JPH06307997A - Molding box for concrete strength test piece - Google Patents

Abstract

PURPOSE:To facilitate molding and mold releasing while allowing reuse by providing a pair of arcuate tubular members and a bottom plate with the pair of tubular members being coupled through a hinge means. CONSTITUTION:A protrusion 14b provided on the side edge 14 of a tubular member 10 is fitted between a holding piece and the surface of a protrusion 23 provided on the side edge 23 of a tubular member 20 while the edge of a bottom plate 30 is fitted in a groove of the member 20 thus assembling the bottom plate 30. The member 10 is then shifted to a position where the side 11 the of abuts on the side of the member 20 and the protrusion is fitted in the groove thus bringing the side of the member 10 into tight contact with the side of the member 20. Five protrusions 12...12 provided on the side edge 11 of the member 10 are then contained in five engaging boards 22...22 provided on the side edge of the member 20 thus forming a bottomed molding box for test piece. When concrete is poured from the upper port, the molding box is subjected to enlarging force but the concrete does not leak through the joint. Furthermore, the molding box can be released easily after hardening of concrete.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for molding a specimen for strength test of concrete.

[0002]

2. Description of the Related Art As a molding form or container of a specimen for a strength test of concrete, a container made of a metal form such as a tin plate and a metal plate such as a tin plate, which has been conventionally defined in JIS, is used. Alternatively, a disposable container provided with a cutting line as shown in JP-A-62-12048 is used.

[0003]

According to the definition of the JIS standard, the metal mold frame defined by the JIS standard is a metal cylinder and has side and bottom plates having one or two joints in the vertical direction. After being hardened, the concrete, which has been made of the above-mentioned material, is hardened and then taken out from the inside of the mold by separating the side plates along the joint. However, in a metal mold according to the JIS standard, a pair of side plates that are combined to form a bottomed cylindrical body are fixed to each other with bolts. Therefore, when assembling the side plates to form a form, the side edges of the side plates are brought into contact with each other to form a cylindrical body, and then the two seams are closely attached by tightening bolts. , It is necessary to fix the pair of side plates to each other.
Further, when taking out the hardened concrete from the formwork, it is necessary to loosen and remove the bolts, and then separate the pair of side plates from the joint parts at two places to remove from the concrete. Assembly and disassembly work was not always easy.

On the other hand, a container formed by forming a thin metal plate such as a tin plate into a cylindrical shape has no seam when the hardened concrete is taken out of the container, and therefore the metal forming the container is not formed. The plate had to be torn off with a jig such as pliers and peeled off from the specimen, and the specimen was sometimes damaged during this work. So also
This container was not reusable.

On the other hand, the container disclosed in Japanese Patent Laid-Open No. 62-22048 has a cutting line in advance. Therefore, the side plate constituting the container is cut along the cutting line and peeled off to obtain a container and a specimen. Can be separated, and the specimen is rarely damaged when taken out. On the other hand, like the container using the thin metal plate, it cannot be reused, and it takes a lot of time to tear and tear off the side plate.

Therefore, an object of the present invention is to provide a mold for molding a specimen for concrete strength test, which is extremely easy to disassemble when taking out the assembled and molded specimen, and which can be reused.

[0007]

In order to achieve the above-mentioned object, in the invention according to claim 1, a mold for molding a test specimen for concrete strength test is constructed by a pair of cylinders each having an arc-shaped cross section. Materials 10 and 20, and a pair of the tubular constituent materials 1
0, 20 and a bottom plate 30 that closes the cylinder opening on one side of the cylinder body, and one side of the cylinder constituent members 10, 20 oriented in the axial direction of the cylinder body is continuously provided by a hinge means. Or, it is assumed that the structure is connected.

Further, in the invention according to claim 2, the hinge means is provided in the holding concave portion provided in one of the tubular constituent members 10 and 20 and in the other of the tubular constituent members 10 and 20, and It is composed of a convex portion that is detachably accommodated in the holding concave portion.

Further, in the invention according to claim 3, the hinge means is composed of a thin wall portion connecting one of the tubular components 10, 20 with the other tubular component 10, 20 in series. .

