JP4968645B2 - Terminal mounting structure for corrosion protection of concrete structures - Google Patents

Description

  The present invention is for the electrical protection of a concrete structure for electrically connecting to a steel material subject to electrical protection in concrete as a reference electrode for power supply or monitoring when performing electrical protection on a steel material such as a reinforcing bar of the concrete structure. The present invention relates to a terminal mounting structure.

  Conventionally, cathodic protection has been carried out on concrete structures exposed to seawater, such as harbor structures. This anti-corrosion technology is a technology that actively utilizes the inherent chemical properties (natural potential difference) of metals to prevent electrical corrosion by combining dissimilar metals with different chemical properties. There are two methods, an electric anode method and an external power supply method, both of which use iron as a cathode (cathode) and use a different metal as an anode (anode).

  The galvanic anode method uses a sacrificial electrode piece, such as zinc, aluminum alloy, or magnesium alloy, which has a higher ionization tendency (low potential) than iron, as an anode, and is attached to the concrete structure. , And the two electrodes are connected to each other to form an electric circuit.When this electric circuit is formed, current flows due to the inherent potential difference of the metal, and an anode such as zinc that has a higher ionization tendency than iron Corrosion of iron, which is an object to be protected, is prevented at the sacrifice of the anode by being ionized and eluted.

  In the external power source system, it is desirable to use a metal having a lower ionization tendency than iron of the corrosion-protected body, for example, a noble metal such as platinum, but since it is expensive, platinum-plated titanium wire, lead alloy, graphite or the like is used as the anode piece. Then, lead wires are drawn out from the object to be protected and the anode piece, connected to a DC power source, and a corrosion current is passed from the power source to prevent corrosion of the object to be protected (for example, Patent Document 1).

  In the construction of these anticorrosion, the lead wire connection to the steel material that is the object of anticorrosion in the concrete structure, that is, the structure of the terminal for the anticorrosion has conventionally been a structure as shown in FIG. This terminal is a lead in which a welding metal material 2 made of a conductive material is welded to a steel material 1 such as a reinforcing bar, and a lead wire connecting terminal portion 3 provided integrally with an end portion of the welding metal material 2 is covered with insulation. One end of the wire 4 is electrically connected by soldering or the like, the connecting portion is waterproofed with an insulating material 5, and the other end of the lead wire 4 is led to the surface of the concrete structure 6.

A pull box 7 is fixed to the surface of the concrete structure by an anchor plug 8 and an anchor bolt 9 screwed into the anchor plug 8, and the tip of the lead wire 4 is electrically connected to the power supply conductor 10 in the pull box 7. A large number of pull boxes 7 are installed at regular intervals, and a conductor insertion tube 11 is installed between the pull boxes 7, and a power supply conductor 10 is passed through the pull box 7, and the lead wire 4 is electrically connected to the lead box 4 in each pull box 7. I am letting.
JP 2001-11666 A

  In the above-described conventional terminal structure for anticorrosion, since the lead wire is embedded in the concrete structure and led out to the surface, there is a problem in the durability of the lead wire itself, and the pull box Since fixing is performed with a plurality of retrofitting anchor plugs and anchor bolts that are screwed into the anchor plugs, the drilling work for inserting the anchor plugs and the fixing work with the bolts require a lot of work. There is a problem that a cross-sectional defect is generated.

  In addition, when an anchor plug attached to the pull box is fixed to the concrete structure, there is a limit to the strength of the concrete in which it is fitted, and the anchor plug and the surrounding concrete that holds it are deteriorated. There was a problem that the pull box might fall off.

  In view of the conventional problems as described above, the present invention has a high strength of the anticorrosion terminal itself and does not cause a drop or disconnection, and can easily attach the terminal itself to the concrete structure with less man-hours. Furthermore, the fixing work of the pull box is easy, and a high mounting strength is obtained, and the purpose is to provide a terminal mounting structure for an anticorrosion of a concrete structure having excellent durability.

  A feature of the invention described in claim 1 for solving the conventional problems as described above and achieving an intended purpose is provided with a pull-box-fixing terminal fitting formed of a conductive metal rod, By fixing one end side of the terminal fitting to the steel material to be protected against corrosion, which is embedded in the concrete structure, the other end side of the terminal fitting protrudes from the surface of the concrete structure. The protruding portion is passed through a bottom plate portion of a box-shaped pull box, and a nut is screwed into a male screw portion provided in the protruding portion to fix the pull box to a concrete structure. The lead wire is electrically connected to the protrusion in the box.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, the terminal fitting includes a rod-shaped member having a male screw on at least one outer periphery, and the male screw rod is bent into an L shape. By welding the peripheral surface of the one end side along the steel material, the terminal metal fitting is fixed to the steel material to be protected against electrical corrosion and electrically connected.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, the terminal fitting is passed through a C-shaped channel washer in a pull box, The pull box is fixed by the nut through a washer.

