JPH0460043A - Concrete precast board and synthetic slab using precast board - Google Patents

Abstract

PURPOSE:To thin the thickness of a flat section by integrally protruding multiple protruded stripes in the longitudinal direction on the bottom face of the flat section, and protruding a padding section on the upper face across the protruded stripes on the bottom face. CONSTITUTION:Multiple protruded stripes 1b are integrally protruded in the longitudinal direction on the bottom face 1a of a flat plate section except installation end sections at both ends, and connecting reinforcing bars 2 are protruded into a hoop shape on the upper face. A padding section 1c is integrally protruded on the upper face of the flat section at the position across the protruded stripes 1b except both edge sections of the flat section. Auxiliary reinforcing bars 3, 4 are arranged in the flat section, and auxiliary reinforcing bars 5 are arranged in the padding section 1c on the upper face at both ends. PC steels 6 are longitudinally inserted into the protruded stripes 1b on the bottom face, and the PC steels 6 are stretched to be applied with pre-stress. The bending in the width direction is strengthened, and cracks between the protruded stripes 1b on the bottom face are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a concrete precast slab (hereinafter referred to as PCa slab) used for a composite slab of a multi-story structure, and a composite slab using the PCa slab.

(Prior Art) Conventional PCa plates and composite slabs using PCa plates have structures as shown in FIGS. 8 to 10. In the figure, 21 is a PCa plate, and the PCa plate has a flat plate portion 2.
A plurality of protrusions 21b, 21b are integrally provided on the bottom surface of 1a to project in the longitudinal direction, and a hoop-shaped connecting reinforcing bar 22 for integration with cast-in-place concrete is provided on the top surface.

This PCa plate 21 has a longitudinal protrusion 21b on the bottom surface to increase the bending strength of the PCa plate itself.

Furthermore, in order to increase the strength, an example is also known in which a PC steel material is inserted into the protrusion 21b in the longitudinal direction, and the PC steel material is tensed to apply prestress to the PCa plate.

When using this PCa plate, as shown in Figs. 9 and 10, after passing the ends of the PCa plate 21 over both edges of the girder 23, reinforcing reinforcing bars 24 and 25 are arranged and laid. PC
Cast-in-place concrete 26 is placed continuously on the a-plate 21 and the girder 23, and the 208-plate 1 and the girder 23 are integrated to form a composite slab.

(Problems to be Solved by the Invention) In the conventional PCa plate as described above, the longitudinal protrusions must have a cross-sectional area of a certain value or more in order to develop a certain level of strength.

For this reason, it is necessary to make the flat plate part thinner in order to reduce the overall weight, but if the flat plate part is made thinner, the bending strength in the width direction will decrease, making it easier for cracks to form in the thin parts between the ridges. Therefore, there was a limit to weight reduction. In addition, when stacking PCa plates for storage or transportation, if they are stacked as they are, they will deform due to the weight of the connecting reinforcing bars protruding from the surface or the things on top, so it is necessary to insert spacers such as zero binding material between each PCa plate. It was something that should not have happened.

Furthermore, in conventional composite slabs using such PCa slabs, the flat plate-shaped portion of the PCa slab is extended and hung on the edge of the girder, so the width of both edges of the girder is smaller than the center of the slab. There was a problem in that the strength was low, and there was a risk that stress due to vertical loads would be concentrated on both edges of the girder.

In view of these conventional problems, the present invention provides a PCa plate that has sufficient strength against bending in the width direction and can be made lighter by making the flat plate portion thinner, and provides a PCa plate using the PCa plate. The purpose of this invention is to provide a composite slab that has stronger integration between the PCa plates and can sufficiently handle the horizontal tensile force of the upper portion of the beam.

(Means for Achieving the Object) The gist of the present invention for solving the above-mentioned conventional problems and achieving the intended purpose is to have a rectangular flat plate portion, The bottom surface of the plate-shaped part integrally has a plurality of protrusions parallel to each other in the longitudinal direction except for the construction ends at both ends, and the upper surface of both ends of the flat plate-shaped part has both edges of the flat plate part. Concrete precast plate and PCa which are integrally provided with a built-up part extending between the protrusions except for
A large number of plates are erected side by side in the width direction and extension direction with their respective ends supported on both edges of the girder, and constructed between each built-up part on the upper surface of the precast plates whose sides are adjacent to each other. Connecting reinforcing bars are placed in the recesses to cross over the girder and span both sides, and continuous cast-in-place concrete is placed on each cast plate and the girder to create a composite slab using precast plates. .

(Function) This PCa plate provides strength against bending in the width direction by providing built-up parts on both ends of the top surface of the flat plate-shaped part so as to span between the protrusions on the bottom surface, and the bending stress applied in the width direction. This prevents cracks between the protrusions on the bottom surface that would otherwise occur due to this. Also,
This built-up portion increases the cross-sectional area of the construction ends at both ends, increasing the strength of the construction ends against vertical loads.

In addition, by providing the built-up portion at a position higher than the height of the connecting reinforcing bars protruding from the top surface of the flat plate-shaped part, when stacking PCa plates during storage or transportation, the protruding connecting reinforcing bars can be The reinforcing bars are stacked without contacting the upper PCa plate, and deformation of the connecting reinforcing bars protruding from the surface can be prevented without intervening spacers such as square timbers. In addition, by passing connecting reinforcing bars across both sides of the girder to the four parts constructed between the built-up parts on the upper surface of the PCa plate whose sides are adjacent to each other, Since a sufficient amount of concrete can be secured for the connecting reinforcing bars, it is possible to increase the degree of zero connection between the PCa plates that sandwich the girders.

(Example) Next, an example of implementation of the present invention will be described with reference to FIGS. 1 to 7.

