JPH0949321A - Cast-in-place concrete form and its shaft leg covering pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent pulling-out of a shaft leg and a covering pipe from becoming difficult after concrete is solidified since the pipe is locally crushed in the covering pipe of the shaft leg to fix a frame panel (a concrete panel) of a cast-in-place concrete form to a separator bolt. SOLUTION: A frame panel 6 is sandwiched and fixed by a fastening nut 5 and a receiving member 4 inserted into a stud material 3 installed on the tip of a center bolt 1 through a long nut 2 in a condition of regulating a shaft directional movement, and a covering pipe to prevent sticking of concrete to the stud material 3 is inserted between the long nut 2 and the receiving member 4. In a cast-in-place concrete form constituted in this way, the covering pipe 8 is formed as a soft synthetic resin-made double structure pipe having an inner cylinder 17, an outer cylinder 18 and plural radial ribs 15 to integrally connect both to each other at intervals. Since the stud material 3 enters between the ribs of the crushed covering pipe, the covering pipe is not left as it is in a crushed condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cast-in-place concrete formwork, which has ends of separator bolts (commonly called "separator" or "round separator") used for holding a frame panel (control panel) at a predetermined position. The present invention relates to a structure for fixing a frame panel to a section.

[0002]

2. Description of the Related Art A cast-in-place concrete structure is constructed by constructing a reinforcing bar to be embedded in a concrete body, surrounding it with a frame panel to form a cavity into which the concrete is poured, and then pouring the concrete into the cavity to solidify it. After that, it is constructed by removing the frame panel. Separator bolts are used to keep the assembled frame panels spaced and to receive the pressure of the concrete cast into the cavities.

A concrete structure is, for example, as shown in FIG. 3, in which a stud member 3 is attached to a screw provided at an end portion of a separator bolt 1 via a long nut 2 and is inserted into the stud member. 4 and the fastening nut 5 sandwich and fix the frame panel 6 to hold the position of the frame panel 6 and to hold the pressure of the concrete when the concrete is poured into the cavity 7 by the tensile force of the separator bolt 1. To do. When the concrete in the cavity 7 is solidified, the fastening nut 5 is removed, the frame panel 6 is removed, the stud material 3 is removed from the long nut 2, and the hole after the removal is filled with mortar to prepare the body surface. The separator bolt 1 and the long nut 2 remain embedded in the concrete body.

When concrete adheres to the periphery of the stud material 3, it becomes impossible to remove the stud material 3 after the concrete is solidified. Therefore, the covering pipe 8 for covering the stud material 3 is mounted between the long nut 2 and the receiving member 4. The depth of screwing the stud material 3 into the long nut 2 and the position of the receiving member 4 on the stud material 3 are simultaneously formed at the root portion of the screw when the thread is formed at both ends of the stud material 3 by rolling. It is specified by the flanges 10 and 11 with low height, and therefore, depending on the length of the separator bolt 1,
The interval between the opposing frame panels 6 is determined. In the structure shown in the drawing, a decorative plate 12 made of expanded synthetic resin that forms an uneven pattern is attached to the surface of a concrete frame formed inside the frame panel 6 with nails 13. When such a decorative plate 12 is provided, a through hole 14 having a diameter that allows the covered pipe 8 to be fitted without a gap is provided in a portion to which the separator bolt is attached.

Since the coated pipe 8 needs to be removed after the concrete skeleton has been molded, it is preferable that it is soft, but if it is too soft, it will be crushed by the pressure of the concrete. However, if it is hard, it takes time and effort to remove the covering pipe 8 from the concrete skeleton. Therefore, as shown in FIG. 4, a rib 15 extending radially is provided inside the covered pipe 8, and the tip side of this rib is brought into contact with and supported by the outer diameter of the stud member 3, whereby the covered pipe 8 is crushed. The structure which prevents is proposed. In this structure, the ribs 15 prevent the pipe 8 from being crushed to some extent, so that a softer material can be used as the material of the pipe. If the stud material 3 is extracted and then the pipe 8 is extracted, The pipe 8 can be pulled out relatively easily.

[0006]

However, when a soft coated pipe having such supporting ribs 15 is used, the pipe is locally crushed and the stud material 3 enters between the supporting ribs, and concrete is crushed. It was confirmed that the phenomenon in which it becomes very difficult to extract the stud material 3 and the coated pipe 8 after solidification occurs. Especially when pouring concrete into a formwork, such deformation is likely to occur in the covered pipe of the portion directly exposed to the flow of concrete, and the gravel mixed in the concrete collides, so that the covered pipe 8 is localized. If the stud member 3 is fitted between the support ribs 15 at this time, the pipe may not be restored even if the external force is released, and the concrete may be solidified while the pipe is crushed. Inferred to be the cause.

The present invention has been made on the basis of the discovery of the above new problems, and an object thereof is to provide a simple technical means for solving the problems.