  According to a fourth aspect of the present invention, in addition to the structure of any one of the first to third aspects, the lead wire is fixed to the terminal fitting by a nut in the pull box. .

    In the present invention, it is provided with a pull-box-fixing terminal fitting formed with a conductive metal rod-like material, and by fixing one end side of the terminal fitting to a steel material to be protected against corrosion, embedded in a concrete structure. Electrically connecting to the steel material to be protected against corrosion, projecting the other end of the terminal fitting from the surface of the concrete structure, projecting the other L-shaped linear portion from the surface of the concrete structure, The fact that the pull box is screwed to the part eliminates the need for drilling anchors for attaching the pull box and damages the lead wires previously embedded as in the past and concrete There is no problem that an excess cross-sectional defect occurs in the structure.

  Further, by allowing the protruding portion of the terminal fitting to penetrate the bottom plate portion of the pull box, and fixing the pull box to the concrete structure by screwing a nut into the male screw portion provided in the protruding portion, The fixing operation is remarkably simplified, and the lead wire can be connected to the terminal fitting by tightening the nut, so that a strong and durable connection state can be maintained.

  Further, in the present invention, the terminal fitting is constituted by a rod-shaped material having a male screw on the outer periphery of at least one end, the male screw rod is bent into an L shape, and the peripheral surface on one end side thereof is along the steel material. By fixing the terminal fitting to the steel material subject to anticorrosion by welding and making an electrical connection, the terminal fitting can be constructed simply by bending all existing screw bolts. The conventional anchor plug and the anchor bolt screwed into this Compared with the case of using the steel, the cost can be remarkably reduced and the fixing strength to the steel material can be increased.

  Further, in the present invention, the terminal fitting is passed through a C-shaped channel washer material in the pull box, and the pull box is fixed by the nut through the washer material, so that the screw fitting length of the nut is increased. The pull box can be shortened, the pull box can be fixed at the center height of the pull box, the lead wire can be connected, and workability is good, and the elasticity of the C-shaped channel washer makes the pull box secure to vibration. It can be.

  Next, preferred embodiments of the present invention will be specifically described with reference to the drawings.

  As shown in FIG. 1 (a), this terminal structure for cathodic protection is a steel material embedded in a concrete structure 20, that is, a lead wire 22 connected to a steel material 21 to be catered to lead to the surface of the structure. A galvanic anode method for preventing corrosion by conducting with an anode 23 made of (base) metal having a higher ionization tendency than iron installed in the surface of the concrete or away from the concrete, and concrete as shown in FIG. A lead wire 22 is connected to a steel material embedded in the structure 20, that is, a steel material 21 to be protected against corrosion, and is led out to the surface of the structure. For example, a platinum-plated titanium wire, lead alloy, graphite or the like is installed as the anode 23, the corrosion-protected body and the anode 23 are connected to a DC power source, and an external power source for supplying a corrosion-proof current from the power source Can be applied to the type of cathodic protection

  2 and 3 show an example of a terminal structure for anticorrosion in the above-described anticorrosion in which the present invention is implemented. In this terminal structure, a terminal metal fitting 25 is used which also serves as a pull box fixing metal fitting formed by forming a stainless steel rod-like material, which is a conductive metal rod-like material, into an L shape. The terminal fitting 25 is formed into an L-shape obtained by bending a male screw rod having a screw formed around the entire length of a rod having a circular cross section at a substantially right angle, that is, an L-shape. One of the linear portions is formed as a steel material connecting portion 26, and the other end side, that is, the other L-shaped linear portion is used as a terminal portion 27 leading to the surface of the structure, and the terminal portion 27 is a pull box fixing portion. It is said.

  The terminal fitting 25 is made to be integrated with the steel material 21 by welding, with the steel material connecting portion 26 being brought into contact with the surface of the steel material 21. The tip of the terminal part 27 arranged at right angles to this is fixed to the surface of the concrete structure 20.

  The pull box 30 is a box that accommodates an electrical connection portion between the power supply lead wire 28 and the terminal portion 27, and includes a rectangular box-shaped box body portion 31 that is open on one surface side, and a lid 32 that opens and closes the opening portion. It is made up of. On both side surfaces of the box main body 31, lead insertion pipes 33, 33 for passing the feeding lead wires 28 are opened to communicate.

  The pull box 30 is provided with a mounting hole 34 through which the terminal portion 27 passes through the bottom plate 31a, and the terminal portion 27 protruding from the surface of the concrete structure is fitted to the terminal portion 27. 27, a washer member 35 is fitted, and a nut 36 is screwed and tightened from the front end side to be fastened to the concrete structure 20.

