JP2002349006A - Concrete plate for forming faulting slab, faulting slab structure and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete plate for a faulting slab, the faulting slab and a method for forming it in the market by using the concrete plate with hollow holes in which a prestressed PC steel formed by a slip former is installed lengthwise, especially one that is lightweight and easy to form at low cost. SOLUTION: The concrete plate employs a concrete slab A0 with the hollow holes in which a prestressed PC steel 21 formed by the slip former lengthwise is installed. It is cut in required length. A slit 25 and a broad hollow 27 that reach a hollow hole 20 are formed from the surface 24 of a contact end 23. An anchor reinforcing rod 35 with a hook 39 at the extremity is inserted into the end of a guard 38 in the root of the slit 25 and the broad hollow 27. The anchor reinforcing rod 35 and the concrete plate are unified by filling the slit 25 with mortar 50 or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete plate having a prestressed hollow hole containing PC steel, which is mainly used as a floor material for a high-rise house or the like, and more particularly to a concrete plate for forming a plate having a step in the middle of a slab. The present invention relates to a step slab using the same and a method of forming the same.

[0002]

2. Description of the Related Art Conventionally, a floor having a step in the middle of a slab as described above is used for a part around a water such as a bathroom, and the construction of this part is described in JP-A-8-42035. Concrete slabs and their uses have been announced. The outline of this manufacturing method is as follows. When forming a step in each slab, a steel bar (steel material) of a stress-introduced PC is placed on the upper and lower slabs in the concrete formwork. Are separately inserted, stress is introduced by pre-tension or post-tension, the reinforcing bar of the beam at the step portion is entangled with the PC steel bar, and concrete is cast to form a stepped concrete plate. . In addition, Annual Report of Concrete Engineering, Vol. 17, NO. 2 19
95 discloses two types of strength test reports in which the stepped concrete slab and the PC steel bar are connected obliquely at the stepped portion.

[0003] However, in these methods, each stepped concrete slab is separately formed in a mold, and each time a stress is applied to a PC steel material to form it. Each time, a stress introducing device must be connected to the mold, and the manufacturing process is complicated, and the manufacturing cost is several times that of a normal flat slab. Also,
This stepped concrete slab does not have any hollow holes, so the weight is large, and the frame materials of the buildings that support them need to be durable accordingly. Has a feeling of one step now.

[0004]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a hollow having several hollow holes manufactured by a conventionally known slip forming method and having several prestressed PC steel members integrated in a longitudinal direction. Molded concrete plate (see Fig. 14) A0
To provide a market for a concrete slab for forming a step slab, in which a step slab can be manufactured relatively easily, and which is durable and lighter than one without a hollow hole, and a step slab structure and a step slab used therefor. To provide a manufacturing method to the market.

[0005]

In order to achieve the above-mentioned object, the present invention has several hollow holes manufactured by a slip forming method, and a plurality of prestressed PC steel members are integrally formed in a longitudinal direction. At the position of the hollow hole on the connection end side of the step forming concrete slab composed of the hollow concrete slab that has been formed, a slit for anchor bar insertion that reaches the hollow hole from the upper surface,
A concrete slab for forming a step slab, characterized in that it is cut and provided along the hollow hole.

In order to achieve the above object, in the concrete slab for forming a step slab, the end of the slit is formed to be slightly wider than the diameter of the hollow hole, and the slit is formed in the hollow hole. Mortar or concrete pouring hole (a mortar or a concrete pouring hole reaching the hollow hole from the upper surface of the concrete plate at a position 3 to 7 times the diameter of the hollow hole from the connection end of the hollow hole without the slit). (Hereinafter simply referred to as an injection hole). Further, in order to achieve the above object, in the concrete slab for forming a step slab, at the connection end of the concrete slab for forming a step, from the upper surface, to the position of each hollow hole,
In some cases, the connection beam is dimensionally cut off.

