JPH0444728Y2 - - Google Patents

Description

[Detailed Description of the Invention] Purpose of the Invention Industrial Application Field The present invention relates to a spacer that is attached to reinforcing bars and maintains the distance between the formwork and the reinforcing bars to ensure the cover thickness of the reinforcing bars in reinforced concrete.

Prior Art Conventionally, donut-shaped spacers used to ensure the thickness of reinforcing bars in walls, columns, etc. have been integrally molded entirely from plastic. FIG. 8 is a top view of a conventional spacer 20, where 21 is a reinforcing hole,
22 is a notch for mounting, 23 is a protrusion for preventing falling off,
24 is a void. The spacer 20 has a notch 22
It is installed by passing the reinforcing bar through the reinforcing bar and fitting the reinforcing bar into the reinforcing bar hole 21. When the protrusion 23 is attached to the reinforcing bar, it is elastically deformed and guides the reinforcing bar to the reinforcing bar hole 21, but once attached, the reinforcing bar cannot be easily removed from the reinforcing bar hole 21, and the spacer 20 is prevented from falling off. be. The void 24 is provided primarily to save material.

Problems to be solved by the invention Figure 9 is a cross-sectional view of reinforced concrete using a spacer 20, but since the spacer 20 is made of plastic, there are differences in thermal expansion coefficient with concrete, shrinkage of concrete, etc. A gap 25 is created between the spacer 20 and the concrete C. There is a problem in that moisture such as rainwater and groundwater enters the concrete C from the outside through the gap 25, passes through the spacer 20, reaches the reinforcing bars T, and causes corrosion of the reinforcing bars T.

The present invention provides a spacer that is less likely to form a gap between the reinforcing bar and the concrete that causes corrosion.

Means for Solving Problems in the Structure of the Invention The present invention is a donut-shaped spacer having a central reinforcing bar hole and a notch for attachment extending from the outer circumferential direction to the reinforcing bar hole. It consists of an inner piece made of plastic, an engaging groove or groove is formed on the inner periphery of the outer piece, a corresponding engaging groove or groove is formed on the outer periphery of the inner piece, and the inner piece is attached to the outer piece. This spacer is characterized by having a concave and convex engagement with the spacer so as to be rotatable.

The mortar that forms the outer piece may be a normal mortar made by mixing cement, sand, and water, but it is preferable to improve its strength by press-molding a hard-mixed mortar or by using glass fiber reinforced cement. .

In order to make the inner piece rotatable relative to the outer piece,
It is desirable that the outer diameter of the inner piece be slightly smaller than the inner diameter of the outer piece.

Function The spacer of the present invention is made up of a C-shaped outer piece made of mortar and an inner piece made of plastic that are engaged with each other. Concrete and mortar have approximately the same coefficient of thermal expansion and are compatible with each other and adhere well to each other, so it is difficult to form a gap between the outer piece of the spacer and the concrete. Therefore, there is little risk of moisture passing through the spacer and penetrating into the concrete. The inner piece is rotatably engaged with the outer piece by a concave-convex engagement, so after it is attached to the reinforcing bars, rotate the inner piece and insert the reinforcing bar holes into the mounting notches as shown in Figure 2. On the other hand, if the spacer is closed, the spacer attached to the reinforcing bar will not fall off.
Since the inner piece is made of plastic, it is easy to manufacture, and because it is highly elastic, it can be easily attached to the outer piece so as to be rotatable.

Example 1 Figures 1 to 6 relate to the spacer 1 of Example 1, in which Figure 1 is a top view, Figure 2 is a top view showing a state in which the inner piece is rotated to close the reinforcing bar hole, and Figure 3 is a top view. 1
4 is a perspective view of the inner piece, FIG. 5 is a perspective view of a rotating tool for the inner piece, and FIG. 6 is a perspective view of the formwork.

The spacer 1 consists of a C-shaped outer piece 2 made of mortar and an inner piece 4 made of plastic, and has a central reinforcing bar hole 7 and a notch 8 extending from the outer circumferential direction to the reinforcing bar hole 7, as shown in FIG.

