Core sampling jig and core sampling method

Abstract

To efficiently collect concrete cores while suppressing noise. [Solution] The core sampling jig 1 comprises a core storage container 10 having a storage space 11 for accommodating the top of a cylindrical concrete core formed in a concrete structure, a handle 20 provided on the opposite side of the storage space 11 from the core storage container 10, and a cutting section 30 provided on the edge of the core storage container 10, which is inserted into a part of the circumference of a cylindrical cutting groove 4 between the concrete core and the concrete structure, and which separates the concrete core from the concrete structure when the handle 20 is tilted.

Description

Technical Field

[0001] The present invention relates to a technique for collecting a concrete core formed in a concrete structure.

Background Art

[0002] Conventionally, a core drill is used when evaluating the properties and soundness of an existing concrete structure or when forming a hole in a concrete structure. The core drill rotates a substantially cylindrical core bit around its axis, and causes a cutting edge provided at the tip thereof to cut into the concrete structure to form a cutting groove. Thereby, a columnar concrete core is formed. Thereafter, an operation is performed in which a wedge or the like is inserted into the cutting groove to break the concrete core, and a wire or the like is wound around the broken concrete core to pull it out.

[0003] Patent Documents 1, 2 and 3 all disclose techniques for collecting a concrete core. In Patent Documents 1, 2 and 3, a cylindrical core storage container is used. The core storage container is inserted into a cutting groove formed between the concrete structure and the concrete core to accommodate the concrete core. By pulling up the core storage container in a state where the concrete core is accommodated, the concrete core is pulled out.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of Invention

Problem to be Solved by the Invention

[0005] Conventional concrete core sampling techniques require hammering wedges or similar tools to break the concrete core, resulting in noise pollution. Furthermore, the process of wrapping wire around the broken concrete core is time-consuming, leading to longer working times and increased workload for workers.

[0006] Patent Document 1 describes a concrete core sampling device in which a concrete core is formed by cutting a concrete structure, the concrete core is broken, and then the broken concrete core is pulled out. This shortens the working time. However, in Patent Document 1, in order to secure space for breaking the concrete core, a special core bit is constructed by arranging multiple cutting blades in a multi-stage manner, thereby forming a multi-stage cutting groove. As a result, the noise during cutting is greater than when cutting with a normal core drill. Also, because the cutting groove is multi-stage, the shape of the hole in the concrete structure is not cylindrical. Therefore, there is a need for a new concrete core sampling technology that can efficiently extract concrete cores while suppressing noise. [Means for solving the problem]

[0007] One aspect of the present invention that solves the above problems is a core sampling jig. This core sampling jig comprises a core storage container having a storage space for accommodating the top of a cylindrical concrete core formed in a concrete structure, a handle provided on the opposite side of the storage space from the core storage container, and a cutting part provided on the edge of the core storage container, which is inserted into a part of the circumference of a cylindrical cutting groove between the concrete core and the concrete structure, and which separates the concrete core from the concrete structure when the handle is tilted.

[0008] Another aspect of the present invention is a core sampling method. The first core sampling method is a core sampling method using a jig comprising: a core storage container having a storage space for accommodating the head of a cylindrical concrete core formed in a concrete structure; a handle provided on the opposite side of the storage space from the core storage container; and a cutting portion provided on the edge of the core storage container, characterized in that the cutting portion is inserted into a part of a cutting groove between the concrete core and the concrete structure, the concrete core is separated from the concrete structure by tilting the handle, the head of the concrete core is fitted into the core storage container, and the separated concrete core is pulled out of the cutting groove by pulling up the handle.

[0009] The second core sampling method is a core sampling method using a jig comprising: a core storage container having a storage space for accommodating the head of a cylindrical concrete core formed in a concrete structure; a handle provided on the opposite side of the storage space from the core storage container; and a cutting portion provided on the edge of the core storage container, wherein an opening is provided in the ceiling of the storage space of the core storage container, the handle has a hollow portion to which a suction device can be connected and which communicates with the storage space through the opening, the cutting portion is inserted into a part of the circumference of a cylindrical cutting groove between the concrete core and the concrete structure, the concrete core is separated from the concrete structure by tilting the handle, the head of the separated concrete core is sucked into the core storage container by sucking air from the storage space through the hollow portion with the suction device, and the sucked concrete core is pulled out of the cutting groove by pulling up the handle. [Effects of the Invention]

[0010] According to the present invention, it is possible to efficiently collect concrete cores while suppressing noise. [Brief explanation of the drawing]

[0011] [Figure 1](a) and (b) are diagrams showing the configuration of the core sampling jig. [Figure 2] (a) to (d) are diagrams illustrating the method of separating the concrete core. [Figure 3] (a) to (e) are diagrams illustrating the method of taking concrete core samples. [Modes for carrying out the invention]

[0012] Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. (Core sampling jig) Figure 1 shows an example of the configuration of a core sampling jig, which is one embodiment of the present invention. Figure 1(a) is a perspective view of the core sampling jig 1. Figure 1(b) is a side view of the core sampling jig 1. The core sampling jig 1 of this embodiment is a jig used, for example, when drilling a hole in a concrete structure and sampling a concrete core formed inside the hole using a core drill.

