JPS6110656A - Joint construction method of iron reinforcement - 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 [Field of Industrial Application] The present invention relates to a reinforcing bar joint method. More specifically, the present invention relates to a new reinforcing bar joint method that is easy to implement and highly economical.

In recent years, with the development of large structures such as high-rise buildings and offshore structures, the use of long (large diameter) reinforcing bars as their members has increased, and the long rebars that are bent have the role of supporting the weight, stress, etc. of high-rise structures. Therefore, in addition to the strength of the reinforcing bars themselves, the strength and reliability of the joints that connect them are particularly important.

[Conventional technology]

Traditionally, the method of joining reinforcing bars is to cut male threads on the reinforcing bars,
How to screw this into the Lee Ji sleeve with acid threads cut,
Alternatively, use this method together with epoxy adhesive to prevent screws from loosening (hereinafter referred to as the I/J method)
, methods such as welding or gas pressure welding (hereinafter referred to as welding method), in which reinforcing bars are brought together and heated and fused using a gas burner, are used.

However, the screw method requires too much cost to cut threads into reinforcing bars or sleeves, and the welding method requires special equipment and
There were problems with economy and workability, such as requiring skill and not being easy to implement.

[Purpose of the invention]

The present inventors have conducted intensive studies to develop a new reinforcing bar joint method that is extremely inexpensive and easy to implement compared to conventional methods, and has joint performance with no inferiority in terms of strength compared to conventional methods. As a result, the present invention was achieved.

[Structure of the invention]

That is, the present invention is a reinforcing bar joint method in which the part where two reinforcing bars are butted is surrounded and hardened with an adhesive layer and a layer of metal, plastic, or high-strength fiber.

The reinforcing bar may be a general (commercially available) one, and its diameter and length are specified in JI8G-3112.

As the adhesive, an adhesive having high adhesive strength can be used, which is liquid at the time of use and then hardens to become solid. For example, a two-liquid reaction type urethane resin or epoxy resin type can be used.

It is desirable that these adhesives do not contain compounds that reduce strength such as solvents, but if necessary, talc, silica,
It is also possible to use flame-retardant adhesives containing calcium carbonate, glass fiber refractories, or using bromine-containing epoxy compounds.

As the metal, iron, copper, aluminum or alloys thereof can be used. These shapes can usually be used in the form of a cylinder, a semi-cylindrical shape formed by vertically splitting a cylinder, or a fiber bundle such as a wire mesh or a coil. As the plastic, for example, thermoplastic resins such as hard vinyl chloride resins, ABS resins, acrylic resins, polyester resins, and polyolefin resins, or thermoplastic resins such as epoxy resins, unsaturated polyester resins, and urethane resins can be used. These are preferably reinforced with glass fiber, boron fiber, carbon fiber, aramid fiber, or the like. Plastics are used in round, cylindrical or semi-cylindrical shapes. The cylinder or semi-cylinder in this case may be oval or eccentric. Figure 1 is a side view of a joint using a metal or plastic cylinder, and Figure 2 is a side view of a joint using a metal or plastic cylinder.
is a sectional view thereof. Reference numeral 1.2 indicates two reinforcing bars to be connected, which are joined inside the metal or plastic cylinder 3. The abutting portion 4 is usually located approximately at the center of the cylinder 3. 5 is an adhesive layer filled to tightly fix the reinforcing bar 1.2 and the cylinder 3. Methods for filling the adhesive 5 between the reinforcing bars 11.2 and the cylinder 3 include 1) filling the inside of the cylinder 3 with adhesive in advance and inserting the reinforcing bars 1 and 2 into this, 2) reinforcing bars 1 and 2. .2 are brought together in the cylinder 3, one end is sealed with urethane foam, putty, vinyl tape, etc., and the adhesive is poured from the other end. 3) Insert the adhesive injection port into the cylinder 3. 4) A method of applying adhesive to reinforcing bars 1 and 2 in advance and inserting them into cylinder 3, etc. There are several options available, which can be selected depending on the situation in which the reinforcing bars are connected (vertical or horizontal, etc.).

3 and 4 are a side view and a sectional view of a joint when a metal or plastic semi-cylinder 6 is used.

The structure in this case is almost similar to that when using two cylinders, except that the two semi-cylinders are fixed with an arbitrary number of fixtures 7. The fixture 7 may be any wire, hose band, or the like. Note that the fixing tool is necessary until the adhesive hardens, and after curing, the fixing tool may be removed if the strength is sufficient even if it is not used.

The methods of installation are: 1) Pour an appropriate amount of adhesive into each half cylinder, apply it to the matched reinforcing bars 1.2, and fix it with the fixture 7, 2) Place the two half cylinders first. Fix it with a fixture to make it into a cylindrical shape, and carry out the process in the same way as when using a cylinder as described above. 3) Apply adhesive to the reinforcing bars in advance, and then connect them to form two halves. There are several ways to attach and fix the cylinder.

FIG. 5 is a side view of a joint using high-strength fibers.