According to another aspect of the present invention, there is provided a concrete slab for forming a step slab, wherein an upper surface of the concrete slab is formed with a cotter recess in a transverse direction, and is provided on a ceiling wall in each hollow hole. Also, it is preferable that protrusions following the cotter depressions are formed at a predetermined pitch in the transverse direction. According to another aspect of the present invention, there is provided a concrete slab for forming a step slab, wherein the hollow hole having the slit is provided in the concrete slab according to any one of claims 1 to 4. The roots of anchor rebars having a large diameter or a bent portion at the roots are inserted into the hollow holes at the slit positions, and the tips of these anchor rebars are inside box-box-shaped connecting beam rebars (hereinafter simply referred to as box-box rebars). Can be inserted into the
In addition, it is protruded to a position near the connection end of the concrete slab of the other party, and the roots of reinforcing bars are respectively inserted into the hollow holes without slits, and the tips of these reinforcing bars are the box cages. The hollows at the insertion portions of the anchor rebar and the reinforcing bar are filled with mortar or concrete, and the several anchor rebars and concrete slabs are firmly inserted. A concrete slab for a step slab characterized by being fixed. In order to achieve the above object, any one of the concrete slabs of the invention according to claim 5 of the concrete slab for forming a step slab of the related invention is set to a lower position side, and 6. The concrete slab according to claim 5, wherein the concrete slab is any one of the concrete slabs, and the connection ends thereof are opposed to each other with the box slab rebar positioned therebetween. Anchor bars whose roots have a large diameter or a bent portion are inserted into the slits, and the outer ends of the anchor bars are inserted into the box cage reinforcing bar up to near the opposing concrete slab. Reinforcing reinforcing bars are inserted into the respective hollow holes from the end surfaces thereof, and reinforcing steel for cast-in-place concrete layers are laid on the upper and lower concrete slabs with a step formed therebetween. Rebar Te is the step slabs, characterized in that which had been embedded in poured concrete solidification.

In order to achieve the above object, a related invention is a method invention wherein two concrete slabs according to the fifth aspect of the invention and a box cage rebar are used, while the two concrete slabs are connected to a step. A formwork section provided with two joints facing each other, and a cast-in-place concrete layer formed thereon, and a step formwork provided with a formwork section forming a connecting beam part in the middle thereof. A first step of preparing a grid-like reinforcing bar to be buried in the cast-in-place concrete layer laid on the two concrete slabs, and then installing the step formwork such that each concrete slab is horizontal, A second step of setting the inside of the box cage rebar on a form part forming a connecting beam part of the form or on a part where the concrete for a lower level has been killed; Next, each of the two concrete plates is set with a step provided at a predetermined position in the formwork with the connection end facing the box cage reinforcing bar, and the upper and lower anchor reinforcing bars are respectively inserted, and A third step of inserting an outer end portion into the box cage rebar and installing the hook tips of the respective anchor bars in the box cage rebar approaching the mating concrete slab connection portion; Next, the grid-like reinforcing bars are placed on the upper surface of each concrete plate with a step across the box cage reinforcing bar. Finally, ready-mixed concrete is stepped between all the reinforcing bars and on the two concrete plates. The fourth step of setting. A method of manufacturing a composite step slab including a concrete slab and a cast-in-place concrete layer in which the above steps are sequentially performed. In order to achieve the above object, a method invention which is a related invention is characterized in that, in the third step, the concrete slab in the lower position is the concrete slab according to claim 5, which is the concrete slab according to the invention according to claim 3. In some cases, the method is to install the box cage rebar on a part where a lower concrete plate has been killed.

[0009]

According to the first aspect of the present invention, since it is constructed as described above, the connecting anchor bar can be inserted into each hollow hole through the slit from the upper surface of the concrete slab. If mortar or concrete is injected or press-fit from the slit from the upper surface of the slab, a concrete slab of anchor reinforcement can be firmly bonded. The injection or press-fitting of the mortar and the concrete can be used also when constructing a composite concrete slab using the concrete slab and forming a cast-in-place concrete layer on the upper surface of the concrete slab.

[0010] In the invention of claim 2, since the construction is as described above, the operation of the invention of claim 1 is of course provided. However, since the hollow holes having slits are provided every other line, the concrete plate is not used. There is no danger that the strength of the end will be unnecessarily degraded, and the end of the slit is formed with an enlarged width, so the root of the anchor rebar is attached to a plate with an enlarged diameter or bent to the side When the mortar or concrete is injected or press-fitted into this slit portion and solidified, these are formed with expanded roots on the anchor reinforcing bar in the expanded width portion of the slit, and the anchor reinforcing bar is formed from the hollow hole of the concrete plate. It has the function of not falling out.

