JPH07279246A - Pc beam form - Google Patents

Abstract

PURPOSE:To ensure bending strength in beams effectively by reducing height difference between beam lower end main reinforcing bars and joint reinforcing bars to a column for forming lapped joints and, at the same time, to obtain such a PC beam form as bending strength of the beams can be advantaged by reducing height difference between them against the joint reinforcing bars even if the beams are arranged at right angles. CONSTITUTION:A PC beam form 10 is so precasted that it has a U-shaped section, and a plurality of beam lower end main reinforcing bars 26 are buried in the bottom 10a along the extended direction of the beam from 10. First grooves 30 positioned at sides of the beam lower end main reinforcing bars 26 and for arranging the ends of reinforcing bars 14a of joint reinforcing bars 14 are formed in the bottom 10a into which the beam lower end main reinforcing bars 26 are buried. In the case beams are constructed, the ends of the reinforcing bars 14 on the lower sides of the joint reinforcing bars 14 are arranged to the first grooves 30 in a state to mount the end of the PC beam form 10 on the upper end face of a PC column form 20. Under such a state, concrete is placed in the PC beam form 10 to form lapped joints of the reinforcing bars 14a and beam lower end main reinforcing bars 26 horizontally.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a PC beam form having a U-shaped cross section, and more particularly, a beam lower end main bar embedded in the bottom of this PC beam form has a joint bar to a column and a lap joint. The present invention relates to a PC beam formwork.

[0002]

2. Description of the Related Art In recent years, a precast chemical construction method has been widely used for constructing a building having a reinforced concrete structure, and one of the precast chemical construction methods is, for example, Japanese Patent Publication No. 5-830.
As disclosed in Japanese Patent Publication No. 3, there is a method of forming a beam using a PC beam form having a U-shaped cross section. In this case, as shown in FIGS. 6 and 7, by embedding the beam lower end main bar 2 in the bottom portion 1a of the U (U-shaped) PC (precast concrete) beam formwork 1,
The buried beam lower end main reinforcement 2 is superposed on the joint reinforcement 4 of the column / beam joint 3 and concrete is placed in the PC beam formwork 1 to form a lap joint.

[0003]

However, in the conventional PC beam formwork 1 as described above, the inner surface of the bottom portion 1a in which the beam lower end main reinforcement 2 is embedded is formed flat, and the joint reinforcement of the column-beam joint 3 is formed. 4 is arranged above the beam lower end main reinforcement 2. For this reason, the beam lower end main reinforcement 2 and the joint reinforcement 4 are overlapped in the vertical direction. In this way, the beam lower end main bar 2 and the joint bar 4 are vertically overlapped, which means that the distance from the beam upper surface to the joint bar 4 is shorter than the beam lower end bar 2 in the beam cross section. This means that there is a problem that the bending resistance of the beam is reduced due to the presence of the reinforcing bars arranged in such a short distance.

This is more remarkable when beams are connected to one pillar from four sides and the beams are arranged in a cross shape in a cross shape as a whole. Since the joint bars 4 are arranged vertically and intersect each other in a cross beam shape, a height difference of one direction of the cross bar joint bars 4 in the vertical direction is higher than that in the other direction. Therefore, when the PC beam formwork 1 is butted in the shape of a cross at the same level, the distance from the upper surface of the beam of the joint streak 4 intersecting with the cross girder becomes short, and the bending resistance of the beam becomes insufficient. There was a problem that

In view of the conventional problems, the present invention effectively secures bending strength of the beam by reducing the height difference between the beam lower end main bar and the joint bar to the column which form the lap joint. At the same time, it is an object of the present invention to provide a PC beam form that can reduce the height difference between the joints and the bending strength of the beam even when the beams are arranged orthogonally and can make the bending strength of the beam advantageous.

