Formwork, method for removing a sample, and method for manufacturing a sample

Abstract

The present invention provides a mold that allows for the smooth removal of a sample, a method for removing a sample, and a method for manufacturing a sample. [Solution] The formwork 2 comprises a cylindrical portion 10, a bottom plate portion 20, and a rib structure 30. The bottom plate portion 20 is formed in the shape of a disc with axis AX as its central axis. An introduction hole 20X is formed in the bottom plate portion 20. The rib structure 30 is provided on the outer surface 20G. The rib structure 30 comprises a first surrounding rib 31, a second surrounding rib 32, a third surrounding rib 33, an inner connecting rib 36, and an outer connecting rib 37. The first surrounding rib 31 is a protrusion provided so as to surround the introduction hole 20X. The first surrounding rib 31 is formed in the shape of a circle with radius R31 with axis AX as its central axis. The second surrounding rib 32 is a protrusion provided so as to surround the first surrounding rib 31. The second surrounding rib 32 is formed in the shape of a circle with radius R32 with axis AX as its central axis.

Description

Technical Field

[0001] The present invention relates to a formwork, a method for taking out a test specimen, and a method for manufacturing a test specimen.

Background Art

[0002] Cement concrete, which uses cement as a binder, is prepared by mixing aggregates and water with the cement in appropriate proportions and kneading them together, and is solidified by the hydration reaction of water and cement. It is widely used as a civil engineering and construction material because it has high compressive strength, high rigidity, and can be used to create members and structures with arbitrary shape dimensions.

[0003] Since the quality of such concrete is greatly affected by the mixing of each material such as cement, water, and aggregates, a strength test is conducted to confirm that it has the required strength.

[0004] Regarding concrete, tests are conducted on various strengths such as compressive, bending, tensile, and shear strengths, tests on the strength of cores and stiffness cut from the structure, tests on static and dynamic Young's moduli, shear elastic moduli, and Poisson's ratios, creep tests, durability tests against freezing and thawing, tests on water tightness, tests on volume changes due to drying and temperature, tests on specific heat and thermal diffusivity, and analysis tests of hardened concrete, etc.

[0005] In order to conduct these tests, concrete test pieces (test specimens) must be fabricated with high precision based on the dimensional shapes according to JIS standards, etc.

[0006] Conventionally, as a formwork for specimens satisfying such conditions, a metal cylinder consisting of side plates and a bottom plate with one or two seams in the vertical direction was used, and the side plates were disassembled to take out the specimens. However, since disassembly and assembly were troublesome, in recent years, those consisting of an integral cylindrical side plate and a separate bottom plate or those with the entire cylindrical side plate and bottom plate integrated have been proposed, and they are devised to be demolded using mechanical force or pressurized fluid (for example, Patent Document 1).

Prior Art Documents

[0007] [Patent Document 1] Japanese Patent Publication No. 2001-205612 [Patent Document 2] Japanese Patent Publication No. 2001-121520 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, in the formwork described in Patent Documents 1 and 2, the sample is removed from the formwork using a pressurized fluid, but it is not always possible to remove it smoothly. In such cases, it may be possible to increase the pressure of the pressurized fluid to make it easier to remove the sample, but this method is undesirable as it may cause damage or destruction to the formwork.

[0009] Therefore, in view of these circumstances, the present invention aims to provide a mold that allows for the smooth removal of a sample, a method for removing a sample, and a method for manufacturing a sample. [Means for solving the problem]

[0010] The formwork of the present invention is characterized by comprising a bottomed cylindrical body having an introduction hole in its bottom plate, and a circular or arc-shaped first surrounding rib provided on the outer surface of the bottom plate so as to surround the introduction hole.

[0011] It is preferable to provide a circular or arc-shaped second surrounding rib on the outer surface of the bottom plate portion so as to surround the first surrounding rib. It is preferable to provide an inner connecting rib that connects the first surrounding rib and the second surrounding rib, wherein the second surrounding rib is concentric with respect to the first surrounding rib, and the inner connecting rib extends toward the introduction hole. It is preferable to provide a third surrounding rib on the outer surface of the bottom plate portion so as to surround the second surrounding rib, and an outer connecting rib that connects the second surrounding rib and the third surrounding rib, wherein the third surrounding rib is concentric with respect to the second surrounding rib, and the outer connecting rib extends toward the introduction hole. It is preferable that the number of outer connecting ribs is greater than the number of inner connecting ribs.

