JP2017215292A - Method and device for evaluating bond strength of repair material layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for evaluating the bond strength of a repair material layer, capable of correctly evaluating the bond strength of the repair material layer even in an environment difficult to use an adhesive and evaluating bond strength in a deep portion of the repair material layer, and excellent in safety of work and maintenance of work environment.SOLUTION: A method for evaluating bond strength between a base 1 and a repair material layer 2 formed on the surface of the base 1 comprises: a drilling step of forming an insertion hole 3 in the repair material layer 2; an insertion step of arranging a fixture 4 having a penetration part 21 on the surface 2a of the repair material layer 2 and inserting one or more extension anchors 5 into the insertion holes 3 through the penetration part 21 of the fixture 4; a fixing step of fixing the fixture 4 to the repair material layer 2 by engaging the extension anchors 5 on the inner surfaces of the insertion holes 3; and an evaluation step of adding a tensile load in a direction separated from the base 1 to the fixture 4 to separate a fragment including at least a part of the repair material layer 2 and evaluating the bond strength on the basis of the fragment.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an evaluation method and an evaluation apparatus for adhesion strength of a repair material layer.

In water use facilities such as a drainage channel for agricultural use, the surface of a concrete frame or the like may be worn by running water. In addition, repair may be required due to deterioration of the concrete frame or the like.
For this reason, repair of a concrete frame or the like with a repair material such as cement or polymer cement is performed. For example, a concrete frame can be repaired by forming a repair material layer made of a repair material on the surface of the concrete frame (see, for example, Patent Document 1).
As a method for confirming the secular change or the like of the repair material layer, the adhesion strength of the repair material layer to the structure is evaluated (for example, see Non-Patent Document 1). Hereinafter, an example of a conventional method for evaluating the adhesion strength of a repair material layer will be described with reference to FIG.

As shown in FIG. 14A, after cleaning the surface 2a of the repair material layer 2 formed on the base 1 such as a concrete frame, the fixing jig 54 is bonded to the surface 2a with an adhesive such as an epoxy. After curing and curing the adhesive, as shown in FIG. 14B, a cutting tool 51 such as a disk grinder is used to form a cut 52 surrounding the fixing jig 54 in the repair material layer 2.
As shown in FIG. 14C, a tensile load is applied to the fixing jig 54 by the connecting shaft 42 connected to the fixing jig 54. A part of the repair material layer 2 is broken and separated, and the adhesion strength of the repair material layer 2 can be evaluated based on the tensile load at that time.

Japanese Patent No. 2855563

Mori, et al., “Consideration on Performance Evaluation of Waterway Repair Method”, Rural Engineering Laboratory Technical Report, Rural Engineering Laboratory, No. 210 (2009), p. 203-225

However, in the conventional evaluation method, when the measurement is required in a humid environment or in water in a water channel or the like, the adhesive may not exhibit sufficient adhesive strength, and the adhesion strength of the repair material layer 2 may be set correctly. It was difficult to evaluate.
Further, in the conventional method, since a tensile load is applied to the surface 2a of the repair material layer 2 by the fixing jig 54, the adhesion strength at the deep portion of the repair material layer 2 cannot be evaluated.
Furthermore, since the conventional method uses the cutting tool 51, it is necessary to pay attention to ensuring the safety of the operator. In addition, there has been a problem of deterioration of the working environment due to scattering of cutting powder when forming the cut 52.

  The present invention can correctly evaluate the adhesion strength of the repair material layer even in an environment where it is difficult to use the adhesive, and can evaluate the adhesion strength in the deep part of the repair material layer. An object of the present invention is to provide an evaluation method and an evaluation apparatus for the adhesion strength of a repair material layer that are excellent in terms of maintenance.

