JPH06313333A - Structure of buried frame for beam - Google Patents

Abstract

PURPOSE:To prevent a joined part between beam bottom form materials from causing the crack of a beam by making the joint positions of the fellow beam bottom form materials and of fellow beam side form materials different in each of their longitudinal directions. CONSTITUTION:A buried form 1 for a beam is divided into three pieces of form composing bodies 1A, and the dividing point is set up to be near a changing over point between bending stress and tensile stress in the case where bending load acts on the beam. Next, the form composing body 1A is divided into L-shaped corner form materials 5, 5, a flat plate-shaped beam bottom form material 6, and two sheets of flat plate-shaped beam side form materials 7, and a reinforcing protrusive stripe rib (f) is severally formed on the sides of the insides of the form materials 6, 7 over the whole longitudinal length. Next the joint position P of the fellow form materials 7 and the joint position (t) of the fellow form materials 6 are made to differ in each of their longitudinal directions. Even when the bending load acts on the beam, and resultant stress acts so as to mutually separate the form materials 6, 6, the face part of the form material 7 is made to function so as to back up the form materials 6, 6 against their separation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a precast buried formwork structure for constructing a building beam.

[0002]

2. Description of the Related Art Compared with the construction of wooden concrete panels which are thrown away once or several times, there is less waste of resources, and the construction period is shortened by leaving the precast formwork exposed. Therefore, embedded formwork tends to be widely used for construction of columns, beams or walls.

The embedded formwork for walls is constructed by arranging flat formwork members having a short width whose upper and lower sides correspond to the height of the wall surface in the width direction and butt-joining them. An embedded formwork for a pillar having the shape of a square tube is a formwork material formed by dividing the shape into, for example, four pieces in the circumferential direction in the vicinity of the corner part, that is, a pair of bent parts for corners arranged on both sides in the width direction. Formed in shallow U-groove shape and between the bent parts of this
A flat plate-shaped frame material is formed by butt-joining these end portions to each other.

A buried formwork for a beam having a deep U-shaped groove is also formed in the vicinity of the corner part by circumferentially dividing into, for example, three formwork parts, that is, bent parts for corners on both sides in the width direction. A shallow U-shaped groove-shaped frame member and two flat plate-shaped frame members are joined to each other by butt-joining them.

In this way, the embedded formwork for walls and pillars / beams is divided into a plurality of formwork materials by stacking the formwork materials on top of each other so that a small storage space is required and the formwork material is easily transported. This is because it is also suitable in terms of handling, and because the weight of a single item is also excellent in terms of handling,
Regarding the buried formwork for long beams, in order to make it even better in terms of transportation and handling, divide it into a plurality of formwork structures in the longitudinal direction, and It takes the form of butt-joining the frame components.

[0006]

The problem here is the structure of the buried formwork for the beam. That is, as shown in FIGS. 3 and 4, the structure of the conventional buried mold for a beam has a shallow structure in which a mold structure 11A divided into three in the longitudinal direction is connected to a mold part 12 for a corner. U-shaped groove bottom beam form material 13 and 2
It is divided into a piece of frame material 14 for the beam side portions, and these end portions are butt-joined to each other and erected on the pillar-embedded formwork 15. At this time, the formwork structure is formed. 11
Since the butt joint positions of the end portions of A and 11A, in other words, the joint position h of the beam bottom mold members 13, 13 and the joint position i of the beam side mold members 14, 14 are made to coincide with each other. is there.

However, when the joining lines between the form members for the beam bottom and the beam side portions are connected in a straight line in this manner, a load is applied to the beam and tensile stress acts on the beam lower side. When a stress is applied between the beam bottom mold members 13 so as to separate them from each other, a beam side portion which is in a linear joint state with the joint portion of the beam bottom mold members. The mold material 14 for use is also stressed so as to separate the mold materials 14, 14 from each other between the joint portions thereof, and at this time, the mold material 14 for the beam side portion is used for the beam bottom. Since it does not function as a backup against the separation of the formwork material 12, cracks tend to occur in the beam starting from the joint portion of the beam bottom formwork materials 13, 13 and the joint line is straight. Since they are continuous, there is a problem that cracks easily progress along this joining line.