The outer piece 2 is formed by pressing mortar made by hardening cement, sand, and water into a C shape. On the inner circumference, there is a third
As shown in the figure, a groove 3 is formed.

As shown in FIG. 4, the inner piece 4 is made of plastic and is formed into a C shape, and a protrusion 5 for engaging with the outer piece 2 is formed on the outer periphery. Two small holes 6 for rotation are provided on each of the upper and lower surfaces, and, for example, a protrusion 10 of a rotating tool 9 as shown in FIG. 5 can be fitted into the small holes 6 and rotated.

As shown in Fig. 3, the outer diameter d of the inner piece is formed approximately 1 mm smaller than the inner diameter D of the outer piece, and the grooves 3 and ridges 5 are tapered. to facilitate rotation.

There are two methods for manufacturing the spacer 1. The first method is to manufacture the outer piece 2 and the inner piece 4 separately, and then attach the inner piece 4 to the outer piece 2 through the notch 8 of the outer piece 2 using the elasticity of the inner piece. . The second is to manufacture the inner piece 4 in advance,
As shown in FIG. 6, the inner piece 4 is attached to the circular part 12 of the keyhole-shaped core of the formwork 11, and mortar is poured in and hardened. In this case, if the diameter of the circular part 12 of the keyhole-shaped core is made slightly larger than the inner diameter of the inner piece 4, the outer diameter of the inner piece 4 will return to be smaller than the inner diameter D of the outer piece 2 after demolding.

Embodiment 2 FIG. 7 is a sectional view of a spacer 13 according to Embodiment 2.

The spacer 13 is a C-shaped outer piece 14 made of mortar.
and a plastic inner piece 16. Outer piece 14
A protruding strip 15 is formed on the inner periphery of the inner piece 16, and a groove 17 is formed on the outer periphery of the inner piece 16, which are engaged with each other in a rotatable manner. A protrusion 18 is formed on the upper and lower surfaces of the inner piece 16, on which a finger is placed during rotation.

Effects of the invention The spacer of the invention consists of an outer piece and an inner piece,
Since the outer piece is made of mortar, it adheres well to the concrete, leaving no gaps between the pieces and the concrete, thereby preventing moisture from entering. The inner piece is rotatably engaged with the outer piece, so after attaching the spacer to the reinforcing bar, rotate the inner piece,
By closing the reinforcing bar hole from the mounting notch, the spacer will not fall off from the reinforcing bar. Since the inner piece is made of plastic, it is easy to process, and its elasticity allows it to be easily rotatably engaged with the outer piece.

[Brief explanation of the drawing]

1 to 6 relate to the spacer 1 of Example 1, FIG. 1 is a top view, FIG.
4 is a perspective view of the inner piece, FIG. 5 is a perspective view of a rotating tool for the inner piece, and FIG. 6 is a perspective view of the formwork. Figure 7 shows spacer 1 as Example 2.
3 is a sectional view of FIG. Figure 8 shows conventional spacer 2
0 and FIG. 9 are cross-sectional views of reinforced concrete using the spacer 20. 1...Spacer, 2...Outer piece, 3...Concave groove,
4...Inner piece, 5...Convex strip, 6...Small hole, 7...Rebar hole, 8...Notch, 9...Rotating tool, 10...Protrusion, 11...Formwork, 12...Round Part, 13...Spacer, 14...Outer piece, 15...Convex strip, 16...
...Inner piece, 17...Concave groove, 18...Protrusion, 20...
Spacer, 21... Rebar hole, 22... Notch,
23...Protrusion, 24...Gap, 25...Gap,
T...Reinforced steel.

Claims (1)

[Scope of utility model registration request] It is a donut-shaped spacer with a central reinforcing bar hole and a notch for installation extending from the outer circumference to the reinforcing bar hole, and consists of a C-shaped outer piece made of mortar and an inner piece made of plastic, and is designed to be engaged with the inner circumference of the outer piece. A spacer characterized in that a concave groove or a convex groove is formed, a corresponding convex groove or a concave groove for engagement is formed on the outer periphery of the inner piece, and the inner piece is rotatably engaged with the outer piece. .