[0012] The present invention relates to a method for removing a specimen, comprising: a method for removing a specimen using the above-described mold, the method comprising a release step of supplying air to the bottom surface of the specimen to the mold through the introduction hole, wherein the release step comprises: a first air supply step of supplying air to the bottom surface of the specimen in the range of the bottom plate portion from the introduction hole to the first surrounding rib so as to separate the bottom surface of the specimen from the bottom plate portion; and a second air supply step performed after the first air supply step of supplying air to the range of the bottom plate portion extending radially outward from the first surrounding rib so as to separate the bottom surface of the specimen from the bottom surface of the specimen.

[0013] The present invention provides a method for removing a test specimen, comprising: a molding step of molding a concrete test specimen using the above-described formwork; and a release step of removing the test specimen from the formwork, wherein the release step comprises: a first air supply step of supplying air to the bottom surface of the test specimen so as to separate it from the bottom plate portion in the range from the introduction hole to the first surrounding rib of the bottom plate portion; and a second air supply step performed after the first air supply step of supplying air to the bottom surface of the test specimen so as to separate it from the bottom plate portion in the range extending radially outward from the first surrounding rib. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a mold, a method for taking out a specimen, and a method for manufacturing a specimen, which can smoothly take out the specimen.

Brief Description of the Drawings

[0015] [Figure 1] It is a perspective view showing an outline of the mold. [Figure 2] (A) is a front view showing an outline of the mold. (B) is a plan view showing an outline of the mold. Note that the rear view, right side view, and left side view of the mold are omitted because the same shape appears as the front view. [Figure 3] It is an end view taken along line III-III' showing an outline of the mold. [Figure 4] It is an end view taken along line III-III' showing an outline of the bottom plate portion of the mold. [Figure 5] It is a bottom view showing an outline of the mold. [Figure 6] It is an end view taken along line VI-VI' showing an outline of the bottom plate portion of the mold. [Figure 7] It is an end view taken along line VII-VII' showing an outline of the bottom plate portion of the mold. [Figure 8] It is a flowchart showing an outline of the method for taking out a specimen. [Figure 9] (A) is an end view taken along line III-III' showing a state when the hollow portion of the mold 2 is filled with concrete 70. (B) is an end view taken along line III-III' showing a state of supplying air at a predetermined pressure to the bottom surface of the hardened concrete specimen 80 through the introduction hole X using an air nozzle. [Figure 10] It is a bottom view showing an outline of the mold (modified example). [Figure 11] It is a bottom view showing an outline of the mold (modified example).

Embodiments for Carrying Out the Invention

[0016] Hereinafter, for the convenience of explanation, a predetermined direction in the horizontal plane is defined as the X direction, a direction orthogonal to the X direction in the horizontal plane is defined as the Y direction, and a direction orthogonal to the X and Y directions is defined as the Z direction.

[0017] As shown in FIGS. 1 to 3, the mold 2 includes a cylindrical portion 10, a bottom plate portion 20, a rib structure 30, and a flange portion 40.

[0018] The cylindrical portion 10 is formed in a cylindrical shape with an axis AX extending in the Z direction as the central axis. The opening 10A on one end side (upper side in the Z direction) of the cylindrical portion 10 is open. The bottom plate portion 20 is provided on the other end side (lower side in the Z direction) of the cylindrical portion 10. Therefore, the bottom plate portion 20 and the cylindrical portion 10 are integrated to form a bottomed cylinder.

[0019] The outer peripheral surface 10G and the inner peripheral surface 10N of the cylindrical portion 10 are formed smoothly. Also, the inner peripheral surface 10N of the cylindrical portion 10 has a cylindrical shape with a constant radius R1 from one end side to the other end side. That is, the hollow portion 10X of the cylindrical portion 10 is cylindrical.

[0020] Moreover, it is preferable that the thickness TH10 of the cylindrical portion 10 gradually becomes thinner from one end side toward the other end side. For this reason, when the radius of one end side of the outer peripheral surface 10G of the cylindrical portion 10 is R2 and the radius of the other end side is R3, it is preferable that R2 > R3.

[0021] The flange portion 40 is provided on the outer peripheral surface 10G of one end side of the cylindrical portion 10. When based on the axis AX, the flange portion 40 is provided so as to extend radially outward from the outer peripheral surface 10G.