Since the remaining hollow portion is provided with an injection hole as described above, a reinforcing bar is inserted into each of the hollow holes having the injection hole up to the injection hole portion, and then mortar or concrete is poured from the injection hole portion. If the mortar or concrete is poured from the connection end of the concrete until the mortar or concrete overflows from between the inner wall of the hollow hole and the reinforcing reinforcing bar, the concrete slab and the reinforcing steel bar become a firm bond when they are solidified in the hollow hole. Make Further, since the injection hole is provided at the above-mentioned position, the mortar or concrete is not injected more than necessary and an amount sufficient for bonding is injected.

According to the third aspect of the present invention, as described above, the upper half of the concrete slab at the lower position is killed off at the connection end, so that the step slab is formed using this. In this case, box cage rebar can be placed above the killed part, and when casting in-place concrete, the formwork of the connecting beam part is unnecessary, and the formwork material for slab molding is used. It can save money, and there is no boundary between the connecting beam part and the lower concrete plate, and it is beautiful when viewed from the bottom, and the appearance is not bad even if it is exposed as the ceiling of the lower floor. Other features are the same as those of the first or second aspect.

[0013] In the invention according to claim 4, a cotter depression is formed on the surface of the concrete slab to strengthen the connection with the cast-in-place concrete, and a ridge is provided in each of the hollow holes in the transverse direction. Since the crossing irregularities are formed, after inserting the anchor reinforcing bar or the reinforcing reinforcing bar, a mortar or concrete for fixing these is injected or press-fitted, and when solidified, the mortar or concrete cast in place is the mortar or concrete. In order to solidify following the uneven shape of
These solidified concretes do not fall out of the hollow holes, and are more firmly fixed if these reinforcing bars have irregularly shaped reinforcing bars or flanges, so that they do not fall off the concrete plate.

According to the fifth aspect of the present invention, the anchor reinforcing bar and the reinforcing connecting reinforcing bar are firmly fixed in advance in the respective hollow holes at the connecting ends of the respective concrete plates as described above. It is possible to perform the operation with high reliability of the mounting strength.

The slab according to the sixth aspect of the present invention is a concrete slab having a step, in which a series of slabs having a step is a step slab constituting a composite floor constituted as described above, and furthermore, concrete having a step is sandwiched. Since the slab is a hollow concrete slab containing prestressed PC steel, it is much lighter than a known stepped concrete slab and has the same strength.

According to a seventh aspect of the present invention, each concrete slab having an anchor reinforcing bar and a reinforcing bar, the box cage reinforcing bar, the grid reinforcing bar for the in-situ stratification, and the concrete form are prepared at a construction site or a slab manufacturing plant. By assembling by the above-described method, placing the ready-mixed concrete from above and solidifying it, the stepped slab of the invention according to claim 6 is obtained.

In the invention according to claim 8, the upper side of the connection end of the lower concrete slab is up to the hollow hole level.
Since the slab with a step is used, when laying ready-mixed concrete as a stepped slab, the lower half of the lower concrete slab remains on the lower side of the part that was killed,
In this part, a concrete formwork is unnecessary, the formwork material is small, the formwork assembling work and materials are saved, the lower surface of the connecting portion is beautiful, and a product which can be used as it is as a ceiling surface of a lower floor can be manufactured. .

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIGS. 1 to 3 show an embodiment of the present invention including the first, second and fourth aspects of the present invention. In the figure, A
Numeral 0 is a concrete plate having a plurality of hollow holes 20 and is usually formed by a slit former that runs along a long bed. The PC steel bar or the PC steel material 21 to which the tensile load is applied is buried in the length direction, whereby a compressive force is constantly applied to the concrete slab A0 in the length direction. This concrete plate A
Numeral 0 designates a step slab S having a step in the middle between the horizontal beams B1 and B2 between the beams B and the like and having one end higher and the other end lower. On the upper surface 24 on the connection end 23 side, at the position of the hollow hole 20, the length L is 4 to 6 times the length of the diameter of the hollow hole 20 and has a width b sufficient to insert an anchor rebar described later. The slit 25 is the hollow hole 2
The width b is smaller than the diameter of the hollow hole 20 (the width in a plan view), and is preferably about half. Further, the end 26 of the slit 25 is slightly wider than the width of the hollow hole 20, and the hollow holes 20 in which the wide recesses 27 are provided in the slit 25 are provided every other line. In the example of FIG. 10, the slit 25 is formed to have a wide width and a slightly narrow taper at the connection end 23 side. However, the slit may be parallel in its entire length (see FIG. 3). Of the hollow holes 20,
Each of the hollow holes 20 without the slits 25 has an upper surface 2.
An injection hole 28 for injecting mortar or concrete reaching the hollow hole 20 from the hole 4 is formed.
Is the position of 3 to 7 of the diameter of the hollow hole 20 from the connection end 23, which is the concrete slab A of the first embodiment.