[0010]

The mold for molding a specimen for concrete strength test according to the present invention comprises a pair of tubular components 10, 20 having an arc-shaped cross section, and the pair of tubular components 10, 20.
Bottom plate 30 that closes the cylinder opening on one side of the cylinder formed by
Since the bottom plate 30 and the tubular components 10 and 20 are assembled and separated, the bottom plate 30 and the tubular components 10 and 20 can be freely assembled. Further, the assembled bottom plate 30 and the tubular components 10, 20 can form a concrete driving space for forming a bottomed tubular body to form a test piece.

Further, since one side of the tubular constituent members 10 and 20 oriented in the axial direction of the tubular body is continuously provided by the hinge means or is continuously provided, one of the tubes is centered around the hinge means. The other tubular component 10 or 20 can be moved with respect to the component 10 or 20 to join the edges of both tubular components 10 and 20 on the side where the hinge means is not provided, and the hinge The pair of tubular constituent members 10 and 20 that are assembled around the means are the tubular constituent members 10 and 20 on the side where the hinge means is not provided.
It can be opened and separated from the joint edge of.

[0012]

EXAMPLES Hereinafter, typical examples of the mold for molding a specimen for concrete strength test according to the present invention will be described with reference to FIGS. 1 to 15.

FIG. 1 is an exploded perspective view of a molding frame, FIG. 2 is a perspective view showing one mode of an assembling or disassembling process of the molding frame, and FIG. 3 is a perspective view showing the assembled molding frame. FIG. 4 is a side view showing one of the tubular components 10 constituting the molding frame from the outer peripheral surface side of the tubular component 10, and FIG. 5 is the same tubular component 10 as the inner peripheral surface side of the tubular component 10. 6 is a side view shown from FIG.
5 is a sectional view taken along line AA in FIG. 5, and FIG. 7 is B in FIG.
-B line sectional view, FIG. 8 is a side view showing the other tubular component 20 constituting the molding frame from the outer peripheral surface side of the tubular component 20,
9 is a side view showing the tubular constituent member 20 from the inner peripheral surface side of the tubular constituent member 20, FIG. 10 is a sectional view taken along line CC of FIG. 9, and FIG. 11 is a sectional view taken along line DD of FIG. 12 is an enlarged plan view of an essential part of the E portion in FIG. 3 from the upper side of the molding frame, FIG. 13 is a sectional view taken along the line FF in FIG. 3, and FIGS. FIG. 7 is a plan view of a main part of a molding form frame having a part of the structure different from that of the molding form frame shown in FIG.

The mold for molding a specimen for concrete strength test according to this example is composed of a set of cylinder constituent members 10 and 20 which are combined to form a cylinder, and the set of cylinder constituent members 10 and 2.
And a disk-shaped bottom plate 30 that closes the opening on one side of the cylindrical body formed by 0.

The tubular component 10 is mainly composed of a curved plate having a semi-circular cross section. Of the side edges extending in the vertical direction of the tubular component 10, one side edge 11 has the side edge 1
1 is provided with a joining convex portion 11a protruding outward in the radial direction of an arc formed by the tubular constituent member 10. Of the surfaces of the joining convex portion 11a, the cylindrical component 10
The surface 11a 'facing the inner peripheral side is provided with a ridge 11b having a length extending over the side edge 11. On the other hand, among the surfaces of the joining convex portion 11a, the surfaces 11a ″ facing the outer peripheral side of the tubular component 10 are spaced at substantially equal intervals from the upper end to the lower end of the tubular component 10, respectively. Engagement protrusions 12 are provided at respective locations, and each engagement protrusion 12 extends from the tip edge of the joining protrusion 11a to the base of the joining protrusion 11a protruding from the tubular component 10. It is composed of a rib, and the edge of this rib directed toward the outer peripheral side of the tubular component 10 is an engaging edge 12a, and as shown in Fig. 5, the tip of the joining convex portion 11a of this rib. The edge facing the side is an edge that gradually inclines toward the outside of the tubular component 10 from the tip edge side of the joining convex portion 11a, and a part of this rib is formed from the tip edge. It slightly projects toward the outside of the tubular component 10. The ribs which constitute the projection 12, the tubular structure material 10
The engaging projections 12 and 12 provided on the upper and lower ends of the tube have two threads, and the other engaging projections 12 have four threads, and therefore are provided on the upper and lower ends of the tubular component 10. The engaging protrusions 12, 12 are other engaging protrusions 12.
The width is narrower than that of. In addition, the tubular component 1
0 and the engaging protrusion 12 located at the lower end of 0
The operation plate portion 13 is provided in a protruding shape from the tip edge of the joining convex portion 11a between the engaging projection portion 12 and the engaging projection portion 12 adjacent to the direction of the joining convex portion 11a. .