One aspect of the present invention is an adhesion strength evaluation method for evaluating the adhesion strength between a foundation and a repair material layer formed on the surface of the foundation, wherein the perforation forms an insertion hole in the repair material layer. A step of disposing a fixing jig having a penetrating portion on the surface of the repair material layer, inserting one or more metal anchors into the insertion hole through the penetrating portion of the fixing jig, and A fixing step of fixing the fixing jig to the repair material layer by engaging with the inner surface of the insertion hole; and a tensile load in a direction away from the base is applied to the fixing jig, and at least one of the repair material layers An evaluation method for separating a debris including a portion and evaluating the adhesion strength based on the debris is provided.
In the evaluation step, it is preferable to measure the relationship between the displacement of the fragments and the tensile load.
In the drilling step, it is preferable that a guide jig having a guide hole is disposed on the surface of the repair material layer, and a drilling tool is applied to the repair material layer through the guide hole to form the insertion hole.

  One aspect of the present invention is an adhesion strength evaluation apparatus for evaluating the adhesion strength between a base and a repair material layer formed on the surface of the base, and a perforation for forming an insertion hole in the repair material layer A tool, a fixing jig that has a through-hole and is disposed on the surface of the repairing material layer, and is inserted into the insertion hole through the through-hole of the fixing jig and locked to the inner surface of the repairing material layer A metal anchor that fixes the fixing jig to the repair material layer, and a tension means that applies a tensile load in a direction away from the base to the fixing jig and separates fragments including at least a part of the repair material layer; An apparatus for evaluating the adhesion strength of a repair material layer is provided.

The pulling means has a reaction force portion for taking a reaction force when applying a tensile load to the repair material layer on the fixing jig, and the reaction force portion is an opening through which the fixing jig can pass. It is preferable that the opening is formed so that a range in which a tensile load is applied to the repair material layer by the fixing jig is limited.
The depth from the surface of the repair material layer where the plurality of metal anchors are engaged with the inner surface of the insertion hole, and the outer dimensions of the metal anchor are the conical fracture surface of the metal anchor. The cone projection areas projected onto the surface do not overlap each other, and the total area of the cone projection areas is 80% or more of the maximum total area when the cone projection areas do not overlap. It is preferable that
It is preferable that the penetration part has an open end on an outer peripheral edge of the fixing jig.
The metal anchor has a cylindrical anchor main body having a tip portion divided into a plurality of projecting piece-like expansion portions by slits, and presses the expansion portion from the inside to expand the expansion portion to the inner surface of the insertion hole. It is preferable to have a pressing body to be locked.

According to one aspect of the present invention, since the fixing jig is fixed to the repair material layer by the metal anchor, the adhesion strength of the repair material layer can be correctly evaluated even in an environment where the adhesive material cannot be used.
Since the metal anchor is locked to the inner surface of the insertion hole, a tensile load can be applied to the deep part of the repair material layer. Therefore, strength evaluation in the deep part of the repair material layer is possible.
Further, since it is not necessary to form a cut in the repair material layer, and it is not necessary to use a cutting tool or the like, it is easy to ensure the safety of the operator, and it is possible to avoid deterioration of the working environment due to scattering of cutting powder.
Furthermore, since no adhesive is used, it is not necessary to secure time for curing and curing the adhesive, and the time required for work can be shortened.

It is process drawing explaining the outline of the evaluation method of the adhesion strength of embodiment. It is process drawing explaining the process of forming an insertion hole in a repair material layer in the evaluation method of the adhesion strength of embodiment. (A) It is a top view of a guide jig. (B) It is a side view of a guide jig. It is a figure explaining the operation | work which cleans an insertion hole. It is process drawing which shows the state which has arrange | positioned the fixing jig on the surface of the repair material layer. (A) It is a top view of a fixing jig. (B) It is a side view of a fixing jig. It is process drawing explaining the process of inserting an expansion anchor into an insertion hole, and the process of fixing a fixing jig to a repair material layer. (A) It is a side view which shows the expansion anchor inserted in the insertion hole. (B) It is a side view which shows the expansion anchor latched by the inner surface of the insertion hole. (A) It is a top view for demonstrating a cone-shaped projection area | region. (B) It is sectional drawing for demonstrating a cone-shaped projection area | region. (A) It is a side view of the partial cross section which shows a tensile testing machine. (B) It is a top view which shows the reaction force board of a tensile testing machine. It is process drawing which shows the process of evaluating adhesion strength. It is process drawing following a previous figure. It is a top view of the other example of a fixing jig. It is process drawing explaining the outline of the conventional evaluation method of adhesion strength.

