, and the nut 222 is used. It was screwed.
The height of the rigid beam 12 at this time can be adjusted by the screwing position of the nut 222. For example, in the connecting metal fitting 20 shown in FIGS. 3 to 5, the rigid beam 12 is connected with a gap provided between the beam side plate portion 212 and the rigid beam 12.

However, depending on the conditions of the joist 13, the crosspiece 14, the formwork plywood 15, and the RC deck S, the mounting position of the rigid beam 12 may shift upward.
In that case, by raising the height of the rigid beam 12 high and raising the tightening position of the nut 222, the mounting position of the rigid beam 12 can be adjusted high, for example, as shown in FIG. The position of the rigid beam 12 can be raised to a state where there is no gap between the rigid beam 12 and the beam side plate portion 212.

As described above, the length of the shaft portion of the hanging bolt 221 of the connecting metal fitting 20 is formed so as to form a gap between the top surface 12t of the rigid beam 12 and the beam side plate portion 212. If the rigid beam 12 is moved up and down within this gap and the lower end position of the end portion of the rigid beam 12 is determined by the nut 222, the height position of the rigid beam 12 can be adjusted.

The present invention is suitable for a formwork support structure and a method for constructing formwork support when constructing an RC deck such as a bridge.

10 Formwork support structure 11 Main girder 111 Upper flange 112 Web 113 Mounting bracket 113a Through hole 12 Rigid beam 12t Top surface 12b Bottom surface 12a Reinforcing plate 13 Nut 14 Plywood 15 Formwork plywood 20, 30 Connecting bracket 21 Metal fitting body 211 Main girder side plate part 211a Through hole 212 Beam side plate part 212a Through hole 22 Hanging member 221 Hanging bolt 222 Nut 223 Square washer 224 Round washer 23 Fastening member 231 Bolt 232 Nut 233 Round washer 234 Square washer F1 Vertical direction F3 length direction S RC floor slab

The present invention relates to a formwork support structure when constructing an RC floor slab.

Therefore, an object of the present invention is to provide a formwork support structure that facilitates construction and can ensure the quality of concrete.

The present invention is suitable for a formwork support structure when constructing an RC deck such as a bridge.

Claims (6)

A formwork support structure in which a rigid beam for holding a formwork arranged between main girders supporting an RC deck is supported by a connecting metal fitting provided on the web of the main girder. The connecting metal fitting is fastened to connect the metal fitting body formed in an inverted L shape, a hanging member for suspending the rigid beam, and a mounting metal fitting provided on the web of the main girder. The formwork support structure according to claim 1, further comprising a member. The through holes formed in the top surface and the bottom surface of the rigid beam are formed in the elongated holes along the length direction of the rigid beam.
The mounting bracket has a thick surface welded along the vertical direction of the web and protrudes in the width direction of the RC deck.
The metal fitting body protrudes from the upper end of the main girder side plate portion connected to the mounting bracket by the fastening member and the upper end of the main girder side plate portion in a direction orthogonal to the width direction, and the rigid beam is formed by the hanging member. The formwork support structure according to claim 2, further comprising a beam side plate portion for suspending the structure. The hanging member is formed of a hanging bolt and a nut screwed to the threaded portion of the hanging bolt.
The shaft portion of the suspension bolt is passed through the through hole formed in the beam side plate portion, and the shaft portion of the suspension bolt is passed through the through hole of the rigid beam to suspend the suspension bolt. The formwork support structure according to claim 3, wherein the nut is screwed to the threaded portion of the bolt. The formwork support structure according to claim 4, wherein the shaft portion of the hanging bolt is formed to have a length such that a gap is formed between the beam side plate portion and the rigid beam. A construction method of formwork support in which a rigid beam for holding a formwork arranged between main girders supporting an RC deck is supported by a connecting metal fitting provided on the web of the main girder.

Images