JP2017155553A - Adhesive material of concrete and metal and adhesive method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To firmly adhere a metallic member to a concrete hole such as a ceiling part of a reinforced-concrete tunnel by a one-fluid epoxy adhesive so as to provide permanent joining force.SOLUTION: An outer peripheral surface 5 of a metallic female screw part 4 of an insert anchor construction unit 3, has an irregular rough surface of a period of 0.8-10 μm, and a fine irregular surface of a period of 10-300nm exists on its rough surface, and its surface is covered with a ceramic hard thin layer such as metallic oxide and metallic phosphoric oxide. A female screw part 4 of the insert anchor construction unit 3 is inserted into a concrete hole 2 of a concrete wall 1, and a one-fluid epoxy adhesive is pushed in by a bolt 7, and is adhered by heating-hardening by a heater 9.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a bonded material between concrete and metal and a bonding method thereof. More specifically, the present invention relates to a concrete-metal adhesive and its bonding method for fixing a metal member such as an anchor to a concrete structure such as a tunnel, and fixing lighting, blower equipment and the like to the metal member.

  It is said that the cause of the fall of the ceiling board in a highway tunnel, which has become a topic in recent years, is due to the corrosion of anchor bolts fixed to concrete due to secular change and the decrease in the adhesion between anchor bolts and concrete. ing. The cause was that both the deterioration of the concrete itself and the corrosion of the implanted anchor bolt itself destroyed the joint system due to water leakage around the anchor bolt hole. Furthermore, the secular change of those members after the construction of the infrastructure facilities was predicted, but sufficient maintenance management was not sufficient, resulting in a sudden collapse and a major accident. The present invention is the relationship between metals and epoxy adhesives that the inventors of the present invention have continued research and development for many years, that is, between metals, metals and CFRP (Carbon fiber reinforced plastics), metals and ceramics with epoxy adhesives, Using a technique that extended the technique of strong bonding, we examined a method that would not cause such an accident. In reaching the present invention, the following are already known information and related technologies.

(Reinforced concrete)
Concrete is water permeable and can pass carbon dioxide, oxygen, salt, etc. dissolved in water. Concrete is a basic substance, and even if the passing water is acidic water containing carbon dioxide gas etc., it becomes basic water, and the basic water does not corrode the steel material and the rebar can withstand long-term use. However, in particular, when microcracks or the like occur in concrete, it becomes a passage for rainwater and other water, and when the water-soluble basic substance of the concrete in this passage is completely melted and acidified from neutrality, corrosion of the reinforcing bars will occur. Begins. This corrosion expands the rebar and enlarges cracks in the concrete, and further increases the amount of water passing through. When the acidity of the passing water rises, the cement part that holds sand and gravel is dissolved and the concrete becomes brittle, so the weakening of both the reinforcing bars and concrete eventually accelerates.

  In order to maintain at least the surface shape and surface strength of concrete placed in such a natural environment, the most effective method is a method of coating a resin material applied to the concrete surface. Yes. Specifically, the coating of the resin material is painting using an epoxy-based floor paint. By coating the concrete with a resin material, the entrance and exit of water are closed and the passage of deterioration-causing substances is greatly suppressed. Of course, as for the reinforcing bars constituting the reinforced concrete, in recent years, painted reinforcing bars covered with an epoxy paint have become widespread, and measures against passing water in the concrete can be taken.

(NAT)
The present inventors have proposed an adhesion method named NAT (Nano adhesion tech.) Theory as an invention in the past (References 1 to 9). This bonding method has made it possible to increase the adhesive strength between metal pieces, between metal pieces and CFRP, and between metal pieces and ceramics by about twice or more than before the NAT theory was proposed. The NAT theory includes a technique for forming a metal surface with an ultra-fine concavo-convex shape that is considered to be optimal when bonding metal surfaces with an adhesive, and the type of adhesive is not limited in principle. Basically, one-component adhesive should be used (convenience of use). A metal material that has been subjected to the best NAT treatment (chemical conversion treatment according to NAT theory) can obtain a bonding force close to 80 MPa with a cured product of a one-component epoxy adhesive. In recent years, it has begun to be used in the mobile machinery manufacturing industry such as automobile aircraft. Moreover, if used correctly, the long-term water resistance and moist heat resistance of the bonding strength is high.

  However, as a difficult point, in order to use a one-component epoxy adhesive, a heat curing step of 150 to 180 ° C. is required, and although it is easy as an operation in a factory, it is difficult to construct on a civil engineering site. Therefore, it has not received much attention as an adhesive for civil engineering. Two-component cured paints, two-component epoxy adhesives, silicone sealants, etc. are commonly used as surface coatings and gap fillers in buildings such as houses and civil engineering structures. These are types that cure in a few tens of minutes to several days near room temperature, and are a group of thermosetting resins that do not require a heating operation. If the NAT-treated metal piece is bonded with a two-component epoxy adhesive instead of the one-component epoxy adhesive, unfortunately the adhesive strength is halved.