Hereinafter, with reference to drawings, the evaluation method of the adhesion strength of the repair material layer of embodiment is demonstrated.
In irrigation facilities such as a drainage channel for agricultural drainage, a base (concrete frame or the like) can be repaired by forming a repair material layer made of a repair material on the surface of the base that is a concrete frame or the like.

[Evaluation equipment for adhesion strength of repair material layer]
In order to confirm the secular change of the repair material layer, the adhesion strength of the repair material layer can be evaluated.
Drawing 1 is a flowchart explaining the outline of the evaluation method of the adhesion strength of an embodiment. The evaluation apparatus shown in FIG. 1 can be used for the evaluation method of this embodiment. This evaluation apparatus includes a drilling tool 14, a guide jig 11, a fixing jig 4, an expansion anchor 5, and a tensile tester 40 (a tension means, a measurement unit).
The evaluation method of the adhesion strength of the repair material layer according to the present embodiment includes a drilling step, an insertion step, a fixing step, and an evaluation step. Hereinafter, each step will be described in detail.

[Method for evaluating adhesion strength of repair material layer]
<Punching process>
1A and 2 are process diagrams illustrating a process of forming the insertion hole 3 in the repair material layer 2 in the adhesion strength evaluation method of the embodiment. FIG. 3A is a plan view of the guide jig 11. FIG. 3B is a side view of the guide jig 11. FIG. 4 is a diagram illustrating an operation for cleaning the insertion hole 3.
3A and 3B, the X direction and the Y direction are directions along one end face 11a of the guide jig 11 and are orthogonal to each other. The Z direction is a direction orthogonal to the X direction and the Y direction, and is a direction along the central axis C1.

As shown in FIG. 2, the foundation 1 is a concrete frame such as a water channel to be repaired, for example. The repair material layer 2 is made of a repair material such as an inorganic material such as cement (for example, mortar) or polymer cement (for example, polymer mortar). The thickness of the repair material layer 2 is, for example, 5 to 50 mm (preferably 5 to 20 mm).
As shown in FIGS. 3A and 3B, the guide jig 11 is, for example, cylindrical, and has a plurality of guide holes 12 along the direction of the central axis C1. A discharge recess 13 for discharging the cutting powder in the guide hole 12 is formed on the side surface of the guide jig 11. For example, the discharge recess 13 is formed over the entire circumference along the circumferential direction of the guide jig 11. The guide jig 11 is formed with a handle 20 for facilitating the handling of the guide jig 11. The handle 20 is formed so as to protrude from the side surface of the guide jig 11 outward in the radial direction of the guide jig 11, for example.

  The guide hole 12 is perpendicular to the end face 11 a and is formed in accordance with the position where the insertion hole 3 is to be formed in the repair material layer 2. The guide hole 12 is formed through the guide jig 11 from one end surface 11a to the other end surface 11b. The guide hole 12 has, for example, a circular cross section, and the inner diameter thereof is substantially the same as or slightly larger than the outer diameter of the drilling tool 14. Therefore, tilting of the drilling tool 14 can be restricted when the drilling tool 14 is inserted.

As shown in FIG. 3A, the guide holes 12 can be provided, for example, at four locations. Of the four guide holes 12, the first and second guide holes 12A and 12B are formed at positions away from the third and fourth guide holes 12C and 12D in the Y direction. The first and third guide holes 12A and 12C are formed at positions away from the second and fourth guide holes 12B and 12D in the X direction.
As shown in FIG. 2, one end surface 11 a of the guide jig 11 is a contact surface that contacts the surface 2 a of the repair material layer 2.

  The dimension L1 of the guide jig 11 in the central axis direction is determined when the drill portion 15 of the drilling tool 14 is inserted into the guide hole 12 and the insertion hole 3 having a predetermined depth is formed in the repair material layer 2. It is preferable that the 14 step portions 17 have such a size as to contact the end surface 11b.

  As the drilling tool 14, a rotary tool such as a hammer drill or a core drill can be used. The drilling tool 14 has, for example, a drill part 15 and a base part 16 whose outer dimension is larger than the outer diameter of the drill part 15. A stepped portion 17 is formed at the tip of the base portion 16 due to the difference in the external dimensions of the base portion 16 and the drill portion 15.

