JPH10205039A - Manufacture of pca slab for composite floor slab and constructing method of composite floor slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method, in which the manufacture of a PCa slab for a composite floor slab and the construction of the composite floor slab can be conducted easily at low cost in a short time by a simple process. SOLUTION: A bottom force 11 formed while being brought into contact with the whole underside of a thin base 2a and a top force 12 formed while being brought into contact with the whole top face of the thin base 2a and at least the upstanding side faces of projecting ribs 2b are assembled, the inside of the bottom force 11 and the top force 12 is filled with high fluid fresh concrete, and the PCa slab 2 containing the thin base 2a and the projecting ribs 2b is molded. A large number of recessed spherical cotter sections 5 are formed to the top face of the thin base 2a by projecting sections 12a shaped to the top force 12 at the same time as the molding of the PCa slab 2. The molded PCa slabs 2 are bridged to the beams of a building, and cast-in-place concrete is placed on the PCa slabs 2, thus building the composite floor slabs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing a composite floor slab for a building and a method for producing a PCa (precast concrete) plate used for the construction.

[0002]

2. Description of the Related Art As shown in FIG.
There is known a technique of constructing a composite floor slab 4 having a two-layer concrete structure as shown in FIG. 16 by laying a Ca plate 2 and placing a cast-in-place concrete 3 thereon. The PCa plate 2 is usually composed of a thin base 2a having a thickness of about 35 to 40 mm and a plurality of protruding ribs 2b in order to reduce the weight and increase the bending strength. In the case of a condominium such as a condominium, the lower surface of the composite floor slab 4 serves as a ceiling downstairs.
The lower surface of the base 2 is formed smoothly, and the ridge rib 2b is
a.

In manufacturing the PCa plate 2, conventionally, as shown in FIG. 17, the inside of a lower mold frame 31 and an upper mold frame 32 are filled with fresh concrete to form a thin base 2a and a ridge rib 2b. The method is widely adopted.
In order to ensure high strength and early generation of strength, hardened fresh concrete is usually used for this fresh concrete. However, the hardened fresh concrete has poor fluidity (slump value is about 8 cm).
Less than. Before the vibration is applied by the vibrator, the vibrator has a dry shape, and after the vibration, it has a rice cake shape. ), There are various restrictions on the shape of the mold, the casting method, and the like.

That is, as shown by a two-dot chain line in FIG.
If it is spread out, the hardened fresh concrete having poor fluidity does not flow into the narrow portion between the two molds 31 and 32, so that the thin base 2a cannot be formed after all. For this reason, the one upper mold frame 32 is in contact with only a part of the upper surface of the thin base 2a from the rising side surface of the ridge rib 2b, and is not in contact with most of the upper surface of the thin base 2a. It was formed in an L shape, and a number of the upper mold frames 32 were assembled above the lower mold frame 31. Then, the thin-walled base 2a is first cast by intermittently repeatedly inputting the hardened fresh concrete and applying vibration by the vibrator.
After a certain degree of curing, a plurality of ridge ribs 2b were sequentially driven.

[0005]

The method for producing the PCa plate 2 has the following problems. Since it was necessary to intermittently carry out the loading of the hardened fresh concrete and the application of vibration by the vibrator many times, the process became complicated, and labor and cost were increased. Since the thin base 2a and the ridge rib 2b cannot be driven at the same time, the number of steps is increased and the manufacturing time is long. A large number of elongated upper mold frames 32 are required (for example, in the case of three protruding ribs 2b, six upper mold frames 32 are required), so that assembling and disassembling operations are troublesome.

In order to integrate the PCa plate 2 and the cast-in-place concrete 3 firmly to enhance the shear strength of the composite floor slab 4, as shown in FIG.
It is necessary to form a plurality of cotter portions (concave or convex engaging portions) 5 with which part of the cast-in-place concrete 3 meshes on the upper surface of the concrete (see Design Registration No. 647417). However, since the upper mold frame 32 does not cover most of the upper surface of the thin base 2a, the cotter 5
Cannot be formed. Therefore, conventionally, the cotter portion 5 is formed by, for example, manually rolling a roller with small projections on the upper surface of the thin-walled base 2a in a semi-cured state after the casting, thereby increasing the number of steps and the cost. It was hanging.

