JP7282515B2 - Carbon fiber material with monitoring function - Google Patents

Description

The present invention relates to steel bridges, steel girders and beams in steel buildings, steel structures such as steel members of mechanical devices, concrete structures such as prestressed concrete bridges, etc. (hereinafter referred to as steel structures (including concrete structures, etc.), it functions as a reinforcing material for repairing and reinforcing structures (hereinafter simply referred to as "reinforcement"), In addition, detection that can monitor the occurrence and progress of fatigue cracks in reinforced locations, or the separation of reinforcing materials from structures, and grasp the state of reinforcement such as damage and deformation of reinforced structures. It relates to a carbon fiber material with a monitoring function that has a function as a material. Furthermore, the present invention can be used as a structural member such as a housing member for aircraft, machinery, etc., and a carbon fiber with a monitoring function that can monitor the progress of fatigue cracks and corrosion deterioration of members. It is about materials.

For example, in a steel bridge, which is a steel structure, many damages due to fatigue, corrosion, etc. are found in girders, beams, and other steel members of the steel bridge. Also, in order to cope with the increased load, there are increasing cases where reinforcement of steel members is required. Once a fatigue crack occurs in a steel member, the crack progresses gradually, and there is a possibility that the steel member may break.

Therefore, in Patent Document 1, a plurality of continuous carbon fiber reinforced plastic (CFRP) wires, in which carbon fibers are impregnated with a matrix resin and cured, are arranged in a thread shape in the longitudinal direction, and an adhesive is applied to the surface of the steel structure. A carbon fiber reinforced plastic wire sheet for reinforcing a steel structure by adhering with a tack, and in particular, a predetermined carbon fiber reinforced plastic wire among the carbon fiber reinforced plastic wires has terminal electrodes at both ends of the wire. Disclosed is a carbon fiber reinforced plastic wire sheet that is attached and used as a carbon fiber reinforced plastic wire sensor capable of measuring the electrical resistance of the wire.

Furthermore, Patent Document 1 discloses a steel structure that detects the reinforcement state of a reinforced steel structure by measuring the electric resistance of the carbon fiber reinforced plastic wire rod sensor of the carbon fiber reinforced plastic wire rod sheet bonded to the steel structure. A method of reinforcing a structure is disclosed. According to this reinforcement method, when the electrical resistance value of the carbon fiber reinforced plastic wire rod sensor is R, the initial resistance value is Ro, and Rcr represented by the following formula is the electrical resistance change rate,
Rcr=(R−Ro)/Ro
(1) Measure the electrical resistance value (R) of the carbon fiber reinforced plastic wire rod sensor, and when a region where the electrical resistance change rate (Rcr) is increasing occurs, the region where the electrical resistance change rate is increasing Determining that either the corresponding reinforced steel structure has cracked or has progressed, or that corrosion deterioration has progressed in the steel structure, and
(2) Measure the electrical resistance value (R) of the carbon fiber reinforced plastic wire rod sensor, and when an area where the electrical resistance change rate (Rcr) is decreasing occurs, the area where the electrical resistance change rate is decreasing determine that delamination of the fiber sheet has occurred from the steel structure reinforced by
I'm doing it.

In addition, Non-Patent Document 1 describes that in concrete structures such as prestressed concrete bridges, it is adopted as a conventional reinforcement method for PC girders based on the recognition that PC steel materials corrode and break due to poor grout filling. In the tension reinforcement method using the carbon fiber reinforced reinforcing material (CFRP plate) that has been developed, the function of the reinforcing tendon and the PC girder due to the fracture of the PC steel material for the CFRP plate tendon as the reinforcing material of the structure. It is described that it also functions as a monitoring material for deformation monitoring.

Here, Non-Patent Document 1 applies copper plating to both ends of the CFRP plate tendon to form electrodes, measures the electrical resistance of the CFRP plate tendon, and monitors changes in the electrical resistance value of the CFRP plate tendon. It teaches that it is possible to detect breakage of PC steel materials by

JP 2016-186209 A

"Study on Deformation Monitoring of PC Girder due to PC Steel Fracture Using Carbon Fiber Plate Tendon", Concrete Engineering Annual Proceedings, Vol. 39, No. 2, 2017, pp. 1273-1278

As described above, according to the method described in Patent Document 1, the steel structure is effectively reinforced, and fatigue cracks occur, crack progress, and corrosion deterioration progresses in the reinforced portion at the time of reinforcement. It is possible to detect the reinforcing state of the steel structure by monitoring the peeling of the reinforcing sheet.

However, in the terminal electrode of the carbon fiber reinforced plastic wire sensor of Patent Document 1, specifically, both ends of the carbon fiber reinforced plastic wire project slightly more than other carbon fiber reinforced plastic wires, and the surfaces of the projecting ends are to remove the resin on the impregnated surface, then attach the protruding end by winding an electrical wire, then apply a conductive adhesive to the terminal part where the wire is wound, and cure It is made by letting Such work is complicated, and further improvement is desired.

Further, in the carbon fiber reinforced plastic wire sensor described in Patent Document 1, the initial resistance value Ro is larger than the initial resistance theoretical value Roth represented by the following formula (2) due to poor adhesion of the terminal electrode to the carbon fiber reinforced plastic wire. In some cases, the resistance measurement value is not stable, and further improvement is desired as a detection material for monitoring.
Roth=ρ×(L/As) (2)
Roth: initial resistance theoretical value ρ: volume resistivity L: length of electrical resistance measurement section As: cross-sectional area per carbon fiber reinforced plastic wire rod sensor

On the other hand, in Non-Patent Document 1, according to the results of research experiments by the present inventors, electrodes are formed by applying copper plating to both ends of the CFRP plate tendon. That is, the problem that the initial resistance value may increase due to poor adhesion of the terminal electrode to the CFRP plate tendon has been resolved.

However, according to the results of further research by the present inventors, the terminal electrode configuration formed by copper plating described in Non-Patent Document 1 has a problem that the initial electrical resistance value increases over time. I found out that I do. This is thought to be due to the corrosion resistance of the copper plating being a problem, and the contact resistance between the CFRP plate tendon, which is a carbon fiber reinforced resin material, and the copper plating change over time. Therefore, as described in Non-Patent Document 1, with respect to the CFRP plate tendon as a reinforcing material for structures, it has a function of a reinforcing tendon and a monitoring material for monitoring deformation of the PC girder due to fracture of the PC steel material. It was found that it is necessary to further improve the electrode structure of the carbon fiber reinforced resin material in order to combine the functions. In other words, it has been found that it is important to solve the adhesion failure of the terminal electrode to the CFRP plate that occurs over time, that is, to follow the elongation of the CFRP plate without peeling off the electrode plating that constitutes the terminal electrode. rice field.

Therefore, as a result of conducting more research experiments on metal plating electrodes for carbon fiber reinforced resin materials, by specifying the material and physical properties of the metal plating for electrodes, the plating layer peels off against the elongation of the CFRP plate. It is possible to keep the initial electrical resistance constant over time by solving the problem of the initial electrical resistance value fluctuation of the carbon fiber reinforced resin material possessed by Patent Document 1 and Non-Patent Document 1. Found it. In particular, it is important to have toughness, yield strength, wear resistance, etc. that can compete with CFRP plates. It has been found that the physical properties of the plating layer, such as tensile strength, elongation, hardness, and electrodeposition stress, must be specified within specific ranges.

The present invention is based on such novel findings by the present inventors.

The object of the present invention is to have a function as a reinforcing material for repair and reinforcement of steel structures, concrete structures, etc., and to accurately monitor the reinforcement state such as damage and deformation of the reinforced structure over a long period of time. It is an object of the present invention to provide a carbon fiber material with a monitoring function, which also has a function as a monitoring material capable of stably grasping the

Another object of the present invention is that it can be used as a structural member such as a lightweight, high-strength housing member used in aircraft, machinery, etc., and it can be used for a long period of time to prevent fatigue cracks and corrosion deterioration of the member. To provide a carbon fiber material with a monitoring function capable of stably monitoring over a long period of time with high accuracy.