(Bar heater and thermocouple)
Due to the advancement of metal materials, resin materials, inorganic material chemistry, and metal processing technology, small bar heaters that can be heated at high temperatures with high lifetimes are mass-produced and offered at low cost. In other words, bar heaters with a diameter of 3 mm or less and capable of heating up to 300 ° C., and sheathed thermocouples with a diameter of 1 mm or less capable of measuring the temperature are also mass-produced and easily marketed without the need for special specifications. There are benefits that can be obtained. With these, it would be possible to work on site with a one-part epoxy adhesive, but as far as the present inventor is aware, it has not been adopted.

WO2008 / 114669 WO2008 / 133096 WO2008 / 133296 WO2008 / 126812 WO2008 / 133030 JP2010-064397 WO2008 / 146833 WO2009 / 084648 WO2009 / 116484 Japanese Patent Application No. 2015-97750 JP2011-26457 JP2011-148937A

  In recent years, the ceiling board collapsed in the Isogo tunnel of the Central Expressway, causing a painful injury. As a result of knowing this verification result, the present inventor thought that as an advocate of the NAT theory described above, a proposal should be made to solve a technical problem to prevent such an accident. For example, heavy equipment such as lighting equipment, a blower, and a traveling display board must be installed on the ceiling and side walls of the tunnel because of their functions. In order to prevent accidents, it is technically difficult to completely control the hanging tool fixed to the ceiling, the side wall or the like with an adhesive because there is no alternative means. For this reason, heavy equipment must be hung and attached with a lifting tool fastened to an anchor such as a bolt fixed to concrete with an adhesive. Even if a rule is made to support heavy equipment placed on the ceiling of a tunnel, etc., with a frame structure that is all set up from the side wall installed on the ground, it is judged inappropriate from the viewpoint of cost.

  Therefore, the bonding between the ceiling concrete and the metal fittings of the hanging tool is made technically reliable. On this basis, if there is no inspection for 10 years after installation, then a clear rule will be established, such as checking once every few years, and a rule, system, etc. will be established so that no omission inspection will occur. That is realistic. However, for that purpose, it is important to maintain the adhesive strength between the ceiling concrete and the anchor and monitor the deterioration over time. In order to maintain the adhesive strength, the technical level is such that the durability of the adhesive structure system itself including the surface shape of the concrete hole periphery including the concrete and the surface shape of the metal parts can be guaranteed for, for example, about 20 years without inspection. It must be. Only with these reliability and assurance by model verification, the above-mentioned rules come to life. The present invention has been invented from the above problems, and solves the following problems.

It is an object of the present invention to provide a concrete-metal bond and its bonding method, in which a concrete hole and a metal anchor bonded to the concrete hole have high bonding strength and durability and reliability. It is in.
Another object of the present invention is to heat a one-part epoxy adhesive in a concrete hole and a metal anchor bonded to the concrete hole to harden it by reducing the generation of voids. An object of the present invention is to provide an adhesive and an adhesion method thereof.

  Still another object of the present invention is to provide a concrete hole and a metal anchor bonded to the concrete hole, in which the one-part epoxy adhesive can be reliably filled in the gap between the concrete hole and the anchor. It is another object of the present invention to provide a metal adhesive and its bonding method.

The method of adhering concrete and metal of the present invention 1
There is a rough surface with irregularities with a period of 0.8 to 10 μm, and there are fine irregularities with a period of 10 to 300 nm on the rough surface, and the surface of the fine irregularities is made of metal oxide or metal phosphorous oxide. Anchor construction comprising a metal or metal alloy anchor covered with a ceramic hard thin layer, and a heater embedded member that is detachable from the anchor and has a hole that can accommodate a heater for heating. Prepare the unit and
On the other hand, a hole is drilled in the concrete wall, and the drilled hole diameter forms a concrete hole with a larger hole diameter than the outer diameter of the anchor,
After inserting the anchor into the concrete hole and filling the gap formed in the outer periphery of the anchor with a one-component epoxy adhesive, the heater is loaded into the hole of the anchor and energized, Heating to cure the one-component epoxy adhesive.

The method for adhering concrete and metal according to the present invention 2 in the present invention 1,
The anchor is a nut or a bolt in which a female screw or a male screw is formed, and the anchor and the concrete hole are temporarily fixed before being filled with the one-component epoxy adhesive.
The method for adhering concrete and metal according to the present invention 3 in the present invention 1 or 2,
The anchor construction unit is provided with a heater insertion hole for inserting and arranging the heater, and the rod-shaped heater is disposed in the heater insertion hole.

The method of adhering concrete and metal according to the fourth aspect of the present invention is the first or second aspect of the present invention.
The anchor construction unit is provided with a temperature measuring device for measuring the temperature of the heating by the heater.

