JPH0752265Y2 - Precast concrete pillars - Google Patents

Description

[Detailed description of the device]

[0001]

This invention relates to a precast concrete column.

[0002]

2. Description of the Related Art As a conventional example of a steel structure in which a rectangular steel pipe column is covered with precast concrete, as shown in FIG.
There is a steel frame structure which is covered with No. 1 and in which the main pillar reinforcement 104 and the reinforcement bar 102 for reinforcement are braided in the concrete 101.

Further, as a conventional example of a concrete-covered steel frame structure in which an elastic material is arranged on the surface of the steel frame, there is Jitsuko Sho 48-9051. As shown in FIG. 6, a steel frame 113 made of H-shaped steel is used. There is a steel-framed concrete member in which the recess is filled with an elastic material, that is, a synthetic resin foam 120, and the outer peripheral surfaces of the steel frame and the synthetic resin foam are covered with concrete 111.

[0004]

[Problems to be Solved by the Invention] In the precast concrete column shown in FIG.
There is a problem that cracks are concentrated on the corners of the concrete covering the outer surface of the concrete rectangular steel pipe column due to the difference in the coefficient of thermal expansion from that of No. 1 and the dry shrinkage of the concrete.

Further, the synthetic resin foam disposed inside the H-shaped steel of the steel concrete member shown in FIG. 6 reduces the volume of the concrete covering the steel frame to reduce the weight of the steel concrete member. It is intended only for the purpose of preventing cracks due to hardening shrinkage of concrete on the concrete surface covering the upper and lower flange surfaces of the steel frame, and there is a problem that there is no effect of preventing cracks. .

Therefore, the present invention has been made in view of the above problems, and provides a precast concrete column capable of preventing cracks generated on the concrete surface due to difference in thermal expansion coefficient between concrete and steel frame and drying shrinkage of concrete. Especially.

[0007]

The present invention has been made in view of the above-mentioned object, and its gist is a precast in which at least two adjacent outer surfaces of a rectangular steel pipe column are surrounded and molded by concrete. In concrete columns,
A precast concrete column is characterized in that an elastic material that absorbs drying shrinkage of concrete and prevents cracking of the concrete surface is interposed at a corner portion of an outer surface in the axial direction of the rectangular steel pipe column surrounded by concrete.

[0008]

In the precast concrete column of the present invention, as described above, the elastic material interposed in the outer surface corner of the rectangular steel pipe column concentrates in the outer surface corner of the rectangular steel pipe column, and the concrete shrinks due to concrete drying and the steel frame and concrete. It absorbs the strain caused by the difference in the coefficient of thermal expansion between and to prevent the occurrence of cracks on the concrete surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a front view of a precast concrete column according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. The precast concrete pillar according to the present invention is a rectangular steel pipe pillar 3
An elastic material 5 adhered to the four corners of the outer surface of the rectangular steel tube column 3 in the axial direction, studs 4a, 4b and 4c welded to the outer circumference of the rectangular steel tube column 3, and a band fixed to the stud. The streaks 2 and the four outer peripheral surfaces of the rectangular steel pipe column 3 are
It is composed of the elastic material 5, the studs 4a, 4b, 4c and the concrete 1 which covers with the stirrup 2.

As the elastic material 5, a material having a hardness that does not deform when pouring concrete, for example, a synthetic resin foam material such as styrene sponge, acrylic sponge, and phenol sponge is suitable. In addition, the studs have a reference numeral 4 at both upper and lower ends of the rectangular steel pipe column 3.
Formed by welding three deformed rebars on each surface as indicated by a and 4c, and welding two deformed rebars 4b between the upper and lower ends at each height of each surface. Formed by. The studs can be formed of round steel or bolts, and the number and interval of each height of each surface of the rectangular steel pipe column 3 can be appropriately changed. The strip 2 is formed of deformed bar or round steel, and is tightly connected to the stud by a binding wire or fixed to the stud by welding.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention, in which one side of the pillar is used as a part which is open from the concrete coating and contacts the wall. The structure of the present embodiment includes a rectangular steel pipe column 13, an elastic material 15 attached to two corners of the rectangular steel pipe column 13 whose two adjacent surfaces are covered with concrete, and the elastic material. The studs 14 respectively welded to the three outer peripheral surfaces of the rectangular steel pipe column 13 including the two corners adhered together, the stirrup 12 fixed to the stud, and the three outer peripheral surface of the rectangular steel pipe column 13 described above.
It is composed of the elastic material 15, the studs 14, and the concrete 11 that covers together with the stirrup 12. Material of elastic material 15, number and material of studs 14, band 1
The material and fixing method of No. 2 are the same as those of the embodiment shown in FIG.

FIG. 4 is a cross-sectional view showing another embodiment of the present invention, in which the two surfaces of the pillar are used as a part which is open from the concrete coating and contacts the wall. The structure of the present embodiment includes a rectangular steel pipe column 23, an elastic material 25 attached to one of the four corners of the rectangular steel pipe column 23 where two adjacent surfaces are covered with concrete, and the elastic material. The studs 24 welded to the two outer peripheral surfaces of the rectangular steel pipe column 23 including the one corner attached thereto, the band 22 fixed to the stud, and the outer peripheral two faces of the rectangular steel pipe column 23.
It is composed of the elastic material 25, the stud 24, and the concrete 21 that covers together with the stirrup 22. Material of elastic material 25, number and material of studs 24, stirrup 2
The material and fixing method of No. 2 are the same as those of the embodiment shown in FIG.

As described above, in order to manufacture the precast concrete columns of the present invention, in the above-mentioned Examples 1 to 3 (FIGS. 2 to 4), first, the required positions on the surface of the rectangular steel pipe columns 3, 13, 23 are firstly formed. The studs are welded to, the braids are knitted, a form is placed around these, and concrete is cast on at least two surfaces of the rectangular steel pipe to finish.

The structure of the present invention shown in FIGS. 1 to 4 is
In the manufacturing process of the precast factory, the inside of the rectangular steel pipe pillar is manufactured in a hollow state, and concrete is filled as needed at the construction site.

[0016]

[Effect of the invention] The precast concrete of the present invention is
It is possible to prevent cracks occurring on the concrete surface due to the difference in thermal expansion coefficient between the pillar concrete and the steel frame and the drying shrinkage of the concrete.

[Brief description of drawings]

FIG. 1 is a front view of an embodiment of a precast concrete column according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view of an embodiment of the precast concrete column of the present invention.

FIG. 4 is a sectional view of an embodiment of the precast concrete column of the present invention.

FIG. 5 is a cross-sectional view showing a conventional example.

FIG. 6 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Concrete 2 Strips 3 Rectangular steel pipe column 4 Stud 5 Elastic material 15 Elastic material 25 Elastic material

Claims (1)

[Scope of utility model registration request] 1. In a precast concrete column in which at least two adjacent outer surfaces of a rectangular steel pipe column are surrounded and molded by concrete, in a corner of an outer surface in the axial direction of the rectangular steel pipe column surrounded by concrete, dry shrinkage of concrete occurs. A precast concrete column characterized by interposing an elastic material for absorbing cracks and preventing the occurrence of cracks on the concrete surface.