[0022] As shown in FIGS. 2 to 3, the bottom plate portion 20 is formed in a disk shape with the axis AX as the central axis, and the inner surface 20N of the bottom plate portion 20 is formed flat. The thickness TH20 of the bottom plate portion 20 is constant. Also, it is preferable that the thickness TH20 of the bottom plate portion 20 is thinner than the thickness TH10 of the cylindrical portion 10.

[0023] As shown in Figures 3-4, a disc-shaped boss 20Y with axis AX as its central axis is provided in the center of the base plate portion 20, protruding from the outer surface 20G. The introduction hole 20X with axis AX as its central axis extends in the Z direction so as to penetrate the base plate portion 20 and the boss 20Y. The introduction hole 20X comprises a circular hole 20X1 with axis AX as its central axis and a circular tapered hole 20X2 communicating with the circular hole 20X1. The circular hole 20X1 is provided in the base plate portion 20 and extends from the inner surface 20N to the outer surface 20G. The circular tapered hole 20X2 is provided in the boss 20Y and extends from the outer surface 20G toward one end side (upward in the Z direction) of the cylindrical portion 10. Furthermore, it is preferable that the circular tapered hole 20X2 has a frustoconical shape with axis AX as its central axis.

[0024] The radius R11 of the circular hole 20X1 is constant in the Z direction. The radius of the circular tapered hole 20X2 gradually increases from the inner surface 20N toward the outer surface 20G. The radius of the circular tapered hole 20X2 on the inner surface 20N side is equal to the radius R11 of the circular hole 20X1. Here, if the radius of one end side (upper side in the Z direction) of the cylindrical portion 10 of the boss 20Y of the circular tapered hole 20X2 is R12, then the value of (R12 / R11) is preferably, for example, 2 or more and 5 or less, and preferably 3 or more and 5 or less. Also, if the length of the circular hole 20X1 in the Z direction is L1 and the length of the circular tapered hole 20X2 in the Z direction is L2, then the value of L2 / L1 is preferably, for example, 0.5 or more and 3 or less.

[0025] As shown in Figures 4-7, the rib structure 30 is provided on the outer surface 20G and protrudes downward in the Z direction from the outer surface 20G of the bottom plate portion 20.

[0026] The rib structure 30 comprises a first surrounding rib 31, a second surrounding rib 32, a third surrounding rib 33, an inner connecting rib 36, and an outer connecting rib 37.

[0027] The first surrounding rib 31 is a protrusion provided to surround the introduction hole 20X. The first surrounding rib 31 is formed in a circular shape with a radius R31 and the axis AX as its central axis. The second surrounding rib 32 is a protrusion provided to surround the first surrounding rib 31. The second surrounding rib 32 is formed in a circular shape with a radius R32 and the axis AX as its central axis. The third surrounding rib 33 is a protrusion provided to surround the second surrounding rib 32. The third surrounding rib 33 is formed in a circular shape with a radius R33 and the axis AX as its central axis.

[0028] The value of (R32 / R31) is preferably, for example, 1.5 to 3. Also, the value of (R33 / R31) is preferably, for example, 2 to 4.

[0029] The height H31 of the first surrounding rib 31 and the height H32 of the second surrounding rib 32 are equal when relative to the outer surface 20G. Note that height H31 may be greater than height H32. Also, the height H32 of the second surrounding rib 32 and the height H33 of the third surrounding rib 33 are equal when relative to the outer surface 20G. Note that height H32 may be greater than height H33.

[0030] The inner connecting ribs 36 connect the first enclosing rib 31 and the second enclosing rib 32. With the axis AX as the reference, the inner connecting ribs 36 are formed to extend radially from the first enclosing rib 31 to the second enclosing rib 32. Six inner connecting ribs 36 are formed. With the axis AX as the reference, each of the inner connecting ribs 36 is aligned circumferentially at a predetermined forming pitch θ36 (Figure 5).

[0031] The outer connecting ribs 37 connect the second enclosing rib 32 and the third enclosing rib 33. With the axis AX as the reference, the outer connecting ribs 37 are formed to extend radially from the second enclosing rib 32 to the third enclosing rib 33. Eighteen outer connecting ribs 37 are formed. With the axis AX as the reference, each of the outer connecting ribs 37 is aligned circumferentially at a predetermined forming pitch θ37 (Figure 5).

