JP2653338B2 - Steel embedded formwork for wall members - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steel buried formwork for a wall member used in a narrow space where workability of formwork is poor.

[0002]

2. Description of the Related Art Forming method of web concrete of box-shaped girder found in many prestressed concrete cable-stayed bridges includes a formwork on both sides of a wall, such as a general concrete wall member. Are generally connected by a foam tie or a separator, or a method of further providing a support material in a box-shaped section girder space. After the concrete is hardened, the mold is removed from the mold and carried out through a space such as a narrow manhole.

[0003]

The main girder (box-shaped girder) of a prestressed concrete cable-stayed bridge is designed to transmit the force caused by its own weight or vehicle load acting on the main girder to the diagonal cable without difficulty. A horizontal girder in the direction perpendicular to the bridge axis is provided at the part connected to the timber cable. Therefore, after completion in the longitudinal direction as well as the lateral direction, the inside of the box-shaped section girder is almost a closed space except for the manhole. For this reason,
The workability of various works in this narrow box-shaped girder, especially the formwork work such as carrying out the formwork after use, was poor.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to reduce the formwork work in such a narrow place. In addition to having the function of a rectangular steel plate, this rectangular steel plate is used as a buried formwork.The steel plate has a function of sufficient shear reinforcement and ensures the integrity with concrete. A bent reinforcing bar is provided at each end.

The bent reinforcing bars provided at each end of the steel plate are:
The upper slab, the lower slab adjacent to the wall member, and the reinforcing bars of the horizontal girder are connected and integrated via joints.

In the steel buried formwork for a wall member according to the present invention, it is preferable that a stud dowel or an angle steel for dovetails is welded to a steel plate in advance for the purpose of improving fixation to concrete. As the steel plate, not only a flat steel plate but also a corrugated steel plate is used. In the case of a corrugated steel plate, it is preferable to use the corrugated steel plate so that the direction of the groove is vertical in order to sufficiently spread the concrete.

In the steel buried formwork for a wall member according to the present invention, the steel plate surface is exposed after the concrete is cast, but since it is used in a closed space, corrosion of the steel plate surface does not usually pose a problem.

[0008] In an environment where there is a possibility of significant corrosion, it is desirable to subject the steel plate surface to corrosion prevention processing.

[0009] The steel buried formwork is formed by arranging two forms on the wall member surface in the same manner as the conventional formwork, connecting them with a foam tie or a separator, and using a supporting material as necessary.
It fully demonstrates its function as a formwork.

According to the present invention, a steel plate as a substitute for a shear reinforcement can be used as an embedded mold, and not only is the shear reinforcement unnecessary, but also the removal, transfer,
Steps such as cleaning can be omitted.

In the above description, a box-shaped cross-section girder was cited as a place to use the steel buried formwork for a wall member of the present invention, but this is an example, and the steel member for a wall member of the present invention is also used in other places. It goes without saying that a buried formwork is used.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a buried formwork of the present invention.
(A) is an elevation view, (b) is a side view.

A steel plate 2 is overlapped and welded to each end of a rectangular steel plate 1 having a function of a shear reinforcing bar of a wall member, and the reinforcing steel groups 3, 4, 5 bent approximately 90 ° inward toward the wall member.
Are butt-welded. A stud dowel 12 is provided inside the steel plate 1. Reinforcing bar groups 3, 4,
The number and position of each of 5 are determined in consideration of the number of reinforcing bars and the arrangement of reinforcing bars of members adjacent to the wall member. The shape, size, and interval of the stud dowel 12 are determined in consideration of the shearing force between the concrete and the steel plate 1, the buckling stress of the steel plate 1, and the like. In this example, the rebar groups 3, 4, and 5 are welded to the steel plate 1 via the steel plate 2, but there is no problem if they are directly welded to the steel plate 1. In addition, the welding of the rebar groups 3, 4, and 5 to the steel plate may be either butt welding or lap welding.

The mode of use of the buried formwork of the present invention will be described by taking the above-mentioned box-shaped section girder as an example.

FIG. 2A is a cutaway perspective view of a box-shaped girder, and FIG. 2B is a longitudinal sectional view of an inner web. The box-shaped girder of this example is composed of an upper slab 10, a lower slab 11, and an outer web 1
3, the front and rear cross beams 8 and the inner web 9.

The case where the embedded formwork of the present invention is used as the formwork of the inner web 9 will be described. As shown in FIG. 2B, two molds are arranged on the surface to be the inner web 9, and are connected by a foam tie or a separator. On the other hand, the reinforcing bar group 3 welded to the upper end portion of the steel plate 1 is connected to the reinforcing bar 6 in the lateral direction (the direction perpendicular to the bridge axis) of the upper slab 10 via a joint,
Similarly, the reinforcing bar group 4 welded to the lower end is connected to a reinforcing bar in the lateral direction (the direction perpendicular to the bridge axis) of the lower slab 11 via a joint,
In addition, the reinforcing bar groups 5, 5 welded to both ends are connected to reinforcing bars in the direction perpendicular to the bridge axis of the cross beam 8 via joints. As a result, the steel sheet 1 is connected to and integrated with the surrounding reinforcing bars, and functions as a shear reinforcing bar of the inner web 9 and also functions as a formwork. Concrete is poured into the thus-configured formwork. (Note that the reinforcing bar group 5 is omitted in FIG. 2 (b).) As a connecting joint between the reinforcing bar groups 3, 4, and 5 and the reinforcing bars of other members, a normal joint is adopted. FIG. 3A shows an example in which a lap joint performed through adhesion to concrete or a lap joint formed by welding rebars is used, and FIG. 3B shows a mechanical joint such as a coupler joint or a sleeve joint. This is an example adopted.

In FIG. 2B, the case where the buried formwork of the present invention is used on both sides of the inner web 9 has been described.

[0019]

As described above, the steel plate as a substitute for the shear reinforcement can be used as the buried form, and not only the shear reinforcement is unnecessary, but also the steps of removing, transferring, and cleaning the form are omitted. Can be.

[Brief description of the drawings]

FIG. 1 shows an example of a buried formwork of the present invention, wherein (a) is an elevation view and (b) is a side view.

FIG. 2 (a) is a cross-sectional view of a box-shaped cross-section girder,
(B) is a longitudinal sectional view of the inner web.

3A and 3B are cross-sectional views illustrating a joint of a reinforcing bar, wherein FIG. 3A shows a lap joint and FIG. 3B shows a mechanical joint.

[Explanation of symbols]

1 ・ ・ Steel plate 、 2 ・ ・ Steel plate at end ・ 3 ・ ・ Reinforcing bar 、 4 ・ ・
Lower reinforcing bar, 5 lateral reinforcing bar, 6 other reinforcing bar, 7
・ Mechanical joint, 8 ・ ・ Girder, 9 ・ ・ Inner web, 10 ・
・ Top floor version, 11 ・ ・ Low floor version, 12 ・ ・ Stud dowel,
13. Outer web, 14. Manhole

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hiroshi Shinbo 2-9-1-1, Tobita-Shi, Chofu-shi, Tokyo Kashima Construction Co., Ltd. Technical Research Institute (56) References JP-A-61-294006 (JP, A) Kaisho 63-59901 (JP, U)

Claims (1)

(57) [Claims] 1. A steel embedded mold for a wall member having a bent steel bar at each end of a rectangular steel plate.