JPH08165733A - Half slab - Google Patents

Abstract

PURPOSE: To make PC steel materials generate required up and down without using any spacer and to contribute to the increase of execution accuracy and the reduction of a construction period by using ribs and/or groove to arrange unbonded PC steel materials. CONSTITUTION: A pair of rids 5 are provided on the surface of a half slab main body 1 for forming a floor slab of reinforced concrete construction at a proper interval in the direction of the arrangement of unbonded PC steel material 3. A plurality of grooves 2 corresponding to the arrangement of the unbonded PC steel materials 3 are provided on an intermediate section between the ribs 5 on the surface of the half slab main body 1. When the unbonded PC steel materials 3 are borne on the ribs 5, a part of them is sunk into the grooves 2, and a sinking part is hung down by its dead weight. Since an extent of up and down of the PC steel materials 3 under such a state is fixed in constant by the height of the rib 5, the depth and length of the groove 2, the up and down of the PC steel materials 3 are properly generated without providing any spacer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a half slab for forming a slab made of reinforced concrete.

[0002]

2. Description of the Related Art A conventional reinforced concrete floor slab is
As shown in FIG. 12, the formwork 13 is supported by the support 8 and the unbonded PC steel material 3 is arranged on the spacer 14 installed on the formwork 13 so that the unbonded PC steel material 3 rises and falls. Then, the concrete 4 was cast from above, and after the concrete 4 was hardened, the unbonded PC steel material 3 was pulled from both sides to be tensioned.

When the unbonded PC steel material 3 is tensioned in this way, a lifting force is generated in the unbonded PC steel material 3 to cancel the load applied to the floor slab, and a lateral compressive force is generated to increase the strength against the tensile force. It is strengthened and can prevent cracking.

However, in such a construction method, the formwork 13 is used on site.
It is difficult to obtain high construction accuracy and a long construction period is required because it is necessary to install a supporter 8 and a spacer 14 to raise and lower the unbonded PC steel material 3. .

On the other hand, there was a half slab as shown in FIG. 13 in which a concrete slab 15 was combined with a reinforcing bar truss 7. Since this conventional half slab can be manufactured in a factory, the reinforcing bar truss 7 is less disturbed and relatively high construction accuracy can be obtained.

Further, since the concrete slab 15 has a function as a formwork and can be supported without supporting work, if this half slab is used, the formwork can be used on site.
The floor slab can be formed by simply placing the concrete 4 from above and integrating them without using the 13 and the supporting work 8, and the construction period can be relatively short.

However, the floor slab formed by using this conventional half slab is not so high in strength, and in order to further increase the strength, it is necessary to use the unbonded PC steel material 3. When using unbonded PC steel material 3, spacers are placed on the concrete slab 15 on site in the same manner as in the above case.
Since it was necessary to install 14, the effects of improving the construction accuracy and shortening the construction period were not sufficiently obtained.

[0008]

SUMMARY OF THE INVENTION Therefore, the present invention
An object of the present invention is to provide a half slab that can increase the strength of a floor slab by using unbonded PC steel and can sufficiently obtain the effects of improving the construction accuracy and shortening the construction period.

[0009]

In order to solve the above-mentioned problems, the present invention takes the following technical means.

The half slab of the present invention is a half slab for forming a floor slab made of reinforced concrete,
The upper surface is provided with a groove into which a portion of the unbonded PC steel material is immersed,
The unbonded PC steel material is arranged so as to hang down in the groove.

Alternatively, a half slab for forming a reinforced concrete floor slab, which has an unbonded PC on its upper surface.
The ribs that support the steel material may be provided in pairs at appropriate intervals in the arrangement direction of the unbonded PC steel material, and the unbonded PC steel material may be arranged so as to hang between the both ribs.

Further, an unbond P is formed on the top of the rib.
The recess for mounting the C steel material may be formed along the arrangement direction of the unbonded PC steel material.

[0013]

As a result of adopting the above means, the present invention has the following effects.