Accordingly, an object of the present invention is to solve the above-mentioned problems, and to provide a method for producing a PCa plate for a composite floor slab and constructing the composite floor slab in a simple process in a short time, easily and inexpensively. To provide.

[0008]

In order to solve the above-mentioned problems, the present invention relates to a method of manufacturing a PCa plate for a composite floor slab including a thin base and a plurality of ribs protruding from the upper surface thereof. A lower mold frame formed by contacting the entire lower surface of the base and an upper mold frame formed by contacting the entire upper surface of the thin-walled base and at least the upright side surface of the ridge rib are assembled, and the lower mold frame and the upper mold frame are combined. The inside is filled with high-fluidity fresh concrete, and a PCa plate including a thin-walled base and a rib is formed.

Here, it is preferable that the lower mold frame and the upper mold frame are filled with high-fluidity fresh concrete by being poured at a stretch substantially to simultaneously form the thin base and the ridge rib. “Substantially put in at once” means that substantially all of the input is completed before the first input is not cured, and also includes a case where a part of the input is formally delayed.

It is preferable that a concave or convex cotter portion is formed on the upper surface of the thin base by a convex or concave portion provided on the upper mold frame simultaneously with the molding of the PCa plate.

Another aspect of the present invention is a method of constructing a composite floor slab comprising a PCa plate including a thin base and a plurality of ribs protruding from an upper surface thereof, and a cast-in-place concrete cast on the upper side of the PCa plate. The lower mold frame formed by contacting the entire lower surface of the thin base and the upper mold frame formed by contacting the entire upper surface of the thin base and at least the upright side surface of the ridge rib. The inside of the frame is filled with high-fluidity fresh concrete to form a PCa plate including a thin-walled base and a ridge rib, and the PCa plate is erected on a beam of a building, and is cast in place on the PCa plate. It is characterized by casting concrete.

Here, simultaneously with the molding of the PCa plate, a convex or concave portion provided on the upper mold frame forms a concave or convex lid support portion on the upper surface of the thin base or on the rising side surface of the ridge rib.
After the PCa plate is erected on the beam of the building, a lid is placed on the lid support to form a hollow portion between the lid and the upper surface of the thin base. Cast-in-place concrete can also be cast on top.

The PCa plate manufactured by the present invention is not limited to a PCa plate in which a general reinforcing bar is buried in concrete, but also a PC (prestressed) plate in concrete.
Includes PC and PCa versions with steel wires embedded to increase toughness.

The high-fluidity fresh concrete used in the present invention is not limited to a specific one, but the slump value is preferably 25 to 85 cm, more preferably 55 to 75 cm. Examples of the composition of the high-fluidity fresh concrete include those disclosed in JP-A-7-144949. The high-fluidity fresh concrete disclosed in the disclosure comprises a hydraulic component consisting of Portland cement and blast furnace slag fine powder, fine aggregate, coarse aggregate, a cement dispersant, a thickener, and water, A specific water-soluble vinyl copolymer is used as a dispersant, a specific partially saponified polyacrylamide is used as a thickener, and an aqueous solution having a predetermined surface tension and viscosity in which both are dissolved in water is used as kneading water. It is.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. First, FIGS. 1 to 3 show a first embodiment, and FIG. 1 shows a PCa used for construction of a composite floor slab.
FIG. 2 shows the cross section of the plate 2 and the manufacturing method, FIG. 2 shows the entire shape of the manufactured PCa plate 2, and FIG. 3 shows the cross section of the composite floor slab 4 constructed using the PCa plate 2.

The PCa plate 2 manufactured in the present embodiment includes a rectangular thin base 2a and three protruding ribs 2b protruding from the upper surface of the thin base 2a and extending in the longitudinal direction. Accordingly, the upper surface of the thin base 2a is
, And a number of concave spherical cotter portions 5 are formed on each upper surface. Further, a reinforcing reinforcing bar 6 is buried in substantially the entire area inside the thin base 2a. The dimensions of the PCa plate 2 vary depending on the specifications of the synthetic floor slab, but for example, a length of 6000 mm and a width of 20 mm.
A typical example is 00 to 2400 mm, 150 to 200 mm in height, and 35 to 40 mm in thickness of the thin base 2a.

