JPH10292557A - Reinforcing bar for concrete product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain decline of strength by a method wherein spacers contacting with the inner surface of a form for concrete and deciding covering depth for concrete are formed of resin by integral molding at least at places near corners of a reinforcing bar main body formed of core material by resin molding in a netlike shape. SOLUTION: A U-shape channel made of a reinforcing bar by bending into a U-shape for being buried in a structure having a specified covering depth of concrete and a channel cover made of a reinforcing bar 5 by forming into a flat plate shape for being buried in a structure having a specified covering depth of concrete are provided. And for the flat plate shaped reinforcing bar 5 for the channel cover, spacers 12-15 contacting with the inner surface of a form for concrete and deciding covering depth of concrete for the reinforcing bar main body 10 are formed of resin by integral molding at the corners of the reinforcing bar main body 10 formed of core materials 7-9 into a netlike shape by resin molding. Then, the spacers 14, 15 are set at the inside of the form so that covering depth of concrete for the reinforcing bar main body 10 can be selected in accordance with the thickness of molding of the channel cover, and the channel cover is formed with concrete cast into the form. Therefore, reinforcing cost can be reduced greatly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to reinforcing bars embedded in concrete products.

[0002]

2. Description of the Related Art For example, a flat plate for a sidewalk, a curb of a pavement, a rainwater basin, a U-shaped groove, a groove cover, a cable trough, a trough cover, etc.
Reinforcing bars are embedded in various concrete products to increase strength.

[0003] When the reinforcing bars are set in the form of the concrete product, the setting position of the reinforcing bars with respect to the inner surface of the form is determined according to a specified dimension, and the concrete covering thickness with the reinforcing bars (in other words, the reinforcing bars). Burial depth)
Needless to say, it is extremely important to ensure that

Conventionally, as shown in FIG. 10, a reinforcing bar 22 formed by welding a reinforcing bar 21 in a mesh shape, for example, at a corner portion, is made of a synthetic resin in order to avoid being exposed to the surface of a concrete product and rusting. Provided spacer 23,
The reinforcing bars 22 can be set at predetermined positions in the concrete formwork.

The spacer 23 includes three types of cross-shaped spacer members 24 of three different lengths, and one spacer member 25 orthogonal to these.
Among the cross-shaped spacer members 24, an elastic fitting portion 26 for elastically fitting the rebar core material 21 to the spacer members 24, 24 having substantially the same length, and a position straddling the rebar core material 21. And a positioning portion 27 for preventing displacement.
The positioning portion 27 is straddled over the rebar core material 21 at the corner of the reinforcing bar 22, and the elastic fitting portion 26 is elastically fitted to the rebar core material 21. 3
The spacer members 24, 24, 25 can be provided in three-dimensional directions.

[0006]

However, the work of setting the plurality of spacers 23 made of synthetic resin on the reinforcing bars 22 is very troublesome, and the individual spacers 23
Are easily displaced in the axial direction of the rebar core material 21 and a spacer 23 made of a synthetic resin, which is structurally complicated separately from the reinforcing bar 22 made of the rebar core material 21, is required. Therefore, there was a problem that the reinforcing cost of the concrete product was high. Furthermore, when hair cracks occur in the concrete product, there is also a problem that the reinforcing core 21 rusts due to the water that has penetrated through the cracks and the strength of the concrete product is reduced.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is based on the fact that the entire reinforcing bar is made of synthetic resin so as to integrally include a spacer for defining the covering thickness of concrete. is there.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A reinforcing bar according to the present invention embedded in a concrete product is applied to an inner surface of a concrete form at least near a corner of a reinforcing bar main body formed by resin-molding a core material into a net shape. It is characterized in that a spacer that is in contact with and defines the concrete covering thickness of the reinforcing bar main body is integrally resin-molded.

According to the present invention having the above-mentioned characteristic structure, there is no need to set a spacer on the reinforcing bar main body, and no displacement of the spacer occurs. Therefore, even if a crack occurs in the concrete product, there is no fear of rusting at all, and a decrease in the strength of the concrete product can be effectively suppressed. In addition, the spacer which was a separate object in the past was resin molded integrally with the reinforcing bar main body,
The cost of reinforcing concrete products can be significantly reduced.

When the concrete product in which the reinforcing bars are to be embedded is a flat plate such as a sidewalk flat plate or a gutter, a reinforcing bar having a reinforcing bar body formed in a single flat plate is used. When the concrete product has a semicircular groove shape,
A reinforcing bar configured in a single flat plate shape is used by being curved. If the concrete product and thus the reinforcing bars are small in shape, it is sufficient to provide the spacer only near the corners of the reinforcing bar body.However, if the reinforcing bars are large in shape, the peripheral edge or surface of the reinforcing bar body is sufficient. A spacer may be appropriately provided at a predetermined position in the inside.