[0006]

In order to achieve the above object, the present invention comprises a beam lower end main bar embedded in the bottom, and this beam lower end main bar constitutes a lap joint with a joint bar to a column. In a PC beam form having a U-shaped cross section, a groove for arranging the joint bar is formed in the bottom portion in which the beam bottom main bar is embedded, and the groove is arranged on the side of the beam bottom main bar, and the joint is formed in the groove. Arrange the muscles to form a lap joint.

In order to achieve such an object, the present invention is provided with a beam lower end main bar embedded in the bottom part, and this beam lower end main bar is superposed on the four-sided projecting portions of the girder-like joint bar arranged in the column. In a PC beam form having a U-shaped cross-section, which constitutes a lap joint in each overlapped portion and protrudes in a cross shape from the column, the beam bottom main bar is embedded in the bottom part in which the beam bottom main bar is embedded. Forming grooves for arranging the joint bars, which are located on the side of, and the bottom surface of the groove arranged in one direction among the PC beam formwork protruding in a cross shape from the pillar,
In addition to setting the same height as the lower side of the beam bottom main bar, set the bottom of the groove arranged in the other direction to the same height as the upper side of the beam bottom main bar, and arranging joint bars in each groove. Construct a lap joint.

[0008]

According to the PC beam formwork of the present invention having the above-mentioned structure, when the lap joint is constituted by the beam lower end main bar and the joint bar,
Since the joint reinforcement is arranged in the groove formed in the bottom portion where the beam bottom main reinforcement is embedded, the height difference between the beam bottom main reinforcement and the joint reinforcement can be eliminated. Therefore, it is possible to sufficiently secure the distance to the joint reinforcement as well as the distance from the upper surface of the beam to the main reinforcement at the lower end of the beam, and it is possible to effectively secure the bending strength of the beam.

Further, the PC beam formwork of the present invention is configured to project in a cross shape from a column via a cross girder-like joint streak,
The bottom of the groove where the four-sided protruding parts of the cross girder-shaped joint bar is arranged is set to the same height as the lower side of the beam bottom main bar with one direction protruding in a cross shape and the other direction is beam Since it is set to the same height as the upper side of the lower end main bar, the height difference between the beam lower end main bar and the joint bar can be made small. It is possible to secure a sufficient distance to the joint bar almost in the same manner as the distance to the lower end main bar. Therefore, it is possible to arrange the PC beam form in a cross shape while reducing the difference in height with respect to the intersection of the joint lines to make the bending strength of the beam advantageous.

[0010]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. 1 to 5 show one embodiment of the PC beam formwork of the present invention, and FIG. 1 is an end view of the PC beam formwork in one direction,
2 is an end view of the PC beam formwork in another direction, FIG. 3 is a plan view showing the central portion of the joint bar, FIG. 4 is an end plan view of the PC beam formwork arranged in one direction, and FIG. It is a side view of the connection part of the PC beam formwork arranged in the direction.

That is, as shown in FIG. 3, the PC beam formwork 10 of this embodiment is connected in four directions with respect to one column 16 through the connecting girder-like joint bars 14 provided in the column / beam joint 12. To be done. The joint bar 14 includes four rebars 14a, 1 having a predetermined length.
Four reinforcing bars 14b, 14b ... Are laid on the upper side of 4a. The column-beam joint portion 12 is formed by installing the cross-shaped joint bar 14 on the upper end of the column 16, and both ends of the joint bar 14 are projected from the column 16 in all directions. Then, the P-shaped joint bar 14 is provided at the portion where the pillar-shaped joint bar 14 projects from the column 16 in all directions.
The C-beam formwork 10 is connected, and this PC beam formwork 10 has pillars 16
They are arranged in a cross shape with a pinch in between. Also, the PC beam form 1
The width of 0 may be made wider than the normal width so that it is substantially equal to the width of the pillar 16.

The pillar 16 is a rectangular PC pillar formwork 20.
And a plurality of column main bars 22 vertically arranged along the inside of the PC column form 20 are
Is arranged so as to penetrate through the outer side of the overlapping portion. A hoop muscle 24 is wound around the outer periphery of the column main muscle 22.

