JPS58120960A - Construction of concrete wall - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of constructing a concrete wall that prevents cracks from occurring in a concrete slab by tensioning PC (prestressed concrete) steel and dispersing anchors at one point.

In the wall of the PC tank, it is possible that the vertical PC steel is placed at the bottom and decreases toward the top due to the member stress.

However, since there was no good way to properly anchor the prestressing steel in the middle of the wall, the common practice was to place the prestressed steel in a continuous manner from the bottom to the top of the concrete wall, and tension it at the top of the concrete wall. There is.

One possible method of securing the prestressed steel material in the middle of the wall is to anchor it by tensioning it when the concrete is poured up to the middle. Cracks tend to occur from the parts.

If such a rack occurs, the anchor etc. will come into direct contact with outside air, moisture, etc., leading to problems such as a decrease in the strength of the tank and a problem of leakage.

The present invention was made to solve these problems.
Construct a concrete wall in which the PC steel material and cable anchor connected by a turnbuckle are buried with the turnbuckle part located in the recess, and then tighten the PC and II materials by jacking in the bent recess. After absorbing the elongation of the PC steel material due to the tension in the turnbuckle,
This invention relates to a method for constructing a concrete wall body, characterized in that the jacks are removed and the recesses are filled with concrete.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1.2 shows an example of the present invention, in which recesses for tensioning the prestressed steel material are formed in advance at predetermined positions in the concrete wall 1. Moreover, inside the concrete 411, a prestressed steel material 4 is buried in advance such that the part Ma where the screw 2 is cut projects into the recess 75i3 by the required length, and a cable anchor 5 is fixed to one end by welding or the like. The other end of the connecting rod 6 has a screw 7 in the opposite direction to the screw 2 and is embedded in the recess 3 in a protruding state so as to face the end of the PCM material 4.

The screw 2 of the PC steel material 4 is provided with a turnbuckle 1° that is screwed into both parts of the screw 2 through the washer 8, and between the circumferential metal 8 and the bottom surface 11 of the recess 3. A hydraulic jack 12 is detachably provided. 13 in the diagram
14 shows concrete for filling the recess 3 after the jack 12 is removed, and 14 shows hydraulic piping.

When constructing a concrete tank by pouring a concrete wall 1, a recess 3 is formed in the concrete wall 1 in advance, and a nut 9 is screwed onto the screw 2 of the PC steel material 4 through a washer 8. , and the PC steel material 4 and the cable anchor 5, which have been connected by screwing the screws 2 and 7 into the turnbuckle 1° by the required amount, are attached to the turnbuckle 10.
The concrete wall 1 is constructed by pouring concrete with the nut 9 placed at the required position in the recess 3.

Next, a jack 1 is installed between the washer 8 and the bottom surface 11 of the recess 3.
2 is equipped, and the jack 12 is operated to extend. Then, the PC steel material 4 is stretched and stretched through the washer 8 and the nut 9, and this stretch is absorbed by rotating the turnbuckle 1o.

When the jack 12 is loosened under tension, the PC steel material 4
The tension force is transmitted to the cable anchor 5 via the turnbuckle 1o. At this time, the cable anchors 5 are dispersed at one anchor point, and there is no stress concentration, so there is no fear of cracks occurring.

After removing the jack 12, the recess 3 is filled with concrete 13.

Thereby, it is possible to tension the PC steel material 4 at any intermediate position of the concrete wall 1 and apply prestress to improve the strength. This method is particularly effective in maintaining the strength of the bottom corners of concrete tanks, where stress is high.

It should be noted that the present invention is not limited only to the above embodiments,
It goes without saying that the present invention can be applied even when the buried position of the PC steel material changes considerably, and that various other changes can be made without departing from the gist of the present invention.

According to the concrete wall construction method of the present invention described above, the following excellent effects can be achieved.

(+) Since prestress can be applied at any intermediate position on the concrete wall, the strength of the entire tank can be improved by applying prestress intensively to the locations where stress occurs.

G) Since it is possible to prevent the occurrence of cracks in the concrete wall by applying prestress, it is possible to eliminate the problem of a reduction in tank strength due to corrosion of anchors etc. due to the occurrence of cracks.

■Problems such as leakage can be prevented by preventing the occurrence of cracks.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view showing an embodiment of the present invention, and FIG. 2 is a view taken along arrows 1--2 in FIG. 1 is a concrete wall, 2 and 7 are screws, 3 is a recess, and 4 is a P
C steel material, 5 is a cable anchor, 8 is a washer, 9 is a nut, 10 is a turnbuckle, 12 is a jack, and 13 is concrete. Patent application Hitoshi Kawajima Harima Heavy Industries Co., Ltd.

Claims (1)

[Claims] 1) Connect the PC steel material and the cable anchor connected by a turnbuckle, with the turnbuckle part located in the recess! Construct a concrete wall to be installed, then tension the PC steel material in the recess with jacks, absorb the elongation of the PC steel material due to the tension with the turnbuckle, remove the jacks, and tighten the concrete wall in the recess. A method of constructing a concrete wall characterized by filling it with.