  The washer member 35 uses a steel C-shaped channel member cut into a short cylindrical shape, with the C-shaped opening 35a facing toward the pull box bottom plate 31a and the bottom plate portion 35b on the opposite side. The terminal part 27 is passed through the opened terminal part insertion hole 37, and the pull box 30 is fixed by screwing and tightening the nut 36 from the tip side.

  Note that the width of the bottom plate portion 35b of the washer member 35 has a length close to or more than twice the diameter of the nut, and when the nut 36 is tightened, the nut is prevented from loosening by elastic deformation of the bottom plate portion. I am doing so.

  In the pull box 30, a ring-shaped bare crimping terminal 38 and a terminal crimping nut 39 are screwed onto the distal end side of the nut 36 for fixing the pull box of the terminal portion 27, and the nut 39 is tightened. A bare crimp terminal 38 is crimped between the nuts 36 and 39 to make electrical connection to the terminal portion 27.

  The lead wire 40 integrated with the bare crimping terminal 38 is electrically connected by soldering to the above-described power supply lead wire 28.

  When the terminal structure for anticorrosion constructed as described above is applied to a new concrete structure, an L-shaped terminal fitting 25 is welded to the steel material 21 before the concrete is placed. After that, it can be installed by placing a concrete.

  When the concrete structure after the concrete is placed, that is, an existing concrete structure, the concrete structure 20 is suspended from the surface, and the steel material 21 is exposed as much as the terminal fitting 25 is welded. The terminal fitting 25 is welded to the steel material 21 that has been made. After that, the terminal fitting 25 is attached by refilling and repairing the suspended portion with concrete.

  In the above example, a male screw is formed on the outer peripheral surface over the entire length of the terminal fitting, but the male screw is long enough to screw a nut from the tip of the terminal part. That's all you need. Moreover, although what was shape | molded in the L shape as a terminal metal fitting is shown, you may use the thing of a linear form and other shapes. Further, the terminal fitting may be fixed to and conductive with the steel material 21 by a clip or other means in addition to being fixed to the steel material 21 by welding. Furthermore, this terminal fitting can be implemented as a reference electrode structure for monitoring in addition to being implemented as a terminal for conducting to a steel material when performing anticorrosion.

  The structure for attaching an anticorrosion terminal constructed in this way is to construct an electric connection terminal for feeding or monitoring by means of a terminal fitting made of a rod-like material, and for anchoring a concrete structure for fixing a pull box. Drilling is not necessary, and the terminal fitting and pull box are not held by concrete, but are held by steel embedded in the interior, so when an external force greater than the concrete strength is applied Also does not fall off easily.

It is a circuit diagram which shows an example of the electric power feeding circuit for anti-corrosion which implements the anti-corrosion of this invention, (a) is a flowing current anode system, (b) has shown the external power supply system. It is sectional drawing which shows an example of the terminal attachment structure for anticorrosion which concerns on this invention. It is the sectional view on the AA line in FIG. It is sectional drawing which shows an example of the conventional terminal attachment structure for anticorrosion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 Concrete structure 21 Steel material to be protected against corrosion 22 Lead wire 23 Anode 25 Terminal fitting 26 Steel material connection portion 27 Terminal portion 28 Lead wire 30 Pull box 31 Box body portion 31a Bottom plate 32 Lid 33 Conductor insertion tube 35 Washer material 35a Opening 35b Bottom plate Part 36 Nut 37 Terminal part insertion hole 38 Bare crimp terminal 39 Nut 40 Lead wire

Claims (4)

  Provided with a pull-box-fixing terminal fitting formed with a conductive metal rod-like material, and fixing the one end side of the terminal fitting to the corrosion-resistant steel material embedded in the concrete structure Electrically connected, the other end of the terminal fitting protrudes from the surface of the concrete structure, the protruding portion penetrates through the bottom plate portion of the box-shaped pull box, and the male screw portion provided in the protruding portion A structure for attaching an anticorrosion terminal for a concrete structure, wherein the pull box is fixed to the concrete structure by screwing a nut, and a lead wire is electrically connected to the protrusion in the pull box.   The terminal fitting is constituted by a rod-shaped material having a male screw on the outer periphery of at least one end, the male screw rod is bent into an L shape, and a circumferential surface on one end side thereof is welded along the steel material, The terminal mounting structure for corrosion protection of a concrete structure according to claim 1, wherein the terminal fitting is fixed to and electrically connected to a steel material to be protected against corrosion.   3. The device according to claim 1, wherein the terminal fitting is passed through a C-shaped channel washer in the pull box, and the pull box is fixed by the nut through the washer. Terminal mounting structure for anti-corrosion of concrete structures in Japan.   The said lead wire is a terminal attachment structure for anticorrosion of a concrete structure according to any one of claims 1 to 3, wherein the lead wire is fixed to a terminal fitting with a nut in the pull box.

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