[0013] A core drill cuts into a concrete structure by rotating a ring-shaped core bit. This creates a cylindrical cutting groove, forming a cylindrical concrete core. In this state, the concrete core is integrated with the concrete structure at its base. A hole is formed in the concrete structure by pulling out the concrete core. When pulling out the concrete core, it is first broken to separate it from the concrete structure, and then the separated concrete core is pulled out of the hole.

[0014] The core sampling jig 1 of this embodiment is used for separating a concrete core from a concrete structure and for extracting the separated concrete core from a hole. The core sampling jig 1 consists of a core container 10, a handle 20, and a cutting section 30.

[0015] The core storage container 10 has a storage space 11 for storing the head of a concrete core separated from a concrete structure. The inner diameter of the core storage container 10 is substantially the same as the diameter of the head of the concrete core, so that the concrete core can fit therein. A sponge 12 serving as a spacer is attached to the storage space 11 (omitted in Fig. 1(a)). The sponge 12 provides a gap between the ceiling 13 of the storage space 11 and the concrete core. The sponge 12 also functions as a cushioning material to mitigate impact when the concrete core is stored into the storage space 11. The sponge 12 may be annular, but it is sufficient that the sponge is provided on a part of the ceiling 13. An opening 14 is provided on the ceiling 13 of the storage space 11.

[0016] The handle 20 is provided on the opposite side of the storage space 11 of the core storage container 10. Although details will be described later, when the handle 20 is tilted by an operator, the core sampling jig 1 separates the concrete core from the concrete structure. In addition, the handle 20 serves as a grip to be pulled up by the operator when pulling out the concrete core separated from the concrete structure from the hole.

[0017] The handle 20 is cylindrical and has a hollow portion 21 that communicates with the storage space 11 of the core storage container 10 via the opening 14. The hollow portion 21 of the handle 20 can be connected to a dust collector (not shown). The dust collector functions as a suction device that sucks air in the storage space 11 of the core storage container 10 through the hollow portion 21. As the air inside the storage space 11 is sucked by the dust collector, the concrete core is adsorbed to the core storage container 10.

[0018] When the concrete core has a predetermined weight or more, the concrete core may slip out of the storage space 11 due to its own weight and cannot be pulled out from the hole of the concrete structure. In such a case, by sucking the concrete core into the storage space 11 with the dust collector, the concrete core can be prevented from slipping out of the storage space 11 due to its own weight.

[0019] Note that dust collectors have conventionally been used when cutting concrete structures with core drills. When a concrete structure is cut with a core drill, dust such as concrete fragments generated by cutting is produced. The dust enters between the core bit attached to the core drill and the concrete structure, reducing the cutting efficiency of the core bit. The dust collector is used to suck in such dust. By sucking the dust with the dust collector, the dust between the core bit and the concrete structure can be removed, and the cutting efficiency of the core bit can be maintained. In the present embodiment, such a dust collector is used as a suction device. Therefore, it is not necessary to newly prepare a suction device for collecting concrete cores.

[0020] The cutting portion 30 is provided on the side of the accommodation space 11 of the core accommodation container 10. The cutting portion 30 extends from a part of the edge of the core accommodation container 10, and is inserted into a cutting groove formed between the concrete structure and the concrete core. The cutting portion 30 is a plate-shaped member bent in an arc shape. The cutting groove is cylindrical. The cutting portion 30 is inserted into a part of the circumference of the cutting groove. The cutting portion 30 of the present embodiment is formed in a semicircular arc shape, and is inserted into half of the circumference of the cutting groove. The cutting portion 30 is not limited to a semicircular arc shape, and only needs to be inserted into a part of the circumference.

[0021] (Method for Separating Concrete Core) Figure 2 is an explanatory diagram of the method for separating a concrete core. As shown in Figure 2(a), a cutting groove 4 is bored in the concrete structure 2, and a concrete core 3 is formed. The cutting groove 4 is annular when viewed from the surface side of the concrete structure 2 (the head side of the concrete core 3), and is cylindrical. In the core collection jig 1, the cutting portion 30 is inserted into the cutting groove 4 (Figure 2(b)). At this time, the edge of the core accommodation container 10 is not inserted into the cutting groove 4.

