Demolding auxiliary jig

Abstract

Easier removal of the specimen from the formwork to which it is attached. [Solution] The demolding auxiliary jig includes an extrusion member with a convex portion that abuts against the bottom plate portion of a punch formwork used to create specimens for compression strength tests, and a spacer member that is placed on the side opposite the bottom plate portion of the punch formwork and that forms a predetermined space between the formwork body and the pressure section of a press machine.

Description

[Technical Field]

[0001] The present disclosure relates to a demolding auxiliary jig used to demold a specimen from a punching form used to prepare a specimen for a compressive strength test of concrete. [Background technology]

[0002] Patent Document 1 discloses a formwork for preparing test specimens used in concrete compressive strength tests (JIS A 1108). The method for preparing these test specimens is specified in JIS A 1132. This formwork has a substantially cylindrical formwork body and a bottom plate that is arranged to be freely raised and lowered within the formwork body. With the bottom plate placed at the bottom of the formwork body, mineral oil or a release agent is applied to the inside of the formwork, and then concrete is filled in. The formwork body is slightly tapered so that the upper diameter is larger than the lower diameter. After a predetermined time has passed, the test specimen can be removed by pushing up the bottom of the bottom plate with an extraction jig. Automatic machines that can remove test specimens from this type of formwork and clean the formwork are also commercially available (see, for example, Non-Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Publication No. 61-014357 [Non-patent literature]

[0004] [Non-Patent Document 1] Shinozaki Co., Ltd., "Product Introduction", [online], [Retrieved May 23, 2025], Internet<URL:http: / / shino-zaki.co.jp / seihin / > Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been an increase in the use of expansive additives to prevent cracking in concrete structures. These expansive additives literally have the property of expanding concrete in order to suppress shrinkage strain caused by drying shrinkage and temperature changes. Therefore, when attempting to create a specimen using the above-mentioned formwork, the filled concrete tends to adhere to the formwork, making it difficult to demold using the demolding device described in Non-Patent Document 1.

[0006] Currently, the problem is addressed by hitting the bottom plate of the formwork to which the specimen is attached with a hammer before placing it in the demolding device, but this places a heavy burden on on-site staff.

[0007] The present disclosure aims to provide a demolding auxiliary jig that can facilitate demolding of a specimen from a form to which it is fixed. [Means for solving the problem]

[0008] According to a first aspect, there is provided a demolding auxiliary jig including an extrusion member having a convex portion that abuts against the bottom plate portion of a punch formwork used to prepare specimens for compressive strength tests, and a spacer member that is arranged on the side opposite the bottom plate portion of the punch formwork and that forms a predetermined space between the punch formwork and the pressure unit of a press machine. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a demolding auxiliary jig that can facilitate demolding of a specimen from a formwork to which it is fixed. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a perspective view showing a configuration of a demolding auxiliary jig according to a first embodiment of the present disclosure. FIG. [Figure 2] 3 is a schematic cross-sectional view for explaining a method of using the demolding auxiliary jig according to the first embodiment of the present disclosure. FIG. [Figure 3] 3 is a schematic cross-sectional view for explaining dimensions of each part of the demolding auxiliary jig according to the first embodiment of the present disclosure. FIG. [Figure 4]3 is a schematic cross-sectional view for explaining a method of using the demolding auxiliary jig according to the first embodiment of the present disclosure. FIG. [Figure 5] 3 is a schematic cross-sectional view for explaining a method of using the demolding auxiliary jig according to the first embodiment of the present disclosure. FIG. [Figure 6] 1 is a perspective view showing a configuration of a demolding auxiliary jig according to a first embodiment of the present disclosure. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] [First embodiment] Next, a first embodiment of the present disclosure will be described in detail with reference to the drawings. Fig. 1 is a perspective view showing the configuration of a demolding auxiliary jig according to the first embodiment of the present disclosure. Referring to Fig. 1, the demolding auxiliary jig is shown as a combination of a push-out member 20 and a spacer member 10.