[0032] It is preferable that the number of outer connecting ribs 37 be greater than the number of inner connecting ribs 36. Furthermore, it is preferable that the formation pitch θ37 of the outer connecting ribs 37 be smaller than the formation pitch θ36 of the inner connecting ribs 36 (Figure 5).

[0033] The inner connection point P36 between the second surrounding rib 32 and the inner connecting rib 36, and the outer connection point P37 between the second surrounding rib 32 and the outer connecting rib 37, are separated by a predetermined distance θD (Figure 5) in the circumferential direction.

[0034] When the outer surface 20G is used as a reference, the height H36 of the inner connecting rib 36 (Figure 6) and the height H37 of the outer connecting rib 37 (Figure 7) are equal. Note that height H36 may be greater than height H37.

[0035] Furthermore, it is preferable that the height H20Y of boss 20Y be equal to or lower than the heights H31, H32, H36, and H37.

[0036] Next, we will explain how to use formwork 2.

[0037] As shown in Figure 8, the sample removal method 100 comprises a filling step S1, a molding step S2, and a demolding step S3.

[0038] In filling step S1, concrete containing water, cement, and aggregate is poured into the formwork 2, filling the hollow part of the formwork 2 with concrete 70 (Figure 9(A)).

[0039] In molding step S2, the concrete 70 filled into the formwork 2 is dried in order to harden it.

[0040] The demolding step S3 is performed to remove the hardened concrete from the formwork 2. In demolding step S3, the formwork 2 is inverted so that the opening 10A faces downward, and then air at a predetermined pressure is supplied to the bottom surface 80TM of the hardened concrete specimen 80 through the introduction hole 20X using an air nozzle AN capable of supplying air (Figure 9(B)).

[0041] The release step S3 comprises a first air supply step S31, a second air supply step S32, and a third air supply step S33.

[0042] In the first air supply step S31, air is supplied to the bottom plate portion 20 in the range from the introduction hole 20X to the first surrounding rib 31 so that the bottom surface 80TM of the test specimen 80 moves away from the bottom plate portion 20. With respect to the test specimen 80, it is preferable to supply air so that the radially inner portion A1 moves away from the bottom plate portion 20 preferentially over the radially outer portion, with respect to the first surrounding rib 31.

[0043] In the second air supply step S32, air is supplied to the bottom plate portion 20 in the range from the introduction hole 20X to the second surrounding rib 32 so that the bottom surface 80TM of the test specimen 80 moves away from the bottom plate portion 20. With respect to the test specimen 80, it is preferable to supply air so that the radially inner portion A2 moves away from the bottom plate portion 20 preferentially over the radially outer portion, with respect to the second surrounding rib 32.

[0044] In the third air supply step S33, air is supplied to the area A3 of the bottom plate portion 20 from the introduction hole 20X to the third surrounding rib 33 so that the bottom surface 80TM of the test specimen 80 is separated from the bottom plate portion 20.

[0045] Thus, according to the present invention, in the release step S3, it is possible to supply air so that the radially inner portion separates from the bottom plate portion 20 preferentially over the radially outer portion, using the first surrounding rib 31 and the second surrounding rib 32 as a reference. As a result, it is possible to smoothly remove the sample while suppressing destruction or damage to the mold.

[0046] In each step S31 to S33 of the demolding step S3, it is preferable that the air nozzle AN engages with the boss 20Y or the first surrounding rib 31.

[0047] In the above embodiment, the inner connection point P36 between the second surrounding rib 32 and the inner connecting rib 36 and the outer connection point P37 between the second surrounding rib 32 and the outer connecting rib 37 are separated by a predetermined distance θD (Figure 5) in the circumferential direction. However, the present invention is not limited to this, and the inner connection point P36 and the outer connection point P37 may be connected in a straight line in the radial direction (predetermined distance θD=0) (Figure 10).