As shown in FIGS. 1 and 2, the PC beam form 10 is precast in a U-shaped cross section, and a plurality of beam lower end main bars 26 are provided on the bottom 10a thereof along the extending direction of the beam form 10. Buried. A shear reinforcing bar 28 is simultaneously embedded in the PC beam form 10. Here, in the present embodiment, the PC beam form 10 is connected to the reinforcing bar 1 under the double girder joint bar 14.
The extension direction of 4a, that is, the left-right direction in FIG. 3 is set as one direction (X direction), and the PC beam form 10 arranged in this one direction is set as the one-direction PC beam form 10X, and the upper reinforcing bar 14 is provided.
The extension direction of b (vertical direction in FIG. 3) is the other direction (Y direction), and the PC beam form 10 arranged in this other direction is the other direction PC beam form 10Y. In addition, unidirectional PC beam formwork 10X
Is shown in FIG. 1, and another direction PC beam form 10Y is shown in FIG.

In the unidirectional PC beam form 10X, the beam lower end main bar 2 is formed on the bottom portion 10a in which the beam lower end main bar 26 is embedded.
First grooves 30 are formed on the sides of 6 for arranging the end portions of the reinforcing bar 14a of the joint bar 14. At this time, the bottom surface 30a of the first groove 30 is set at the same height as the lower side of the buried beam lower end main reinforcement 26. On the other hand, the other direction PC beam form 10Y is the one direction PC beam form 10X.
Similarly to the above, the second groove 32 for arranging the end portion of the reinforcing bar 14b of the joint bar 14 is formed in the bottom portion 10a. The bottom surface 32a of the second groove 32 is set at the same height as the upper side of the beam lower end main bar 26.

When constructing the beam, the ends of the one-direction PC beam form 10X and the other-direction PC beam form 10Y are placed on the upper end surface of the PC column form 20. Then, the above-mentioned cross girder-shaped joint bar 14 is inserted from above to the column main bar 22
The end of the reinforcing bar 14a on the lower side of the bar-shaped joint bar 14 is laid in the first groove 30, and the end of the upper bar 14b is laid on the second groove 32. At this time, the joint muscle 1
The four reinforcing bars 14a and 14b are arranged in contact with the bottom surfaces 30a and 32a of the first and second grooves 30 and 32, and in this state, concrete is placed in the respective PC beam forms 10X and 10Y. As a result, the rebars 14a, 14b
And the beam lower end main bars 26 corresponding to each other form a lap joint.

With the above construction, the PC beam formwork 1 of this embodiment
In 0, one direction PC beam form 10X and other direction P
The C-beam form 10Y is projected in four directions from the column 16 via the cross-shaped joint bar 14. At this time, the unidirectional PC beam form 10
The bottom surface 30a of the first groove 30 formed in X is set at the same height as the lower side of the buried beam lower end main reinforcement 26, while the second groove 32 formed in the other direction PC beam form 10Y. The bottom surface 32a of the same is set at the same height as the upper side of the beam lower end main bar 26. Therefore, if the above-mentioned PC beam forms 10X and 10Y are arranged in a cross shape and placed on the upper end of the PC column form 20 to construct a beam, the height difference between the beam lower end main bar 26 and the joint bar 14 can be reduced. Therefore, the distance to the joint bar 14 can be sufficiently secured almost in the same manner as the distance from the constructed beam upper surface to the beam lower end main bar 26. Therefore, the PC beam form frames 10X, 10 are formed in a cross shape while reducing the height difference between the cross beam-shaped joint bars 14 and making the bending strength of the beam advantageous.
Y can be arranged and constructed.

In the present embodiment, the bottom surface 30a of the first groove 30 is set to the same height as the lower side of the beam lower end main bar 26, and the bottom surface 32a of the second groove 32 is set to the beam lower end main bar 26. Although the case where it is set to the same height as the upper side and is in the ideal state is disclosed, the present invention is not limited to this, and the groove may be simply formed in the bottom portion 10a.

