JPH0827936A - Hollow slab structure partially provided with thin part, and construction method thereof - Google Patents

Abstract

PURPOSE:To realize hollow slab structure partially provided with a thin part, at low cost. CONSTITUTION:A solid part 3 of the same thickness as a hollow slab general part 2 is provided between the hollow stab general part 2 and a thin part 1, in the direction parallel to the direction of communicating a hollow molded member 12 with a precast concrete floor foundation bed 11. Unbonded prestressing steel 40 is disposed at the solid part 3. and floor concrete 6 is placed in the state of the solid part 3 and the hollow slab general part 2 being insulated by a joint 7 and a joint space 7a. After applying prestress to the solid part 3, joint concrete 8 is filled in the joint space 7a for integration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hollow slab structure provided with a thin portion in a part used as a floorboard of a building and a method of constructing the hollow slab structure.

[0002]

2. Description of the Related Art Hollow slabs are medium- and high-rise buildings because there are no beams and the bottom surface is smooth, which facilitates interior work and facility piping work, and saves labor, and has good floor sound insulation. Has been widely used as the floor of apartment houses.

Conventionally, it has been considered difficult to make a part of a hollow slab thinner by simply eliminating the hollow part, except when the thinned part is small, for reasons of structural strength. Currently, when a relatively large thin part is required, a solid part with the same thickness as the hollow slab general part without the hollow part is formed around the part to be thinned and reinforced with reinforcing bars as flat beams. By doing so, the yield strength is increased more than that of a general hollow portion, and the structural yield strength of the hollow slab lost due to the existence of the thin portion is attempted to be compensated. In addition, a method of arranging an unbonded PC steel material over the entire cross section of the hollow slab and introducing prestress to increase the structural yield strength is also performed.

[0004]

Among the parts of the middle- and high-rise condominiums, parts with drainage and sanitary equipment such as bathrooms, toilets, and washrooms need to be installed with the drain pipes drawn horizontally. Requires a floor floor that is larger than the part. As a result, in the case of a building with hollow slabs of equal thickness, the floor finish in that part will be higher than in other parts.

With the advent of an aging society in recent years, it has been desired that the floor surface of a house be smooth and have no difference in height throughout the dwelling unit for the safety of the elderly or the convenience of using a wheelchair. ing. In order to respond to the request, it is possible to increase the floor space of all parts of the dwelling unit, but this is not an economical and realistic solution because it causes a rise in construction costs.

As another method, there is a method in which the hollow slab portion of a portion requiring a high floor slab is formed as a thin portion, and as a result, the floor finishing surface of the house is made smooth over the inside of the dwelling unit. The conventional method of thinning a part of the hollow slab is to eliminate the hollow part around the part to be thinned and make it a solid part, and reinforce this with flat bars as flat beams. Although the structural strength of the hollow slab lost due to the presence of the thin portion can be compensated, the cross-sectional performance hardly increases,
It has a drawback that the edge stress becomes large with respect to the existing bending stress and cracks may occur. Moreover, if the thin portion becomes large, it becomes impossible to supplement the ultimate structural strength.

The other method, that is, the method of introducing prestress over the entire surface of the hollow slab, increases the cost, is not economical, and is not a realistic solution. The present invention is intended to solve the above-mentioned inconvenience that occurs when an attempt is made to make a floor finish surface of a house smooth in the dwelling unit without height difference in a building such as an apartment house having a hollow slab. To aim.

[0008]

In order to solve the above-mentioned problems and to achieve the object, the present invention provides a hollow slab structure comprising a hollow slab general portion and a portion thinner than the hollow slab general portion. , Between the hollow slab general portion and the thin portion, a solid portion having the same thickness as the hollow slab general portion is provided in a direction parallel to the direction in which the hollow portion communicates, and the solid portion is formed of unbonded PC steel material. I was nervous and fixed, and moreover,
Disclosed is a hollow slab structure in which a thin portion is provided in a part, wherein the solid portion and the hollow slab general portion are integrated by being filled with joint concrete.