[0022] In this state, the handle 20 is tilted by the operator, as shown in Figure 2(c). When the handle 20 is tilted, the entire core sampling jig 1 tilts. The handle 20 is tilted toward the side where the cutting section 30 is provided. In the example in Figure 2(c), it is tilted to the left.

[0023] Since the cutting section 30 is only inserted into a part of the annular cutting groove 4, it tilts inside the cutting groove 4 when the handle 20 is tilted. As a result, the base end of the cutting section 30 on the core housing container 10 side contacts the concrete structure 2, and the tip contacts the concrete core 3. The point where the operator pushes the handle 20 is the point of force application A, the point where the cutting section 30 contacts the concrete structure 2 is the fulcrum B, and the point where the cutting section 30 contacts the concrete core 3 is the point of application C. A force F acts on the concrete core 3 at the point of application C. The concrete core 3 breaks and separates from the concrete structure 2 due to this force F (Figure 2(d)).

[0024] By utilizing the principle of leverage in this way, the worker tilting the handle 20 can quickly break the concrete core 3 with less force than when using a wedge as in the conventional method. Furthermore, when using a wedge, noise is generated because the wedge is struck with a hammer or similar tool, but in this embodiment, since the worker only needs to tilt the handle 20, no noise is generated.

[0025] By using a handle 20 of a predetermined length, the worker can perform the work while standing. This reduces the workload and makes it possible to efficiently separate the concrete core 3. The longer the handle 20, the greater the force that can be applied to the point of application F. The length of the handle 20 is determined by the hardness of the concrete structure 2, the weight of the concrete core 3, etc. However, if the handle 20 is too long, the core sampling jig 1 itself becomes heavier, making it difficult to pull out the concrete core 3 as described later. For this reason, there is a limit to the length of the handle 20.

[0026] The shorter the length of the cutting portion 30 inserted into the cutting groove 4, the greater the force F acting on the concrete core 3. However, the shorter the length of the cutting portion 30 inserted into the cutting groove 4, the closer the point of application C becomes to the tip, which is the head of the concrete core 3. In this case, the concrete core 3 may break midway rather than at a position close to the base end, which is the connection end with the concrete structure 2. If the concrete core 3 breaks midway, the remaining concrete core 3 must be broken again and pulled out, which increases the time required for the work.

[0027] Therefore, the length of the cutting portion 30 inserted into the cutting groove 4 is determined such that the point of application C is at a position where the concrete core 3 does not break midway. The length of the cutting portion 30 inserted into the cutting groove 4 is determined by, for example, the hardness of the concrete structure 2 and the length of the concrete core 3.

[0028] In this embodiment, there is no need to form the cutting groove 4 in a multi-stage manner. In this embodiment, since the cutting groove 4 is formed in a cylindrical shape, there is no need to use a core bit with a special shape in the core drill. Furthermore, the noise generated when drilling the cutting groove 4 is not greater than in conventional methods.

[0029] (Method for extracting concrete cores) Figure 3 is an explanatory diagram of the method for extracting the concrete core 3 using the core sampling jig 1. Figure 3(a) shows the state in which the concrete core 3 has been separated from the concrete structure 2 by the method described in Figure 2. In Figure 3(a), the core sampling jig 1 is omitted, but in actual work, the cutting portion 30 of the core sampling jig 1 may remain inserted in the cutting groove 4 during the series of operations from separating the concrete core 3 to extracting it.

[0030] Once the concrete core 3 is separated from the concrete structure 2, the worker inserts the edge of the core container 10 into the cutting groove 4 and fits the head of the concrete core 3 into the storage space 11 of the core container 10 (Figure 3(b)). At this time, the sponge 12 prevents the head of the concrete core 3 from coming into contact with the ceiling 13 of the storage space 11. Because the edge of the core container 10 is annular, it is inserted into the entire cutting groove 4. Also, as described above, since the inner diameter of the core container 10 is approximately the same as the diameter of the head of the concrete core 3, the head of the concrete core 3 is accommodated without any gaps at the edge of the core container 10.

[0031] If the concrete core 3 is lightweight, the worker can simply pull the handle 20 upwards to remove the concrete core 3. If the concrete core 3 is heavy, the worker may cause the concrete core 3 to fall out of the containment space 11 due to its own weight if the worker simply pulls the handle 20 upward. Therefore, in this case, the worker uses a dust collector to hold the concrete core 3 in the containment space 11. First, the worker connects the dust collector to the hollow portion 21 of the handle 20 in the state shown in Figure 3(b) and activates the dust collector. This creates negative pressure in the containment space 11. As a result, the concrete core 3 is held in place by the core containment container 10 (Figure 3(c)). In this state, the worker can pull the handle 20 upward to remove the concrete core 3 (Figure 3(d)).