Of the side edges extending in the vertical direction of the tubular component 10, the other side edge 14 is directed toward the outer side in the radial direction of the arc formed by the tubular component 10 over the side edge 14. The joining convex part 14a which projects is provided. This joint protrusion 1
A protrusion 14b corresponding to the protrusion in the claims is provided at the tip of 4a so as to protrude toward the outer peripheral side of the tubular component 10, and the joint protrusion 14a is provided with the protrusion 14b. An engagement concave surface 14a ″ is formed on the outer peripheral side of the tubular component 10. Further, a surface 14a ′ of the joining convex portion 14a facing the inner peripheral side of the tubular component 10 extends over the side edge 14. A ridge 14c having a length is provided.

On the outer peripheral surface of the upper end portion (the upper side of the tubular component material 10 in FIG. 1) of the tubular component material 10, a circumferential gap is provided between the upper end edge and the outer circumferential surface of the tubular component material 10. Rib 1
5 ... 15 are provided. In addition, the tubular component 10
Ribs 16 ... 1 extending in the circumferential direction of the tubular component 10 on the outer peripheral surface of the lower end (lower side of the tubular component 10 in FIG. 1).
6 is provided.

Further, on the inner peripheral surface of the lower end portion (the lower side of the tubular component material 10 in FIG. 1) of the tubular component material 10, the tubular component material 10 is provided.
A groove 17 extending in the circumferential direction is provided.

On the other hand, the tubular member 20 is also composed mainly of a curved plate having a semi-arcuate cross section. Of the side edges extending in the vertical direction of the tubular constituent member 20, one side edge 21 has a joining projection protruding toward the outer side in the radial direction of the arc formed by the tubular constituent member 20 over the side edge 21. The part 21a is provided. A groove 21b having a length extending over the side edge 21 is provided on a surface 21a 'of the joint convex portion 21a facing the inner peripheral side of the tubular component member 20. The groove width of the groove 21b is set so that the convex strip 11b provided on the surface 11a 'of the joining convex portion 11a of the tubular component 10 is accommodated therein. Further, at the tip edge of the joining convex portion 21a,
Five engaging plates 22 ... 22 are provided at substantially equal intervals from the upper end to the lower end of the tubular component 10. Each engagement plate 22 is provided on the tip edge of the joining convex portion 21a of the tubular component 20 so as to project toward the outer side in the circumferential direction of the tubular component 20, and also has a hole 22a in the thickness direction. Is provided so as to face toward the tip edge side of the joining convex portion 21a and is substantially parallel to the tip edge. The hole 2 provided in the engaging plate 22
2a is sized to accommodate the engagement protrusion 12 of the tubular component 10.

Of the side edges extending in the vertical direction of the tubular component 20, the other side edge 23 is directed toward the outer side in the radial direction of the arc formed by the tubular component 20 over the side edge 23. A protruding protrusion 23a is provided. This joint protrusion 2
Of the surfaces 3a, a surface 23a 'facing the inner peripheral surface of the tubular component 20 has a groove 23b having a length extending over the side edge 23.
Is provided. A holding plate portion 23c is integrally provided at the tip end edge of the joining convex portion 23a so as to project outward from the tip end edge in the circumferential direction of the tubular component member 20.
In addition, at the tip edge of the holding plate portion 23c, the cylindrical component 2
Plate-like holding pieces 23c '... 23c' are provided at five positions at substantially equal intervals from the upper end to the lower end of 0. Each of the holding pieces 23c '... 23c' is provided so as to be substantially orthogonal to the surface of the holding plate portion 23c from the tip end portion of the holding plate portion 23c and project toward the inside of the tubular component 20. Further, the tip end of the holding piece 23c 'is bent toward the surface 23a' of the joining convex portion 23a. Therefore, the holding piece 23c 'and the holding plate 2
By 3c, the holding recessed portion in the claims is formed. In this embodiment, the joint protrusion 23
A portion 23a 'of the side of the holding piece 23c' is provided with a window 23a "whose width and length are slightly larger than the holding piece 23c '. The window 23a" is formed according to this embodiment. It is provided for the purpose of facilitating the molding of the holding piece 23c 'when the molding frame is formed by molding a plastic material such as synthetic resin.