The present invention further provides a method for constructing a hollow slab comprising a hollow slab general portion and a portion thinner than the hollow slab general portion, wherein the hollow slab general portion is provided between the hollow slab general portion and the thin portion. A solid part is formed in which unbonded PC steel material is arranged in a direction parallel to the communicating direction of the hollow part formed in, and the floor concrete is poured in a state in which the solid part and the hollow slab general part are insulated in the joint space. Also disclosed is a hollow slab construction method in which a thin portion is provided in a part, which is characterized in that the joint is formed by filling the joint with joint concrete after introducing prestress into the solid portion.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a hollow slab structure having a thin portion and a construction method thereof according to the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of an apartment house showing an embodiment of the present invention, in which a drainage pipe is horizontally installed at a portion including a drainage sanitary facility such as a bathroom 51, a toilet 52, a washroom 53, and a kitchen 54. The case of thinning the floor of the part where the above is required will be described in detail below.

FIG. 2 is a plan view showing the floor structure of the plan view of FIG. 1, 1 being a thin portion, 2 a hollow slab general portion, 3
Is a solid part, 60 is a pillar, and 70 is a wall. 3 is a sectional view taken along the line III-III of FIG.
Is a thin-walled precast concrete floor base, and 12 is a hollow forming material such as a foamed resin that is previously attached to the floor base to form a hollow portion. First, the floor base 11 is laid on the supporting pillars 5 and the supporting shog 5a using a crane.

Floor base 11 constituting the hollow slab general portion 2
The hollow forming material 12 and the truss reinforcement 13 are attached to (11a), while the truss reinforcement 23 having a height lower than that of the truss reinforcement 13 is provided on the floor base 11 (11c) constituting the thin portion 1. Is attached. However, as shown in the drawing, the floor base 11a that constitutes the hollow slab general portion 2
A truss reinforcement 23a having the same height as the truss reinforcement 13 is attached to the floor base 11 (11b) arranged close to the floor base 11a at a position close to the floor base 11a. It is said that Further, a thin portion 1 is formed on a part of the floor base 11b.

Floor base 11 constituting the hollow slab general portion 2
The reference character a has a hollow forming material 12 arranged continuously or partially intermittently on the support shovel 5a in a direction perpendicular to the paper surface, and the floor base 11a and the floor base 11 adjacent to the floor base 11a.
They are arranged so as to be separated from b by the joint 7. After laying out the floor bases 11a, 11b, and 11c, the floor base 11
The unbonded PC steel material 40 is wired on the spacers 41, 41 provided in b while maintaining the required number and height according to the design stress.

After that, the main upper end reinforcing bar 15 and the subordinate upper end reinforcing bar 16 are arranged across the hollow slab general portion 2 and the solid portion 3. Further, a main upper end reinforcing bar 25 and a subordinate upper end reinforcing bar 26 are arranged also in a portion forming the thin portion 1. At this time, the upper end reinforcing bars 25, which are main, are arranged so that sufficient fixation can be obtained in the solid portion where the unbonded PC steel material 40 is arranged.

Next, inside the portion of the floor base 11b where the unbonded PC steel material 40 is placed (on the right side in the figure), a spine having a thickness not less than the difference between the thickness H of the hollow slab general portion 2 and the thickness h of the thin portion 1 is exceeded. An anchoring mold material 30 having a height is arranged. Further, the fastening frame members 35, 35 are arranged in the portion where the floor base 11a constituting the hollow slab general portion 2 and the base 11b adjacent thereto are opposed to each other over the entire length in the width direction (direction perpendicular to the paper surface). The height of the retaining frame members 35, 35 is set to be equal to or higher than the height H of the hollow slab general portion 2.