Hereafter, each said element which comprises the technical idea of this invention is demonstrated in detail.
(Adhesive strength between metal and epoxy adhesive)
The present invention is an adhesive product between a metal material and concrete. This can be understood by dividing into an adhesive force between a metal material and an epoxy adhesive and an adhesive force between concrete and an epoxy adhesive. In the present invention, the NAT theory proposed by the present inventors is basically applied in order to maximize the adhesion between the metal material and the one-component epoxy adhesive. According to the experience of the present inventors, the adhesive force between the concrete and the one-component epoxy adhesive is inferior to the adhesive force between the metal material to which the NAT theory described above is applied and the one-component epoxy adhesive. Therefore, in the bonding operation with a one-component epoxy adhesive between the concrete and the metal, it is only necessary to consider only thorough the surface treatment operation on the concrete side, and therefore it is easy to find the optimum working method.

  That is, in the NAT theory, based on this theory, the bonding strength between the NAT-treated metal materials by the one-component adhesive is maximized. More specifically, the metal piece is first subjected to a surface treatment called NAT treatment. The NAT treatment is performed by subjecting the metal piece to various types of chemical conversion treatment, and as a result, (1) 0.8 to 10 μm. (2) A fine uneven surface having a period of 10 to 300 nm (preferably, a period of 50 to 100 nm) is provided on the rough surface, and (3) the entire surface of the fine uneven surface. Is a treatment method for forming a ceramic hard thin layer such as metal oxide or metal phosphate. And there are two more requirements, and the adhesive used should be (4) one-component adhesive (in the case of the present invention, one-component epoxy adhesive), (5) To include a “soaking process” step. The present inventors call the bonding work itself including (4) and (5) as the NAT bonding method.

  Actually, when the above (1) to (5) are completely carried out, the shear bond strength between the metal pieces is 70 to 80 MPa, and the tensile bond strength is 50 to 80 MPa (depending on the metal type). Different). In addition, according to the latest technology, by carrying out a more detailed surface treatment on a metal material, a method has been found in which the shear bond strength is equivalent to NAT but the tensile bond strength is 100 MPa ( (See Patent Document 10). If a metal species is selected, even if a metal pair (test piece) bonded according to the NAT theory is placed in an environment of high humidity and submersion, the adhesive force hardly decreases. For example, there is a metal species that can observe an adhesive force close to the original adhesive force even when placed in a testing machine that reproduces a high-temperature, high-humidity environment at 85 ° C. and 85% humidity.

  At present, according to the view of the inventors of the present invention, it is possible to establish a surface treatment method capable of such an adhesive pair having a long-term moisture and heat resistant function, such as aluminum, aluminum alloy, aluminum-plated steel, titanium, Titanium alloy, copper, and stainless steel of SUS304 and SUS316 (technology established as of June 2015 by the present inventors). For example, as a high-strength material for suspending and fixing a base material such as a blower or a road guide plate installed on a tunnel ceiling on a road, it is selected from the metals described above in the view of the inventors of the present invention. If present, SUS304 stainless steel is preferable from the viewpoint of the metal material price, the rust prevention power of the metal material itself, and the like.

(Theory about the adhesive strength between concrete and epoxy adhesive)
Concrete is a combination of sand and gravel with cement paste, and the concrete strength is governed by cement paste. That is, sand and gravel are called aggregates, but the adhesive strength between the aggregate and the cement paste is the strength of the concrete itself. In the case of Portland cement, add water to make a cement paste, then add and mix aggregates, place in a formwork and solidify over several days. During this time, the cement paste is solidified by changing the water to crystal water. Normally, if the curing period is 28 days after placement and curing is performed under favorable conditions, the concrete will have the highest strength after 28 days. Generally, high strength concrete has a compressive strength of 50 to 150 MPa, a tensile strength of 5 to 15 MPa, and a shear strength of 10 to 30 MPa.

  Concrete strength generally refers to the compressive strength described above, and the strength of high-strength concrete is expressed as 50 MPa or more. However, it is mainly the tensile strength and shear strength that are relevant to the present invention. That is, as described above, the adhesive force between the aggregate and the cement paste has a tensile bond strength of 5 to 15 MPa and a shear bond strength of 10 to 30 MPa. Such adhesive strength is the same level as the adhesive strength of the pair (test piece) obtained by bonding glass and ceramic materials with one-component epoxy adhesive. It is inferior to the adhesive force between a used metal piece and a one-component epoxy adhesive.

(Ensure strong adhesion between concrete and metal)
Therefore, in order to secure a high adhesive force with a one-component epoxy adhesive between concrete and metal, the necessary condition is on the concrete side rather than on the metal side. Therefore, the concrete side has to select the surface preparation method (scraping method) and clean the surface to be bonded more carefully. That is, the concrete part to be bonded is preferably cut by a cutting tool having a diamond blade or the like that can be cut well, and the drilling method of digging mainly using vibration is not preferable. Further, after the drilling operation, it is necessary to carefully remove the generated sand, cement dust, etc., keep the surface clean, and send hot air or the like to dry. By doing so, the highest adhesion between concrete and one-part epoxy adhesive is obtained. The present invention thought that this reasoning should be used first.