In the figure, 1 is a PCa plate, and on the bottom surface 1a of the flat plate-like part, a plurality of protrusions 1b, 1b are integrally provided in the longitudinal direction except for the construction ends at both ends, and on the top surface, there are A connecting reinforcing bar 2 is protruded in a hoop shape to be integrated with poured concrete. Furthermore, a built-up portion IC is integrally provided on the upper surface of the flat plate-shaped portion, excluding both edges of the flat plate-shaped portion, and extending between the protrusions 1b.

Reinforcement reinforcing bars 3.4 are arranged within the flat plate-like part, and reinforcing reinforcing bars 5 are arranged in the built-up parts IC at both ends of the upper surface. A PCm material 6 is inserted into the protruding portion lb on the bottom in the longitudinal direction,
The PCG4 material 6 is tensioned and prestressed.

Also, the built-up portion 1 on the upper surface of the flat plate-like portion. In the flat plate part between c and Ic, there is a connecting reinforcing bar 2 with one end buried in the protrusion 1b, or a hoop-shaped protrusion so that its height does not exceed the height of the built-up part on the upper surface. .

5 and 6 show a composite slab using the PCa plate 1, and in FIG. 0, 7 is a girder.

This composite slab is constructed by placing the PCa plates 1 and 1 side by side between the girders 7, connecting reinforcing bars 2 protruding from the PCa plates 1 on the upper surface, connecting reinforcing bars 8 and reinforcing bars 9 provided on the girder 7. , 10 are tied together.

The PCa plates 1, 1 and 1 have built-up parts 1c and 1. Reinforcement reinforcing bars 11 that span the PCa plates 1.1 whose sides are adjacent to each other, and large-diameter connecting reinforcing bars 12 that span both sides of the girder are arranged in the recess formed between the gaps c and c.

Reinforcement reinforcing bars 11 and connecting reinforcing bars 12 arranged in the recessed portion
Since the reinforcing bars 9 and 10 are placed at a lower position than the other reinforcing bars 9 and 10, sufficient concrete cover can be ensured.

After laying the PCa plate and arranging the reinforcement as described above, the PC was laid by pouring cast-in-place concrete 13.
A composite slab is molded that is integral with the a-plate.

FIG. 7 shows a case in which PCa plates are stacked during storage or transportation.

The protrusion 1b on the bottom of the loaded PCa plate 1 is placed on the built-up part IC on the top surface of the PCa plate 1 below, so the protrusion 1b is provided lower than the height of the top or inner part IC and protrudes. The connecting reinforcing bars 2 do not come into contact with the PCa plate 1 loaded on top.

(Effects of the Invention) As described above, in the PCa of the present invention, the built-up parts protruding from both ends of the upper surface of the PCa plate serve as reinforcement against bending in the width direction and at the same time, reinforcement against shear force due to vertical loads at the ends of the construction. Therefore, the thickness of the flat plate part can be made thinner than before, and a lightweight PCa plate can be formed.

In addition, connecting reinforcing bars that cross the girder and span the PCa slabs on both sides are placed in the recess formed between the built-up parts of the top surface of the PCa slabs that are passed over the girder, and sufficient concrete is applied to the connecting reinforcing bars. By placing cast-in-place concrete with a covering amount, it is possible to strengthen the connection between the opposing PCa slabs via the girder, and it is possible to sufficiently cope with the horizontal tensile force of the upper part of the beam.

In addition, by providing a built-up part on the edge of the top surface of the PCa plate at a position higher than the connecting reinforcing bars, when stacking PCa plates during storage or transportation, the connecting reinforcing bars can be placed on the loaded PCa plates. This also eliminates the risk of deformation due to contact.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing an embodiment of the PCa plate of the present invention, Fig. 2 is a front view of the same, Fig. 3 is a sectional view taken along line AA in Fig. 2, and Fig. 4 is a sectional view taken along line BB in Fig. 2. 5 is a sectional view showing an embodiment of the composite slab of the present invention, FIG. 6 is a sectional view taken along the line CC in FIG. 5, and FIG. 7 is a sectional view of stacked PCa plates.
FIG. 8 is a perspective view of a conventional PCa plate, FIG. 9 is a sectional view of a conventional composite slab, and FIG. 10 is a sectional view taken along the line DD in FIG. 9. 1...PCa version, 1a...Bottom surface of flat plate portion, 1b...Protrusion on bottom surface, IC...
Overlay part, 2.8... Connection reinforcing bar, 3.4.5.9.10.11. ...Reinforcement reinforcing bars,
6...PC steel material, 7...Girder, 12.
...Connection reinforcing bars, ...Cast-in-place concrete. Patent applicant Kurosawa Kenpatsu Trap Stock Kunin Figure 8 Figure 9 Figure 10

Claims (2)

[Claims] (1) The flat plate has a rectangular shape, and the flat plate has a plurality of protrusions on the bottom surface that are parallel to each other in the longitudinal direction except for the construction ends at both ends; A concrete precast plate comprising a built-up part integrally provided on the upper surface of both ends of the plate-shaped part, extending over the ridges except for both edges of the flat plate-shaped part. (2) It has a rectangular flat plate part, and has integrally a plurality of protrusions parallel to each other in the longitudinal direction except for the construction ends at both ends on the bottom surface of the flat plate part, and the flat plate part A large number of precast plates each having a built-up part integrally provided on the upper surface of both ends of the plate-like part in a manner spanning between the protrusions except for both ends of the flat plate-like part are installed at the construction ends of each of the two ends. are supported on both edges of the girder and lined up in the width direction and extension direction, and placed in the recess formed between each built-up part on the upper surface of the precast plate whose sides are adjacent to each other, across the girder on both sides. A composite slab using precast slabs, with connecting reinforcing bars spanning the walls, and continuous cast-in-place concrete placed on each cast slab and girder.