The present invention provides a buried formwork structure for a beam, which is difficult to induce a crack and which can effectively suppress the progress of the crack even if the crack is induced by an extremely simple and rational improvement. The purpose is to do.

[0009]

A buried formwork structure for a beam according to the present invention comprises a precast formwork structure divided into at least a beam bottom formwork and a beam side part formwork material. In the longitudinal direction, the embedded formwork structure for the beam, which is configured by joining in the longitudinal direction, and the joining position between the beam bottom formwork members and the joining position between the beam side formwork members are respectively positioned in the longitudinal direction. There is a structural feature in that they are different. In addition, it is desirable that the beam bottom mold members are not joined to each other at the center position in the beam length direction.

[0010]

According to the above characteristic structure, the butt joint lines at the ends of the formwork structure are zigzag-shaped, and the beam side formwork members are connected to the joints between the beam bottom formwork members. Since there is a surface part, even if stress acts so as to separate the beam bottom formwork materials from each other due to bending load on the beam, the surface part of the beam side formwork material above will not Since it functions as a backup against the separation of the form material, it is prevented that the joint portion of the beam bottom form material causes a crack in the beam.
Even if a beam crack occurs at the joint of the beam bottom formwork material, the butt joint line at the end of the formwork structure is zigzag, so the progress of the crack along the joint line is effective. Be restrained.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embedded formwork 1 for precast beams,
The embedded formwork 1 for beams is installed across a pair of precast column-made embedded formworks 2 and 2 which are vertically arranged at a predetermined interval.

As shown in FIG. 2, the embedded formwork 2 for the pillar is in the shape of a rectangular tube, and in this embodiment, four L-shaped pieces each having a size corresponding to the length of the pillar. The corner mold material 3 is divided into four flat plate-shaped mold materials 4 that are butted and joined to the end surfaces of the corner mold material 3.
In addition, concave and convex portions a and b that mesh with each other are formed on the joint surfaces of butting, and further, reinforcing rib ribs c are formed over the entire length in the longitudinal direction on the inner surface side of the flat plate-shaped frame member 4. The concave and convex portions a and b at the ends are abutted and meshed with each other via an adhesive to be integrated.

As the embedded formwork 2 for the pillar, a pair of shallow U-shaped groove formwork members in which the corner formwork members are integrally connected to the flat plate-shaped formwork member and the pair of corners are used. The present invention can be implemented by dividing it into two flat plate-shaped frame members extending over the mold frame member, and joining and joining these end portions to each other.

The embedded mold 1 for a beam has a shape of a deep U-shaped groove, and the embedded mold 1 for a beam has three molds in the longitudinal direction of the beam as shown in FIG. Frame structure 1A
The division point is near the switching point between bending stress and tensile stress when a bending load is applied to the beam, and the length of the longest intermediate part 1A Is set so that the length is suitable for transportation.

Each of the formwork structures 1A has, for example, five formwork materials 5 to 5 in the circumferential direction in the vicinity of the corners.
7, and more specifically, two L-shaped corner frame members 5 and 5 and a flat plate-shaped beam positioned between these corner frame members 5 and 5 and joined together. It is divided into a bottom mold frame 6 and two flat plate-shaped beam side frame molds 7, 7 that are raised and joined to the other side of the corner mold frame 5, respectively. Concavo-convex parts d and e are formed on the joint surface of the butts, which mesh with each other, and reinforcing ribs f are provided on the inner surfaces of the beam bottom mold member 6 and the beam side mold member 7 in the longitudinal direction. It is formed over the entire length, and the concavo-convex portions d and e at the ends are abutted and meshed with each other via an adhesive to be integrated.

As for the formwork constructs 1A on both sides in the longitudinal direction, as shown in FIG. An uneven portion 7a that meshes with the uneven portions a and b of 3 is formed (a similar uneven portion is also formed at the end of the corner mold member 5, but it is not shown in the drawing). As is apparent from FIG. 1, the length of the corner side frame member 5 and the length of the beam bottom frame member 6 is different from the length of the beam side frame member 7 in each of the frame components 1A. By, for example, about 10 cm, and the joining positions of the frame components 1A and 1A, more specifically,
With respect to the joint position p of the beam side frame members 7, the joint position r of the corner frame members 5 and the joint position t of the beam bottom frame members 6 are made different from each other in the longitudinal direction. There is.