[0012] The extrusion member 20 has a configuration in which a protrusion 21 that abuts against the bottom plate of a punching formwork for preparing a test specimen is attached to a base plate 22. In the example of Fig. 1, the protrusion 21 is configured from a hollow cylindrical member, but the protrusion 21 does not have to be hollow.

[0013] The spacer member 10 is composed of a hollow cylindrical member and is capable of forming a predetermined space between the formwork body and the pressure unit of the press. Leg-like guide members 11 are attached to the outer periphery of the spacer member 10 to guide its placement on the formwork body. In the example shown in FIG. 1, the guide member 11 is composed of three legs, but the number of legs is not limited to three. The length of the legs is not particularly limited. For example, as shown in FIGS. 2 and 3, the punching formwork 30 may have a protruding portion (handle) on its outer periphery. In this case, it is preferable to set the leg length so that it does not interfere with the protruding portion (handle) on the outer periphery of the punching formwork when the spacer member 10 is attached to the punching formwork.

[0014] Next, referring to FIG. 2, a punching formwork 30 for preparing specimens for compressive strength tests will be described. Referring to FIG. 2, the above-mentioned extrusion members 20 and spacer members 10 are shown at the top and bottom of the punching formwork 30. A tapered portion capable of supporting a bottom plate portion 31 is provided at the bottom of the punching formwork 30, allowing the bottom plate portion 31 to be installed. After the bottom plate portion 31 is installed in the punching formwork 30, concrete is poured into it. After the concrete hardens, the bottom plate portion 31 is pushed up from below, allowing the specimen 33 to be removed. The automated machine described in Non-Patent Document 1 automates the removal of the specimen 33 from the punching formwork 30 and the cleaning of the punching formwork 30. When an expansive additive is added to the concrete, the concrete expands and hardens within the punching formwork 30, causing this type of automated machine to have insufficient punching pressure.

[0015] Figure 3 is a schematic cross-sectional view illustrating the dimensions of each part of the demolding auxiliary jig of the present disclosure. Guide member 11 of spacer member 10 is disposed outside the upper flange portion of punching formwork 30, which has a diameter D1, and is capable of preventing horizontal movement of spacer member 10 placed on punching formwork 30. Note that in the cross-sectional views of Figures 2 to 5, for convenience of explanation, legs of guide member 11 are shown on the left and right, but since there are actually three legs, the legs are not shown symmetrically.

[0016] The outer diameter D2 of the spacer member 10 is set smaller than the outer diameter of the top of the punching formwork 30. Furthermore, the inner diameter D3 of the spacer member 10 is set larger than the diameter of the test piece. As a result, the spacer member 10 forms a predetermined space between the formwork body of the punching formwork 30 and the pressure part of the press machine, and is also able to accommodate the head of the test piece protruding from the punching formwork 30. The thickness of the spacer member 10 is (outer diameter D2 - inner diameter D3) / 2, and a material that can withstand the pressure of the press machine, such as a steel pipe, is selected.

[0017] The extrusion member 20 is provided with a protrusion 21 that comes into contact with the bottom plate 31 of the punching formwork 30, and by pressing with the press machine, it is possible to push up the bottom plate 31 of the punching formwork 30. Note that a press machine used for compressive strength testing can be used as this press machine, so there is no need to install a dedicated press machine.

[0018] Next, the demolding operation (head exposing process) of the specimen 33 using the demolding auxiliary jig of the present disclosure will be described. As shown in FIG. 3, a spacer member 10 is placed in a punching formwork 30. Then, an extrusion member 20 is placed in the bed portion of a press machine, and the punching formwork 30 with the spacer member 10 set therein is positioned above it. When pressed in this state, the convex portion 21 of the extrusion member 20 pushes upward against the bottom plate portion 31, as shown in FIG. 4. This causes the specimen 33 to be demolded from the punching formwork 30, with the head of the specimen 33 entering inside the spacer member 10.