In the first embodiment, as described above, the concrete plate A0 containing the PC stress steel material 21 is formed with a hollow hole by a slip former on a long forming bed (not shown) by a known method. We use what we did. At this time, the upper surface 24 of the concrete slab A0 is pressed with a long cotter forming rod in the transverse direction to improve the connection with the concrete layer cast in place, and the cotter recess 30 is formed.
Is formed, but when forming this, the hollow hole 20
On the ceiling wall surface 22 of the pit, gently corrugated irregularities 31 having ridges in the transverse direction of the hollow hole 20 are formed at the same pitch as the cotter pitch in the longitudinal direction of the hollow hole 20 (FIGS. 2 and 5).
reference).

Operation of the First Embodiment To use the concrete slab A of the first embodiment,
The required number of anchor reinforcing bars 35 and reinforcing reinforcing bars 36 shown in FIG. 1 are prepared. The anchor reinforcing bar 35 has a flange 37
8 are integrally fixed, and the outer diameter or one side of the disc-shaped or square-plate-shaped flange 38 is a dimension that can be just fitted into the hollow hole 20 or a dimension corresponding to the wide recess 27 ( (See FIG. 1). Further, a hook 39 is provided at the tip end, and at the connection end portion of the concrete plate A in the middle of the anchor reinforcing bar 35, the anchor reinforcing bar 35 is bent upward by 15 ° to 20 ° in the lower concrete plate A1, The anchor reinforcing bar 35a of the upper concrete slab A1 is formed to be inclined downward and at the same angle (see FIGS. 1 and 7).

The required number of straight reinforcing bars 36 are also prepared. This is preferably provided with a flange 38b at the inner end.
Is not necessary.

The anchor reinforcement 35 as described above is aligned with the slit 25 through the flange 38 at the position of the wide recess 27. In the lower concrete plate A2, an anchor reinforcement 35b which is bent upward is prepared. An anchor reinforcing bar 35a bent downward is inserted into the upper concrete slab A1, and a hollow hole 2 having no slit 25 is inserted.
The reinforcing bar 36 is inserted into the hole 0 (see FIGS. 1 and 7). Before inserting the above-mentioned reinforcing bars 35, 36, it is preferable to fill the mortar or concrete 50 with a stopper 40 for preventing the inflow of the concrete 50 slightly behind the insertion position of each reinforcing bar 35, 36 in each hollow hole. The plug 40 may be a synthetic resin molded product, a metal plate press molded product, or other concrete molded product. In short, it is only necessary that the mortar or concrete 50 does not move due to the dynamic pressure at the time of pouring. In this way,
If the mortar or concrete is injected or press-fitted from the slit 25 and the injection hole and the reinforcing bars are respectively fixed to the concrete plate A, the state shown in FIG. 7 can be obtained.
These are the third embodiment of the invention described in claim 5 described later.

Embodiment 2 FIG. 6 shows an embodiment including the third aspect of the present invention. The difference from the first embodiment is that at the connection end, the concrete plate A is killed down from the upper surface 24 to the lower limit of the hollow hole 20, and only the bottom portion becomes a plate-shaped portion 29 connected to the lower concrete plate A2. As the lower concrete plate A2.