In the above embodiment, the joint position r between the corner mold members 5 and the joint position t between the beam bottom mold members 6 are the same, but the joint positions r and t are also long. The position may be different depending on the direction.

In the above structure, the beam reinforcing bars are arranged in the beam embedded mold 1, the column reinforcing bars are also arranged in the column embedded mold 2, and the concrete is formed in each of the molds 1 and 2. By placing the
The pillar is constructed, but with respect to the beam, the butt joint lines at the ends of the formwork constructing body 1A have a zigzag shape, and the beam side parts are provided at the joints between the beam bottom formwork members 6. Since the surface portion of the form material 7 exists, even if stress acts so as to separate the form materials 6 and 6 for the beam bottom from each other due to bending load on the beam, Since the surface portion of the partial form material 7 functions as a backup against the separation of the beam bottom form materials 6 and 6, the joint portion of the beam bottom form materials 6 and 6 causes a crack to the beam. Is prevented.

Even if a beam crack occurs at the joint between the beam bottom form members 6 and 6, the butt joint line at the end of the formwork constructing body 1A is zigzag-shaped, and therefore, along the joint line. The progress of all cracks is effectively suppressed.

As the beam frame forming body 1A, for example, a shallow U-shaped groove type frame member in which the corner frame members 5 are integrally connected to both sides of the beam bottom frame member 6 in the width direction, The configuration is divided into two flat plate-shaped beam side frame members 7 that are raised and joined to the corner frame members 5, and the corner frame members 5 are divided into beam side frame members 7. It is divided into a pair of L-shaped form members integrally provided on the lower end side and one flat plate-shaped beam bottom form member 6 which is butted and joined between the corner form members 5 and 5. It is also possible to make such a configuration that the joint positions of the beam bottom form members and the joint positions of the beam side form members are different from each other in the longitudinal direction.

In either embodiment, at the lower end of the beam,
Since the tensile stress is most generated at the central position in the beam length direction,
It is desirable that the beam bottom formwork members are not joined to each other at the center position in the beam length direction. Also, the beam side part frame material 7
The deviation between the joint position p between the beam bottom mold members 6 and the joint position t between the beam bottom frame members 6 is effective even if it is about 20 mm.

[0022]

As described above, according to the buried formwork structure for a beam according to the present invention, the joining line of the formwork structure divided into a plurality of parts and abutted and joined in the longitudinal direction is zigzag. In addition, the ratio of the joint position of the beam bottom formwork members and the joint position of the beam side formwork members to each other in the longitudinal direction is changed by a rational improvement technology, and the joint part of the formwork material causes the crack to be caused. The situation is prevented, and even if a crack occurs, the progress of the crack can be effectively suppressed.

[Brief description of drawings]

FIG. 1 is a side view in which an embedded formwork for a beam is installed on an embedded formwork for a pillar.

FIG. 2 is a perspective view showing an erected portion of a beam embedded mold with respect to a column embedded mold.

FIG. 3 is a side view in which a buried mold for a beam is installed on a buried mold for a pillar of a conventional example.

FIG. 4 is a perspective view showing a erected portion of an embedded formwork for a beam with respect to an embedded formwork for a pillar in a conventional example.

[Explanation of symbols]

1A ... Formwork construct, 6 ... Beam bottom formwork, 7 ... Beam side formwork, p, t ... Joining position.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mamoru Funazaki, 32-32-1, Shiba, Minato-ku, Tokyo Haseko Corporation

Claims (2)

[Claims] 1. A precast mold frame structure divided into at least a beam bottom mold member and a beam side mold member.
An embedded formwork structure for a beam, which is configured by joining in the longitudinal direction, wherein the joining positions of the beam bottom formwork members and the joining positions of the beam side formwork members are different in the longitudinal direction. An embedded formwork structure for beams, which is characterized by being provided. 2. The embedded formwork structure for a beam according to claim 1, wherein the beam bottom formwork members are not joined to each other at the center position in the beam length direction.