(Adhesion operation to attach a metal member to the ceiling of the tunnel)
However, the problem seems to be work know-how on whether the expected adhesive strength can actually be obtained at the ceiling in the tunnel. Adhesion operation using a one-part epoxy adhesive is not easy to achieve perfect adhesion strength close to the adhesion theory. The reason (1) is simply because the adhesive is paste-like or paste-like that maintains a high viscosity at room temperature. When the temperature is raised to 50 to 90 ° C., the viscosity decreases and becomes a low-viscosity liquid. When the temperature is further raised, a polymerization reaction occurs, and solidification proceeds.

  In short, since the viscosity of the adhesive decreases during the temperature rise, if the adhesive is not confined in a place to be bonded during the temperature rise, the adhesive will flow down and the adhesive will be absent. This is the most important measure for ceiling operation. Next, the reason for (2) is that a general one-component epoxy adhesive has a high curing temperature of 150 to 180 ° C., and moisture contained in the one-component epoxy adhesive, for example, moisture mixed in the manufacturing process. This means that the moisture contained by sucking moisture in the air during storage, the trace amount of low-boiling compounds contained in the production process, etc. are vaporized to form voids. As countermeasures, the layer thickness of the adhesive layer is made as thin as possible to reduce the amount of adhesive unnecessary for adhesion contained in the adhesive surface, and the place where the adhesive is present is completely sealed, The pressure is automatically increased by the expansion of itself and the evaporation of moisture at the time of temperature rise.

  The inventors of the present invention have found that the gist of the gluing operation that directly affects the gluing force is that NAT and a new method have been developed, and the tensile gluing strength of a gluing pair of metal materials is as high as 100 MPa. Because it was found to be. That is, prior to the invention of NAT, the adhesive strength of a one-part epoxy adhesive was limited to 30 to 40 MPa. With such a low level of adhesive strength, the precautions such as (1) and (2) described above do not need to be emphasized. In this regard, the present inventors have carefully studied the shape and structure on the metal material side to be bonded, and decided to propose a shape and structure with a mechanism to be described later. If the metal material having this structure is used and the bonding operation is performed according to the operation method designated by the present inventors, the measures (1) and (2) described above can be automatically performed. In short, according to the present invention, in a portion where a concrete plank forms a ceiling, a hole is made there, a metal material as an anchor is inserted, and adhesive hardening is performed with a one-component epoxy adhesive.

  The concrete-to-metal bonded material and the bonding method thereof according to the present invention are a one-part epoxy bonding method in which a concrete hole and an anchor made of metal bonded to the concrete hole have high bonding strength, durability and reliability. The agent is heated to reduce the generation of voids and harden, and the gap between the concrete hole and the anchor can be reliably filled with the one-component epoxy adhesive.

FIG. 1 is a cross-sectional view showing an intermediate part of an insert anchor that is drilled into a concrete wall according to the present invention. FIG. 2 is an adhesive pair showing the shape of a metal piece bonded with an adhesive, and is a test piece for measuring the shear bond strength of the bonded pair.

  FIG. 1 is a cross-sectional view showing an intermediate part of an insert anchor that is punched into a concrete wall according to the present invention. A concrete hole 2 for an insert anchor is drilled in a concrete wall surface (ceiling surface or the like) 1 with a concrete drill (not shown). After this drilling, the chips and the like in the concrete hole 2 are removed and cleaned. The female screw portion 4 of the insert anchor construction unit 3 is inserted into the concrete hole 2. The outer peripheral surface 5 of the female screw portion 4 has a surface subjected to NAT treatment according to the NAT theory described above. A through hole is formed in the female screw portion 4, and a female screw 6 is formed on the inner peripheral surface.

  The through hole 7 in which the female screw 6 is formed is filled with a one-component epoxy resin. Further, the male screw portion 8 of the bolt 7 is screwed into the female screw 6. A rod-shaped cartridge heater 9 having a diameter of 4 mm is disposed by being inserted into the center of the bolt 7. Further, a thermocouple 10 is inserted into the bolt 7. The thermocouple 10 measures the temperature of the bolt 7 heated by the cartridge heater 9. A socket 11 for inserting a hexagonal spanner (not shown) and turning the bolt 7 is formed at the head of the bolt 7.

[Construction method]
The outer peripheral surface 5 of the female thread portion 4 of the insert anchor construction unit 3 has a surface that has been subjected to NAT processing according to the NAT theory described above. That is, this surface has a rough surface with irregularities with a period of 0.8 to 10 μm, and has a fine irregular surface with a period of 10 to 300 nm on the rough surface, and the surface is a metal oxide or a metal phosphorous oxide. It is a metal or metal alloy covered with a ceramic hard thin layer. On the other hand, a concrete hole 2 having a hole diameter larger than the outer diameter of the outer peripheral surface 5 of the female screw portion 4 is drilled in the concrete wall 1 with a concrete drill.