By placing the guide jig 11 on the surface 2a with the end face 11a facing the surface 2a of the repair material layer 2, inserting the drilling tool 14 into the guide hole 12, and hitting the repair material layer 2 through the guide hole 12 An insertion hole 3 is formed in the repair material layer 2.
The insertion hole 3 is formed in the thickness direction of the repair material layer 2. The insertion hole 3 is formed in part or all of the thickness range of the repair material layer 2 from the surface 2 a of the repair material layer 2, and does not reach the base 1.
The guide jig 11 is formed such that when the insertion hole 3 having a predetermined depth is formed in the repair material layer 2, the stepped portion 17 of the drilling tool 14 abuts against the end surface 11b and the lowering is restricted. The insertion hole 3 does not become too deep, and the insertion hole 3 having an appropriate depth can be formed.
Moreover, since the attitude | position of the drill part 15 of the drilling tool 14 is optimized by the guide hole 12, the formation direction of the insertion hole 3 is optimized. Therefore, the insertion hole 3 can be accurately formed in a direction perpendicular to the surface 2 a of the repair material layer 2.
Part of the cutting powder generated when the insertion hole 3 is formed in the repair material layer 2 is discharged from the guide hole 12 to the outside through the discharge recess 13.

  As shown in FIGS. 1B and 4, cutting powder of the repair material layer 2 generated when the insertion hole 3 is formed by the drilling tool 14 remains in the insertion hole 3. The suction pipe 19 is inserted into the insertion hole 3, and the cutting powder is sucked and removed through the suction pipe 19. Thereby, the inside of the insertion hole 3 can be cleaned.

<Insertion process>
As shown in FIG. 5, the fixing jig 4 is disposed on the surface 2 a of the repair material layer 2.
As shown in FIGS. 6A and 6B, the fixing jig 4 is formed in a thick plate shape having a rectangular shape in plan view. One surface of the fixing jig 4 is a contact surface 4 a that faces the repair material layer 2. The other surface of the fixing jig 4 is referred to as an outer surface 4d.
6A and 6B, the X direction and the Y direction are directions along the contact surface 4a of the fixing jig 4 and are orthogonal to each other. The Z direction is a direction orthogonal to the X direction and the Y direction and is the thickness direction of the fixing jig 4. Of the four sides of the fixing jig 4 in plan view, the opposite sides 4b and 4b (the first opposite side 4b1 and the second opposite side 4b2) parallel to each other are sides along the Y direction.

The fixing jig 4 has a plurality of through portions 21 for positioning the expansion anchor 5 and a connection portion 22 to which a connection shaft 42 of the tensile testing machine 40 is connected.
The penetration part 21 penetrates the fixing jig 4 in the thickness direction, and is formed to open to the contact surface 4a. The fixing jig 4 has, for example, four penetrating parts 21, and these four penetrating parts 21 are slit-like having open ends 21 a on outer peripheral edges 4 c and 4 c of opposing sides 4 b and 4 b of the fixing jig 4 that are parallel to each other. Is formed.

Of the four penetrating parts 21, two penetrating parts 21 having an open end 21a on the first opposing side 4b1 are perpendicular to the first opposing side 4b1 from the first opposing side 4b1 toward the second opposing side 4b2 in plan view. (Ie, along the X direction). The two penetration parts 21 are formed at intervals in the length direction of the first opposing side 4b1.
The remaining two penetrating portions 21 are formed perpendicularly to the second opposing side 4b2 (that is, along the X direction) from the second opposing side 4b2 toward the first opposing side 4b1 in plan view. The two penetration parts 21 are formed at intervals in the length direction of the second opposing side 4b2.

The innermost part of the penetrating part 21 is a movement restricting part 21 b that can be positioned by contact with the expansion anchor 5. The planar view position of the movement restricting portion 21b is determined according to the planar view position of the insertion hole 3 (see FIG. 5). Since the movement restricting portion 21b is formed along the Z direction, when the expanding anchor 5 is brought into contact with the movement restricting portion 21b, the expanding anchor 5 is easily inserted into the insertion hole 3.
The width W1 (dimension in the Y direction) of the penetrating portion 21 is determined so that the expanded anchor 5 can pass through. It is preferable that the penetration part 21 has a fixed width | variety in the length direction (X direction) from the open end 21a to the movement control part 21b.

