JP2729131B2 - Precast concrete column construction method - Google Patents

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 precast concrete column or the like on a concrete foundation.

[0002]

2. Description of the Related Art As a method of constructing a precast concrete column, a construction method as shown in FIG. 4 has been generally used. In this method, a connecting steel bar 30 is protruded from a foundation concrete 20 and a pedestal block 40 is installed. Then, a precast concrete column 50 is erected on the pedestal block 40. In this standing, the precast concrete column 50 is fixed to the foundation concrete 20 by the connecting steel bar 30 while being supported by being lifted by a crane.
Is to give a prestress.

[0003]

However, in the method of constructing a precast concrete column as described above, when the precast concrete column is erected, the precast concrete column is fixed by a connecting steel bar while being supported by a crane or the like. Therefore, there is a problem that work efficiency is extremely poor. The present invention has been made in view of the above-described problems, and an object of the present invention is to efficiently build a precast concrete pillar when building it, and to increase the work efficiency.

[0004]

Means for solving the above-mentioned problem is that concrete steel bars having a connecting steel bar projecting from the upper surface thereof are used.
When a groove is formed on the foundation and mortar is cast in the groove
Precast concrete columns with footings
And insert the connecting steel rod into the insertion hole of the footing.
After the precast concrete pillars are
Before hardening the mortar, connect the connecting steel bar to the footing.
Temporarily fix the precast concrete columns by primary tension,
After the mortar has hardened, the connecting steel rods are secondarily tensioned and fixed .

[0005]

[Action] The molar barrel in the concave groove which is Da設by writing denominated precast concrete column having a footing, can the precast concrete pillar to easily and efficiently denominated included work on concrete foundation by self At the same time, the precast concrete column is temporarily tensioned and temporarily fixed with the connecting steel bar before the mortar is hardened, so that unevenness of the mortar can be adjusted, so that the mounting accuracy can be improved. .

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a construction method of a precast concrete column according to the present invention. FIG. 1 is a cross-sectional view when a precast concrete column of the present invention is built.

First, a foundation concrete 1 is cast at a construction site by a conventional method. This concrete foundation 1
A concave groove 3 having a depth of several tens of cm is formed at a location where the precast concrete column 2 is built, and a mortar 4 whose upper surface is horizontally finished is poured into the bottom surface of the concave groove 3 in a soft state. . The concave groove 3 is slightly larger than the footing 5 of the precast concrete column 2 described later, and a connecting steel rod 6 whose lower end is buried in the foundation concrete 1 projects from the bottom surface.

Then, the precast concrete column 2 is erected on the mortar 4 before hardening in the concave groove 3. The precast concrete column 2 is integrally formed in advance with a length of about two layers of a building, and is pre-stressed by a PC steel wire 2a inserted into a square portion of the column. A projection 2b for projecting a girder is provided at the lower end thereof, and a footing 5 is provided at the lower end thereof.

At the four corners of the footing 5, insertion holes 5a penetrating vertically are formed. The connecting steel bars 6 are inserted into the insertion holes 5a, and the precast concrete columns 2 are self-standing in the concave grooves 3. The footing 5 is provided with an air vent groove 5b. The air vent groove 5b is formed on the bottom surface of the footing 5 radially from the center to the outside, and functions to release air to the outside. The air vent groove 5b is not limited to the radial shape as described above, and may be formed in a lattice shape or a cross shape as shown in FIG. 3 (2).

Next, while the mortar 4 of the concave groove 3 is soft, the connecting steel rod 6 inserted into the insertion hole 5a is primarily tensioned by a tension jack, and a nut 6a is screwed onto the upper end thereof to screw the precast concrete column. 2 is temporarily fixed. This tension is a tension required for the precast concrete column 2 to be self-supporting. If the tension is adjusted while adjusting the unevenness of the upper surface of the mortar, the mortar 4 is pushed out and the peripheral surface of the footing 5 and the inner surface of the concave groove 3 are moved. It is raised in the middle and cured as it is.

After the precast concrete column 2 is temporarily fixed as described above, when the mortar 4 is hardened, the connecting steel bar 6 is secondarily tensioned by a tension jack to be finally fixed. As a result, the precast concrete column 2 and the foundation concrete 1 have a cantilever structure that is mechanically integrated. The girders are supported between the precast concrete columns 2 by supporting the jaws of the girders on the girder receiving projections 2b projecting in advance from the precast concrete columns 2 thus erected.

[0012]

According to the present invention, a concrete bar in which a connecting steel bar projects from the upper surface.
When a groove is formed on the foundation and mortar is cast into the groove
Both are precast concrete with footing
Install the pillar and insert the connecting steel rod into the footing insertion hole.
After inserting and making the precast concrete columns self-supporting,
Before hardening of the mortar, the connecting steel rod is
To temporarily fix precast concrete columns
After the mortar is hardened, the connecting steel bar is fixed with secondary tension.
By doing so, the precast concrete columns can be efficiently built, the construction time can be shortened, and the work efficiency can be increased, because the construction time can be shortened.

By installing a precast concrete column provided with a footing in the concave groove, the precast concrete column can be temporarily fixed and finally fixed in a self-standing state.

Since the mortar is hardened, that is, temporarily tensioned and temporarily fixed in a soft state, the primary tension can be adjusted while adjusting the unevenness of the upper surface of the mortar.
The accuracy of precast concrete pillars can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a precast concrete pillar built on a concrete foundation.

2A is a sectional view taken along line aa of FIG. 1, and FIG.
It is a precast concrete column showing an example.

FIG. 3A is a bottom view of a footing, and FIG. 3B is a bottom view of a footing showing another embodiment.

FIG. 4 is a cross-sectional view of a precast concrete column built by a conventional building method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Concrete foundation 2 Precast concrete column 3 Groove 4 Mortar 5 Footing 6 Steel bar for connection

Claims (3)

(57) [Claims] 1. A concrete concrete in which a connecting steel bar projects from an upper surface.
When a groove is formed on the foundation and mortar is cast into the groove
Both are precast concrete with footing
Install the pillar and insert the connecting steel rod into the footing insertion hole.
After inserting and making the precast concrete columns self-supporting,
Before hardening of the mortar, the connecting steel rod is
To temporarily fix precast concrete columns
After the mortar is hardened, the connecting steel bar is fixed with secondary tension.
The method of building precast concrete columns, characterized by the following: 2. The method according to claim 1, wherein the precast concrete columns are prestressed concrete columns. 3. The method for constructing a precast concrete column according to claim 1, wherein the primary tension is caused by a tension that allows the precast concrete column to stand by itself.