In manufacturing the PCa plate 2, FIG.
As shown in the figure, a lower mold frame 11 formed by contacting the entire lower surface of the thin base 2a, and four upper mold frames 12 formed by contacting the entire upper surface of the thin base 2a and the upright side surface of the ridge rib 2b.
And to use. The upper mold frame 12 of the present embodiment includes
Do not cover the top surface of b. The reinforcing bar 6 is arranged immediately above the lower mold frame 11, and four upper mold frames 12 are arranged slightly above the reinforcing bar 6 and assembled to the lower mold frame 11.

The two upper mold frames 12 on both edges are substantially L-shaped in cross section. The two upper mold frames 12 in the middle cover the upper surface of the thin base 2a and have two projecting ribs 2b, respectively. Since it can be formed in a channel shape so as to cover the standing side surface, FIG.
The number of the upper mold frames 12 can be reduced as compared with the conventional example, and the assembling process can be simplified. In a portion of the upper mold frame 12 formed in contact with the upper surface of the thin base 2a, a large number of convex spherical convex portions 12a are provided so that the cotter portion 5 can be molded.

Next, a high-fluidity fresh concrete having a slump value of 55 to 75 cm is placed on the lower mold 11 and each upper mold from the upper end opening of each upper mold 12 (the portion not covering the upper surface of the rib 2b). The inside of the frame 12 is substantially filled at a stretch to fill the thin base 2 a and the ridge rib 2.
and b are simultaneously formed. The space between the lower mold frame 11 and the portion of the upper mold frame 12 formed by contacting the upper surface of the thin base 2a is a narrow portion having an interval of only 35 to 40 mm. Even if it does not divide many times or use a vibrator, it flows into the narrow portion in a short time, and fills all the insides of the molds 11 and 12. At the same time, the protrusion 12a provided on the upper mold frame 12
Thereby, the cotter portion 5 is molded on the upper surface of the thin base 2a. Therefore, production of the PCa plate 2 and the cotter 5
Can be formed easily and inexpensively in a short time by a simple process.

After the high-fluidity fresh concrete is hardened to some extent and further cured for a predetermined time, the molds 11 and 12 are disassembled and the PCa plate 2
Demold products. At the time of curing, air curing at normal temperature, moist curing, film curing to prevent evaporation of water,
Known curing methods such as steam curing using heated steam can be applied.

As shown in FIG. 3, the manufactured PCa plate 2
Is erected on the beam 1 of the building, reinforcing steel 8 is laid on the PCa plate 2 if necessary, and then the cast-in-place concrete 3 is cast to construct the composite floor slab 4. I do. When the part of the cast-in-place concrete 3 meshes with the cotter portion 5 of the thin base 2a, the PCa plate 2 and the cast-in-place concrete 3 are firmly integrated, and the shear strength of the composite floor slab 4 is enhanced.

Next, FIG. 4 shows a PCa version of the second embodiment, and FIG. 5 shows a manufacturing method thereof. This PCa version 2
In the above, the cotter portion 5 having a concave spherical shape is
Is formed not only on the upper surface but also on the upper surface of the ridge rib 2b.
In manufacturing the PCa plate 2, one continuous upper mold frame 12 formed by contacting the entire upper surface of the thin base 2a and the upright side surface and the upper surface of the ridge rib 2b is used as the upper mold frame 12. In the upper mold frame 12, a large number of convex spherical convex portions 12 a are formed in a portion formed by contacting the upper surface of the thin base 2 a and the upper surface of the protruding rib 2 b so that the cotter portion 5 can be molded. Is provided. Also, the upper mold 1
An inlet (not shown) for inputting high-fluidity fresh concrete and an air vent hole 12b are formed at a part of the top of 2.