The length of the plate-like portion 29 is set to a length corresponding to a box-shaped connecting beam for connecting the lower concrete slab A2, and is set such that a box cage reinforcing bar 45 to be described later can be just placed thereon. Therefore, the anchor rebar 35 and the reinforcing rebar 3
The connection end 23 into which the wire 6 is inserted is a root portion of the plate-shaped portion 29, and the slit 25 and the injection hole 28 are formed from the upper surface 24 of this portion. In addition, the same reference numerals as those in the first embodiment in the drawings denote the same constituent members or constituent parts, and the slit 2
5 and an injection hole 28 are provided. In addition, in the figure,
The same reference numerals as in Embodiment 1 denote the same components or components, and provide the same functions and effects.

Operation of Embodiment 2 In addition to the operation similar to that of Embodiment 1 described above, the plate-like portion 29 is connected to the box cage when two upper and lower concrete slabs A1 and A2 are connected using a step. Instead of the bottom form plate of the reinforcing steel 45, the form form 46 is saved, and the floor surface after joining becomes clean.

Embodiment 3 An embodiment including the invention described in claim 5, which is shown in FIG. The concrete slab A2 of the first embodiment is used for the lower concrete slab A2, and the lower anchor rebar 35b is used for each hollow hole 20 having the slit 25. The anchor rebar 35a is located on the upper surface at the position of the slit 25. A straight reinforcing bar 36 is inserted into the hollow hole 20 which is inserted from the slit 24 and has no slit 25, and mortar or concrete is injected from the slit 25 and the injection hole 28, and the anchor reinforcing bar 35a is reinforced concretely. It is fixed to the plate A and is referred to as a lower concrete plate A2. This anchor rebar 35b is
It is inclined upward by 12 ° to 20 ° and protrudes from the connection end 23.

On the other hand, the upper concrete slab A1 is exactly the same as the concrete slab A described above, except that the anchor stiffener 35 is different from the lower concrete slab A1 except for the use of the anchor rebar 35a bent downward. The downward inclination angle of the anchor reinforcing bar 35a is also the inclination angle β12.
° to 20 ° (α ° = β °).

Embodiment 4 FIG. 6 shows an embodiment according to claim 5, which differs from the above-mentioned embodiment in that the concrete slab A2 for lower order is the one used in embodiment 2. For this reason, the embedding and fixing structures of the other anchor reinforcing bars 35b and the reinforcing reinforcing bars 36 are not different from those of the third embodiment. The difference is that the plate-like portion 29 connected to the lower surface of the connection end 23 is formed to project below the anchor reinforcing bar 35b.

Operation of Embodiments 3 and 4 In these embodiments, the upper concrete slab A1 to which the downwardly sloping anchor reinforcing bar 35a is attached.
And the connection end of the lower concrete slab A2 to which the anchor bar 35b inclined upward is attached, is connected to the beam B of the construction part on the site.
The upper and lower concrete slabs A1, A2 and the formwork 46 are horizontally supported by using a suitable support material 49 between the first and the second concrete slabs, or the pair of upper and lower concrete slabs are respectively set in appropriate formworks at a factory. A1 and A2 are opposed to each other, and the anchor reinforcing bars 35a and 35b and the reinforcing reinforcing bars 3
6 are respectively inserted into box cage rebars 45 located in the middle of these, and cast-in place cast concrete 51 is cast on the upper surfaces of the concrete plates A1 and A2 and the box cage rebars 45, and is solidified. And a step slab S formed by combining a pair of concrete slabs having a predetermined height. In particular, when the structure of the fourth embodiment is used, when the step slab S is used, the lower surface of the connecting portion has a concrete plate A for lowering the lower surface.
When the lower surface of 2 is used as it is and the plate-like portion 29 is integrally connected, it acts as a part of a kind of formwork,
Even when the step slab S is formed, the lower surface is cleaned. The step slur S formed in this manner is an embodiment of the invention according to claim 6.