[0018]

As described above, according to the first aspect of the present invention.
In the PC beam formwork shown in Fig. 4, when forming a lap joint with a beam lower end main bar embedded in the bottom and a joint bar to a column, a groove formed in the bottom part on the side of the beam lower end main bar. Since the above-mentioned joint reinforcement is arranged, the height difference between the beam lower end main reinforcement and the joint reinforcement can be eliminated. Therefore, it is possible to sufficiently secure the distance to the joint reinforcement as well as the distance from the upper surface of the beam to the main reinforcement at the lower end of the beam, and it is possible to effectively secure the bending strength of the beam.

Further, in the PC beam formwork according to claim 2 of the present invention, the PC beam form projects from the column in a cross shape through the cross girder-shaped joint bars, and the four sides of the girder-shaped joint bars are formed. The bottom surface of the groove where the protruding part is arranged is set to the same height as the lower side of the beam lower end main bar with one direction protruding in a cross shape,
Since the height in the other direction is set to the same height as the upper side of the beam bottom main bar, the height difference between the beam bottom main bar and the joint bar can be reduced, and even in the case of a joint bar assembled in a cross beam shape. As with the distance from the beam upper surface to the beam lower end main bar, the distance to the joint bar can be sufficiently secured. Therefore, there are various excellent effects that the bending strength of the beam can be advantageously secured by reducing the difference in height with respect to the intersection of the joint lines, and that the beam can be attached smoothly.

[Brief description of drawings]

FIG. 1 is an end view of a unidirectional PC beam formwork showing an embodiment of the present invention.

FIG. 2 is an end view of a PC beam formwork in another direction showing an embodiment of the present invention.

FIG. 3 is a plan view showing a central portion of a joint bar showing an embodiment of the present invention.

FIG. 4 is a view showing an embodiment of the present invention, in which P is arranged in one direction.
It is an end part top view of a C-beam form.

FIG. 5 shows another embodiment of P arranged in the other direction.
It is a side view of the connection part of a C-beam form.

FIG. 6 is a sectional view showing a conventional PC beam formwork.

FIG. 7 is a side view of a main portion showing a joint portion of a conventional PC beam formwork.

[Explanation of symbols]

 10 PC Beam Formwork 10a Bottom Part 12 Column / Beam Joint 14 Joint Bars 14a, 14b Reinforcing Bar 16 Column 26 Beam Bottom Main Bar 30, 32 Groove

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masataka Sekine, Inventor Masataka Sekine 4-640 Shimoseido, Kiyose City, Tokyo Obayashi Corporation Technical Research Institute

Claims (2)

[Claims] 1. A PC beam form having a U-shaped cross section, which comprises a beam lower end main bar embedded in the bottom part, and the beam lower end main bar forms a lap joint with a joint bar to a column. In the embedded bottom portion, a groove is formed on the side of the beam lower end main bar for arranging the joint bar,
A PC beam formwork characterized by arranging a joint bar in this groove to form a lap joint. 2. A beam lower end main bar embedded in the bottom portion, and the beam lower end main bar overlaps with four-sided projecting portions of a cross girder-shaped joint bar arranged in a column, and each overlapped portion constitutes a lap joint. Then, in the PC beam formwork having a U-shaped cross section that protrudes in a cross shape from the column, the joint bar is located at a side of the beam lower end main bar in the bottom portion where the beam lower end main bar is embedded. Grooves for arranging are formed respectively, and the bottom surface of the groove arranged in one direction of the PC beam formwork projecting in a cross shape from the pillar is set to the same height as the lower side of the beam lower end main bar, The bottom of the groove that is placed in the other direction,
A PC beam formwork, characterized in that it is set at the same height as the upper side of the beam lower end main bar, and a joint bar is arranged in each groove to form a lap joint.