[0008]

According to the first aspect of the present invention,
The frame panel 6 is clamped and fixed by the receiving member 4 and the fastening nut 5 which are inserted in the stud member 3 attached to the tip of the separator bolt 1 via the long nut 2 with the axial movement restricted. In a cast-in-place concrete formwork in which a covering pipe 8 for preventing adhesion of concrete to the stud material 3 is inserted between the nut 2 and the receiving member 4, the covering pipe 8 includes an inner cylinder 17 and an outer cylinder 18. Is a double-structured pipe made of a soft synthetic resin, which is provided with a plurality of radial ribs 15 that are integrally connected to each other at intervals.

A shaft foot covered pipe of a cast-in-place concrete form according to claim 2 is provided with a soft synthetic resin provided with an inner cylinder 17 and an outer cylinder 18 and a plurality of radial ribs 15 which integrally connect the both with an interval. It is made of an extruded product.

[0010]

According to the structure of the present invention described above, even if a large external force is locally applied and the coated pipe 8 is deformed, the radial ribs 15 are only bent, and the presence of the inner cylinder 17 causes
It is impossible for the stud member 3 to be fitted between the deformed radial ribs 15. Therefore, even if the gravel or the like comes into contact with the concrete when the concrete is cast and locally deforms the coated pipe 8, the coated pipe 8 is restored to its original shape and the concrete is solidified thereafter. The concrete does not solidify while it is crushed, and the stud material 3 and the covered pipe 8 do not easily come out after molding.

The coated pipe having the above-mentioned shape can be economically produced by extrusion molding.

[0012]

1 and 2 are diagrams showing an embodiment of the present invention. In this embodiment, the present invention is applied to the conventional structure described with reference to FIG. 3, and only parts different from the conventional structure will be described below.

The covering pipe 8 fitted so as to cover the stud member 3 between the long nut 2 and the receiving member 4 has a double structure including an inner cylinder 17 and an outer cylinder 18, as shown in FIG. In the pipe, the inner cylinder 17 and the outer cylinder 18 have six radial ribs 15.
Are connected at intervals. The inner diameter of the inner cylinder 17 is a diameter that is just fitted to the stud member 3 and is relatively thin. The thickness of the rib 15 should be appropriately determined according to the softness of the resin used, but it is better to make the rib 15 thicker by using a soft resin so that the structure can withstand the pressure of concrete. is there.

The coated pipe 8 is formed by extrusion molding, cut into a required length and fitted to the stud member 3. The covering pipe 8 is made slightly longer than the distance between the receiving member 4 and the long nut 2 when the frame panel 6 is fixed, and is slightly axially compressed between the receiving member 4 and the long nut 2. To be retained. By slightly applying stress in the axial direction of the coated pipe 8 in this way, the adhesion between the coated pipe 8 and the through hole 14 of the decorative plate is improved, and the resistance of the coated pipe 8 to crush is increased.

The procedure of fixing the frame panel 6 by using the stud material with the coated pipe 8 of the present invention and the work of removing the stud material 3 and the coated pipe 8 after solidification of concrete are the same as those of the conventional structure. Done.

[0016]

According to the present invention described above, even when an external force is locally applied to a soft coated pipe attached to a shaft foot, the coated pipe does not remain crushed,
Therefore, it is possible to prevent a situation in which the work of removing the stud material of the shaft foot and the covering pipe from the concrete body after solidification is troublesome.

[Brief description of drawings]

FIG. 1 is a partially enlarged sectional view of a formwork of an embodiment.

FIG. 2 is a perspective view of a coated pipe according to an embodiment.

FIG. 3 is a partially enlarged sectional view of a formwork having a conventional structure.

FIG. 4 is a cross-sectional view of a conventional coated pipe.

[Explanation of symbols]

 1 Separator bolt 2 Long nut 3 Stud material 4 Receiving member 5 Fastening nut 6 Frame panel 8 Covered pipe 15 Support rib 17 Inner cylinder 18 Outer cylinder

Claims (2)

[Claims] 1. A receiving member (4) and a fastening nut which are inserted into a stud member (3) attached to a tip of a separator bolt (1) through a long nut (2) in a state in which axial movement is restricted.
The frame panel (6) is sandwiched and fixed by (5), and the covered pipe (8) that prevents concrete from adhering to the stud material (3) between the long nut (2) and the receiving member (4). In the cast-in-place concrete formwork in which is inserted, the covered pipe (8) and the inner cylinder (17) and the outer cylinder (18) are connected to each other with a plurality of radial ribs (15). A cast-in-place concrete formwork, which is a double-structured pipe made of soft synthetic resin with and. 2. A cast-in-place product made of a soft synthetic resin extruded product having an inner cylinder (17), an outer cylinder (18), and a plurality of radial ribs (15) integrally connecting the inner cylinder (17) and the outer cylinder (18) at intervals. Shaft foot covered pipe for concrete formwork.