JPH0245962B2 - KONKURIITOP AIRUSEIZOHO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a concrete pile for the purpose of increasing impact force, shear force, axial force, and bending moment by locally thickening concrete columns at arbitrary positions. It is something.

Conventionally, centrifugally formed concrete piles have been recognized to have remarkable strength-enhancing properties, but due to centrifugal forming, the walls inevitably have the same thickness, and it has been considered extremely difficult to locally increase the wall thickness.

However, in this invention, a partition plate is installed in advance in the mold, concrete is poured into the mold in two parts, and centrifugal molding is repeated to form a hollow concrete pile with a predetermined thickness at the appropriate location of the column. It was successful. In this invention, since it is sufficient to install a partition plate in advance in the thick part of the concrete pile, the thick part can be formed not only at the ends but also at the middle part. Therefore, depending on the purpose of use of the concrete pile, the thick portion can be provided at a corresponding position.

That is, to explain this invention with reference to an embodiment, the shaft reinforcement 2 and the screw reinforcement 3 are installed in the centrifugal mold 1, and the screw reinforcement 3 is densely formed over an appropriate length (for example, 3 m) from one end. At the same time, a ring-shaped partition plate 4 is installed inside at right angles to the central axis, and a spacer 5 is temporarily attached to the shaft reinforcement.

Next, an appropriate amount of concrete is poured into the mold, and the mold is rotated to form the first wall 6. Then, by pouring a predetermined amount of concrete into only one side of the mold and rotating the mold again (the mold may continue to rotate even when concrete is being poured), the second wall 7 can be integrally molded. In the above, since the second wall 7 is molded before the first wall 6 is hardened, the two walls are of course integrated. Moreover, since the partition plate is ring-shaped, there is no fear that the first wall 6 will be divided in the axial direction by the partition plate 4.

In the above embodiment, a thick wall portion was provided over an appropriate length from one end of the concrete pile, so only one partition plate 4 was required, but when only the middle portion of the concrete pile is made thick. In this case, it is sufficient to install the partition plates 4, 4a at the same interval as the required length.

Regarding the reinforcing bars, in addition to tightly wrapping the threaded bars as in the above example, it is possible to use measures such as making the threads thicker or making them double wrapped, and if necessary, fixing a partition plate to one end. Reinforcement cage 10 (axial bar 8 and screw bar 9)
It is also conceivable that the interior be equipped with Further, the thick portion is not limited to one location, and may be provided over an appropriate length at each end of the concrete pile, for example. In the figure, 11 is an end plate.

That is, according to the present invention, since a ring-shaped partition plate is provided and concrete is poured multiple times and centrifugally formed, it is possible to easily manufacture concrete piles with locally improved various strengths. Furthermore, since the necessary reinforcing means are provided at the necessary locations, it is possible to obtain a purpose-built concrete pile at a relatively low cost.

[Brief explanation of drawings]

Figure 1 is a partial sectional view of reinforcing bars etc. installed in the mold of this invention, Figure 2 is a partial sectional view of a concrete pile formed according to this invention, and Figure 3 is a concrete pile of another structure. FIG. 4 is a sectional view taken along line AA in FIG. 2. 1... Centrifugal mold, 2... Axial bar, 3... Spiral bar,
4... Partition plate, 6... First wall, 7... Second wall.

Claims (1)

[Claims] 1. Putting a predetermined amount of concrete into a centrifugal mold, rotating the centrifugal mold to form a hollow concrete column with a predetermined thickness, and then installing a partition plate in the centrifugal mold. 1. A method for manufacturing a concrete pile, comprising: pouring an appropriate amount of concrete into a section, and rotating the mold to provide sections with different wall thicknesses in the axial direction. 2. The concrete pile manufacturing method according to claim 1, wherein the partition plate is a ring-shaped plate having approximately the same width as the wall thickness to be formed second time. 3. The concrete pile manufacturing method according to claim 1, wherein reinforcing bars are installed in advance in the thick portions. 4. The concrete pile manufacturing method according to claim 3, wherein the reinforcing bars are large-diameter spiral bars, small-diameter spiral bars with increased density, or double-wound spiral bars.