On the outer peripheral surface of the upper end portion (upper side of the tubular component material 20 in FIG. 1) of the tubular component material 20, a circumferential gap is provided between the tubular component material 20 and the upper end edge, and the circumferential direction of the tubular component material 20 is covered. Rib 2
4 ... 24 are provided. In addition, the tubular component 20
Ribs 25 ... 2 extending in the circumferential direction of the tubular constituent member 20 on the outer peripheral surface of the lower end portion (lower side of the tubular constituent member 20 in FIG. 1).
5 are provided.

Further, on the inner peripheral surface of the lower end portion of the tubular component material 20 (the lower side of the tubular component material 20 in FIG. 1), the tubular component material 20 is provided.
A groove 26 extending in the circumferential direction is provided.

A set of tubular components 1 having such a structure
In this embodiment, the molding frame is constructed by assembling the bottom plates 30 and 0 and 20 as follows.

First, as shown in FIG. 2, between the surface 23a 'of the joint projection 23a provided over the side edge 23 of the tubular component 20 and the holding piece 23c'. , The tip of the protrusion 14b provided over the side edge 14 of the tubular component 10 is accommodated, and the plate edge of the bottom plate 30 is accommodated in the groove 26 of the tubular component 20, The bottom plate 30 is assembled to the tubular component 20. Here, the protrusion 14 b of the tubular component 10 is projected toward the outer peripheral surface side of the tubular component 10, while the tubular component 20 is
The holding piece 23c ′ of the above is projected toward the inner peripheral surface side of the tubular component 20, and the tip end portion thereof is connected to the joining convex portion 21.
Since it is bent toward the surface 23a 'of a, the holding piece 23c' and the protrusion 14b can be engaged and temporarily fixed. Therefore, the tubular component 10 can be fixed from the state shown in FIG. It is possible to move the holding piece 23c ′ and the protrusion 14b toward the tubular component 20 side, centering on the engagement position. That is, in this embodiment, the holding piece 23c 'and the ridge 14b constitute the hinge means in the claims.

Next, as shown in FIG. 3, when the tubular component 10 is moved to a position where the side edge 11 of the tubular component 10 and the side edge 21 of the tubular component 20 contact each other, FIG. As shown in FIG.
Is housed between the bent tip portion of the holding piece 23c 'of the tubular component 20 and the holding plate portion 23c, and the bent tip portion of the holding piece 23c' of the tubular component 20 is It is accommodated in the engaging concave surface 14a ″ formed between the ridge 14b and the outer peripheral surface of the tubular component 10, and at the same time, is provided on the joining convex portion 14a of the tubular component 10. The projected ridge 14c is housed in the groove 23b of the tubular component 20. As a result, the tubular component 10 and the tubular component 20 are assembled with the side edges 14 and 23 in close contact with each other. To be

Further, there are five engaging projections 1 in the joint projection 11a provided over the side edge 11 of the tubular component 10.
2 ... 12 are provided, while the tubular component 20 is provided.
The joining convex portion 21a provided over the side edge 21 of the pair is provided with five engaging plates 22 ... 22 corresponding to the engaging protrusions 12 ... 12, respectively. The corresponding engaging protrusions 12 ... 12 can be housed in the holes 22a of the engaging plates 22.
Here, since the rib of the engaging projection 12 has its tip slightly projected from the tip edge of the joining projection 11a of the tubular component 10, the engaging projection is inserted into the hole 22a of the engaging plate 22. By accommodating 12, the engaging edge 12a of the engaging protrusion 12 can be engaged with the engaging edge 22b facing the hole 22a of the engaging plate 22. At the same time,
The ridges 11b provided on the joining protrusions 11a of the tubular component 10 are tightly housed in the grooves 21b of the tubular component 20. As a result, the tubular component 10 and the tubular component 2
0 means that the side edge 11 and the side edge 21 are closely attached to each other.

As for the plate edge of the bottom plate 30 assembled to the tubular component 20, both tubular components 10 and 20 are shown in FIG.
At the stage of assembling as shown in (1), it is housed in the groove 17 provided in the tubular component 10,
As a result, a bottomed cylindrical molding frame for molding the specimen is formed.