Fifth Embodiment A step slab S described in the operation of the third and fourth embodiments, which is shown in FIGS.
The present invention includes the method described in claim 7. First, a formwork 46 for the step slab for forming the step slab, the concrete plates A1 and A2 described in the third embodiment, and the box cage rebar 45 are prepared. The first step,

Next, as a third step, the formwork 46 is installed between the beams B1 and B2 on which the step slab is to be constructed, and this is supported by a conventionally known suitable support material (support material) 49, and the box basket is supported. When the reinforcing bar 45 is installed, and then a pair of concrete plates A1 and A2 for the upper and lower sides are installed with the connecting ends 23 facing each other and with a step, the opposite reinforcing bar 35 is installed.
The positions a and 35b are in contact with each other and are inclined substantially in parallel within the box cage reinforcing bar 45, and the reinforcing bars 46 also protrude into the box cage reinforcing bar 45, respectively (see FIGS. 9 and 10). At this time, a part of the formwork 46 is formed as an upright wall 47 so that the cast-in-place concrete 51 does not spill to the side, particularly on the lower concrete plate A2 side. A plurality of lower concrete plates A2 may be installed in the width direction. FIG. 12 shows an example in which two sheets are successively installed in the width direction.

The above-mentioned formwork 46 is an example, and the bottom surface other than the box cage reinforcing bar 45 does not necessarily require the formwork 46, and this method is also an embodiment of the present invention. In particular, the concrete slab A1 at the upper position is provided adjacent to the slabs of the same level connected thereto, and these same level portions are used to cast the cast-in-place concrete 51.
In some cases, neither the side plate nor the bottom plate is required for the formwork 46. The case where such a mold is partially used is also included in the embodiment of the method invention. Next, as a fourth step, first, a normal lattice reinforcing bar is laid on the low-grade concrete A2, and a cast-in-place concrete 51 is cast thereon with a desired thickness. In this place, cast-in-place concrete 5 to the same level in the box cage rebar 45
1 flows in (see FIG. 11).

Next, after this part has been solidified to some extent, the surrounding formwork 48 is attached as a part of the formwork 46 so that the cast-in-place concrete 51 to be cast next will not flow into this lower concrete plate part. Around the upper concrete A1, a batch cast-in-place concrete 51 is cast on the upper concrete A1 and on the adjacent slab of the same level as this, and also on the box cage rebar 45 part. Concrete A1, part cast-in-place concrete 51
Thus, the fourth step is completed (see FIG. 13).

Embodiment 6 In the above-described method, a method of directly applying to a structure at a site has been described, but only the step slab S is formed in advance in a factory or the like. The procedure is the same as in the fourth and fifth embodiments. The step slab S formed in this manner is also included in the invention of claim 6.

Embodiment 7 An anchor reinforcing bar 35 and a reinforcing bar 36 according to Embodiment 4
Instead of using the concrete slabs A1 and A2 of the first or second embodiment to which the anchor reinforcing bars 35 and the reinforcing reinforcing bars 36 are not attached,
6, these are inserted into the hollow holes 20 from the slits 25 of the concrete slabs A1 and A2, and reinforcing reinforcing bars 36 are inserted from the end surfaces of the hollow holes 20. 2
5 and the injection hole 28, various rebars are incorporated in the same manner as in the fifth embodiment, and cast-in-place concrete 51 is cast, and the whole is formed as an integrated step slab S. In each of the above-described embodiments, an example in which the anchor reinforcing bars 35a and 35b are bent in the middle has been exemplified. Item 8 includes the scope of the invention.
When straight anchor bars 35a and 35b are used, it is preferable to add bracing bars to the box cage bar 45.

[0036]

According to the first and second aspects of the present invention, since the structure and operation are performed as described above, the anchor rebar can be easily fitted into the hollow hole portion before use.
If raw mortar or concrete is poured from the slit, the concrete slab and these rebars are firmly connected,
After the connection, there is no danger that these rebars will fall out of the hollow holes and the connection portion will not be deteriorated. Moreover, it can be used as a concrete for a lower position or a higher layer by using one having a different inclination angle of the anchor rebar, or as a concrete slab for a purpose having a different step size.

According to the second aspect of the present invention, since the above structure is adopted, the anchor reinforcing bars and the reinforcing reinforcing bars are alternately attached to every other hollow hole, and each of the anchor reinforcing bars and the reinforcing reinforcing bars are inserted into the hollow holes without slits. Also, since the injection hole is provided, the raw mortar or concrete can be injected from this, and it can be injected until it is confirmed that the raw mortar or concrete overflows from the connection end of the concrete slab. Is also effective in obtaining a strong bond. Other effects are the same as those of the first aspect.