The above objects are achieved by a carbon fiber material with a monitoring function according to the present invention. In summary, the first aspect of the present invention is a carbon fiber with a monitoring function having a carbon fiber material that can be bonded to the surface of a structure with an adhesive to reinforce the structure, or can be used as a structural member. material,
Metal-plated electrodes for measuring the electrical resistance of the carbon fiber material are provided at least two locations apart from each other on the carbon fiber material, and the metal-plated electrodes are:
or
(b) A nickel alloy plating layer containing 25 wt% or more and less than 100 wt% of nickel as a main component, and the balance of additives and inevitable impurities, wherein the mixing ratio of the additives to the nickel is changed. A multi-layer nickel alloy plating layer with a laminated structure in which the
has
The single-layer nickel alloy plating layer having the single-layer structure has an electrodeposition stress in the range of −15 kg/mm ² to +15 kg/mm ² ,
The multi-layered nickel alloy plating layer having the laminated structure has an electrodeposition stress obtained by combining the electrodeposition stresses of the nickel alloy plating layers having the laminated structure, and the combined electrodeposition stress is - within the range of 15 kg/mm ² to +15 kg/mm ² ;
The single-layer nickel alloy plating layer and the multiple-layer nickel alloy plating layer have a tensile strength of 25 to 90 kg/mm ² , an elongation of 3% or more, and an Hv hardness of 150 to 650.
It is a carbon fiber material with a monitoring function characterized by

According to an embodiment of the first invention, the additive is one or more selected from the group consisting of phosphorus, tungsten, cobalt, iron and sulfur.

A second aspect of the present invention is a carbon fiber material with a monitoring function that can be used as a structural member by adhering to the surface of a structure with an adhesive to reinforce the structure. ,
Metal-plated electrodes for measuring the electrical resistance of the carbon fiber material are provided at least two locations apart from each other on the carbon fiber material, and the metal-plated electrodes are:
(a) a single-layer cobalt alloy plating layer having a single-layer structure containing 25 wt% or more and less than 100 wt% of cobalt as a main component, and the balance of additives and inevitable impurities; or
(b) A cobalt alloy plating layer containing 25 wt% or more and less than 100 wt% of cobalt as a main component, and the balance of additives and unavoidable impurities, wherein the mixing ratio of the additives to the cobalt is changed. A multilayer cobalt alloy plating layer with a laminated structure in which the
has
The single-layer cobalt alloy plating layer having the single-layer structure has an electrodeposition stress in the range of −15 kg/mm ² to +15 kg/mm ² ,
The multilayer cobalt alloy plating layer having the laminated structure has an electrodeposition stress obtained by combining the electrodeposition stresses of the respective cobalt alloy plating layers having the laminated structure, and the combined electrodeposition stress is - within the range of 15 kg/mm ² to +15 kg/mm ² ;
The single layer cobalt alloy plating layer and the multiple layers cobalt alloy plating layer have a tensile strength of 25 to 90 kg/mm ² , an elongation of 3% or more, and an Hv hardness of 150 to 650.
It is a carbon fiber material with a monitoring function characterized by

According to an embodiment of the second invention, the additive is one or more selected from the group consisting of phosphorus, tungsten, nickel, iron and sulfur.

A third aspect of the present invention is a carbon fiber material with a monitoring function that can be used as a structural member by adhering to the surface of the structure with an adhesive to reinforce the structure. ,
Metal-plated electrodes for measuring the electrical resistance of the carbon fiber material are provided at at least two locations on the carbon fiber material that are spaced apart from each other;
The metal plated electrode has a zinc alloy plated layer containing 51 wt% or more and less than 100 wt% of zinc as a main component, and the balance additives and inevitable impurities,
The zinc alloy plating layer has a tensile strength of 20 to 250 kg/mm ² , an elongation of 3% or more, and an Hv hardness of 100 to 250.
It is a carbon fiber material with a monitoring function characterized by

According to an embodiment of the third aspect of the present invention, the zinc alloy plated layer has an electrodeposition stress in the range of -15 kg/mm ² to +15 kg/mm ² .

According to another embodiment of the third invention, the additive is nickel.

According to other embodiments of the first, second and third aspects of the present invention, the metal plated electrode has a gold plated layer or a platinum plated layer as the outermost surface layer metal plated layer, or The metal plating electrode has a conductive DLC layer as the outermost layer.

According to the other embodiments of the first, second, and third aspects of the present invention, the carbon fiber material is a carbon fiber sheet formed by aligning carbon fibers in one direction and impregnating the carbon fiber sheet with a matrix resin. , a cured carbon fiber reinforced composite material, or the carbon fiber material is a carbon fiber impregnated with a matrix resin, and a plurality of continuous carbon fiber reinforced plastic wires that are cured are arranged in a blind shape in the longitudinal direction. Is it a carbon fiber strand sheet that is aligned and formed into a sheet form, or is the carbon fiber material a carbon fiber material impregnated with a matrix resin, and is a continuous carbon fiber reinforced plastic rod with a substantially cross-sectional shape that is cured? Alternatively, it is a carbon fiber reinforced plastic plate having a substantially rectangular cross section, or the carbon fiber material is formed by laminating a plurality of string-like carbon fibers in which carbon fibers are arranged in one direction and impregnated with a matrix resin and cured. It is a carbon fiber grid material formed by arranging vertical reinforcing bars and horizontal reinforcing bars in a grid pattern.

According to the other embodiments of the first, second and third aspects of the present invention, the electrode-forming portion in which the metal-plated electrode is formed at the end of the carbon fiber material has an inclined surface inclined in the thickness direction. and the electrode forming portion in which the metal plating electrode is formed on the inclined surface or the metal plating electrode is formed at the end of the carbon fiber material has a curved shape with a curved end, The metal plating electrode is formed on the curved surface.

According to other embodiments of the first, second, and third aspects of the present invention, the carbon fibers are pitch-based or PAN-based carbon fibers,
The matrix resin is a thermosetting resin or a thermoplastic resin, and the thermosetting resin is a room temperature or thermosetting epoxy resin, epoxy acrylate resin, acrylic resin, MMA resin, vinyl ester resin, unsaturated Polyester resin, phenolic resin, or photocurable resin, and the thermoplastic resin is nylon or vinylon.

The carbon fiber material with a monitoring function of the present invention can function as a reinforcing material for repairing and reinforcing steel structures, concrete structures, etc., and can monitor the reinforcement state such as damage and deformation of the reinforced structure over a long period of time. It can be grasped stably with high accuracy, and can also achieve the function as a monitoring material.

In addition, the carbon fiber material with a monitoring function of the present invention can be used as a structural member such as a lightweight, high-strength housing member used in aircraft, mechanical devices, etc. can be stably monitored over a long period of time with high accuracy.

FIG. 1(a) is a perspective view showing an embodiment of the carbon fiber material with a monitoring function according to the present invention, and FIG. 1(a-1) shows the carbon fiber material with a monitoring function removed from the measuring instrument. FIG. 1(b) is a cross-sectional view of one embodiment showing a state in which the carbon fiber material with a monitoring function according to the present invention is adhered to a structure, and FIG. 1(c) is a diagram illustrating another modification of the plating electrode formation positions in the carbon fiber material with a monitoring function according to the present invention. FIG. 2 is a perspective view showing an embodiment of the carbon fiber material used for the carbon fiber material with monitoring function according to the present invention. FIGS. 3(a) and 3(b) are perspective views showing other examples of the carbon fiber material used for the carbon fiber material with monitoring function according to the present invention. 4(a) and 4(b) are cross-sectional views showing an embodiment of a carbon fiber reinforced plastic wire rod used for a carbon fiber material with a monitoring function according to the present invention. FIGS. 5(a) and 5(b) are perspective views showing other examples of the carbon fiber material used for the carbon fiber material with monitoring function according to the present invention. FIGS. 6(a) and 6(b) are perspective views showing other examples of the carbon fiber material used for the carbon fiber material with monitoring function according to the present invention. FIGS. 7(a) to 7(d) are perspective views for explaining the form of the metal-plated electrode of the carbon fiber material with a monitoring function according to the present invention. FIGS. 8(a) to (d) are perspective views for explaining the form of the metal-plated electrode of the carbon fiber material with monitoring function according to the present invention. FIG. 3 is a diagram for explaining electrical resistance characteristics of a carbon fiber material with a monitoring function according to the present invention in comparison with a comparative example;

Hereinafter, the carbon fiber material with a monitoring function according to the present invention will be described in more detail with reference to the drawings.