In the present embodiment, the same steps as in the first embodiment are performed, except that the configuration of the upper mold frame 12 is different as described above.
The PCa plate 2 is manufactured, and a composite floor slab 4 (not shown) is constructed. And in addition to the same effect as the first embodiment,
Since the cotter portion 5 is also formed on the upper surface of the ridge rib 2b, the PCa plate 2 and the cast-in-place concrete 3 (not shown) are further firmly integrated.

Next, FIGS. 6 to 11 show modified examples of the cotter section. The cotter portion 21 in FIG. 6 has a convex spherical shape, and the cotter portion 22 in FIG. 7 includes a square concave portion. The cotter portion 23 in FIG. 8 includes the thin base 2a and the ridge rib 2b.
The cotter portion 2 shown in FIG.
Numeral 4 also comprises an L-shaped recess. The cotter portion 25 in FIG. 10 includes a concave portion of the thin base 2a and a convex portion of the ridge rib 2b, and the cotter portion 26 in FIG. 11 is configured by arranging rectangular convex portions in different directions. In these modified examples, the convex cotter portion is provided with a concave portion in the upper mold frame 12 so that the PC is filled with high-fluidity fresh concrete.
It can be formed at the same time as the production of the plate 2. In addition to these modified examples, the uneven shape of the cotter portion can be arbitrarily changed.

Next, FIG. 12 shows the PCa plate 2 used for constructing the hollow composite floor slab of the third embodiment, and FIG. 13 shows the hollow composite floor slab 4. This PCa version 2
, A plurality of lid support portions 7 are protrudingly provided at the lower part of the upright side surface of the ridge rib 2b. The lid support portion 7 can be formed simultaneously with the production of the PCa plate 2 by filling high-fluidity fresh concrete by providing a concave portion in the upper mold frame 12 similarly to the cotter portion.

In this embodiment, the PCa plate 2 is manufactured through the same steps as in the first embodiment. When the hollow composite floor slab 4 is constructed, the PCa plate 2 is erected on a beam (not shown) of the building, and then a lid 13 made of concrete or the like is placed on the lid support portion 7 so that the lid 13 and the lid 13 are connected to each other. A hollow portion 14 is formed between the thin base 2a and the upper surface of the thin base 2a. Reinforcing reinforcing steel 8 is arranged on the lid 13 and the ridge rib 2b as necessary, and then the cast-in-place concrete 3 is cast. I do. This makes it possible to easily construct a lightweight synthetic floor slab 4 having a hollow structure and excellent sound insulation properties. In the case of the hollow composite floor slab 4, the thickness of the thin base 2a needs to be equal to or larger than a predetermined dimension in order to give the floor slab a certain level of fire resistance.

Also, in this embodiment, similarly to the second embodiment, if a cotter is formed on the upper surface of the ridge rib 2b, the PCa plate 2 and the cast-in-place concrete 3 are firmly integrated.

FIG. 14 shows a modification of the third embodiment. By making the upper surface of the ridge rib 2b and the upper surface of the lid 13 the same horizontal plane, the upper surface after the PCa plate 2 is erected and before the cast-in-place concrete 3 is cast is leveled. (Arrangement of bars, etc.) can be performed efficiently.

It should be noted that the present invention is not limited to the above-described embodiment, and may be embodied by appropriately changing the scope of the invention as follows, for example, as follows. (1) Embedding a PC steel wire in concrete and applying it to the production of PC / PCa plates with higher toughness. (2) Increasing or decreasing the number of ribs 2b. In addition, the shape of the ridge ribs 2b may be appropriately changed, for example, to a planar lattice shape other than the plane parallel shape.

[0030]

As described in detail above, according to the first or second aspect of the present invention, the production of a PCa plate for a synthetic floor slab can be performed easily and inexpensively in a short time by a simple process.

In addition to the above effects, according to the third aspect of the present invention,
The production of the PCa plate for a synthetic floor slab can be performed easily and inexpensively in a short time by a simple process including formation of a cotter portion.

Next, according to the invention of claim 4, construction of a composite floor slab can be performed easily and inexpensively in a short time by a simple process.

