JP3064943U - Composite floors and precast concrete boards for composite floors - Google Patents

Abstract

(57) [Problem] To provide a composite floor with an increased allowable shear stress at a joint surface between a precast concrete plate and concrete. SOLUTION: At least a precast concrete plate 11 laid between beams and concrete 16 integrally cast on the precast concrete plate 11 are provided.
A composite floor 13 in which a plurality of cotters 12 are formed, each cotter 12 is formed in a large size, and the total area of the cotters 12 occupies 40 to 60% of the surface area of the precast concrete plate 11. Thirteen.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a composite floor constructed by casting concrete on the upper surface of a precast concrete plate suspended between beams and the like, and a precast concrete plate for a composite floor.

[0002]

[Prior art]

 Conventionally, on composite floors, multiple cotters are provided on the surface of the precast concrete plate to prevent shear displacement at the joint surface between the precast concrete plate and the concrete slab cast in place, and the concrete at the joint surface is Strengthening integration with the slab.

As a precast concrete plate provided with the cotter described above, for example, a precast concrete plate for a composite floor disclosed in Japanese Patent Publication No. 63-47861 is known as a conventional example.

As shown in FIG. 5, the precast concrete plate of this conventional example has a plurality of hollow holes 2, 2,... A plurality of PC steel wires 3, 3,... Are buried under the hollow holes 2, 2,.

[0005] On the upper surface of the precast concrete plate 1, a large number of cotters 4, 4,... As shown in FIG. 6, each cotter 4 is formed in a tapered shape in which the diameter of the bottom portion is reduced from the upper portion of the vertical inner wall. The height h is 5 mm, and the angle α of the tapered surface is 45 degrees.

[0006]

[Problem to be Solved by the Invention] In the precast concrete plate 1 used for the composite floor of the conventional example, since the individual cotters 4 are formed in a small shape by being depressed into short columns, a concrete slab to be cast is used. The contact area was small, that is, the allowable shear stress at the joint surface was small.

Therefore, in the precast concrete plate 1 used for the composite floor in the conventional example, the allowable shear stress on the joint surface is increased by increasing the area of the cotter, and for example, in a warehouse having a particularly large loading load. There is a problem that must be solved in order to be applicable to floors and floors on which large vehicles run.

[0008]

[Means for Solving the Problems]

 As a specific means for solving the problems of the conventional example, the present invention has at least a precast concrete plate laid between beams and concrete integrally cast on the precast concrete plate. A composite floor having a plurality of cotters formed on the surface of the slab, each cotter being formed in a large format, and having a total area of 40 to 60% of the surface area of the precast concrete slab. It is intended to provide a composite floor characterized by the above.

Further, the present invention is a precast concrete plate formed integrally with concrete to construct a composite floor, and a plurality of large-sized cotters are provided on the surface of the precast concrete plate; The present invention provides a precast concrete plate for a composite floor, wherein the total area of the cotter occupies 40 to 60% of the surface area of the precast concrete plate.

In the composite floor according to the present invention and the precast concrete plate for the composite floor, the contact area with the concrete slab is increased due to the increase of the area of the cotter as compared with the conventional one, that is, The allowable shear stress at the joint surface increases. In other words, the present invention can be applied to a floor of a warehouse having a particularly large loading load or a floor on which a large vehicle runs.

[0011]

[Embodiment of the invention]

 Next, an embodiment of the present invention will be described with reference to the drawings. Note that, for easy understanding, the same reference numerals are given to the portions described in the section of the related art for the description.

First, in FIG. 1, reference numeral 11 denotes a precast concrete plate for a composite floor, and the precast concrete plate 11 is formed in a plate shape. The length is about 1 m, the length in the longitudinal direction is about 6 m, and the plate thickness is about 150 mm.

A plurality of hollow holes 2, 2,... Are opened through the inside of the thickness of the precast concrete plate 11 in the longitudinal direction, and a lower portion of the hollow holes 2, 2,. (Or upper and lower positions), a plurality of PC steel wires 3, 3,...