Next, the method of using the molding frame according to this embodiment will be described. First, concrete is poured into the inside of the mold through the upper tube mouth of the mold for molding. Due to the internal pressure of the concrete injected here, the tubular component 1
0 to 20 are directed from the inner side to the side, and the tubular component 10,
Although a force to push 20 apart is generated, the side edge 11 of the tubular component 10 and the side edge 2 of the tubular component 20 are generated.
1 is a plurality of engaging protrusions 12 provided at equal intervals from the upper end to the lower end of the tubular component 10.
... 12 are joined by engaging a plurality of engaging plates 22 ... 22 provided at equal intervals from the upper end to the lower end of the tubular constituent member 20, The side edge 14 of the tubular constituent member 10 and the side edge 23 of the tubular constituent member 20 have a ridge 14b provided from the upper end to the lower end of the tubular constituent member 10, and
Since they are joined by engaging a plurality of holding plates 23c ... 23c, which are provided at equal intervals from the upper end to the lower end of 0, the tubular constituent members 10, 2
Both tube components 10, at any part of the joint edge of 0,
The joined state of 20 is sufficiently ensured, and the two tubular components 10, 20 do not open from the joined edge due to the internal pressure. Further, the ridge 11b provided on the side edge 11 of the tubular component 10 is housed and joined in the groove 21b provided on the side edge 21 of the tubular component 20, while the side of the tubular component 10 is provided. Since the ridges 14c provided on the edge 14 are housed in and joined to the grooves 23b provided on the side edges 23 of the tubular component 20, the leakage of concrete or the like from each joining edge is sufficiently achieved. It can be prevented.

Then, after waiting for the concrete that has been poured into to harden, the concrete that is molded, that is, the specimen, is taken out from the inside of the molding frame. In this take-out, first, the engaging edges 22b of the respective engaging plates 22 ... 22 of the assembled tubular constituent member 20 of the respective assembled engaging projections 12 ... 22 is slightly opened toward the outside in the diametrical direction of the tubular component 20 so as to be disengaged from the engaging edge 12a, and the tubular component 10 is viewed from the state shown in FIG. 2 until the state shown in FIG. 2 is reached.
The tubular component 20 is removed from the test piece by moving around the engagement position between the ridge 14b and the ridge 14b. It should be noted that this movement can be performed more easily by gripping the operating plate portion 13 provided on the tubular component 10 and pressing the operating plate 13 in a direction away from the tubular component 20. it can. Next, from the state shown in FIG.
4 is pulled out from between the holding piece 23c 'of the tubular component 20 and the surface 23a' of the joining convex portion 23a to separate the tubular components 10 and 20 from each other, and then from the specimen. The tubular component 20 is removed. That is, in the molding die according to this embodiment, the pair of the cylindrical components 10 and 20 constituting the molding die are not separated at the two joint edges at the same time, and the cylindrical composition is removed from the specimen. Material 10
The sample can be removed and the sample can be taken out easily and smoothly.

The molding mold according to this embodiment is characterized by the above structure, and the material thereof may be metal or plastic. However, when the molding frame is formed by molding a plastic material such as a synthetic resin, the plastic material is hard to be plastically deformed, but is easily elastically deformed, so that concrete is cast into the molding frame. In order to fill the gaps that occur in the concrete that has been hammered, the cylinder component 1 is created with a mallet or the like.
There is an advantage that the tubular components 10, 20 and the like will not be deformed even if the outer surface of 0, 20 is hit. Further, when the specimen is taken out, the surface of the specimen and the cylindrical components 10, 2
Even if the inner peripheral surface such as 0 is adhered, the tubular component 1
By bending 0, 20, etc. to the outside, the tubular components 10, 20 can be easily peeled from the surface of the specimen, and the molding work of the specimen can be performed smoothly. When molding a plastic material to form the molding frame, the groove 17 of the tubular component 10 or the tubular component 20 is used.
Alternatively, the bottom plate 30 is provided at a portion corresponding to either the groove 26.
The number of molding dies can be reduced by adopting a structure in which the plate edges are integrally connected.