In addition to the above effects, according to the invention of claim 5,
The construction of the hollow composite floor slab, including the formation of the lid support,
It can be performed easily and inexpensively in a short time by a simple process.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a method for manufacturing a PCa plate according to a first embodiment of the present invention.

FIG. 2 is a perspective view of the PCa version of FIG.

FIG. 3 is a cross-sectional view of a composite floor slab constructed using the PCa version of FIG.

FIG. 4 is a perspective view showing a PCa version according to a second embodiment of the present invention.

FIG. 5 is a sectional view showing a method of manufacturing the PCa plate of FIG.

FIG. 6 is a perspective view showing a modified example of a cotter unit.

FIG. 7 is a perspective view showing a modified example of a cotter unit.

FIG. 8 is a perspective view showing a modified example of a cotter unit.

FIG. 9 is a perspective view showing a modified example of a cotter unit.

FIG. 10 is a perspective view showing a modified example of a cotter unit.

FIG. 11 is a perspective view showing a modified example of a cotter unit.

FIG. 12 is a perspective view of a PCa plate for a hollow composite floor slab according to a third embodiment of the present invention.

FIG. 13 is a sectional view of a hollow composite floor slab constructed using the PCa version of FIG.

FIG. 14 is a sectional view showing a modified example of the hollow composite floor slab.

FIG. 15 is a front view of a composite floor slab.

FIG. 16 is a perspective view showing a partially cut-out synthetic floor slab.

FIG. 17 is a cross-sectional view showing a method for manufacturing a conventional PCa plate for a synthetic floor slab.

[Explanation of symbols]

 2 PCa plate 2a Thin base 2b Ridged rib 3 Cast-in-place concrete 4 Synthetic floor slab 5 Cotter part 6 Reinforcing bar 7 Lid support part 11 Lower mold frame 12 Upper mold frame 12a Convex part 12b Through hole 13 Lid 14 Hollow part 21 Cotter part 22 Cotter 23 Cotter 24 Cotter 25 Cotter 26 Cotter

Claims (5)

[Claims] 1. A method of manufacturing a PCa plate for a composite floor slab including a thin base and a plurality of ribs protruding from an upper surface thereof, wherein a lower mold frame formed by contacting the entire lower surface of the thin base; Assembling the entire upper surface of the base and an upper mold frame formed by contacting at least the upright side surface of the ridge rib, filling the lower mold frame and the upper mold frame with high-fluidity fresh concrete, A method for producing a PCa plate for a synthetic floor slab, comprising forming a PCa plate including a base and a ridge rib. 2. The thin mold base and the ridge rib are simultaneously formed by filling the lower mold frame and the upper mold frame by charging the high-fluidity fresh concrete substantially at a time. 2. The method for producing a PCa plate for a synthetic floor slab according to 1 above. 3. The composite floor according to claim 1, wherein a concave or convex cotter portion is formed on an upper surface of the thin base by a convex portion or a concave portion provided on the upper mold frame simultaneously with the molding of the PCa plate. Manufacturing method of PCa plate for slab. 4. A method of constructing a composite floor slab comprising a PCa plate including a thin base and a plurality of ribs protruding from an upper surface thereof, and a cast-in-place concrete cast on the upper side of the PCa plate. Assembling a lower mold frame formed by contacting the entire lower surface of the base, and an upper mold frame formed by contacting the entire upper surface of the thin base and at least the upright side surface of the ridge rib, and the lower mold frame and the upper mold frame are assembled. Is filled with high-fluidity fresh concrete, and a PCa plate including the thin-walled base and the ridge rib is formed. The PCa plate is erected on a beam of a building, and is cast on the PCa plate in place. A method for constructing a composite floor slab, comprising casting concrete. 5. Simultaneously with the molding of the PCa plate, a convex or concave portion provided on the upper mold frame forms a concave or convex lid support portion on the upper surface of the thin base or the upright side surface of the ridge rib. After laying the PCa plate on a beam of a building, a lid is placed on the lid support to form a hollow portion between the lid and the upper surface of the thin base, and the lid and the ridge rib are formed. The method for constructing a composite floor slab according to claim 4, wherein cast-in-place concrete is cast on the floor.