Example 1
1(a), (a-1), and (b) show an embodiment of a carbon fiber material 1 with a monitoring function according to the present invention and its mode of use. As shown in FIG. 1(a), the carbon fiber material 1 with a monitoring function of the present invention includes a carbon fiber material 10 and at least two locations spaced apart from each other along the length (L) direction of the carbon fiber material 10. It has a formed metal plating electrode 11 . That is, the electrode forming regions 10s are provided at two or more locations apart from each other along the length (L) direction of the carbon fiber material 10, and each electrode forming region 10s has a length (L11) in the length (L) direction. A metal plating electrode 11 is formed extending in the width (W) direction.

In the embodiment shown in FIG. 1(a), the metal plating electrodes 11 are formed at both ends in the longitudinal direction of the carbon fiber material 10, as indicated by solid lines in FIG. 1(a). In some cases, as shown by the dashed line in FIG. can be formed. In some cases, the metal plating electrodes 11 are arranged not at the ends of the carbon fiber material 10 but at a distance (Ls ) can be formed at a plurality of locations.

The separation distance (Ls) between the metal plating electrodes 11, 11 depends on the length (L) of the carbon fiber material 10, but is appropriately set in the range of 0.1 to 50 m, for example. At this time, the separation distance (Ls) between the metal plating electrodes may be the same distance (equal interval) or may be different distances (unequal interval).

Each metal plated electrode 11 formed on the carbon fiber material 10 can be connected to an external measuring instrument 50 via a terminal 13 with a conducting wire 12 for measuring the electrical resistance value of the carbon fiber material 10 . In the carbon fiber material 10 shown in FIG. 1(a), as indicated by the solid line, the metal plated electrodes 11 formed on both ends are connected to an external measuring instrument 50 via the terminals 13 by the conducting wires 12. However, when a plurality of metal-plated electrodes 11 are formed, a lead wire 12 is connected to each electrode 11 and can be connected to an external measuring instrument 50 via a terminal 13 .

When the metal plating electrodes 11 are formed at three or more locations in the length (L) direction, the resistance value of the carbon fiber material 10 is measured by selecting two predetermined metal plating electrodes, and then one, Alternatively, both electrodes can be switched to the other electrode and measured. In this way, by performing a plurality of measurements by switching the measurement points, it is possible to more precisely ascertain changes in the reinforcing state of the structure made of the carbon fiber material.

Further, the carbon fiber material 1 with a monitoring function configured as described above is applied to the surface of the structure 100, for example, in order to reinforce the structure 100 such as a steel structure or a concrete structure, as shown in FIG. 1(b). They are adhered with an adhesive 101 . Of course, the monitoring function-equipped carbon fiber material 1 is tensioned according to a conventional tension reinforcement method, that is, by applying a predetermined tension force to the monitoring function-equipped carbon fiber material 1 , and the structure 100 is bonded to the structure 100 with an adhesive in a tensioned state. It may be fixed by adhesive. Furthermore, although not shown, the carbon fiber material 1 with a monitoring function of the present invention itself can be used, for example, as a structural member such as a housing member for an aircraft or mechanical device. Using the metal plated electrode 11, progress of fatigue cracking and corrosion deterioration of the structural member can also be monitored.

When the carbon fiber material 1 with monitoring function is not connected to the measuring instrument 50, as shown in FIG. 1(a-1), the terminals 13, 13 removed from the measuring instrument 50 are , can be stored in a protective container 30 or the like attached to an appropriate location of the structure 100, and the protective container 30 can be filled with a filler (for example, heat-resistant putty) 31 for storage.

In the above embodiment, the carbon fiber material 1 with a monitoring function is described as having the metal plating electrode 11 extending over the entire area in the width (W) direction of the carbon fiber material 10. However, FIG. As shown in (c), it can also be provided in a partial region (W11) in the width direction.

Next, each constituent member constituting the carbon fiber material 1 with a monitoring function of the present invention will be described.

(carbon fiber material)
Various types of carbon fiber materials 10 can be used for the monitoring function-equipped carbon fiber material 1 of the present invention. The carbon fiber material 10 will be specifically described as specific examples 1 to 5, but the form of the carbon fiber material 10 used in the present invention is not limited to these specific examples.

Example 1
FIG. 2 shows a specific example of the carbon fiber material 10 that can be used in the present invention. In Specific Example 1, the carbon fiber material 10 is a carbon fiber sheet Fs that is formed into a sheet shape by aligning pitch-based or PAN-based carbon fibers f as continuous reinforcing fibers in one direction as shown in FIG. A carbon fiber sheet impregnated with resin Re and cured with the resin, that is, a plate-like carbon fiber reinforced composite material (CFRP plate) 10A. The carbon fibers f are used by arranging, for example, a plurality of resin-unimpregnated single fiber bundles in which 6000 to 24000 single fibers (carbon fiber monofilaments) having an average diameter of 7 μm are bundled in parallel in one direction. The fiber basis weight of the carbon fiber sheet 10A is usually 30-1000 g/m ² . Of course, this carbon fiber sheet 10A can be a CFRP plate having a plate thickness (T) of about 0.5 to 10 mm, consisting of a single layer or multiple layers in which fibers are arranged in one direction.

A thermosetting resin or a thermoplastic resin can be used as the resin Re in the carbon fiber sheet 10A. Examples of the thermosetting resin include room-temperature-curing or thermosetting epoxy resins, vinyl ester resins, and MMA resins. , an acrylic resin, an unsaturated polyester resin, or a phenol resin are preferably used, and as a thermoplastic resin, an epoxy resin, nylon, vinylon, or the like can be preferably used. Also, the fiber volume content (Vf) is 40 to 75%, preferably 50 to 70%.

The length (L) and width (W) of the carbon fiber sheet 10A thus formed are appropriately determined according to the dimensions and shape of the structure to be reinforced. The full width (W) is 100-1000 mm. In addition, the length (L) can be manufactured in a strip shape of about 1 to 5 m or 100 m or more, but it is cut as appropriate for use.

Examples 2-5
3 to 6 show other specific examples 2 to 5 of the carbon fiber material 10 that can be used in the present invention.

In Specific Example 2, as shown in FIG. 3A, the carbon fiber material 10 is a thin continuous carbon fiber reinforced plastic wire (strand) containing carbon fibers f as reinforcing fibers impregnated with a matrix resin R and cured. A plurality of the wire rods 2 are aligned in the longitudinal direction in a threaded manner, and the wire rods 2 are fixed to each other by the wire rod fixing member 3 to form a carbon fiber sheet, a so-called carbon fiber strand sheet 10B.

As shown in FIGS. 4(a) and 4(b), the carbon fiber reinforced plastic wire 2 has a substantially circular cross-sectional shape (FIG. 4(a)) with a diameter (d) of 0.5 to 3 mm, or It can have a substantially rectangular cross-sectional shape (FIG. 4(b)) with a width (w) of 1 to 10 mm and a thickness (t) of 0.1 to 2 mm. Of course, various other cross-sectional shapes can be used as desired.