On the other hand, when a metal material is used, there is an advantage that the flatness of the bottom plate 30 can be easily increased and the requirements of the JIS standard can be easily satisfied.

As shown in FIGS. 14 and 15 (both of which are sectional views showing the portion of the molding frame corresponding to the hinge means), the embodiment shown in FIGS. In place of the holding piece 23c ′ and the ridge 14b forming the hinge means of the molding die according to the example, the tubular component 10 and the tubular component 20 are provided on the side edge 14 and the side edge 23, respectively. The hinge means may be configured by molding plastic so that the corresponding portions are integrally connected and forming the connecting portion R as a thin portion. It should be noted that in FIG. 14, both the tubular constituent members 10 and 20 are centered around the connecting portion R.
Fig. 15 shows a state in which the left and right are opened and separated.
Shows a state in which both the tubular constituent members 10 and 20 are closed around the connecting portion R so that the edges on the side where the connecting portion R is not provided are joined to each other.

[0033]

EFFECTS OF THE INVENTION A concrete strength test sample forming mold according to the present invention comprises a pair of tubular components 10 and 20 having a circular arc-shaped cross section, and the pair of tubular components 1.
And a bottom plate 30 that closes a cylinder opening on one side of a cylinder constituted by 0 and 20, and the bottom plate 30 and the cylinder constituent members 10 and 2 are provided.
0 can be assembled and separated freely to form a bottomed tubular body to form a concrete driving space for forming a specimen, so that it can be used for concrete strength tests required by the JIS standard. The specimen can be easily molded, and the specimen can be easily taken out of the mold without damaging the mold. In addition, the form can be separated and transported easily and can be reused.

Further, one side of the tubular constituent members 10 and 20 oriented in the axial direction of the tubular body is or is continuously provided by a hinge means, and one tubular configuration is centered on the hinge means. By moving the other cylindrical component 10 or 20 with respect to the member 10 or 20, it is possible to join the edges of both cylindrical components on the side where the hinge means is not provided,
In addition, the pair of tubular components 1 assembled in this way
Since 0 and 20 can be opened and separated from the joint edge of both the tubular constituent members 10 and 20 on the side where the hinge means is not provided, the pair of the cylindrical constituent members 10 constituting the molding frame can be separated. It is not necessary to engage 20 at each of the two joining edges, and it is possible to remove one of the tubular components 10 and 20 from the specimen without separating them at the same time.
It is possible to take out the specimen easily and smoothly.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a molding frame.

FIG. 2 is a perspective view of a molding frame.

FIG. 3 is a perspective view of a molding frame.

FIG. 4 is a side view showing one component of the molding form.

FIG. 5 is a side view showing one component of the molding form.

6 is a cross-sectional view taken along the line AA in FIG.

7 is a sectional view taken along line BB in FIG.

FIG. 8 is a side view showing one component of the molding frame.

FIG. 9 is a side view showing one component of the molding form.

FIG. 10 is a sectional view taken along line CC in FIG.

11 is a cross-sectional view taken along the line DD in FIG.

12 is an enlarged plan view of an E portion in FIG.

13 is a sectional view taken along line FF in FIG.

FIG. 14 is a plan view of an essential part of a molding frame.

FIG. 15 is a plan view of an essential part of a molding frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cylinder constituent material 11 Side edge 12 Engagement protrusion 13 Operation plate part 14 Side edge 15 Rib 16 Rib 17 Groove 20 Cylinder constituent material 21 Side edge 22 Engagement plate 23 Side edge 24 Rib 25 Rib 26 Groove 30 Bottom plate R connection part

Claims (3)

[Claims] 1. A cylindrical body comprising: a pair of cylindrical constituent members having an arc-shaped cross section; and a bottom plate configured to close a cylindrical opening on one side of the cylindrical body composed of the pair of cylindrical constituent members. 1. A concrete strength test specimen forming formwork, characterized in that one side of the tubular component oriented in the axial direction is continuously provided by hinge means or continuously provided. 2. The hinge means comprises a holding recess provided in one of the tubular components, and a protrusion provided in the other tubular component and releasably housed in the holding recess. A mold for molding a specimen for a concrete strength test, which is characterized by being configured. 3. A mold for molding a specimen for concrete strength test, characterized in that the hinge means is composed of a thin-walled portion connecting one of the tubular components and the other of the tubular components. frame.