As shown in FIG. 1C and FIG. 7, the expansion anchor 5 (metal anchor) is inserted into the insertion hole 3 through the through portion 21 of the fixing jig 4.
Since the expansion anchor 5 is restricted from moving inward (moving away from the open end 21a along the X direction) by the movement restricting portion 21b, the expansion anchor 5 is adjusted to a position where the expansion anchor 5 can be inserted into the insertion hole 3. Operation is easy.

As shown in FIG. 8A, the expansion anchor 5 includes an anchor main body 30 having an insertion hole 31 and a core rod 32 (pressing body) inserted into the insertion hole 31. The anchor main body 30 includes a cylindrical main portion 33 and a head portion 34 provided at the base end of the main portion 33. Since the head portion 34 has an outer dimension (outer diameter) larger than the width of the penetrating portion 21, the anchor main body 30 has the length in the length direction of the anchor main body 30 when the head portion 34 abuts on the outer surface 4 d of the fixing jig 4. Positioning is done.
The expansion anchor 5 is made of metal (for example, stainless steel).

A bulging portion (not shown) that bulges inward is formed on the inner surface of the insertion hole 31 in a predetermined length range from the tip 30a of the anchor body 30.
A plurality of slits 36 are formed along the length direction of the main portion 33 from the distal end 30 a to the distal end portion 35 which is a portion including the distal end 30 a of the anchor main body 30, and the distal end of the anchor main body 30 is formed by these slits 36. The part 35 is divided into a plurality of projecting piece-like expansion parts 37.
The expansion part 37 can be deformed radially outward (expansion direction) when pressed outward by the distal end part 32 a of the core rod 32.

<Fixing process>
As shown in FIG. 7, the core rod 32 inserted into the insertion hole 31 of the expansion anchor 5 is driven into the anchor main body 30 with a hammer 38 or the like.
As shown in FIG. 8B, when the core rod 32 is driven, the distal end portion 32a of the core rod 32 presses the bulging portion (not shown) of the anchor body 30 outward, and the expansion portion 37 is expanded. To be engaged with the inner surface of the insertion hole 3.
Thereby, since the expansion anchor 5 is fixed to the repair material layer 2, the fixing jig 4 can be fixed to the repair material layer 2.

  In the example shown in FIG. 8B, the distal end of the expanded portion 37 of the expanded anchor 5 is locked at a depth D1 from the surface 2a of the repair material layer 2, but the length of the main portion of the anchor body is different. If the expansion anchor is used, the depth position of the locking portion of the expansion anchor can be adjusted. This makes it possible to evaluate the adhesion strength at an arbitrary position in the depth direction of the repair material layer 2.

9 (A) and 9 (B), a conical portion (conical fracture portion 24) in the case where a conical fracture occurs in the repair material layer 2 by applying a force in the pulling direction to the expansion anchor 5 is shown. ).
The cone-shaped fracture portion 24 has a conical shape that spreads toward the surface 2 a of the repair material layer 2 with the tip of the expansion anchor 5 (tip of the extension portion 37) as a vertex. A cone-shaped fracture surface 24 a that is a side surface of the cone-shaped fracture portion 24 is inclined at 45 ° with respect to the surface 2 a of the repair material layer 2.

As shown in FIG. 9A, a projection area obtained by projecting the cone-shaped fracture surface 24 a onto the surface 2 a of the repair material layer 2 is defined as a cone-shaped projection area 25. The cone-shaped projection area 25 is circular, for example. The area of the cone-shaped projection region 25 is referred to as an effective projection area (effective horizontal projection area).
The depth D1 (see FIG. 8 (B)) of the locking portion of the expansion anchor 5 and the outer dimensions (the outer diameter of the expansion portion 37) of the locking portion of the expansion anchor 5 are as follows. It is preferable that the cone-shaped projection regions 25 are designed so as not to overlap each other and the total area of the cone-shaped projection regions 25 is maximized. The total area of the cone projection region 25 is maximized when the circles forming the cone projection region 25 are in contact with each other. The total area of the cone projection regions 25 is preferably 80% or more with respect to the maximum value of the total area. Thereby, the tensile load applied by the expansion anchor 5 can be efficiently transmitted to the repair material layer 2.