[0048] In the above embodiment, the first surrounding rib 31 is formed in a circular shape, but the present invention is not limited thereto. The first surrounding rib 31 may be interrupted in the middle, as long as it surrounds the introduction hole 20X. For example, the first surrounding rib 31 shown in Figure 11 comprises a semi-circular partial rib 31A centered on axis AX and a semi-circular partial rib 31B centered on axis AX. The radius of partial rib 31A and the radius of partial rib 31B are equal. Also, in the circumferential direction with respect to axis AX, the end of partial rib 31A and the end of partial rib 31B are separated by a predetermined distance D. Although the first surrounding rib 31 shown in Figure 11 has two arc-shaped partial ribs, the present invention is not limited thereto, and three or more partial ribs may be provided to surround the introduction hole 20X. Similarly, the second surrounding rib 32 may be two or more partial ribs arranged apart from each other, as long as it has a shape that surrounds the first surrounding rib 31. Similarly, the third surrounding rib 33 may be two or more partial ribs arranged apart from each other, as long as it has a shape that surrounds the second surrounding rib 32.

[0049] Furthermore, it is preferable that the widths of the first to third surrounding ribs 31 to 33 are all approximately equal. It is also preferable that the widths of the inner connecting rib 36 and the outer connecting rib 37 are approximately equal.

[0050] In the first air supply step S31, the second air supply step S32, and the third air supply step S33, the pressure of the air injected from the air nozzle AN may increase or remain approximately the same as the first air supply step S31, the second air supply step S32, and the third air supply step S33.

[0051] In the above embodiment, a boss 20Y is provided in the center of the bottom plate portion 20, but the present invention is not limited thereto. For example, the boss 20Y may be omitted. In this case, an introduction hole 20X having a circular hole 20X1 and a circular tapered hole 20X2 may be provided in the bottom plate portion 20.

[0052] It should be noted that the present invention is not limited to the embodiments described above, and various modifications can be made without departing from the spirit of the invention. [Explanation of Symbols]

[0053] 2 Formwork 10 Cylindrical section 10A opening 10X hollow part 10X opening 20 Bottom plate part 20G outer surface 20N inner surface 20X introduction hole 20 x 1 circular hole 20x2 circular tapered hole 30 Rib structure 31. First Enclosed Rib 31A Partial Rib 31B Partial Rib 32. Second Enclosed Rib 33 Third Enclosed Rib 36 Inner connecting ribs 37 Outer connecting ribs 40 Guard section 70 Concrete 80 samples 80TM bottom 100 Method for extracting sample

Claims

1. A bottomed cylindrical body with an inlet hole in the bottom plate, A formwork characterized by comprising a circular or arc-shaped first surrounding rib provided on the outer surface of the bottom plate portion so as to surround the introduction hole.

2. The formwork according to claim 1, characterized in that it comprises a circular or arc-shaped second surrounding rib provided on the outer surface of the bottom plate portion so as to surround the first surrounding rib.

3. It includes an inner connecting rib that connects the first surrounding rib and the second surrounding rib, The second surrounding rib is concentric with respect to the first surrounding rib. The formwork according to claim 2, characterized in that the inner connecting rib extends toward the introduction hole.

4. A third surrounding rib is provided on the outer surface of the bottom plate portion and is provided so as to surround the second surrounding rib, It comprises an outer connecting rib that connects the second surrounding rib and the third surrounding rib, The third surrounding rib is concentric with respect to the second surrounding rib. The formwork according to claim 3, characterized in that the outer connecting rib extends toward the introduction hole.

5. The formwork according to claim 4, characterized in that the number of outer connecting ribs is greater than the number of inner connecting ribs.

6. A method for removing a sample using a mold according to claims 1 to 5, The mold is provided with a release step that supplies air to the bottom surface of the specimen through the introduction hole, The aforementioned demolding step is, A first air supply step involves supplying air to the bottom plate portion in the range from the introduction hole to the first surrounding rib so that the bottom surface of the test specimen is separated from the bottom plate portion, A second air supply step is performed after the first air supply step, and supplies air in a range extending radially outward from the first surrounding rib, such that the bottom plate portion is separated from the bottom surface of the specimen. A method for removing a sample, characterized by comprising the following:

7. A molding step of molding a concrete sample using the formwork described in claims 1 to 5, The system includes a demolding step of removing the sample from the mold, The aforementioned demolding step is, A first air supply step involves supplying air to the bottom plate portion in the range from the introduction hole to the first surrounding rib so that the bottom surface of the test specimen is separated from the bottom plate portion, A second air supply step is performed after the first air supply step, and supplies air in a range extending radially outward from the first surrounding rib, such that the bottom plate portion is separated from the bottom surface of the specimen. A method for manufacturing a sample, characterized by comprising the following:

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