According to the third aspect of the present invention, since the construction and operation are performed as described above, when these stepped slabs are constructed, the anchor rebar and the reinforcing rebar are provided in the same manner as in the first or second aspect. Is used to form the lower concrete, and if this is used, the box cage rebar of the connection part can be installed on this plate-shaped part, and the lower surface can use the lower concrete as it is, forming the lower surface of this part No formwork is required, and the seam is not formed on the lower side, resulting in a beautiful one. Other effects are the same as those of the first and second aspects.

According to the fourth aspect of the present invention, since the mortar or concrete poured into the interior is solidified in accordance with the irregularities on the ceiling surface of the hollow hole, the anchor is constructed because the mortar or concrete injected therein is solidified. Even if a tensile load is applied to the reinforcing bar or the supplementary reinforcing bar, there is no possibility that the mortar or concrete and the reinforcing bar filled and solidified in the hollow hole come off from the hollow hole.

According to the fifth aspect of the present invention, the concrete slab, the anchor rebar and the reinforcing bar are strong, the reliability of the connection is high, and the step slab is constructed. It is only necessary to assemble the box cage rebar inside the formwork, which facilitates construction on site.

According to the sixth aspect of the present invention, since it is constructed as described above and functions, it is much lighter than a known step slab without a hollow hole and has the same strength.

According to the seventh aspect of the present invention, the effect that the slab of the sixth aspect of the present invention can be easily formed by performing the above-described method.

According to the eighth aspect of the present invention, by performing the above-described method, a slab having a clean lower surface of the connection portion can be formed, and a mold is not necessarily required at this portion at the time of molding, and the construction is simple. .

[Brief description of the drawings]

FIG. 1 is a perspective view of a concrete slab according to a first embodiment of the present invention, and an anchor reinforcing bar and a reinforcing reinforcing bar used therein.

FIG. 2 is a partially longitudinal side view showing a relationship with an anchor reinforced concrete slab.

FIG. 3 is a plan view of a slit and an injection hole portion of a concrete plate.

FIG. 4 is a plan view showing a connection state between an anchor reinforcing bar and a concrete slab.

FIG. 5 is a longitudinal sectional side view showing a connection state between a reinforcing reinforcing bar and a concrete slab.

FIG. 6 is a partially longitudinal side view of the second embodiment.

FIG. 7 is a perspective view of a pair of upper and lower concrete slabs shown in the third embodiment.

FIG. 8 is a perspective view of a box cage reinforcing bar and a lattice reinforcing bar.

FIG. 9 is a vertical sectional side view of a connection portion of the step slab.

FIG. 10 is a plan view showing a state of an anchor reinforcing bar of a connection portion.

FIG. 11 is a longitudinal sectional side view showing a state after casting cast-in-place concrete on a lower-order concrete slab and before placing concrete for upper-layer concrete.

FIG. 12 is a vertical sectional side view taken along line 12-12 of FIG. 11;

FIG. 13 is a longitudinal sectional side view after concrete is cast on the upper concrete slab.

FIG. 14 is a perspective view of a known concrete slab.

[Explanation of symbols]

 A0 Known concrete plate with hollow hole A Concrete plate A1 Concrete plate for upper layer A2 Concrete plate for lower layer B1, B2 Beam 20 Hollow hole 21 Prestressed PC steel 22 Ceiling surface 23 Connection end 24 Top surface 25 Slit 26 Terminal 27 Wide dent 29 Plate Form part 30 Cotter recess 31 Irregularity 35 Anchor reinforcement 35a Upper anchor reinforcement 35b Lower anchor reinforcement 36 Reinforcement reinforcement 37 Root 38 Flange 38b Flange 39 Hook 40 Plug 45 Box cage type connection beam reinforcement (= box cage reinforcement) 46 Formwork 47 Upright wall 50 Mortar or concrete 51 Cast-in-place concrete 52a Upper grid-shaped reinforcing bar 52b Lower grid-shaped reinforcing bar

Claims (8)