As described above, in the carbon fiber strand sheet 10B in which the carbon fiber reinforced plastic wires 2 are aligned in one direction and formed into a blind shape, the wires 2 are closely spaced apart from each other by a gap (g) of 0.05 to 3.0 mm. Then, it is fixed by the wire rod fixing member 3 . Further, the length (L) and width (W) of the carbon fiber strand sheet 10B thus formed are appropriately determined according to the dimensions and shape of the structure to be reinforced. , Generally, the total width (W) is 100 to 1000 mm. In addition, the length (L) can be manufactured in a strip shape of about 1 to 5 m or 100 m or more, but it is cut as appropriate for use.

The wires 2 of the carbon fiber strand sheet 10B are pitch-based or PAN-based carbon fibers f as reinforcing fibers, for example, a plurality of single fiber bundles in which 6000 to 24000 single fibers (carbon fiber monofilaments) having an average diameter of 7 μm are converged. It can be used by arranging it in parallel in one direction. Further, the matrix resin R with which the carbon fiber reinforced plastic wire 2 is impregnated can be a thermosetting resin or a thermoplastic resin. , vinyl ester resins, MMA resins, acrylic resins, unsaturated polyester resins, phenol resins, etc., and as thermoplastic resins, epoxy resins, nylons, vinylons, etc. can be suitably used. Also, the fiber volume content (Vf) is 40 to 75%, preferably 50 to 70%.

As a method of fixing each wire 2 with a wire fixing member 3, for example, as shown in FIG. It is possible to employ a method in which a wire rod sheet made of the wire rod 2 of the book is driven into the wire rod at a constant interval (P) perpendicularly to the wire rod and knitted. The pitch (P) of the weft threads 3 is not particularly limited, but is usually selected in the range of 10 to 100 mm, taking into account the handleability of the manufactured fiber sheet 1 . At this time, the weft thread 3 is a thread obtained by bundling a plurality of glass fibers or organic fibers having a diameter of 2 to 50 μm, for example. As organic fibers, nylon, vinylon, polyester and the like are preferably used.

As another method for fixing each wire 2 in a blind shape, a mesh support sheet 3 can be used as the wire fixing member 3 as shown in FIG. 3(b). That is, the surfaces of the warp yarns 4 and weft yarns 5 constituting the mesh-like support sheet 3 are pre-impregnated with a low-melting-point thermoplastic resin, and the mesh-like support sheet 3 is arranged in a sheet-like strand (carbon fiber). The warp yarns 4 and weft yarns 5 of the mesh-like support sheet 3 are welded to the carbon fiber strand sheet by laminating them on one or both sides of the mesh support sheet 3 under heat and pressure. As the thread of the wire rod fixing member 3, for example, a double structure conjugate fiber having a glass fiber in the core portion and a heat-sealable polyester having a low melting point disposed around it is also preferably used. The mesh support sheet 3 can also be provided on both sides of the carbon fiber strand sheet 10B.

Further, other specific examples 3 and 4 of the carbon fiber material 10 that can be used in the present invention are shown in FIGS. 5(a) and 5(b).

The carbon fiber materials 10 of specific examples 3 and 4 shown in FIGS. 5(a) and 5(b) are continuous carbon fiber reinforced plastic rods (CFRP rods) containing carbon fibers f impregnated with a matrix resin R and cured, respectively. 10C and a carbon fiber reinforced plastic plate (CFRP plate) 10D. The carbon fiber reinforced plastic rod 10C and the carbon fiber reinforced plastic plate 10D have the same configuration as the carbon fiber reinforced plastic wire (strand) 2 described with reference to FIGS. The only difference is that the cross-sectional area is made larger.

That is, the elongated carbon fiber material 10 of Example 3 having a circular cross section shown in FIG. 5(a) is a carbon fiber reinforced plastic rod 10C having a substantially circular cross section with a diameter (D10) of 8 to 10 mm. Further, the elongated carbon fiber material 10 of Concrete Example 4 having a substantially rectangular cross section shown in FIG. This is a carbon fiber reinforced plastic plate 10D.

The carbon fiber reinforced plastic rod 10C and the carbon fiber reinforced plastic plate 10D shown in Specific Examples 3 and 4 can be used to reinforce structures. It can be used as a structural member such as a plate member.

In Specific Example 5, as shown in FIG. 6(a), the carbon fiber material 10 is composed of a plurality of stripes that are arranged in a lattice that intersects at right angles, that is, vertical lattice stripes 21 and horizontal lattice stripes 22. It is a carbon fiber reinforced plastic (CFRP) lattice material 10E made of. Each of the stripes 21 and 22 of the lattice material 10E is formed by arranging carbon fibers as reinforcing fibers in one direction and laminating a plurality of belt-shaped reinforcing fibers impregnated with a matrix resin. Each muscle 21, 22 has a width (w) of 3 to 10 mm and a thickness (t) of 1 to 5 mm. Also, each muscle is formed with a distance (Lx, Ly) of 3 to 15 cm. The metal-plated electrodes 11 can be formed in the electrode formation regions 10s at both ends of any one of the vertical lattice bars 21 of the grid material 10E, or in electrode formation regions at predetermined locations other than both ends (not shown). .

In this specific example, as shown in FIG. 6B, at least the horizontal lattice bars 23 at both ends of the lattice material 10E are formed wider than the other horizontal lattice bars 22, and the wide portions A metal plating electrode 11 can also be formed in the electrode forming region 10s.

Such a lattice material 10E is attached to a structure with a fixing material such as mortar and used for reinforcing the structure.

(Plating electrode)
As described above with reference to FIG. 1(a), the carbon fiber materials 1 with a monitoring function of the present invention are spaced apart from each other in the longitudinal direction of the carbon fiber materials 10 (10A to 10E) having the various configurations described above. Metal plating electrodes 11 are formed in at least two locations. Next, a method for forming the metal plating electrode 11 on the carbon fiber material 10 shown in the above specific example will be described.

As shown in FIGS. 1A and 7A, the carbon fiber material 10, which is the carbon fiber sheet 10A which is the CFRP plate shown in FIG. Metal plating electrodes 11 are formed by applying metal plating to 10s by a wet plating method (electrolytic plating or electroless plating).

Before the electrode forming region 10s is plated, it is preferable to polish the hardened surface resin layer of the surface layer with a polishing means such as a sander to expose the carbon fibers. Of course, as shown in FIG. 1(a), even when the metal plating electrode 11 is formed in the intermediate portion of the carbon fiber material 10, the electrode forming region 10S is subjected to polishing means such as a sander before plating. It is important to polish the hardened surface resin layer of the surface layer with a brush to expose the carbon fibers.

In addition, as shown in FIG. 7B, when the metal plating electrodes 11 are formed on both ends of the carbon fiber material 10, the ends forming the metal plating electrodes 11 are arranged outwardly. It is preferable to form a tapered surface (inclined surface) 10st inclined in the thickness direction toward the edge portion. As a result, the metal plating electrode 11 can come into contact with the carbon fiber f on the inclined surface 10st of the carbon fiber material 10, and the contact area between the electrode 11 and the carbon fiber material 10 is increased. It is possible to measure the stable resistance value of In addition, there is an advantage that the end face of the carbon fiber material 10 is not exposed to the outside, is not affected by the outside air, and is resistant to corrosion. Thereby, the electrical conductivity of the carbon fiber material 10 can be improved, and the resistance change of the carbon fiber material 10 can be measured more stably.

Further, as shown in FIG. 7(c), an electrode forming region 10s can be formed by molding the end portion of the carbon fiber material 10 into a curved shape, and a metal plating electrode 11 is formed in this electrode forming region 10s. is also possible.

As shown in FIG. 8(a), the carbon fiber material 10 used as the carbon fiber strand sheet 10B shown in FIG. Metal plating electrode 11 is formed by applying metal plating to region 10s. The strands 2 on which the metal plating electrodes 11 are formed are formed on a plurality of strands at a rate of one for 10 to 100 strands 2 constituting the carbon fiber strand sheet 10B. can be done.

In the electrode forming region 10s where the metal plating electrode 11 is formed, it is preferable to polish the hardened surface resin layer on the surface with a polishing means such as a sander before plating to expose the carbon fibers. Of course, even when the metal plating electrode 11 is formed in the middle portion of the carbon fiber material 10 as shown in FIG. , It is important to polish the hardened surface resin layer on the surface to expose the carbon fibers.