When the concrete product in which the reinforcing bars are to be embedded is an L-shaped curb or a U-shaped groove, two or three flat reinforcing bars are used in combination in an L-shape or a U-shape. However, instead of this, a fragile portion that facilitates bending of the reinforcing bar main body is linearly formed over a predetermined portion of the core material,
By making the flat reinforcing bars deformable into an L-shape or a U-shape, the reinforcing bars can be formed into a single flat plate, but the reinforcing bars can be formed into L-shaped or U-shaped concrete products. It can correspond to molding. At this time, a spacer is integrally formed with a spacer also on the body portion corresponding to the outside of the bending in the vicinity of the fragile portion so that the concrete covering thickness of the bent portion of the reinforcing bar main body can be defined.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a combination of each of a U-shaped groove 1 which is a concrete product and a groove cover 2 thereof.
A reinforcing bar 3 bent into a letter shape is embedded in a concrete structure 4 in a state of having a predetermined concrete covering thickness.
Is embedded in the concrete structure 6 in a state of having a predetermined concrete covering thickness.

The flat reinforcing bar 5 for the lid is shown in FIGS.
As shown in FIG. 4, the corners of the reinforcing bar body 10 formed by resin-molding the core members 7 to 9 are brought into contact with the inner surface of the concrete form 11 to define the concrete covering thickness of the reinforcing bar body 10. The spacers 12 to 15 are integrally formed by resin molding. Reference numeral 16 in the figure denotes a liner formed when the reinforcing bar 5 is formed by resin molding, and its tip is cut off so that the projecting length is shorter than that of a spacer 14 described later.

The reinforcing bar main body 10 has a plurality of long (three in the illustrated example) first core members 7 that are slightly shorter than the length of the groove lid 2 and a width that is slightly longer than the width of the groove lid 2. A plurality of short (six in the illustrated example) short second core members 8 and two core members 9 extending in a diagonal direction of a rectangle formed by four outer core members 7 and 8 are formed in a single plane. The core members 7 and 8 are formed by resin molding in a net shape so as to be integrated with each other, and the ends of the core members 7 and 8 are protruded outward from the outer core members 7 and 8.

The protruding end portions of the outer core members 7, 8 are made different from each other so as to be longer than the protruding end portions of the other core members 7, 8 and, specifically, are reinforced. When the streak body 10 is placed in the concrete form 11 for groove cover, the form 11
The protruding length is set so that the protruding end portion abuts on the inner surface of the first portion, and the protruding end portions having different lengths are used as the first and second spacers 12 and 13. In addition, the first spacer 12
Although the cross-sectional shape of each of the core members 7 to 9 including the above is a convex shape, it can be deformed into a square, a rectangle, a circle, or the like.

The third and fourth spacers 14, 15 are
The first and second spacers 12, 13 are formed with resin by integrally forming the outer corners of the four core members 7, 8 with the projecting lengths different from each other in a direction orthogonal to the projecting direction of the first and second spacers 12, 13. It is easy to remove from the mold,
Its cross-sectional shape is circular.

In the reinforcing bar 5 having the above configuration,
When the groove cover 2 is formed, as shown in FIG.
The reinforcing bar 5 is set up and down in the concrete form 11 so as to select the concrete covering thickness of (i), that is, to select one of the third and fourth spacers 14 and 15; Moreover, by casting concrete in the mold 11, the concrete groove lid 2 in which the reinforcing bar 5 is embedded at a predetermined depth is formed.

Next, regarding the reinforcing bar 3 for the U-shaped groove, the reinforcing bar 3 is different from the reinforcing bar 5 for the lid in terms of its planar size, the number of the core members 7 to 9, and the spacer. Although the arrangement configuration is different, the configuration is the same as the reinforcing bar 5 for the lid. Specifically, as shown in FIG. 5 and FIG. 6, a plurality of (9 in the illustrated example) first core members 7 slightly shorter than the unit length of the U-shaped groove 1 and the U-shaped groove 1 A plurality of (seven in the illustrated example) second core members 8 slightly shorter than the total length of three sides 8
And a total of six core members 9 provided in a diagonal direction by setting three of the second core members 8 as a set, and resin-molded in a net shape so as to be integrated with each other on a single plane. Reinforcing bar body 1
It is set to 0.

The ends of the cores 7, 8 are made to protrude outward from the outer cores 7, 8, and the protruding ends of the outer cores 7, 8 are connected to other cores. 7 and 8, which are longer than the protruding ends of the first and second spacers 1 and 2.
2 and 13, and the third and fourth spacers 1 are arranged in a direction orthogonal to the projecting direction of the spacers 12 and 13.
4 and 15 are integrally resin-molded with the reinforcing bar main body 10, respectively.

