JP2000186395A - Connecting structure of reinforcement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain sufficient joint strength without changing the shape of reinforcement itself. SOLUTION: This connecting structure of the reinforcements is formed of a mortar filling type reinforced joint, by which the reinforcements are joined by inserting the end sections 3 of the reinforcements 2 into a sleeve 1 while filling the inside of the sleeve with mortar 1a. A plurality of rings 5, in which outside diameters are formed in size larger than the outside diameters of knots at reinforcement end sections inserted into the sleeve, are fitted among the knots 4 at that time. The adjacent rings are fitted preferably while holding the two knots. The height of the crests of the rings is formed in size larger than the height of the crests of the knots by values from 2 mm to 5 mm, and 4-8 rings are fitted at the end sections of the reinforcements.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joint structure for reinforcing bars using a mortar-filled reinforcing joint in precast reinforced concrete construction, and more particularly to a joint structure for reinforcing bars suitable for joining deformed reinforcing bars having a short pitch between nodes.

[0002]

2. Description of the Related Art Conventionally, in precast reinforced concrete construction or the like, a mortar-filled reinforcing joint in which the ends of two rebars are inserted into a sleeve, mortar is filled in the sleeve, and the two rebars are joined. The joint structure of the reinforcing steel by using is widely known. In the joint structure of a reinforcing bar using the mortar-filled reinforcing bar joint, the reinforcing bar inserted into the sleeve is fixed by the hardening force of the mortar.

[0003]

However, in the case of a short-pitch reinforcing bar, the area of the shearing surface of the mortar filled between the nodes of the reinforcing bar is small because the interval between the nodes and the height of the nodes are literally short. For this reason, there is a problem that sufficient shear strength cannot be obtained, and the reinforcing steel comes off from the mortar. Further, in order to solve this problem, Japanese Patent Application Laid-Open No. HEI 10-121657 discloses that the nodes of a reinforcing bar inserted into a sleeve are partially deleted, thereby increasing the node intervals to secure the shear strength of the mortar. An invention relating to a joint structure of a reinforcing bar is disclosed. However, with respect to the joint structure of the reinforcing bar according to Japanese Patent Application Laid-Open No. 10-121657,
A new problem arises in that the shape of the rebar itself must be partially changed.

[0004] The present invention has been made to solve such a problem, and without changing the shape of the reinforcing bar itself,
An object of the present invention is to provide a joint structure of a reinforcing bar capable of obtaining a sufficient joint strength.

[0005]

In order to solve the above-mentioned problems, the present invention employs a method in which an end of a reinforcing bar is inserted into a sleeve and mortar is filled in the sleeve to join the reinforcing bar. In a joint structure of reinforcing bars using a mortar-filled reinforcing bar joint, a plurality of rings whose outer diameters are larger than the outer diameters of the nodes are fitted between the nodes at the ends of the reinforcing bars inserted into the sleeve. By this means, the shear strength of the mortar is increased by increasing the area of the shear surface of the mortar between the reinforcing bar and the integral ring.

[0006] Preferably, adjacent rings are fitted with two joints therebetween. Thereby, the attachment interval of the ring having a large contact area is set to twice or more of the node pitch, and the shear strength of the mortar is greatly increased. For example, the height of the ring
It is formed to be larger than the height of the knot by 2 mm or more and 5 mm or less. For example, 4 or more rings and 8
Fit below.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the invention of a joint structure for reinforcing bars according to the present invention will be described in detail with reference to FIGS. As shown in FIG. 1, two short-pitch deformed reinforcing bars to be joined, for example, end portions 3 of a threaded reinforcing bar 2 are inserted from both ends of an iron reinforcing joint sleeve 1 formed in a cylindrical shape, respectively. The sleeve 1 is filled with a mortar 1a. As shown in FIGS. 1 and 2, at the end 3 of the reinforcing bar 2,
Between the nodes 4, a steel circular ring 5 whose outer diameter is larger than the outer diameter of the node 4 is fitted. As shown in FIG. 2, the ring 5 has an opening 6 in a part thereof.
The outer diameter of the ring 5 is such that when the ring 5 is fitted to the reinforcing bar 2, the peak height is 2 mm or more larger than the peak height of the node 4 and
mm. As shown in FIG. 1, a total of five rings 5 are fitted between the first joints 4 and 4 from the tip of the reinforcing bar 2 and thereafter, with the two joints 4 interposed therebetween. .

As described above, the outer diameter of the ring 5 is larger than the outer diameter of the node 4, and the height of the ring is 2 mm larger than the height of the node 4.
It is formed so as to be greater than or equal to 5 mm or less, and since the adjacent rings 5 are fitted with the two nodes 4 and 4 interposed therebetween, the shearing surface of the mortar 1a between the two adjacent rings 5 is formed. The area increases, and the shear strength of the mortar 1a can be increased.

The reinforcing bars are not necessarily limited to deformed reinforcing bars. In addition, the ring may not be fitted with two nodes as described above, but may be arranged one by one or three or more nodes as necessary. Furthermore, the number of rings is not necessarily limited to five, but should be four or more in order to ensure safety, and eight or less from the viewpoint that the sleeve length is not unnecessarily increased. Is desirable. The shape of the ring is not necessarily limited to a circle, an oval,
Various things such as triangles and squares are conceivable. It is not necessary to provide an opening in the ring, and the ring may not have an opening.

[0010]

As described in detail above, the reinforcing bar joining structure of the present invention is a mortar-filled reinforcing bar for joining the reinforcing bar by inserting the end of the reinforcing bar into the sleeve and filling the mortar into the sleeve. In a joint structure of a reinforcing bar by a joint, a plurality of rings each having an outer diameter larger than the outer diameter of the node are fitted between nodes of an end portion of the reinforcing bar inserted into the sleeve. Therefore, there is an excellent effect that the rebar can be prevented from coming out of the mortar without changing the shape of the rebar itself.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a joint structure of a reinforcing bar according to the present invention.

FIG. 2 is a sectional view taken along the line II-II of FIG.

[Explanation of symbols]

1 sleeve, 1a mortar, 2 rebars, 3 ends,
Section 4, 5 rings, 6 openings

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasuharu Abe 596-36 Yokokura, Oyama-shi, Tochigi F-term in the Technical Development Center, Tokyo Iron and Steel Corporation (reference) 2E164 AA02 BA01 BA02 BA25

Claims (4)

[Claims] A mortar-filled rebar joint for inserting an end (3) of a rebar (2) into a sleeve (1) and filling a mortar (1a) into the sleeve to join the rebar. In the joint structure, a plurality of rings (5) each having an outer diameter larger than the outer diameter of the knot are fitted between the knots (4) at the end of the rebar inserted into the sleeve. Reinforced joint structure. 2. The device according to claim 1, wherein the adjacent rings (5) are fitted with two joints (4) therebetween.
The joint structure of a reinforcing bar according to item 1. 3. The reinforcing bar according to claim 1, wherein the height of the ring (5) is greater than the height of the node (4) by 2 mm or more and 5 mm or less. Joint structure. 4. The ring (5) is connected to the rebar end (3).
The joint structure of a reinforcing bar according to any one of claims 1 to 3, wherein four or more and eight or less pieces are fitted to the joint.