  The female screw portion 4 of the insert anchor construction unit 3 is inserted into the concrete hole 2 and temporarily fixed. Even if the female screw part (a kind of nut) 4 is inserted into the concrete hole 2 having a larger diameter than the outer diameter of the female screw part 4, it cannot be fixed. I do. This temporary fixing is performed by the following method. That is, the female screw part 4 is dropped by other methods such as inserting a spacer such as a crushed stone piece or a metal piece, a jig or the like into the gap between the concrete hole 2 and the female screw part 4 or tapering the female screw part 4. Temporarily fix to stop. Furthermore, in the construction of ceilings, etc., an adhesive that cures at room temperature, such as a two-part epoxy adhesive, or a silicone filler, so that the adhesive does not leak before the one-part epoxy adhesive is heated and cured. The gap may be sealed in the outlet portion or with a sealing tape or the like. As described above, when the temporary fixing is completed, the cartridge heater 9 is energized and the bolt 7 is heated with the female screw portion 4 inserted into the concrete hole 2. Then, the bolt 7 is rotated and screwed into the female screw portion 4.

  As a result of this screwing, the through hole 15 in which the female screw 6 is formed is filled with the one-component epoxy resin. Fill the gap. Since the bolt 7 is heated, the one-component epoxy resin is also heated and is heated until the temperature reaches a predetermined temperature (for example, 150 ° C. or higher) to cure the one-component epoxy resin. The temperature at this time is measured by the thermocouple 10. When the one-component epoxy resin is cured, the bolt 7 is reversely rotated and removed. A fixing bolt for mounting the device is screwed into the female screw portion 4.

[1. Metal material]
Any practical metal or metal alloy material can be used as the metal material that can be used in the present invention. However, there are metal alloy types for which no NAT treatment method has been developed. For these, it is necessary to develop a new surface treatment method. The metal species that the inventors have not fully experimented with are pure nickel, and the practical metal species that have not been tested at all are tin, lead, gold, silver, pure iron, and the like. However, although not disclosed, the present inventors have data on NAT treatment methods for several hundred types of metal alloy materials.

[1-1. Metal material shape]
Needless to say, a nut such as the female screw portion 4 illustrated in FIG. That is, as long as a hole is made in a wall surface such as a concrete floor or ceiling, a rod-shaped metal material is inserted, and adhesive bonding is performed, the structure is not limited to the two-part structure as shown in FIG. The structure shown in FIG. 1 has to be adopted because the present invention is required to securely bond the metal material to the downward surface of the concrete structure at a high position such as a tunnel ceiling. This is because the operation to perform is the most troublesome and difficult.

[1-2. Various metals and their chemical surface treatment]
The surface treatment may be performed according to the NAT theory described above. That is, there is also a new treatment method (NAT2 treatment method: the method described in Patent Document 10) that does not necessarily follow the surface treatment method according to the NAT theory, and these are somewhat different from the NAT treatment 2 conditions (the above (1) and (2)). It is a detached shape. However, these can also be used in the present invention. In short, it is sufficient that a sufficiently high adhesive force is generated. Specific examples of the surface treatment in the NAT theory are described in Patent Documents 1 to 9. The standard procedure for NAT treatment is as follows. That is, it depends on four steps: (1) degreasing, (2) chemical etching, (3) fine etching, and (4) surface hardening.

  The basic idea is to clean the surface with chemical etching (2) (excluding dirt and rust) and at the same time create the rough surface with the micron order period (1) required by NAT. Next, the fine etching of (3) is to create a fine concavo-convex surface with a period of several tens of nanometers using a chemical method. By the processing so far, a double uneven surface shape formed by a rough surface of micron order and fine unevenness with a period of several tens of nanometers is obtained. The surface composition of the double irregular surface may have a hard and thin surface hardened film structure that can be said to be ceramic, such as metal oxide, metal phosphate, or cementite in steel. However, when the cured film on the surface is still thin and it is judged that the surface cured film structure is insufficient, or when it is prone to become a metal hydroxide (rust) quickly due to moisture, etc. The surface hardening step (4) may be placed.

(NAT metal adhesive pair with moisture and heat resistance for adhesion)
Assume that NAT-treated metal pieces are NAT-bonded with a one-component epoxy adhesive, and the adhesive pair is placed at 85 ° C and 85% humidity. Power is only gradually reduced. This is because the NAT bonding method includes “soaking treatment”. “Soaking and soaking” is a one-part epoxy adhesive with a ketone-based solvent such as MIBK. Once a low-concentration suspension is created, this is applied to a surface-treated metal piece, and then blown at a low temperature. It refers to a technique that allows the adhesive to enter the bottom of the ultra-fine concave portion of the fine uneven surface on the metal, such as drying and volatilizing and removing the solvent.

  When NAT bonding is performed, there is no gap between the metal and the cured epoxy adhesive. In other words, if it is a story on the order of nm, if there is a gap between the cured adhesive and the surface layer of the metal piece, it diffuses in the cured adhesive, and water molecules, oxygen molecules, etc. gather in this gap and the water molecules are liquid. Make Aimizu. When metal ions are dissolved in this liquid phase water, it becomes metal hydroxide (rust), which will fill the gap and expand further to push up the cured adhesive and create a new gap. Eventually, the adhesive strength will decrease. Therefore, the “soaking process” that suppresses the formation of gaps is very important in ensuring long-term wet heat resistance of the adhesive force.