<Evaluation process>
As shown in FIG. 10A, a tensile tester 40 is prepared.
The tensile testing machine 40 includes a testing machine main body 41 provided with a connecting shaft 42, a plurality of legs 43 provided on the testing machine main body 41, a reaction force plate 44 (reaction force part), and the testing machine main body 41. A driving unit 45 for driving and a data processing unit 46 are provided.
The tester main body 41 has, for example, a hydraulic cylinder (shaft moving mechanism). The drive unit 45 can move the connecting shaft 42 in the length direction by operating the hydraulic cylinder of the tester main body 41 by rotating the rotary handle 47.
The connecting shaft 42 is connected to the connecting portion 22 of the fixing jig 4 by screwing or the like.

As shown in FIG. 10B, the reaction force plate 44 has, for example, a rectangular shape in plan view. The reaction force plate 44 has an opening 44a through which the fixing jig 4 can pass. The opening 44a preferably has a plan view shape that matches the outer shape of the fixture 4 in plan view. The lower surface 44 b of the reaction force plate 44 can come into surface contact with a region surrounding the fixing jig 4 in the surface 2 a of the repair material layer 2. When the connecting shaft 42 applies a tensile load to the fixing jig 4, the reaction force plate 44 can apply a reaction force to the repair material layer 2 in an area surrounding the fixing jig 4 in a plan view.
The reaction force plate 44 is preferably fixed to the tip of the leg portion 43.
The data processing unit 46 has a display unit (not shown) for displaying the tensile load.

As shown in FIGS. 10A and 11, the tensile testing machine 40 is installed so that the reaction force plate 44 abuts the region surrounding the fixing jig 4 on the surface 2 a of the repair material layer 2, and the connecting shaft 42. Is connected to the connecting portion 22 of the fixing jig 4.
By operating the hydraulic cylinder of the testing machine main body 41 by rotating the rotary handle 47, the connecting shaft 42 is raised, and a tensile load in a direction away from the base 1 is applied to the fixing jig 4.

As shown in FIG. 10 (B), the reaction force plate 44 has an opening 44a in which the fixing jig 4 is disposed, so that the range of the repair material layer 2 to which a tensile load is applied is exposed in the opening 44a. Limited to range. Therefore, the measurement conditions can be made constant and the measurement accuracy can be increased.
Since the range of the repair material layer 2 to which the tensile load is applied is limited to the inside of the opening 44a, the adhesion of the repair material layer 2 based on the measured value of the tensile load applied to the repair material layer 2 and the area of the opening 44a. Strength can be calculated. The unit of adhesion strength is N / mm ² , for example.

As shown in FIG. 12, the tensile load applied to the fixing jig 4 is gradually increased, and the debris 48 including at least a part of the repair material layer 2 is separated from other parts.
The tensile load in the process of separating the fragments 48, that is, the relationship between the tensile load and the displacement of the fragments 48 is displayed on a display unit (not shown) of the data processing unit 46. Based on the relationship between the tensile load applied to the fixing jig 4 and the displacement of the fragments 48, the process of breaking the repair material layer 2 can be estimated.

When the fragments 48 are separated, if the fracture of the repair material layer 2 does not reach the interface with the base 1, the adhesion strength of the repair material layer 2 to the base 1 is greater than the strength of the repair material layer 2 itself. Is also considered high. Therefore, it may be evaluated that the repair material layer 2 is attached to the base 1 with a sufficiently high adhesion strength.
When the fragments 48 are separated at the interface with the base 1 and separated, it is considered that the adhesion strength of the repair material layer 2 to the base 1 is lower than the strength of the repair material layer 2 itself. It can be evaluated that the adhesion strength of the layer 2 is not sufficient.
When the fragments 48 are peeled off at the interface, the tensile load when the fragments 48 are separated can be evaluated as the adhesion strength of the repair material layer 2. The tensile load when the fragments 48 are separated is, for example, the maximum value of the tensile load in the process of separating the fragments 48.
When the rupture extends not only to the repair material layer 2 but also to the base 1, the adhesion strength of the repair material layer 2 to the base 1 is considered to be higher than the strength of the base 1 itself. In some cases, it can be evaluated that the substrate 1 has a sufficiently high adhesion strength.
In this way, the adhesion strength of the repair material layer 2 to the base 1 can be evaluated based on the fragments 48.