Further, the first three cores 7 are sequentially formed into a set, and the pitch between the adjacent cores 7, 7 is made smaller than the pitch of the set of three cores. On the second core material 8 between the core materials 7 and the core material 9 in the diagonal direction, thin-walled weak portions a and b which facilitate bending of the reinforcing bar body 10 to the front side and the back side are formed in a straight line. A spacer 17, which defines the concrete covering thickness of the reinforcing bar main body 10, is also provided at a predetermined portion of the main body portion corresponding to the outside of the bending to the front side and the back side near the fragile portions a, b.
18, like the third and fourth spacers 14 and 15,
Each is integrally molded with the reinforcing bar main body 10 by resin.
The ends of the adjacent core members 8 protrude in the same manner as the first spacer 12, and are used as spacers 19.

In the reinforcing bar 3 having the above configuration,
This can of course be used for forming a flat concrete product such as the groove cover 2 or the like.
7 and 8, the reinforcing bar main body 10 is bent into a U-shape based on the weakened portions a or b of each set (in the example shown, the reinforcing bar main body 10 is
Is bent. 9), this is set in a concrete form 11 as shown in FIG. 9, and concrete is poured into the form 11 to form a concrete U-shaped reinforcing bar 3 embedded at a predetermined height. The groove 1 is formed.

The reinforcing bar main body 1 is based on only one of the two sets of fragile parts a and b among the two sets of fragile parts a and b.
By bending 0 in an L-shape, the reinforcing bars 3 can be used for forming an L-shaped concrete product. Alternatively, the reinforcing bar main body 10 is bent into a crank shape based on one set of the brittle portions a and the other set of the brittle portions b, so that the reinforcing bars 3 are used for forming a crank-shaped concrete product. Can be.

At this time, only one of the fragile portions a and b in the reinforcing bar main body 10 and the spacer 17
Alternatively, the reinforcing bars 3 may be formed exclusively for the U-shaped concrete product, or only one set of the fragile portions a and b and the spacers 17 and 18 may be formed outside the bent portions in the vicinity thereof.
Only the reinforcing bars 3 may be formed exclusively for L-shaped concrete products.

Further, three of the flat reinforcing bars 5 having no fragile portions a and b are combined in a U-shape, or two of them are combined in an L-shape and set on the concrete form 11. It is needless to say that a U-shaped or L-shaped concrete product can also be formed. Further, in the flat reinforcing bar 5 for the groove cover, the spacers 12 to 15 are integrally resin-molded only at the corners of the reinforcing bar main body 10. In such a case, the same applies to the reinforcing bar 3 for the U-shaped groove. However, a spacer may be provided at a predetermined position in the peripheral portion or the inner portion of the reinforcing bar main body 10.

As a synthetic resin material for forming the reinforcing bars 3 and 5, an ABS resin, a polypropylene resin, a nylon resin, a polyamide resin, an FRP resin, or the like is arbitrarily selected.

[0026]

As described above, according to the reinforcing bars of a concrete product according to the present invention, when the net-shaped reinforcing bar body made of a core material is molded with a resin, the concrete covering thickness of the reinforcing bar main body is defined. By molding the spacer integrally with the reinforcing bar body, the cost of reinforcing concrete products can be significantly reduced, and no spacer setting work is required, and the spacer does not shift. Furthermore, even if a crack occurs in the concrete product, since the reinforcing bars are entirely made of a synthetic resin and do not rust, a decrease in the strength of the concrete product can be effectively suppressed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a cross section of a U-shaped groove and a groove cover thereof.

FIG. 2 is a perspective view of a reinforcing groove for a groove cover.

FIG. 3 is a plan view showing a set state of a groove cover reinforcing bar with respect to a mold.

FIG. 4 is a side view showing a setting state of a groove cover reinforcing bar with respect to a mold.

FIG. 5 is a perspective view of a reinforcing groove for a U-shaped groove.

FIG. 6 is a partial perspective view showing a weak portion of a U-shaped groove reinforcing bar.

FIG. 7 is a partial perspective view showing a state where the U-shaped groove reinforcing bar is bent at a weak portion.

FIG. 8 is a perspective view of a reinforcing bar bent in a U-shape at a fragile portion.

FIG. 9 is a side view showing a setting state of a U-shaped groove reinforcing bar with respect to a mold.

FIG. 10 is an explanatory diagram of a conventional example in which a spacer made of a synthetic resin is set on a reinforcing bar made of a reinforcing bar core material.

[Explanation of symbols]

7-9: Core material, 10: Reinforcing bar body, 11: Concrete formwork, 12-15, 17-19: Spacer, a, b ...
Vulnerable part.

Claims (2)

[Claims] 1. A reinforcing bar buried in a concrete product, wherein the reinforcing bar is formed by resin-molding a core material into a mesh shape at least in the vicinity of a corner of the reinforcing bar body and abuts against an inner surface of a concrete formwork. A reinforcing bar for a concrete product, wherein a spacer for defining a concrete covering thickness is formed by integral resin molding. 2. A fragile portion for facilitating the bending of the reinforcing bar main body is formed linearly over a predetermined portion of the core material, and a main body portion corresponding to a bent outside near the fragile portion is also reinforced. The reinforcing bar for a concrete product according to claim 1, wherein a spacer for defining a concrete covering thickness of the bar main body is integrally formed by resin molding.