Furthermore, as shown in FIG. 8(b), also in the carbon fiber material 10 as the carbon fiber strand sheet 10B, the metal plated electrode 11 can be integrally formed with respect to the plurality of strands 2. As shown in FIG. In this case, first, as shown in FIG. 8(b), the gaps (g) between the strands 2 that are spaced apart from each other are filled with conductive wires as shown in FIGS. 8(c) and 8(d). A flexible adhesive Rm is filled to form an electrode forming region 10s, and a metal plating electrode 11 is formed in the electrode forming region 10s.

Prior to plating, the electrode forming region 10s is preferably polished by polishing means such as a sander to polish the hardened surface resin layer on the surface to expose the carbon fibers. Of course, even when the metal plating electrode 11 is formed in the middle portion of the carbon fiber material 10 as shown in FIG. It is important to polish the hardened surface resin layer on the surface of the strands 2 by using a brush to expose the carbon fibers.

Also in this example, when the metal plating electrodes 11 are formed on both ends of the carbon fiber material 10, as shown in FIG. It is also possible to form the film so as to be slanted in the thickness direction, and to apply electroplating to this slanted surface. Alternatively, as shown in FIG. 7C, the electrode forming region 10s having curved ends can be electroplated.

As shown in FIG. 5(a) described in Specific Example 3, when the carbon fiber material 10 has a round bar shape like the carbon fiber reinforced plastic rod 10C, although not shown, FIG. ), or forming the metal-plated electrode 11 in the electrode forming region 10s formed into a curved end shape as shown in FIG. 7(d). can be done.

As shown in FIG. 5B described in Specific Example 4, when the carbon fiber material 10 is a carbon fiber reinforced plastic bar 10D having a rectangular cross section, the carbon fiber material 10 of Specific Example 1 The metal plating electrode 11 can be formed in the manner shown in FIGS. Therefore, re-explanation here is omitted.

In the present invention, the metal plating electrode 11 for the carbon fiber material 10 can be formed by metal plating the carbon fiber material 10 by a wet plating method such as electrolytic plating or electroless plating. When forming a metal plating electrode on a carbon fiber material (CFRP), the present inventors used any plating material with any physical property value in order to prevent separation of the metal plating electrode from the CFRP. It turned out that it is extremely important whether a metal plating layer is formed.

Nickel alloys, cobalt alloys, and zinc alloys are suitable plating materials for the metal plating electrodes used in the present invention. A detailed description is given below.

(1) Nickel alloy
In the present invention, the plating layer constituting the metal plating electrode 11 is
or
(b) A nickel alloy plating layer containing 25 wt% or more and less than 100 wt% of nickel as the main component, and the balance of additives and inevitable impurities, wherein the nickel alloy plating layer with the mixing ratio of the additives to nickel changed A multi-layer nickel alloy plating layer with a laminated structure laminated on the
It is said that As the additive mixed with nickel as the main component, one or more selected from the group consisting of phosphorus, tungsten, cobalt, iron and sulfur can be preferably used.

In the present invention, the content of nickel, which is the main component, is 25 wt% or more and less than 100 wt%. Preferably, the nickel content is 75 wt% or more and less than 100 wt%. is less than 25 wt%. In nickel alloy plating, if the nickel content is less than 25 wt%, a problem arises in terms of corrosion resistance. In addition, by containing one or more of phosphorus, tungsten, cobalt, iron, and sulfur as an additive, the toughness, yield strength, and wear resistance can be improved.

According to the present invention, as described above, the plating layer that constitutes the metal plating electrode 11 has a single-layer structure of nickel containing 25 wt % or more and less than 100 wt % of nickel as the main component, and the balance of additives and unavoidable impurities. An alloy plating layer may be used. In this case, the plating thickness T11 of the nickel alloy plating layer is not particularly limited, but is set to 10 to 500 μm, usually 50 to 100 μm.

Furthermore, according to the present invention, as described above, the plating layer constituting the metal plating electrode 11 is a nickel alloy plating layer containing 25 wt % or more and less than 100 wt % of nickel as the main component, and the balance of additives and unavoidable impurities. A multi-layer nickel alloy plating layer having a laminated structure in which nickel alloy plating layers in which the mixing ratio of the additive to nickel is varied can be vertically laminated.

A multi-layered nickel alloy plating layer having such a laminated structure can be obtained by controlling agitation and current density in units of several seconds for plating conditions in one plating bath. For example, using a nickel-phosphorus alloy, a multi-layer nickel alloy plating with a laminated structure in which an 8 wt% phosphorus-containing nickel alloy plating layer and a 12 wt% phosphorus-containing nickel alloy plating layer are alternately laminated with a thickness of several μm. You can get layers. The thickness of the layer with a small mixing ratio of the additive to nickel and the layer with a large mixing ratio are respectively 1 to 500 μm, preferably 5 to 100 μm, and the layer thickness ratio is in the range of 1:1 to 1:10. be able to. In this case, the total thickness of the multi-layered nickel alloy plating layer of the laminated structure is 10 to 500 μm, usually 50 to 100 μm.

Such a plating method is a technology well known to those skilled in the art, as described in, for example, Japanese Patent Application Laid-Open No. 2015-166483, so further detailed description will be omitted.

In the present invention, the single-layer nickel alloy plating layer of single-layer structure or the multi-layer nickel alloy plating layer of laminated structure has a tensile strength of 25 to 90 kg/mm ² (preferably 30 to 60 kg/mm ² ). , an elongation of 3% or more, usually 50% or less (preferably 4 to 16%), and an Hv hardness of 150 to 650 (preferably 180 to 300).

If the tensile strength is less than 25 kg/mm ² , there is a problem with the strength (yield stress) as an electrode, and if it exceeds 90 kg/mm ² , it will not follow the elongation of the carbon fiber material (CFRP) to which the plating is applied. Such problems arise. Furthermore, if the elongation is less than 3%, there is a problem in toughness, and the elongation is made 3% or more.

Moreover, when the Hv hardness is less than 150, it cannot be manufactured, and when it exceeds 650, there arises a problem that plating cracks occur.

In nickel alloy plating, depending on the current density and bath temperature, the electrodeposition stress remaining in the plating alloy layer (plating film) is either compressive stress or tensile stress, and its value also varies. do. Such electrodeposition stress affects the adhesion to the carbon fiber material 10, which is the material to be plated. /mm ² to +15 kg/mm ² , more preferably -9 kg/mm ² to +9 kg/mm ² . If the electrodeposition stress is outside the range of −15 kg/mm ² to +15 kg/mm ² , problems such as poor adhesion of the plating layer to CFRP and changes in shape and dimensions tend to occur over time.

On the other hand, in a multi-layer nickel alloy plating layer having a laminated structure in which nickel alloy plating layers are stacked vertically by changing the mixing ratio of the additive to nickel, the formed plurality of nickel plating layers each has a different electrodeposition stress, that is, a compressive stress or a tensile stress. will have a combined electrodeposition stress of the nickel plating layer. Therefore, unlike the single-layer nickel alloy plating layer having a single-layer structure, the individual nickel plating layers to be laminated do not need to have an electrodeposition stress within the range of -15 kg/mm ² to +15 kg/mm ² . . However, the composite electrodeposition stress of the plated film formed by the laminated multilayer structure of the nickel alloy plating layer is within the range of −15 kg/mm ² to +15 kg/mm ² .

In the present invention, the metal plating electrode 11 has not only excellent corrosion resistance and wear resistance, but also remarkably improved elongation due to the plating layer having the above structure, and the adhesion to the carbon fiber material (CFRP) is greatly improved. It is possible to follow the elongation of the carbon fiber material (CFRP) without causing the peeling of the plating. Therefore, it is possible to solve the problem when the metal plating electrode is plated with copper, that is, the problem that the contact resistance with the carbon fiber material (CFRP) changes with time.