The debris 48 peeled off from the base 1 is broken and removed from the fixing jig 4 together with the expansion anchor 5.
As described above, since the spreading anchor 5 can pass through the penetrating portion 21, the spreading anchor 5 is moved together with the fragments 48 in the length direction of the penetrating portion 21 (X direction in FIG. 6A). The fixing jig 4 can be easily removed through the open end 21a.
The fixing jig 4 from which the expansion anchor 5 has been removed can be reused in an adhesion strength evaluation test. Unlike the method of fixing the fixing jig to the repair material layer 2 with an adhesive, the evaluation method of the present embodiment re-attaches the fixing jig 4 as it is without performing pre-treatment such as removal of adhered substances (adhesive). Since it can be used, work efficiency can be improved.

In the evaluation method of the present embodiment, the fixing jig 4 is fixed to the repair material layer 2 by the expansion anchor 5, so that the fixing jig 4 can be firmly fixed to the repair material layer 2. Therefore, the adhesion strength of the repair material layer 2 can be correctly evaluated even in an environment where the adhesive cannot be used, such as in a humid environment or in water.
In addition, since the fixing jig 4 can be firmly fixed to the repair material layer 2 by the expansion anchor 5, when the surface 2a of the repair material layer 2 has irregularities, when the surface 2a has adhesion of organic matter, etc. In addition, the adhesion strength of the repair material layer 2 can be correctly evaluated.

Since the expansion anchor 5 is locked to the inner surface of the insertion hole 3, a tensile load can be applied to the deep part of the repair material layer 2. Therefore, strength evaluation in the deep part of the repair material layer 2 becomes possible.
Further, it is not necessary to form a cut in the repair material layer 2, and it is not necessary to use a cutting tool or the like, so that it is easy to ensure the safety of the operator. Since it is not necessary to form a cut in the repair material layer 2, it is possible to avoid deterioration of the working environment due to scattering of cutting powder.
Furthermore, since no adhesive is used, it is not necessary to secure time for curing and curing the adhesive, and the time required for the evaluation test can be shortened.
Moreover, since a cutting tool is not used, an evaluation test can be performed even in an environment without a power source.

The evaluation device of the present embodiment can firmly fix the fixing jig 4 to the repair material layer 2 by the expansion anchor 5, so that the repair can be performed even in an environment where an adhesive cannot be used, such as in a humid environment or underwater. The adhesion strength of the material layer 2 can be correctly evaluated.
Further, since the fixing jig 4 can be fixed to the repair material layer 2 by the expansion anchor 5, it is possible to evaluate the strength of the repair material layer 2 in the deep portion. Further, since it is not necessary to use a cutting tool or the like, it is easy to ensure the safety of the operator, and it is possible to avoid deterioration of the working environment due to scattering of cutting powder.
Since it is not necessary to secure time for curing and curing the adhesive, the time required for the work can be shortened. Moreover, since a cutting tool is not used, an evaluation test can be performed even in an environment without a power source.

The embodiment of the present invention has been described above. However, the configuration in the embodiment is an example, and the addition, omission, replacement, and other modifications of the configuration can be made without departing from the spirit of the present invention.
For example, in the adhesion strength evaluation method of the embodiment, the spread anchor is used as the metal anchor, but the metal anchor may be a metal anchor that can be fixed to the insertion hole by screwing, for example. Further, the expansion anchor is not limited to the core rod driving type, but may be a sleeve driving type, an internal cone driving type, a main body driving type, or the like. The number of metal anchors is preferably plural, but may be one.