In this state, the floor concrete 6 is placed. When placing the floor concrete 6, the floor base 11a forming the hollow slab general portion 2 is placed up to its design thickness H, and the floor base 11c forming the thin portion 1 is placed. Drive up to the design height h. However, as shown in FIG. 3, the floor base 11 that constitutes the hollow slab general portion 2
In the place where a and the floor base 11b adjacent to it are arranged to face each other, concrete is not placed in the joint space 7a defined by the above-mentioned clasp form materials 35, 35,
Further, concrete is poured in the space regulated by the clasp form material 35 arranged on the floor base 11b side and the clasp form material 30 to the same height as the design thickness H of the hollow slab general portion 2. As a result, there is the unbonded PC steel material 40 in that portion, but there is no hollow portion.
Is molded.

By pouring the floor concrete 6 in this manner, the hollow slab general portion is interposed between the hollow slab general portion 2 and the thin portion 1 in a direction parallel to the communicating direction of the hollow forming material 12. The solid portion 3 having the same thickness as that of the hollow portion 2 is formed, and the solid portion 3 and the hollow slab general portion 2 are insulated from each other by the joint 7 and the joint space 7a.

When a certain strength suitable for introducing prestress to the floor concrete 6 is obtained, the unbonded PC steel material 40 is tensioned and fixed by a usual method. At this time, the prestressing force is introduced only in the cross section of the solid portion 3 and the thin portion 1 and is not affected because the hollow slab general portion 2 is insulated by the joint space 7a. As a result, an effective prestressing force can be introduced into the solid portion 3 requiring reinforcement with a small amount of unbonded PC steel material.

After the introduction of the prestress, the support pillar 5 and the support bar 5a of the slab are removed, and the joint space 8a is filled with the joint concrete 8. This completes the construction of the hollow slab.

[0020]

According to the present invention, the solid portion 3 is provided around the thin portion 1 in a direction parallel to the direction in which the hollow forming bodies 12 are continuous, and the unbonded PC steel material 40 is arranged in the solid portion 3 and solid. The part 3 and the hollow slab general part 2 are connected to the joint space 7a.
Since the prestress is introduced in the state of being insulated with, it is effective only in the solid portion 3 and the thin portion 1, and
Prestress can be introduced economically.

After introducing the prestress, the joint space 7
The whole floor can be integrally formed by filling a with joint concrete 8, and it has sufficient in-plane rigidity that a floor structure is required at the time of an earthquake, and its lower surface has no beam and its upper surface. It is possible to form a strong floor having a thin portion in a part of which is less likely to be cracked.

[Brief description of drawings]

FIG. 1 is a schematic plan view of an apartment house in which an embodiment of the present invention is described.

FIG. 2 is a plan view showing a floor structure of the plan view of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG.

[Explanation of symbols]

1 ... Thin part, 2 ... Hollow slab general part, 3 ... Solid part, 5
... Shoring support pillars, 5a ... Shoring support Daihiki, 6 ... Floor concrete, 7a ... Joint space, 8 ... Joint concrete, 11 ... Precast concrete floor base, 12 ... Hollow forming material, 4
0 ... Unbonded PC steel, 41 ... Spacer supporting unbonded PC steel

Claims (2)

[Claims] 1. A hollow slab structure comprising a hollow slab general portion and a portion thinner than the hollow slab general portion, wherein the hollow slab general portion and the thin portion are parallel to the communicating direction of the hollow portion. Is formed in the same direction as the hollow slab general part, and the unbonded PC is formed in the solid part.
A steel material is tensioned and fixed, and the solid portion and the hollow slab general portion are integrated by being filled with joint concrete, and a hollow slab provided with a thin portion in a part thereof. Construction. 2. A method for constructing a hollow slab comprising a hollow slab general portion and a portion thinner than the hollow slab general portion, wherein the hollow slab general portion is formed between the hollow slab general portion and the thin portion. Forming a solid portion in which an unbonded PC steel material is arranged in a direction parallel to the communicating direction of the hollow portion, and placing the floor concrete in a state in which the solid portion and the hollow slab general portion are insulated in the joint space, A method for constructing a hollow slab with a thin portion in one part, which is characterized by being integrally formed by filling joints with joint concrete after introducing prestress to the solid part.