(2) Cobalt alloy
According to another aspect of the present invention, the plating layer constituting the metal plating electrode 11 is
(a) a single-layer cobalt alloy plating layer having a single-layer structure containing 25 wt% or more and less than 100 wt% of cobalt as a main component, and the balance of additives and inevitable impurities; or
(b) A cobalt alloy plating layer containing 25 wt% or more and less than 100 wt% of cobalt as a main component, and the balance of additives and unavoidable impurities, wherein the cobalt alloy plating layer in which the mixing ratio of the additives to cobalt is changed is vertically arranged. A multilayer cobalt alloy plating layer with a laminated structure laminated on the
It is said that As the additive mixed with cobalt as the main component, one or more selected from the group consisting of phosphorus, tungsten, nickel, iron and sulfur can be preferably used.

In the present invention, the content of cobalt, which is the main component, is 25 wt% or more and less than 100 wt%. is less than 25 wt%. In cobalt alloy plating, if the content of cobalt is less than 25 wt%, a problem arises in terms of corrosion resistance. Further, by containing one or more of phosphorus, tungsten, nickel, iron, and sulfur as an additive, toughness, yield strength, and wear resistance can be improved.

According to the present invention, as described above, the plating layer constituting the metal plating electrode 11 has a single-layer structure containing 25 wt % or more and less than 100 wt % of cobalt as a main component, and the balance of additives and unavoidable impurities. An alloy plating layer may be used. In this case, the plating thickness T11 of the cobalt alloy plating layer is not particularly limited, but is set to 10 to 500 μm, usually 50 to 100 μm.

Furthermore, according to the present invention, the plating layer constituting the metal plating electrode 11 is, as described above, a cobalt alloy plating layer containing 25 wt % or more and less than 100 wt % of cobalt as the main component, and the balance of additives and unavoidable impurities. It is also possible to form a multi-layered cobalt alloy plating layer having a laminated structure in which cobalt alloy plating layers having different mixing ratios of additives with respect to cobalt are laminated in the vertical direction.

A multi-layered cobalt alloy plated layer having such a laminated structure can be obtained in one plating bath by controlling stirring and current density in units of several seconds for plating conditions. For example, taking a cobalt-phosphorus alloy as an example, a multi-layer cobalt alloy plating with a laminated structure in which an 8 wt% phosphorus-containing cobalt alloy plating layer and a 12 wt% phosphorus-containing cobalt alloy plating layer are alternately laminated with a thickness of several μm. You can get layers. The thickness of the layer with a small mixing ratio of the additive to cobalt and the layer with a large mixing ratio are each 1 to 500 μm, preferably 5 to 100 μm, and the layer thickness ratio is in the range of 1:1 to 1:10. be able to. In this case, the total thickness of the multilayer cobalt alloy plated layer of the laminated structure is 10 to 500 μm, usually 50 to 100 μm.

Such a plating method is a technology well known to those skilled in the art, as described in, for example, Japanese Patent Application Laid-Open No. 2015-166483, so further detailed description will be omitted.

In the present invention, the single layer cobalt alloy plating layer of single layer structure or the multi-layer cobalt alloy plating layer of laminated structure has a tensile strength of 25 to 90 kg/mm ² (preferably 30 to 60 kg/mm ² ). , an elongation of 3% or more, usually 50% or less (preferably 4 to 16%), and an Hv hardness of 150 to 650 (preferably 200 to 450).

If the tensile strength is less than 25 kg/mm ² , there is a problem with the strength (yield stress) as an electrode, and if it exceeds 90 kg/mm ² , it will not follow the elongation of the carbon fiber material (CFRP) to which the plating is applied. Such problems arise. Furthermore, if the elongation is less than 3%, there is a problem in toughness, and the elongation is made 3% or more.

Moreover, when the Hv hardness is less than 150, it cannot be manufactured, and when it exceeds 650, there arises a problem that plating cracks occur.

As described above in relation to nickel alloy plating, even in cobalt alloy plating, depending on the current density and bath temperature, the electrodeposition stress remaining in the plating alloy layer (plating film) is reduced to compressive stress. It is referred to as stress or tensile stress, and its value also varies. Such electrodeposition stress affects the adhesion to the carbon fiber material 10, which is the material to be plated. However, cobalt alloy plating has better adhesion to the material to be plated than nickel alloy plating, and is less affected by electrodeposition stress. However, in the case of a single-layer cobalt alloy plated layer having a single-layer structure, the electrodeposition stress is in the range of -15 kg/mm ² to +15 kg/mm ² , particularly in the range of -9 kg/mm ² to +9 kg/mm ² . preferably within. If the electrodeposition stress is outside the range of −15 kg/mm ² to +15 kg/mm ² , problems such as poor adhesion of the plating layer to CFRP and changes in shape and dimensions tend to occur over time.

On the other hand, in a multilayer cobalt alloy plating layer having a laminated structure in which cobalt alloy plating layers are stacked vertically by changing the mixing ratio of the additive material to cobalt, the plurality of cobalt plating layers formed are different from each plating layer. has a different electrodeposition stress, that is, a compressive stress or a tensile stress. will have a combined electrodeposition stress of the cobalt plating layer of . Therefore, unlike the case of the single-layer cobalt alloy plating layer having a single-layer structure, the individual cobalt plating layers to be laminated need not have an electrodeposition stress within the range of −15 kg/mm ² to +15 kg/mm ^{2 .} However, the plating film formed by the laminated multilayer cobalt alloy plating layer preferably has a combined electrodeposition stress in the range of -15 kg/mm ² to +15 kg/mm ² . .

In the present invention, the metal plating electrode 11 has not only excellent corrosion resistance and wear resistance, but also remarkably improved elongation due to the plating layer having the above structure, and the adhesion to the carbon fiber material (CFRP) is greatly improved. It is possible to follow the elongation of the carbon fiber material (CFRP) without causing the peeling of the plating. Therefore, it is possible to solve the problem when the metal plating electrode is plated with copper, that is, the problem that the contact resistance with the carbon fiber material (CFRP) changes with time.

(3) Zinc alloy
According to another aspect of the present invention, the plating layer constituting the metal plating electrode 11 is
(a) Zinc alloy plated layer containing 51 wt% or more and less than 100 wt% of zinc as the main component, and the balance of additives and inevitable impurities;
It is said that Nickel is preferably used as an additive mixed with zinc as the main component.

In the present invention, the content of zinc, which is the main component, is 51 wt% or more and less than 100 wt%. %. In zinc alloy plating, if the zinc content is less than 51 wt%, the plating thickness usually does not reach 1 μm, which poses a problem in terms of corrosion resistance. In the present invention, by setting the zinc content to 51 wt % or more, the plating thickness T11 can be increased to 10 to 50 μm or more, and corrosion resistance can be increased.

Further, by containing nickel as an additive, toughness, yield strength, and wear resistance can be improved.

In the present invention, the zinc alloy plating layer has a tensile strength of 20 to 250 kg/mm ² (preferably 30 to 170 kg/mm ² ) and an elongation of 3% or more and usually 50% or less (preferably 3 to 170 kg/mm 2 ). 20%) and an Hv hardness of 100 to 250 (preferably 100 to 180).

If the tensile strength is less than 20 kg/mm ² , there is a problem with the strength (yield stress) as an electrode, and if it exceeds 250 kg/mm ² , it will not follow the elongation of the carbon fiber material (CFRP) to which the plating is applied. Such problems arise. Furthermore, if the elongation is less than 3%, there is a problem in toughness, and the elongation is made 3% or more.

Moreover, when the Hv hardness is less than 100, it cannot be manufactured, and when it exceeds 250, there arises a problem that plating cracks occur.