The shapes of the fixing jig and the penetrating portion are not limited to the examples shown in the embodiment. For example, the planar view shape of the fixing jig is not limited to a rectangle, and may be a circle or a polygon other than a rectangle (for example, a triangle or a hexagon).
The shape of the penetrating portion is not limited to a shape having an open end on one of the two opposing sides of the rectangular fixture in plan view, and the shape of the four penetrating portions may be a shape having open ends on four sides, respectively. Good.
FIG. 13 shows a fixing jig 4A as another example of the fixing jig. The fixing jig 4A has a circular shape in plan view, and has a through portion 21A having an open end 21Aa on the outer peripheral edge 4Ac.

  The structure to be repaired is not particularly limited, and examples include structures constructed by civil engineering techniques, building techniques, and the like. Examples of the structure include an underground tunnel, an underground passage, a culvert, an abutment, a retaining wall, a breakwater, and a protective wall.

DESCRIPTION OF SYMBOLS 1 Ground 2 Repair material layer 2a Surface of repair material layer 3 Insertion hole 4 Fixing jig 4a Contact surface 4c Outer periphery 5 Expanding anchor (metal anchor)
12 guide hole 11 guide jig 21 penetrating part 21a open end 30 anchor body 32 core rod (pressing body)
35 Tip part 36 Slit 37 Expansion part 40 Tensile tester (tensile means)
44 reaction force plate (reaction force part)

Claims (8)

An adhesion strength evaluation method for evaluating the adhesion strength between a foundation and a repair material layer formed on the surface of the foundation,
A drilling step of forming an insertion hole in the repair material layer;
An insertion step of disposing a fixing jig having a penetration part on the surface of the repair material layer, and inserting one or a plurality of metal anchors into the insertion hole through the penetration part of the fixing jig;
A fixing step of fixing the fixing jig to the repair material layer by locking the metal anchor to the inner surface of the insertion hole;
A repairing step comprising: applying a tensile load in a direction away from the base to the fixing jig, separating a piece including at least a part of the repair material layer, and evaluating the adhesion strength based on the piece. Evaluation method of adhesion strength of material layer.   The evaluation method of the adhesion strength of the repair material layer according to claim 1, wherein the relationship between the displacement of the fragments and the tensile load is measured in the evaluation step.   The said drilling process WHEREIN: The guide jig which has a guide hole is arrange | positioned on the surface of the said repair material layer, A drilling tool is applied to the said repair material layer through the said guide hole, and the said insertion hole is formed. To evaluate the adhesion strength of repair material layers. An adhesion strength evaluation apparatus for evaluating adhesion strength between a ground and a repair material layer formed on the surface of the ground,
A drilling tool for forming an insertion hole in the repair material layer;
A fixing jig having a penetrating portion and disposed on the surface of the repair material layer;
A metal anchor for fixing the fixing jig to the repair material layer by being inserted into the insertion hole through the penetration portion of the fixing jig and locking to the inner surface of the repair material layer;
An apparatus for evaluating the adhesion strength of a repair material layer, comprising: a tensile unit that applies a tensile load in a direction away from the base to the fixing jig and separates fragments including at least a part of the repair material layer. The tension means has a reaction force portion for taking a reaction force when applying a tensile load to the repair material layer on the fixing jig,
The reaction force portion has an opening through which the fixing jig can pass,
The apparatus for evaluating the adhesion strength of a repair material layer according to claim 4, wherein the opening is formed so that a range in which a tensile load is applied to the repair material layer by the fixing jig is limited.   The depth from the surface of the repair material layer where the plurality of metal anchors are engaged with the inner surface of the insertion hole, and the outer dimensions of the metal anchor are the conical fracture surface of the metal anchor. The cone projection areas projected onto the surface do not overlap each other, and the total area of the cone projection areas is 80% or more of the maximum total area when the cone projection areas do not overlap. The evaluation apparatus for the adhesion strength of the repair material layer according to claim 4 or 5.   The said penetration part is an evaluation apparatus of the adhesion strength of the repair material layer of any one of Claims 4-6 which have an open end in the outer periphery of the said fixing jig. The metal anchor is a cylindrical anchor body having a tip portion divided into a plurality of projecting piece-like extended portions by slits;
The adhesion strength of the repair material layer according to any one of claims 4 to 7, further comprising: a pressing body that presses and expands the extension portion from the inside to lock the extension portion to the inner surface of the insertion hole. Evaluation device.

Images