[0032] Figure 3(e) shows the concrete core 3 after it has been withdrawn. A hole 5 is formed in the concrete structure 2 where the concrete core 3 was located. This is how the concrete core 3 is separated and withdrawn.

[0033] As described above, by using the core sampling jig 1 of this embodiment, workers can easily extract the concrete core 3 formed in the concrete structure 2. The inventors compared the working time when the concrete core 3 is broken and extracted using a conventional wedge with the working time when the concrete core 3 is broken and extracted using the core sampling jig 1. As a result, even for a skilled worker, the conventional method took 25 seconds.

[0034] In contrast, when using the core sampling jig 1 of this embodiment, the working time was 6 seconds when the core length of the concrete core 3 was less than 100 mm and suction was not performed. When the core length of the concrete core 3 was 100 mm or more and suction was performed, the working time was 9 seconds.

[0035] As described above, using the core sampling jig 1 of this embodiment significantly reduces working time compared to conventional methods. Furthermore, because wedges are not used, there is no hammering noise, allowing for quiet operation. In addition, when drilling holes 5 in the concrete structure 2 at the worker's feet, the worker can perform the work while standing. This reduces the workload.

[0036] The above explanation described an example of breaking and extracting a cylindrical concrete core 3 formed in a concrete structure 2, but the object to be extracted is not limited to concrete. For example, when conducting a geological survey, the object to be extracted is a core, which is soil data. The object to be cut by the core drill (the member to be cut) changes from a concrete structure to the ground.

[0037] Furthermore, the core shape is not limited to a cylindrical shape; by changing the shape of the core housing container 10 and the cutting section 30, it is possible to extract cores of various shapes. For example, by forming the core insertion surface of the core housing container 10 into a rectangle and making the cutting section 30 a flat plate, a rectangular prism-shaped core can be broken and extracted.

Claims

1. A core housing container having a housing space for housing the top of a cylindrical concrete core formed in a concrete structure, A handle provided on the opposite side of the storage space from the core housing container, The core housing container is provided with a cutting section that is inserted into a part of the circumference of a cylindrical cutting groove between the concrete core and the concrete structure, and the cutting section is provided on the edge of the core housing container and inserted into a part of the circumference of a cylindrical cutting groove between the concrete core and the concrete structure, and the cutting section is provided that separates the concrete core from the concrete structure when the handle is tilted, A jig for collecting core samples.

2. The core housing container has an inner diameter that is approximately the same as the diameter of the head of the concrete core, and is designed so that the head of the concrete core fits into it. The core sampling jig according to claim 1.

3. The core housing container has an opening in the ceiling of the housing space, The handle has a hollow portion to which a suction device can be connected and which communicates with the housing space through the opening, The suction device draws air from the containment space, causing the detached concrete core to be adsorbed onto the core containment container. The core sampling jig according to claim 1.

4. The core housing container has a spacer between it and the concrete core. The core sampling jig according to claim 1.

5. The aforementioned cut portion is formed in a semi-circular arc shape. The core sampling jig according to claim 1.

6. A core sampling method using a jig comprising: a core storage container having a storage space for accommodating the top of a cylindrical concrete core formed in a concrete structure; a handle provided on the opposite side of the storage space from the core storage container; and a cutting portion provided on the edge of the core storage container, The cutting portion is inserted into a part of the cutting groove between the concrete core and the concrete structure, the handle is tilted to separate the concrete core from the concrete structure, the head of the concrete core is fitted into the core housing container, and the separated concrete core is pulled out of the cutting groove by pulling up the handle. Core sampling method.

7. A core sampling method using a jig comprising: a core storage container having a storage space for accommodating the top of a cylindrical concrete core formed in a concrete structure; a handle provided on the opposite side of the storage space from the core storage container; and a cutting portion provided on the edge of the core storage container, An opening is provided in the ceiling of the containment space of the core containment container, and the handle has a hollow portion to which a suction device can be connected and which communicates with the containment space through the opening. The cutting portion is inserted into a part of the circumference of a cylindrical cutting groove between the concrete core and the concrete structure; the handle is tilted to separate the concrete core from the concrete structure; the suction device is used to suck air from the containment space through the hollow portion, thereby adsorbing the head of the separated concrete core onto the core containment container; and the handle is pulled up to remove the adsorbed concrete core from the cutting groove. Core sampling method.

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