  In the NAT process or the new type process (NAT2 process: Patent Document 10), there are various shapes of the ultra fine uneven surface on the metal to be generated. This ultra-fine irregular surface is related to the type of metal used, but even if a slight gap remains between the metal part and the cured adhesive, the long-term moist heat resistance of the adhesive force can be easily maintained. There are also identified. Such metal species include aluminum, aluminum alloy, titanium, titanium alloy, copper, and SUS304 and SUS316 stainless steel that have undergone NAT2 treatment or new NAT treatment. Therefore, when these are used, the adhesion between the metal material and the one-component epoxy adhesive exhibits a certain long-term wet heat resistance. The inventor believes that SUS304 is suitable as a metal material used for the anchor of the present invention. As described above, although there is a point that moisture and heat resistance is easily obtained, it is not a material that has sufficient strength and is not so expensive.

[2. Concrete material]
The inventors are not tunnel builders and do not know the details of the various regulations in the concrete grades used for tunnels. Therefore, in the present invention, a so-called high-strength concrete made from Portland cement and sand, gravel and water, that is, a concrete having a compressive strength of 50 to 150 MPa, a tensile strength of 5 to 15 MPa, and a shear strength of 10 to 30 MPa. It was.

[3.1 liquid epoxy adhesive]
Many one-component epoxy adhesives are commercially available in Japan and overseas. In the present invention, almost all of these can be used. That is, the one-component epoxy adhesive containing dicyandiamide powder as a curing agent is suitable for the “soaking treatment” using a ketone solvent (described later), and these can be used. Fortunately, dicyandiamide curable one-part epoxy adhesives are the majority of commercial products. When the shear bond strength is measured using an adhesive pair (see FIG. 2) obtained by adhering the above-described NAT-treated metal piece using the adhesion method described later, the adhesive strength at room temperature is determined by these adhesives. In the range of 60 to 90 MPa, most of the pressure was 70 to 80 MPa. In short, the adhesive strength at room temperature does not differ greatly in the one-component epoxy adhesive that is commercially available, and it does not depend on the metal species or metal alloy species as long as it is a treated product according to the NAT theory.

  One-component epoxy adhesives that are commonly used by the present inventors are “Scotch Weld (registered trademark) EW2040 (3M Japan Co., Ltd. (Head Office: Tokyo, Japan))” or “EP106NL (Cemedine Co., Ltd. (Headquarters). : Tokyo, Japan))], both of which are dicyandiamide curing type. Further, when not only the adhesive strength at normal temperature but also the adhesive strength at high temperature, for example, 150 ° C. is important, the use of “EW2040” is preferable. That is, for NAT bonding between NAT-treated A7075Al alloys, a shear bonding strength of 35 MPa at 150 ° C. was recorded by using this adhesive. If a tunnel fire or the like is assumed, it is preferable to use a heat-resistant material.

[4. Adhesive application operation]
In the NAT bonding method, an operation of “soaking treatment” is necessary, but this is the same in the present invention. The “soaking treatment” is an operation for intentionally lowering the viscosity of the one-component epoxy adhesive having a viscosity at room temperature so that the adhesive also enters the ultrafine recesses on the metal piece. Specifically, there are the following two methods.

(Use a sealed container)
Adhesive is applied to the necessary part of the metal piece, put in a desiccator heated to 50 to 70 ° C., and depressurized with a vacuum pump. After reducing the pressure for several minutes, add air and return to normal pressure. Then, the depressurization / normal pressure returning operation of reducing the pressure again is repeated several times, and then the metal piece is taken out from the desiccator. Originally the glue-like adhesive is apparently once in a liquid state, and the metal pieces with the adhesive are bonded together and fixed with clips etc., and then put into a hot air dryer as it is for the curing process. .

(Use ketone solvent)
The method described above is difficult to commercialize because a large piece of metal requires a very large bag or an autoclave. Therefore, the proposed method is very effective when the one-component epoxy adhesive to be used can be used only in the case of a dicyandiamide-curable one-component epoxy adhesive. Since most of the commercially available one-component epoxy adhesives are dicyandiamide curing type, practically all can be used (Patent Documents 11 and 12). The specific usage is as follows.

  First, the same amount or less of MIBK (methyl isobutyl ketone) is added to a one-part epoxy adhesive and mixed well to obtain a low viscosity suspension. The above-described suspension is applied to the necessary part of the metal piece, and the solvent is completely volatilized by putting it in a hot air dryer set at 50 to 60 ° C. for about 20 minutes. This is the “soaking process”. The present invention places importance on the “soaking treatment” using MIBK. The reason is that it is practical, and the soaking state is more reliable than the above-mentioned closed container method. If the amount of adhesive on the metal is thin after removing from the hot air dryer, add the original adhesive and apply a thick coat. Then, the metal pieces with adhesive are joined together, fixed with a fixing jig such as a clip, and further pressed to reduce the thickness of the adhesive layer, and then put in a hot air dryer or energized the built-in bar heater. Heat to enter the curing process.