In the half slab of the present invention, the unbonded PC steel material can be arranged by utilizing the grooves or ribs.
Moreover, when arranging the unbonded PC steel material on the spot, the unbonded PC steel material hangs down because a part of the unbonded PC steel material is immersed in the groove, or hangs down between the ribs forming a pair, without installing a spacer. It is possible to cause a certain rise and fall in the unbonded PC steel material.

If a recess for mounting the unbonded PC steel material is formed on the top of the rib along the arrangement direction of the unbonded PC steel material, the unbonded PC steel material is prevented from falling off from the rib during the arrangement. be able to.

[0016]

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

FIG. 1 is a perspective view of a half slab according to a first embodiment of the present invention, in which a plurality of grooves 2 are formed on the upper surface of a half slab body 1.

This half slab is made of concrete, and the size thereof is not particularly limited and can be appropriately set depending on the case. In this embodiment, the short side is about 3 m, the long side is about 5 m, and the thickness is about 5 m. Is formed to about 5 cm.

As shown in FIG. 2 which is a sectional view of this half slab, the groove 2 is formed in a square shape in cross section and has a width of about 2 cm and a depth of about 4 cm. Approximately 2 slabs are left, leaving both ends on the top surface.
Multiple units are arranged at intervals of 0 cm.

Since this half slab has the above-described structure, it can be produced in a factory and can be transported by being stacked on a truck bed.

When a floor slab is formed using this half slab, the half slab is first supported on the frame structure. The frame structure may be structural type such as RC structure or S structure.

Then, the unbonded PC steel material 3 is arranged by utilizing the groove 2. The unbonded PC steel materials 3 may be arranged, for example, every four grooves 2 of the half slab. In this case, the unbonded PC steel materials 3 are arranged at intervals of about 1 m. A normal reinforcing bar (not shown) is arranged on the groove 2 where the unbonded PC steel material 3 is not arranged.

As shown in FIGS. 3 and 4, a part of the unbonded PC steel material 3 is recessed in the groove 2, and the part recessed in the groove 2 hangs by its own weight. Therefore, it is possible to raise and lower the unbonded PC steel material 3 without installing a spacer. Moreover, this unbonded PC steel material 3
Since the degree of rise and fall that occurs in 1) is fixed depending on the depth and length of the groove 2, it is not necessary to perform the above-described rise and fall adjustment work on site.

After arranging the unbonded PC steel material 3 and the reinforcing bars, concrete 4 is cast on the half slab and hardened in the same manner as in the conventional method using the unbonded PC steel material 3. Then, by tensioning the unbonded PC steel material 3 using a dedicated jack (not shown), a lifting force is generated in the unbonded PC steel material 3 to cancel the load applied to the floor slab and a lateral compression force is generated. By doing so, the strength against the tensile force is strengthened to prevent cracking.

FIG. 5 is a perspective view of a half slab according to a second embodiment of the present invention, in which ribs 5 for supporting the unbonded PC steel material 3 are provided in pairs on the upper surface of the half slab body 1 at appropriate intervals. is there. The half slab body 1 may be the same as that of the first embodiment. A plurality of pairs of ribs 5 forming each pair are provided at both ends in the long side direction at intervals of about 20 cm.

As shown in FIG. 6 which is a cross-sectional view of this half slab, the rib 5 has a substantially trapezoidal cross section, and a recess 6 is formed on the top thereof along the longitudinal direction.

The unbonded PC steel material 3 is supported by the ribs 5 at both ends, and as shown in FIG. 7, the portion supported by the ribs 5 is lifted up and is supported by the ribs 5 between the pair of ribs. The middle part, which is not attached, hangs down by its own weight. The unbonded PC steel material 3 is placed in the recess 6 as shown in FIG.
It has become difficult to fall out of.

In this half slab, after the unbonded PC steel material 3 is placed, concrete 4 is poured from above as in the first embodiment. Then, after the concrete 4 hardens, unbonded P using a dedicated jack (not shown).
C Steel material 3 is tensioned.