[Claims] 1. A connection end of a step forming concrete plate comprising a hollow concrete plate having several hollow holes manufactured by a slip forming method and having several prestressed PC steel members integrated in a longitudinal direction. A slit for forming an anchor streak, which extends from the upper surface to the hollow hole, is cut along the hollow hole at the position of the hollow hole on the side of the concrete plate for forming a stepped slab. 2. An end portion of the slit is formed to be slightly wider than a diameter of the hollow hole, and the slit is provided at every other hole of the hollow hole. Has a hollow hole diameter of 3 to
2. The concrete slab for forming a step slab according to claim 1, wherein a mortar or a concrete pouring hole reaching the hollow hole from an upper surface of the concrete slab is provided at a 7-fold position. 3. The connecting end of the concrete slab for forming a step slab, wherein a dimension equivalent to a connecting beam is cut off from the upper surface to the position of each hollow hole. The concrete plate for forming a step slab according to the above. 4. An upper surface of the concrete slab is formed with a cotter recess in the transverse direction, and projections following the cotter recess are formed at a predetermined pitch in the transverse direction on the ceiling wall in each hollow hole. 3. The method according to claim 1, wherein
Or a concrete plate for forming a step slab according to item 3. 5. The concrete slab according to claim 1, wherein the hollow hole having the slit has a root of an anchor reinforcing bar having a large diameter or a bent portion at the root in the hollow hole at the slit position. The ends of these anchor rebars can be inserted into box cage connection beam rebars,
In addition, it is projected to a position near the connection end of the concrete slab of the other party, and the roots of reinforcing bars are respectively inserted into the hollow holes without slits, and the tips of these reinforcing bars are the box cages. The mortar or concrete is filled in each hollow hole of the insertion portion of the anchor reinforcing bar and the reinforcing bar, and each of the reinforcing bars and the concrete plate are firmly fixed. A concrete slab for forming a step slab, characterized in that the slab is formed. 6. A concrete slab according to claim 5, wherein any one of the concrete slabs according to any one of the first to second and fourth aspects of the present invention is set to the low position side. With the concrete slab as the upper position side, the connection ends facing each other, and a box cage type connection beam rebar is positioned between them, and the slit has an anchor having a base having a large diameter or a bent portion. A bar is inserted, and the outer end of each anchor bar is inserted into the box cage type connecting beam reinforcing bar up to near the opposing concrete slab, while each hollow hole without slit has a respective end face. Reinforcing reinforcing bars inserted are provided, and on the upper and lower concrete slabs, reinforcing steel for cast-in-place concrete layers are laid with steps formed therebetween, and all these reinforcing bars are buried in cast-in-place concrete and upper and lower. Step slabs with concrete panel for step slab molding, characterized in that which had been solidified stepped in the concrete panel portions. 7. A step slab-forming concrete plate according to claim 5 and two box slab-type connecting beam reinforcing bars. On the other hand, the two concrete plates are provided with a step to form a joint at two steps. A formwork part which can be installed facing and formed on-site with a cast-in-place concrete layer, a step formwork having a formwork part forming a connecting beam part in the middle thereof, and a step formwork on the two concrete plates The first step of preparing a grid-like reinforcing bar buried in the cast-in-place concrete layer to be laid. Next, the step formwork is installed so that each concrete plate surface is horizontal,
A second step of setting the box cage type connection beam reinforcing bar on a formwork portion forming a connection beam portion of the formwork or on a killing portion of the lower concrete plate. Next, the two concrete slabs are set with a step at a predetermined position in the formwork with the connection ends facing the box cage connection beam rebar,
The upper and lower anchor reinforcing bars are respectively inserted, and the outer ends of the reinforcing bars are further inserted into the box cage type connecting beam bars, and the hook ends of the respective anchor bars are brought closer to the mating concrete plate connecting ends, and The third step of installation in a box cage type connection beam reinforcing bar. Next, on the upper surface of each concrete slab, the grid-like reinforcing bars are installed with a step across the box-shaped connecting beam reinforcing bar, and finally, ready-mixed concrete is placed between all the reinforcing bars and on the two concrete slabs. The fourth step of attaching and driving. A method of manufacturing a composite step slab comprising a concrete slab and a cast-in-place concrete layer in which the above steps are sequentially performed. 8. The concrete slab according to claim 5, wherein the concrete slab in the lower position is the concrete slab according to the third aspect of the present invention. 8. The method according to claim 7, wherein said method is a method of installing the device on a part where the surface has been killed.
A method for producing the composite step slab according to the above.