[5. Adhesive curing operation (when using a bar heater)]
As mass-produced products in the Japanese market, there is the one with the thinnest, short heat-generating part and a large heat-generating value with a seed diameter of 2.3 mmφ, a heat-generating part length of 20 mm, and a maximum heat-generating value of 10 W. Therefore, the hole diameter to be opened in the metal part should be at least 2.5 mmφ, and the hole depth should be 20 mm or more. The minimum size of the metal part should be designed so that there is no problem in strength after the hole is provided. Furthermore, when adjusting the temperature of the metal part, a thermocouple insertion port should be provided, and the commercially available sheathed thermocouple is the thinnest one with a diameter of 0.15 mm and a hole with a diameter of 0.3 mm. Temperature measurement is possible. If a commercially available ultra-fine drill blade is used, processing is easy if the diameter is 0.3 mm and the hole depth is 10 mm.

[6. Sealing material]
(A rivet-like object is inserted and fixed in the hole opened in the tunnel ceiling.)
A suitable hole is made in the concrete ceiling, and even if the insert anchor construction unit 3 having the shape shown in FIG. 1 is filled with a one-component epoxy adhesive and pushed into the hole, it will still fall, but a concrete piece will be pushed into the gap. Temporarily fix with. Thereafter, the screw 7 is screwed into the female thread portion 4 of the insert anchor construction unit 3 to push out the one-component epoxy adhesive, but before that, the gap opened at the lower part must be sealed. For this simple sealing, an adhesive that cures at room temperature and a sealing material (sealing material) are required.

(Sealing operation and drilling)
Although it may be sealed with a sealing tape or the like, a silicone sealant seems to be most suitable. The last step of the bonding operation is a one-component epoxy adhesive heat-curing step, and a high temperature of about 170 ° C. is also applied to the seal portion, so a certain heat-resistant sealing material is required, but two-component There seems to be no use of epoxy adhesives. Many types of silicone sealing materials are produced and sold, and one-part, room-temperature-curing types that are moderately heat-resistant are commercially available. This work itself has no special points. Similar to the work of seam sealing of the sewer pipe, it is sufficient to sufficiently close the circumferential gap.

  Assuming that the sealing material solidifies after about one day after the sealing operation, it is often the case that an injection needle is inserted into the sealing material to create a sealing leakage point. That is, for sealing with an adhesive, the bolt 7 is screwed into the female screw portion 4 of the insert anchor construction unit 3 in the shape of FIG. 1 to overflow the adhesive, and the entire space between the female screw portion 4 and the concrete hole 2 is filled. I want to fill it with glue, but I have to escape the air that was originally there. If the above-described sealing is complete, and there is no air escape path in concrete, there will be no place for air to flow. Normally, if there is a gap on the top surface of the concrete thick wall that forms the tunnel ceiling, etc., or if there is no strong water pressure, the concrete itself is slightly breathable, so a needle is inserted to intentionally create an air escape route. There is no need. This is therefore a field judgment.

Hereinafter, embodiments of the present invention will be described by way of examples.
(A) Electron microscope observation SEM type electron microscopes “S-4800 (manufactured by Hitachi High-Technologies Corporation (head office: Tokyo))” and “JSM-6700F (manufactured by JEOL Ltd. (head office: Tokyo))” Used and observed at 1-2 KV.
(B) Scanning probe microscope observation “SPM-9600 (manufactured by Shimadzu Corporation (head office: Kyoto))” was used.

[Example of rivet shape] and [Adhesion work example]
FIG. 1 shows a state in which the insert anchor construction unit 3 and its female screw portion 4 are inserted into a concrete hole 2 opened in a concrete ceiling and temporarily fixed. In actual work, the insert anchor construction unit 3 comprising two parts shown in FIG. 1 is created by machining. SUS304 stainless steel was used as the metal material.

  The female screw portion 4 was subjected to a heat and moisture resistant NAT treatment in the following liquid treatment process. That is, an aqueous solution (60 ° C.) containing 10% of a commercially available aluminum degreasing agent was prepared in a tank, and the parts were immersed for 5 minutes and washed with water. Next, an aqueous solution (40 ° C.) containing 1.5% caustic soda was prepared in another tank, and the components were immersed in this for 1 minute and washed with water. Next, an aqueous solution (65 ° C.) containing 5% sulfuric acid and 1% ammonium difluoride was prepared in another tank, and the female screw part 4 was immersed for 8 minutes and washed with water. Then, a 3% nitric acid aqueous solution was prepared in another tank, and the female screw part 4 was immersed for 3 minutes and washed with water. Subsequently, 1% ammonia water was prepared in another tank, and the female screw part 4 was immersed for 3 minutes and washed with water. Next, an aqueous solution (55 ° C.) containing 5% sodium chlorite and 10% sodium hydroxide was prepared in another tank, and the female screw part 4 was immersed for 5 minutes and washed with water. These were placed in a hot air dryer set at 80 ° C. for 15 minutes and dried.