In addition, in zinc alloy plating, as in the case of nickel alloy plating and cobalt alloy plating described above, the electrodeposition stress remaining in the plating alloy layer (plating film) depends on the magnitude of the current density and bath temperature. is a compressive stress or a tensile stress, and its value also varies. Such electrodeposition stress affects adhesion to the carbon fiber material ¹⁰ , which is the material to be plated ^. is preferably within the range of −9 kg/mm ² to +9 kg/mm ² . If the electrodeposition stress is outside the range of −15 kg/mm ² to +15 kg/mm ² , problems such as poor adhesion of the plating layer to CFRP and changes in shape and dimensions tend to occur over time.

In the present invention, the metal plating electrode 11 has not only excellent corrosion resistance and wear resistance, but also remarkably improved elongation due to the plating layer having the above structure, and the adhesion to the carbon fiber material (CFRP) is greatly improved. It is possible to follow the elongation of the carbon fiber material (CFRP) without causing the peeling of the plating. Therefore, it is possible to solve the problem when the metal plating electrode is plated with copper, that is, the problem that the contact resistance with the carbon fiber material (CFRP) changes with time.

According to the present invention, as the metal plating electrode 11, the conventional metal plating electrode 11 is replaced by the copper plating by forming the alloy plating layer of the above-described nickel alloy plating, cobalt alloy plating, and zinc alloy plating. The copper plating formed on the surface of the carbon fiber material 10, which is a problem when it is formed, is easily corroded, and the electrical resistance increases with the passage of time. We were able to solve the problem that it fluctuates and cannot be measured stably.

However, it is preferable to provide a plating electrode protective layer as the outermost layer on the plating layer. As the plating electrode protective layer, for example, a DLC coating layer can be formed by conductive DLC (diamond-like carbon) coating treatment. Note that the DLC coating layer has a thickness of 0.01 to 10 μm.

Moreover, it is preferable to form the said plating layer as a base plating layer, and to form a surface plating layer using gold or platinum as a surface layer (second layer) plating layer thereon.

The plating thickness T11 of the metal plating layer is not particularly limited, but is set to 10 to 500 μm as described above, and when the plating layer is formed as a base plating layer, the plating thickness is 10 to 500 μm (usually 50 to 100 μm), and the plating thickness of the surface layer (second layer) is 1 to 500 μm (usually 1 to 100 μm).

With such a configuration of the metal plating electrode 11, it is possible to solve the problem of the initial electrical resistance value and maintain the initial electrical resistance value constant over time. It is possible to grasp the reinforcement state of such as by monitoring stably with high accuracy over a long period of time.

In other words, it is believed that the alloy plating layer using the alloys described in (1) to (3) above has a strong adhesion to the carbon fiber material 10 and achieves good electrical contact. Therefore, even when the plating layer has a multi-layer structure, the electroconductivity of the plating electrode can be further improved by using these alloy plating layers as the base plating layer and forming gold plating or platinum plating as the surface layer. can be considered.

Experimental examples for proving the effects of the present invention will be described below.

Experimental Example As the carbon fiber material 10, the carbon fiber reinforced plastic plate 10D having a rectangular cross-section as described in Specific Example 4 was used. That is, first, as described in Specific Example 1, a plurality of single fiber bundles in which 24,000 single fibers (carbon fiber monofilaments) f having an average diameter of 7 μm are converged as carbon fibers are arranged in parallel in one direction, and a vinyl ester resin is prepared. was impregnated with, pultruded by the pultrusion method, and then cured. Thus, a carbon fiber reinforced plastic plate 10D having a length (L) of 400 mm, a width (W) of 75 mm, and a thickness (T) of 3 mm was produced. The fiber volume content (Vf) was 65%.

As shown in FIG. 7(b), the carbon fiber reinforced plastic plate 10D thus produced was metal-plated with the electrode forming regions 10s at both ends as inclined surfaces 10st. The length (L11) of the metal plating electrode 11 was 10 mm.

A conductive wire 12 was connected to the metal plated electrode 11 by soldering, and then the soldered portion and the metal plated electrode 11 were covered with epoxy resin.

Conducting wire 12 of carbon fiber material 1 with monitoring function thus produced was connected to measuring instrument 50 via terminal 13, and electrical resistance (initial resistance value R0) was measured. In this experiment, a resistance meter (manufactured by Hioki Electric Co., Ltd.: trade name "RM3545-02") was used as a measuring instrument. A four-terminal measurement method was adopted for the electrical resistance measurement. The results are shown in FIG.

In FIG. 9, the metal plating electrode 11 is nickel alloy plating (containing a small amount of sulfur) with a plating thickness of 100 μm in Experimental Example 1 according to the present invention, and the underlying layer is plated with a thickness of 100 μm in Experimental Example 2. of nickel alloy plating (containing a small amount of sulfur), and the surface layer was gold plating (thickness 1 μm). Moreover, in Comparative Examples 1 and 2 as conventional techniques, copper plating (thickness: 100 μm) was used.

Referring to FIG. 9, in Experimental Examples 1 and 2, which have a plating layer configuration according to the present invention, the initial electrical resistance value of the carbon fiber material 1 with a monitoring function does not fluctuate with the lapse of time. 2 was stable over a long period of time. That is, it can be seen that stable monitoring is possible. On the other hand, in Comparative Examples 1 and 2, it can be seen that the initial electrical resistance value of the monitoring function-equipped carbon fiber material 1 fluctuates over time. In addition, even with the same copper plating, there is a large difference between the two, and it can be seen that it is difficult to obtain plating with constant quality performance. This makes stable measurement, ie monitoring, impossible.

Although not shown in FIG. 9, when a cobalt-based alloy or a zinc alloy other than a nickel-based alloy is used as the metal plating electrode 11, the initial electrical resistance value of the carbon fiber material 1 with a monitoring function is similarly reduced. It was found to be stable over a long period of time with little fluctuation over time.

(Reinforcement method)
Next, a method for reinforcing a structure and a method for monitoring using the carbon fiber material 1 with a monitoring function according to the present invention will be briefly described. As will be understood with reference to FIG. 1(b), as is well known to those skilled in the art, one or more layers of fiber sheets containing reinforcing fibers are adhered to the surface of the structure 100 with an adhesive. The structure is reinforced by integration.

In addition, at least one layer of the fiber sheet used is reinforced using the carbon fiber material 1 with a monitoring function according to the present invention, and after reinforcement, by measuring the electrical resistance of the carbon fiber material 1 with a monitoring function, A determination of crack initiation and/or crack propagation in the reinforced structure may be made. In other words, it is possible to effectively reinforce a structure and to detect the state of reinforcement of the structure by monitoring the occurrence of fatigue cracks, the progress of cracks, etc. Furthermore, it is possible to monitor the progress of corrosion deterioration of the structure, for example, PC steel material, or peeling of the carbon fiber material 10 as a reinforcing material, and detect the reinforcement state of the reinforced structure.

In order to grasp the local state of the structure, it is necessary to efficiently transmit the strain from the structure, which is the object to be reinforced. Therefore, it is effective to arrange the carbon fiber material 1 with a monitoring function closer to the surface of the material to be reinforced. Therefore, although it is not limited, when a plurality of fiber sheets are laminated for reinforcement, the carbon fiber material 1 with a monitoring function constructed according to the present invention is usually arranged at or near the bottom layer. .

Therefore, the electrical resistance of the carbon fiber material 1 with a monitoring function is measured regularly or appropriately as desired, thereby detecting the occurrence and/or propagation of cracks in the reinforced structure. .

At this time, the electrical resistance value (R) of the carbon fiber material 1 with a monitoring function is measured, and when a region where the electrical resistance change rate (Rcr) increases occurs, the electrical resistance change rate (Rcr) increases. It is determined that a crack has occurred in the steel structure to be reinforced corresponding to the area where the

Similarly, for example, when corrosion deterioration progresses in the PC member, the load bearing capacity of the steel member decreases, and the load on the carbon fiber material with monitoring function 1 increases accordingly. 1 increases, resulting in an increase in the rate of change in electrical resistance (Rcr). Therefore, when the electrical resistance value (R) of the carbon fiber material 1 with a monitoring function is measured, and a region where the electrical resistance change rate (Rcr) increases occurs, the electrical resistance change rate (Rcr) increases. It can be determined that deterioration due to corrosion is progressing in the structure to be reinforced corresponding to the area where the reinforced structure is located.