FIG. 9 is a sectional view in the long side direction of the third embodiment of the present invention. Thus, the groove 2 of the first embodiment
And the rib 5 of the second embodiment may be combined.

FIG. 10 is a cross-sectional view in the long side direction of a fourth embodiment of the present invention in which the rib 5 and the reinforcing bar truss 7 of the second embodiment are combined. As shown in FIG. 11 which is a sectional view in the direction of the short side, in the fourth embodiment, the rib 5
And reinforcing bar truss 7 are provided alternately. Further, the rib 5 is gently inclined so that the unbonded PC steel material 3 hangs along this inclination.

A plurality of the half slabs of the fourth embodiment are placed on the large pulling 9 supported by the supporting work 8 at the time of construction, and the reinforcing bar trusses 7, 7 of the adjacent half slabs are connected by the connecting member 10. It is connected.

In FIG. 10, 11 is a beam, 12 is its formwork, and this formwork 12 is a frame structure for supporting the floor slab.

As described above, the half slab of the present invention is
The rib 5 and the reinforcing bar truss 7 can be combined and implemented. The groove 2 may be formed instead of the rib 5. Further, the groove 2, the rib 5 and the reinforcing bar truss 7 may be combined and implemented.

[0034]

Since the half slab of the present invention has the above-mentioned structure, the strength of the floor slab can be increased by disposing the unbonded PC steel material by utilizing the grooves or ribs. Moreover, when arranging the unbonded PC steel,
Part of the unbonded PC steel material immerses into the groove 2 and hangs down, or hangs down between the ribs forming a pair, whereby a constant rise and fall of the unbonded PC steel material is achieved without installing a spacer. Since it can be generated, the effect of improving the construction accuracy and shortening the construction period can be sufficiently obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of a half slab according to the present invention.

FIG. 2 is a sectional view of the first embodiment of the half slab according to the present invention in the short side direction.

FIG. 3 is a cross-sectional view in the long side direction showing a state in which an unbonded PC steel material is arranged in the first embodiment of the half slab according to the present invention.

FIG. 4 is a sectional view in the short side direction showing a state in which an unbonded PC steel material is arranged in the first embodiment of the half slab according to the present invention.

FIG. 5 is a perspective view of a second embodiment of a half slab according to the present invention.

FIG. 6 is a sectional view of a second embodiment of a half slab according to the present invention in the short side direction.

FIG. 7 is a cross-sectional view in the long side direction showing a state in which an unbonded PC steel material is arranged in the second embodiment of the half slab according to the present invention.

FIG. 8 is a sectional view in the short side direction showing a state in which an unbonded PC steel material is arranged in the second embodiment of the half slab according to the present invention.

FIG. 9 is a cross-sectional view in the long side direction showing a state in which an unbonded PC steel material is arranged in a third embodiment of a half slab according to the present invention.

FIG. 10 is a sectional view of a half slab according to a fourth embodiment of the present invention in the long side direction.

FIG. 11 is a sectional view of a half slab according to a fourth embodiment of the present invention in the short side direction.

FIG. 12 is a cross-sectional view illustrating a method of forming a floor slab using a conventional unbonded PC steel material.

FIG. 13 is a cross-sectional view of a conventional half slab.

[Explanation of symbols]

 2 groove 3 unbonded PC steel 5 rib 6 recess

Claims (3)

[Claims] 1. A half slab for forming a reinforced concrete floor slab, wherein a groove into which a part of unbonded PC steel material is immersed is provided on the upper surface, and the unbonded PC steel material is arranged so as to hang down in the groove. A half slab characterized by that. 2. A half slab for forming a reinforced concrete floor slab, wherein ribs for supporting the unbonded PC steel material are provided in pairs at appropriate intervals in the arrangement direction of the unbonded PC steel material on the upper surface. Is arranged so as to hang between the both ribs. 3. The half slab according to claim 2, wherein a recess for mounting the unbonded PC steel material is formed on the top of the rib along the arrangement direction of the unbonded PC steel material.