[0019] 5 shows the punching form 30 with the head of the specimen 33 protruding. As shown in the figure, when the head of the specimen 33 protrudes, the specimen 33 can be removed with a smaller punching pressure, due in part to the tapered shape of the punching form 30. For example, by setting the punching form 30 in this state in the automatic machine of Non-Patent Document 1, the specimen 33 can be removed and washed.

[0020] As described above, the demolding auxiliary jig of this embodiment makes it possible to easily demold the specimen 33 from the punching formwork 30 to which the specimen 33 is fixed.

[0021] [Second embodiment] In the first embodiment described above, an example was given in which independent legs were attached as guide members 11 to the outer periphery of spacer member 10, but the shape of guide member 11 is not limited to this. For example, as shown in FIG. 6, a skirt-shaped guide member 11a may be provided so as to cover the entire outer periphery of spacer member 10. With such a spacer member 10, as in the first embodiment, the spacer member 10 covered with guide member 11a is set in punch formwork 30, an extrusion member 20 is placed on the bed portion of a press machine, and the punch formwork 30 is positioned on top of it and pressed, thereby enabling the head of the test piece to be exposed.

[0022] Although each embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiments, and further modifications, substitutions, and adjustments can be made without departing from the basic technical idea of ​​the present disclosure.

[0023] For example, in the first and second embodiments described above, an example of creating a cylindrical specimen has been described, but the present disclosure can also be applied to creating specimens of other shapes. For example, when creating a rectangular parallelepiped specimen, a demolding auxiliary jig can be configured using a rectangular spacer member 10 and an extrusion member that can push up the bottom plate portion of the formwork.

[0024] Furthermore, a cushioning material such as hard rubber or felt may be attached to the upper end of the spacer member 10 of the first and second embodiments, i.e., the portion that abuts against the working surface (ram bottom) of the press machine. This prevents damage to the working surface of the press machine.

[0025] The disclosures of the above-mentioned patent and non-patent documents are incorporated herein by reference and may be used as the basis or part of the present invention, as necessary. Modifications and adjustments of the embodiments and examples are possible within the scope of the entire disclosure of the present invention (including the claims), and further based on its basic technical concept. Furthermore, various combinations and selections (including partial deletions) of the various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible within the scope of the disclosure of the present invention. In other words, the present invention naturally embraces various modifications and alterations that would be possible by those skilled in the art in accordance with the entire disclosure and technical concept, including the claims. In particular, with regard to the numerical ranges set forth herein, any numerical value or subrange within that range should be construed as specifically set forth, even if not otherwise specified. Furthermore, the disclosures of the above-cited documents may be used, in part or in whole, in combination with the disclosures herein as part of the disclosure of the present invention, as necessary, in accordance with the spirit of the present invention. Such use is also deemed to be included in the disclosures of this application. [Explanation of symbols]

[0026] 10 Spacer member 11 Guide member 20 Extrusion member 21 Convex part 22 Base plate 30 punching formwork 31 Bottom plate part 33 Specimen

Claims

1. an extrusion member having a protrusion that contacts a bottom plate portion of a punching form for preparing a specimen for a compressive strength test; a spacer member disposed on a side of the punching form opposite the bottom plate portion, for forming a space between the punching form and a pressure unit of a press machine that can accommodate a head portion of the specimen protruding from the punching form; Demolding auxiliary jig.

2. In the jig, a guide member is provided around the spacer member to guide placement in the punching formwork; The demolding auxiliary jig according to claim 1,

3. The extrusion member is placed on a bed portion of the press machine; 2. The demolding auxiliary jig of claim 1, wherein the extrusion member is pressed while the punching formwork with the spacer member disposed therein is positioned on top of the extrusion member, thereby exposing the head of the specimen from the punching formwork.

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