Thus, the carbon fiber material with a monitoring function of the present invention has a function as a reinforcing material for repair and reinforcement of steel structures, concrete structures, etc. By using a specific metal alloy as the material, it is possible to solve the problem of the initial electrical resistance value fluctuation of the conventional carbon fiber reinforced resin material and maintain the initial electrical resistance value constant over time. became. Therefore, it has the advantage that the reinforced state of the reinforced structure, such as damage and deformation, can be stably grasped with high accuracy over a long period of time.

In addition, the carbon fiber material with a monitoring function of the present invention can be used as a lightweight, high-strength structural member such as a housing member of a mechanical device used in an aircraft or a mechanical device. It is possible to stably monitor the progress of fatigue cracks and corrosion deterioration over a long period of time with high accuracy.

1 Carbon fiber material with monitoring function 2 Carbon fiber reinforced plastic wire (strand)
REFERENCE SIGNS LIST 10 carbon fiber material 10A carbon fiber reinforced composite material 10B carbon fiber strand sheet 10C carbon fiber reinforced plastic rod 10D carbon fiber reinforced plastic plate 10E carbon fiber lattice material 10s electrode forming area 11 metal plating electrode 12 conducting wire 13 terminal member 50 measuring instrument 100 structure Object 101 Adhesive

Claims (16)

A carbon fiber material with a monitoring function that can be bonded to the surface of a structure with an adhesive to reinforce the structure or can be used as a structural member,
Metal-plated electrodes for measuring the electrical resistance of the carbon fiber material are provided at least two locations apart from each other on the carbon fiber material, and the metal-plated electrodes are:
or
(b) A nickel alloy plating layer containing 25 wt% or more and less than 100 wt% of nickel as a main component, and the balance of additives and inevitable impurities, wherein the mixing ratio of the additives to the nickel is changed. A multi-layer nickel alloy plating layer with a laminated structure in which the
has
The single-layer nickel alloy plating layer having the single-layer structure has an electrodeposition stress in the range of −15 kg/mm ² to +15 kg/mm ² ,
The multi-layered nickel alloy plating layer having the laminated structure has an electrodeposition stress obtained by combining the electrodeposition stresses of the nickel alloy plating layers having the laminated structure, and the combined electrodeposition stress is - within the range of 15 kg/mm ² to +15 kg/mm ² ;
The single-layer nickel alloy plating layer and the multiple-layer nickel alloy plating layer have a tensile strength of 25 to 90 kg/mm ² , an elongation of 3% or more, and an Hv hardness of 150 to 650.
A carbon fiber material with a monitoring function characterized by: 2. The carbon fiber material with a monitoring function according to claim 1 , wherein said additive is one or more selected from the group consisting of phosphorus, tungsten, cobalt, iron and sulfur. A carbon fiber material with a monitoring function that can be bonded to the surface of a structure with an adhesive to reinforce the structure or can be used as a structural member,
Metal-plated electrodes for measuring the electrical resistance of the carbon fiber material are provided at least two locations apart from each other on the carbon fiber material, and the metal-plated electrodes are:
(a) a single-layer cobalt alloy plating layer having a single-layer structure containing 25 wt% or more and less than 100 wt% of cobalt as a main component, and the balance of additives and inevitable impurities; or
(b) A cobalt alloy plating layer containing 25 wt% or more and less than 100 wt% of cobalt as a main component, and the balance of additives and unavoidable impurities, wherein the mixing ratio of the additives to the cobalt is changed. A multilayer cobalt alloy plating layer with a laminated structure in which the
has
The single-layer cobalt alloy plating layer having the single-layer structure has an electrodeposition stress in the range of −15 kg/mm ² to +15 kg/mm ² ,
The multilayer cobalt alloy plating layer having the laminated structure has an electrodeposition stress obtained by combining the electrodeposition stresses of the respective cobalt alloy plating layers having the laminated structure, and the combined electrodeposition stress is - within the range of 15 kg/mm ² to +15 kg/mm ² ;
The single layer cobalt alloy plating layer and the multiple layers cobalt alloy plating layer have a tensile strength of 25 to 90 kg/mm ² , an elongation of 3% or more, and an Hv hardness of 150 to 650.
A carbon fiber material with a monitoring function characterized by: 4. The carbon fiber material with monitoring function according to claim 3, wherein the additive is one or more selected from the group consisting of phosphorus, tungsten, nickel, iron and sulfur. A carbon fiber material with a monitoring function that can be bonded to the surface of a structure with an adhesive to reinforce the structure or can be used as a structural member,
Metal-plated electrodes for measuring the electrical resistance of the carbon fiber material are provided at at least two locations on the carbon fiber material that are spaced apart from each other;
The metal plated electrode has a zinc alloy plated layer containing 51 wt% or more and less than 100 wt% of zinc as a main component, and the balance additives and inevitable impurities,
The zinc alloy plating layer has a tensile strength of 20 to 250 kg/mm ² , an elongation of 3% or more, and an Hv hardness of 100 to 250.
A carbon fiber material with a monitoring function characterized by: 6. The carbon fiber material with a monitoring function according to claim 5 , wherein the zinc alloy plating layer has an electrodeposition stress in the range of -15 kg/mm ² to +15 kg/mm ² . The carbon fiber material with a monitoring function according to claim 5 or 6 , wherein the additive is nickel. The carbon fiber material with a monitoring function according to any one of claims 1 to 7 , wherein the metal-plated electrode has a gold-plated layer or a platinum-plated layer as the outermost surface layer metal-plated layer. The carbon fiber material with a monitoring function according to any one of claims 1 to 7 , wherein the metal plating electrode has a conductive DLC layer as an outermost layer. 10. The carbon fiber material is a carbon fiber reinforced composite material in which a matrix resin is impregnated into a carbon fiber sheet formed by aligning carbon fibers in one direction and cured. Carbon fiber material with a monitoring function according to any one of . The carbon fiber material is a carbon fiber strand sheet formed by arranging a plurality of continuous carbon fiber reinforced plastic wires in which the carbon fibers are impregnated with a matrix resin and cured in the longitudinal direction to form a sheet. The carbon fiber material with a monitoring function according to any one of claims 1 to 9 , characterized in that: The carbon fiber material is a continuous carbon fiber reinforced plastic rod having a substantially rectangular cross section or a carbon fiber reinforced plastic plate having a substantially rectangular cross section. The carbon fiber material with a monitoring function according to any one of claims 1 to 9 . The carbon fiber material is formed by arranging vertical reinforcing bars and horizontal reinforcing bars formed by laminating a plurality of string-like carbon fibers in which carbon fibers are arranged in one direction, impregnated with a matrix resin, and cured, and arranged in a lattice. The carbon fiber material with a monitoring function according to any one of claims 1 to 9 , characterized in that it is a carbon fiber lattice material that The electrode forming portion in which the metal plating electrode is formed at the end of the carbon fiber material is an inclined surface inclined in a thickness direction, and the metal plating electrode is formed on the inclined surface. The carbon fiber material with a monitoring function according to any one of claims 1 to 13 . The electrode forming portion in which the metal plating electrode is formed at the end of the carbon fiber material has a curved shape in which the end is curved, and the metal plating electrode is formed on the curved surface. The carbon fiber material with a monitoring function according to any one of claims 1 to 13 . The carbon fiber is a pitch-based or PAN-based carbon fiber,
The matrix resin is a thermosetting resin or a thermoplastic resin, and the thermosetting resin is a room temperature or thermosetting epoxy resin, epoxy acrylate resin, acrylic resin, MMA resin, vinyl ester resin, unsaturated Carbon with a monitoring function according to any one of claims 1 to 15 , characterized in that it is a polyester resin, a phenol resin, or a photocurable resin, and the thermoplastic resin is nylon or vinylon. fiber material.

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