As shown in FIG. 2, on the upper surface of the precast concrete plate 11, a plurality of large-sized cotters 12 which are depressed into a flat rectangular shape are provided. The cotters 12 adjacent to each other are arranged alternately and continuously. Further, the total area of the cotter 12 is provided so as to occupy 40 to 60% of the surface area of the precast concrete plate 11.

As an example, the size of each cotter 12 is such that the length c of the long side is about 90 mm, the length of the short side is about 26 mm, and the depth d is about 4 mm as shown in FIG. It is about 9 mm. Also, the cotters 12 adjacent to the long side are disposed at intervals of about 17 mm, and the cotters 12 adjacent to the short side are disposed at intervals of about 15 mm.

Next, FIG. 4 shows a composite bed 13 of the present invention. The composite floor 13 has a plurality of the above-mentioned precast concrete plates 11 supported on a steel beam 14 (or a concrete beam), and a reinforcing bar 15 is arranged thereon. 16 and was constructed. Reference numeral 17 in the drawing denotes a headed stud spot-welded to the steel beam 14 and is installed for the purpose of integrating the steel beam 14 and the cast-in-place concrete 16.

The composite floor 13 and the precast concrete plate 11 for the composite floor 13 configured as described above increase the area of each cotter 12 as compared with the conventional cotter 12 and increase the total number of cotters 12. By increasing the area, the contact surface with the cast-in-place concrete 16 is increased, that is, the allowable shear stress at the joint surface is increased, so that the floor of a warehouse with a particularly large loading load or the floor on which a large vehicle runs is used. It can also be applied to

[0018]

[Effect of the invention]

 As described above, the composite floor according to the present invention has at least a precast concrete plate laid between beams and concrete integrally cast on the precast concrete plate. A composite floor having a plurality of cotters formed on its surface, each cotter being formed in a large format, and having a total area of 40 to 60% of the surface area of the precast concrete plate. As a result, the contact area with the concrete slab is increased by increasing the area of the cotter as compared with the conventional one, and the allowable shear stress at the joint surface is increased. In other words, there is an excellent effect that the composite floor can be applied to a floor of a warehouse having a particularly large load and a floor on which a large vehicle runs.

Further, the precast concrete plate for composite floor according to the present invention is a precast concrete plate integrally formed with concrete to construct a composite floor, and a large-sized precast concrete plate is formed on the surface of the precast concrete plate. A plurality of cotters are provided, and the total area of the cotters occupies 40 to 60% of the surface area of the precast concrete plate. The contact surface becomes larger, and the allowable shear stress at the joint surface increases. Therefore, the present invention has an excellent effect that it can be used for a floor of a warehouse having a particularly large load and a floor on which a large vehicle runs.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a part of a precast concrete plate for a composite floor according to the present invention.

FIG. 2 is a plan view showing a part of a precast concrete plate.

FIG. 3 is a sectional view of a cotter.

FIG. 4 is a cross-sectional view showing a state where the composite floor according to the present invention is laid.

FIG. 5 is a perspective view showing a part of a precast concrete plate according to a conventional example.

FIG. 6 is an enlarged vertical sectional view of a cotter according to a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 precast concrete plate 2 hollow hole 3 PC steel wire 4 cotter 11 precast concrete plate 12 cotter 13 composite floor 14 steel beam 15 steel bar 16 concrete 17 stud with head

Claims (2)

[Utility model registration claims] At least a precast concrete plate laid between beams and concrete integrally cast on the precast concrete plate, and a plurality of cotters are formed on a surface of the precast concrete plate. A composite floor, wherein each cotter is formed in a large format and the total area of the cotter occupies 40-60% of the surface area of the precast concrete slab. 2. A precast concrete plate formed integrally with concrete to form a composite floor, wherein a plurality of large-sized cotters are provided on a surface of the precast concrete plate, and a total area of the cotter is provided. Is 40 to 60 of the surface area of the precast concrete plate.
% Precast concrete board for composite floors.