  The middle part of the other part was subjected to the following cleaning process to remove oil and finger grease by machining. That is, an aqueous solution (60 ° C.) containing 10% of a commercially available aluminum degreasing agent was prepared in an immersion tank, and the parts were immersed for 5 minutes and washed with water. Next, an aqueous solution (40 ° C.) containing 1.5% caustic soda was prepared in another tank, and the components were immersed in this for 1 minute and washed with water. These were also put in a hot air dryer set at 80 ° C. for 15 minutes and dried. All parts were stored in aluminum foil or OPP film bags.

  A 12 cm thick reinforced concrete ceiling board was scraped vertically upward using a super steel type concrete drill blade with a diameter of 31 mm to a depth of 81 mm as shown in FIG. Next, high pressure water was fed through a 5 mm diameter pipe to remove scraps. Next, hot air was sent to the top of the hole for 30 minutes using a dryer and dried.

  On the other hand, take several grams of 1-component epoxy adhesive “Scotch Weld EW2040 (3M Japan Co., Ltd.)” in a paper cup, take the same amount of solvent MIBK (methyl isobutyl ketone) and mix well with one chopstick to form a suspension. did. Then, wearing kitchen gloves, the upper part and the lower part of the outer part of the rivet were pinched and the suspension was applied to the entire outer surface with a brush. This was put into a hot air dryer and heated by blowing air at 55 ° C. for 20 minutes to volatilize the solvent (if the small hot air dryer could not be brought to the site, it could be left in the outside air for about 1 hour) . Next, the middle part is screwed into the rivet-like shape shown in FIG. 1, and the one-part epoxy adhesive “EW2040” is filled in the dent portion formed at the top, and the adhesive is filled. Later, rivets were inserted into the concrete holes as far as they could go.

  Then, 3-4 pieces of crushed stone pieces were used in the gap between the rivet-like material formed in the lower portion and the hole, and the insert anchor construction unit 3 was temporarily fixed so as not to fall. Next, the gap was filled using a silicone sealant “POS seal speed (Cemedine Co., Ltd. (head office: Tokyo))”. That is, the depth of about 10 mm of the gap was filled with the sealing material. Then, it was left to harden until the next day.

  It was confirmed by finger pressing that the sealing material was cured, and then the middle part of the insert anchor construction unit 3 was twisted and slowly pushed. When the sealing is complete, the gap portion is in a pressurized state, and a reaction force is felt by turning the pushing bolt 7. In that case, after resting for a while, the screwdriver was turned again, and if the reaction force decreased from the previous time, the screwdriver was advanced again. When the screw is finally turned and the reaction force does not decrease, the needle is inserted into the sealing material to check whether air is discharged. If air comes out, screw it in further and push it in. And when it is pushed all the way to the end, it will be finished, but if the reaction force due to screwing becomes high before pushing, and the syringe needle is pulled out and the adhesive has clogged the needle first, the bolt 7 is further turned only once. Screw in to finish this operation.

  A hole in the rivet is loaded with a bar heater, and a thermocouple is loaded into the narrow hole, and the heating operation is performed at 170 ° C. for 60 minutes. There is a possibility that the sealing part will loosen and the rivet-like object may fall during the temperature rise from room temperature to 170 ° C. To prevent the accident, it is perfectly possible to support the lower part of the rivet-like object with a stick-like object from the lower floor. It is.

Claims (4)

There is a rough surface with irregularities with a period of 0.8 to 10 μm, and there are fine irregularities with a period of 10 to 300 nm on the rough surface, and the surface of the fine irregularities is made of metal oxide or metal phosphorous oxide. Anchor construction comprising a metal or metal alloy anchor covered with a ceramic hard thin layer, and a heater embedded member that is detachable from the anchor and has a hole that can accommodate a heater for heating. Prepare the unit and
On the other hand, a hole is drilled in the concrete wall, and the drilled hole diameter forms a concrete hole with a larger hole diameter than the outer diameter of the anchor,
After inserting the anchor into the concrete hole and filling the gap formed in the outer periphery of the anchor with a one-component epoxy adhesive, the heater is loaded into the hole of the anchor and energized, A method for adhering concrete and metal, comprising heating and curing the one-component epoxy adhesive. In claim 1,
The anchor is a nut or a bolt in which a female screw or a male screw is formed, and the concrete and the concrete hole are temporarily fixed before filling with the one-component epoxy adhesive. Metal bonding method. In the present invention 1 or 2,
The anchor construction unit has a heater insertion hole for inserting and arranging the heater, and the rod-shaped heater is disposed in the heater insertion hole. . In the present invention 1 or 2,
The anchor construction unit is provided with a temperature measuring device for measuring the temperature of the heating by the heater. The method for bonding concrete and metal.

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