To use a layer of high-strength fibers, 1) the high-strength fibers or their woven fabrics are impregnated with an adhesive, semi-cured or B-staged if necessary, and the reinforcing bars 1. 2) Wrapping the fiber or woven fabric around the reinforcing bar a little or two before applying adhesive or press-fitting it, 3) Making a cylinder out of the fiber or woven fabric. In carrying out the invention as described above, it is preferable that the two reinforcing bars be as straight as possible and that their axes do not deviate; It is recommended that the two reinforcing bars be fixed in a vise until hardened. In addition, it is preferable that the axis of the reinforcing bar be located approximately in the center of the surrounding object, such as metal, plastic, or inorganic fiber. A protrusion or the like may be provided. Alternatively, the cylinder or semi-cylinder may be held in a vise or the like.

The adhesive can be cured within a few hours by leaving it for a predetermined curing time, usually one day or night, or by heating it with a heat tape, hair dryer, etc.

The inner diameter of the cylinder or semi-cylinder used above is larger than the outer diameter of the reinforcing bar, and the difference is usually between 0.5 and 20 mm, preferably between 1 and 10 mm. These shapes may be arbitrary, such as circular, oval, polygonal, etc., both on the inside and outside of the cross section. Further, in order to increase the bonding area, the inside of the pipe may have grooves, holes, or protrusions of any shape. Further, as described above, a spacer-like protrusion may be provided to prevent eccentricity of the reinforcing bar. The length of the cylinder or semi-cylinder may be the same as, slightly longer or shorter than the length of the adhesive layer.

The length of the adhesive layer surrounded by the cylinder, semi-cylinder, and fiber layer is
Usually, the diameter is 3 to 30 times, preferably 5 to 15 times, the diameter of the reinforcing bar. In addition, the thickness of the cylinder or semi-cylinder or the thickness of the adhesive layer surrounded by the fiber layer is usually designed so that its strength is greater than the tensile strength of the reinforcing steel, and the inner diameter of these is r.
+ mm, the diameter of the reinforcing bar is r t mm, and the respective tensile stresses are f + and f r K9/mm', and the thickness of the cylinder, etc. The invention is this (
0゜Example 1 Kawasaki Steel Corporation Type 3 No. 2]) 19 reinforcing bars (tensile strength 16
．． 3t) 2 pieces, inner diameter 2.5 cm, length 25
-1 Two reinforcing bars were held together in a vise at the center of an iron cylinder with a wall thickness of 3 mm so that the abutting part was located approximately at the center of the cylinder. Fill the lower end of the gap between the cylinder and the reinforcing bars with about 12 pieces of putty to seal it. After fixing the reinforcing bars so that the axis of the reinforcing bars is located approximately in the center of the cylinder, insert a piece of putty made by Sanyo Chemical Industries, Ltd. from the top. After filling the pieces with epoxy resin adhesive (Unibore BP-1403) so that the axis of the reinforcing bar was located in the center of the cylinder, heat tape was wrapped around the outside of the cylinder and cured at about 80°C for 1 hour.

When the tensile properties of this reinforcing bar were tested according to JISK-2201, the tensile strength was 164 t, and the stress-strain curve was the same as that at the time of fracture of the base material.

Additionally, the rupture occurred at the unreinforced part of the building, and there was no abnormality in the joint.

Example 2 In Example 1, the iron pipe was replaced with a glass fiber-reinforced epoxy resin pipe (see below) with an inner diameter of 25(1), a length of 13 cm, and a wall thickness of 8 mm, and reinforcing bars were connected in the same manner.

When a tensile test was conducted, the joint part (there was no difference 7', and the fracture occurred at a reinforcing bar other than the joint.The tensile strength was 160t, and the stress-strain curve was (311: @ equivalent to the time of fracture) .

The glass fiber-reinforced epoxy resin vibrator used above was prepared in the following manner. Kanebo cut into 13cm (medium) pieces (
Approximately 100 g of a two-component mixture of Galanukross KS-47032mG epoxy adhesive Unibon EP-1403 manufactured by Co., Ltd.
Impregnated. The diameter of this glass fiber coated with a mold release agent is 2.
It was wound around the mold on the third side and cured at 80° C. for 1 hour to obtain a glass fiber reinforced epoxy resin pipe.

〔Effect of the invention〕

Compared to conventional threaded joints, welding, and gas pressure welding, the joints of the present invention do not require expensive materials, transportation of welding machines, or skilled technicians, can be performed by anyone, and have low material costs. has advantages.

In addition, the performance of the joint is in no way inferior to that of conventional methods.
This can fully guarantee the reliability of long (large diameter) reinforcing bars.

[Brief explanation of the drawing]

Figure 1.3. , 5 is a side view of the reinforcing bar joint of the present invention, Figure 2.4
is a cross-sectional view of a reinforcing bar joint. Edition 5

Claims (1)

[Scope of Claim] A reinforcing bar joint method in which a part where one or two reinforcing bars are butted is surrounded and hardened with an adhesive layer and a layer of metal, plastic, or high-strength fiber. 2. The construction method according to claim 1, wherein the adhesive layer is made of epoxy resin. 3. The method according to claim 1 or 2, wherein the layer of metal, plastic, or high-strength fiber is formed by molding the material into a cylindrical shape. 4. Claim 1 or 2, in which the layer of metal, plastic or high-strength fiber is formed into a semi-cylindrical shape.
The construction method described in section.