JPH0619076Y2 - Formwork for manufacturing specimens for concrete strength test - Google Patents

Description

TECHNICAL FIELD The present invention relates to a formwork used for manufacturing a specimen for strength test of concrete.

Conventional technology and its problems JIS specifies how to make concrete strength test specimens, and also specifies the formwork for making the specimens.

Conventionally, as such a mold, a mold made of metal casting as shown in FIG. 9 has been used. This formwork comprises a cylindrical body (20) consisting of two body-constituting halves (21) (22) in the shape of a vertically divided cylinder, and a bottom plate (23) closing the lower end opening of the body (20). It consists of A connecting protrusion (24) having bolt holes (24a) is formed at both ends of the connecting edge of each half (21) (22), and the corresponding connecting portions of both halves (21) (22) are formed. A bolt (25) is inserted through the projecting projection (24), and a nut (26) is screwed into the bolt (25), whereby the two halves (21) and (22) are connected. In addition, a plurality of outward projections (27) having holes (27a) are formed at the lower end of the outer peripheral surface of each half (21) (22) at intervals in the circumferential direction. The bottom plate (23) has a disk shape larger than the outer diameter of the body (20), and has a circular upper protrusion (28) having an outer diameter slightly smaller than the inner diameter of the body (20) on its upper surface. Also, the bottom plate (23)
A screw rod (29) is provided on the outer peripheral edge of the upper protruding portion (28) in a protruding manner corresponding to each outer protruding portion (27) of the case body (20). Then, as the screw rod (29) is inserted into the hole (27a) of each outer protrusion (27), the upper protrusion (28) of the bottom plate (23) is fitted into the lower end opening of the trunk (20). Each screw rod (2
The body (20) and the bottom plate (23) are connected by screwing the nut (30) to the nut (9).

In such a conventional formwork, in order to take out the sample from the formwork, loosen the nut (26) and remove it from the bolt (25), and the bolt (25) into the bolt hole (24) of the connecting projection (24). It is necessary to loosen the nut (30) from the screw rod (29) and disassemble the two halves (21) and (22) as well as remove from (24a), which is a very troublesome operation. is there. Further, since it is made of metal casting, there are problems that productivity is poor and expensive, that it is heavy and difficult to handle, and that maintenance and management are expensive and troublesome.

It is an object of the present invention to provide a mold for producing a concrete strength test specimen that solves the above problems.

Means for Solving the Problems A formwork for producing a specimen for concrete strength test according to the present invention comprises a cylindrical body and a lid closing a lower end opening of the body, and the cylindrical body is spirally wound. In addition, a core body made of two or more layers of band-shaped paper is provided, and the spiral butt joint between the side edges of each band-shaped paper is stepwise in cross section.

In the above, the tubular cylinder and the bottom are formed separately and the bottom is attached to the cylinder. That is, a cylinder is formed of paper or a composite material mainly composed of paper, and a metal is separately formed from the cylinder.
The bottom cover is made of plastic and fixed to the case.
As the belt-shaped paper, it is preferable to use paperboard, paper core paper, or the like.
For the purpose of imparting waterproofness and releasability to the inner peripheral surface of the core, paraffin, at least on the inner peripheral surface of the entire body,
It is preferable to apply a surface treatment using wax or the like to form the release / waterproof layer. Also, instead of the release and waterproof layer,
Synthetic resin-coated paper, synthetic resin-coated aluminum (including aluminum alloys; the same applies below) foil or thin plate, water-repellent impregnated paper lining may be adhered to the inner peripheral surface of the core with an adhesive. . In the case of a synthetic resin-coated paper and a synthetic resin-coated aluminum foil or a thin plate, the synthetic resin-coated layer is used so that it faces the inner surface of the body. In the case of a synthetic resin-coated aluminum foil or a thin plate, it is preferable that kraft paper or the like is attached to the outer surface of the body in advance for adhesion to the core. It is also preferable to bond the same material as the lining to the outer peripheral surface of the core body. However, in the case of synthetic resin coated paper and the same aluminum foil or thin plate, the synthetic resin coated layer is placed on the outer surface side of the body. It is preferable to mark on the outer surface of the outer cover the position of the winding end of each outermost strip of paper in the core.

Further, in the above, the cylinder is cylindrical when manufacturing a specimen for a compression strength test or a tensile strength test, and a square cross section when manufacturing a specimen for a bending strength test. It has a square tubular shape. Also, the body shall not be deformed or leaked when concrete is poured.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In FIGS. 1 to 3, a mold for manufacturing a specimen for concrete strength test is a cylindrical cylinder made of a composite material mainly composed of paper.
(1), a metal bottom cover (2) fixed to the lower end of the body (1) by double winding, and a plastic body fitted in the body (1) and received by the bottom cover (2) It consists of a reinforcing plate (3).

The body (1) is a spirally wound tubular core body (4) consisting of five layers of paperboard (5) and a spirally wound core body (4) covering the entire inner peripheral surface of the core body (4). The lining (6) adhered to the inner peripheral surface of the core body (4) with an adhesive (not shown) and the outer peripheral surface of the core body (4) are spirally wound to cover the entire outer peripheral surface and the core body ( 4) Consists of an outer cover (7) adhered to the outer peripheral surface with an adhesive (not shown).

The side edges of the belt-shaped paperboards (5) in the tubular core body (4) are butt-shaped and not bonded. Also, the spiral butt joints (8A) (8A) between the side edges of each strip paperboard (5)
B), (8C), (8D), and (8E) are stepwise in cross section. The lining (6) is an aluminum foil and a plastic film laminated on the inner surface of the aluminum foil body,
It consists of kraft paper laminated to the outer surface of the aluminum foil body. The outer cover (7) is made of kraft paper which is waterproofed by coating the outer surface of the body with a synthetic resin such as wax. A mark (9) indicating the winding end of the outermost strip paperboard (5) is provided on the upper end of the outer surface of the outer cover (7). The upper end of the torso (1) increases the water resistance of the end and the core (4)
In order to prevent water from seeping into it, it is bent outward so as to have an arcuate cross section. In addition to this, the fourth
As shown in the drawing, it may be bent outwardly downward and folded upward inward, and as shown in FIG. 5, it may be bent horizontally outwardly and folded downward. In addition, the upper end of the peripheral wall of the body (1) is impregnated or coated with a synthetic resin such as a phenolic or polyethylene-based resin or paraffin, or the upper end of the body (1) is a metal foil that does not penetrate water, waterproof paper, It may be covered with an olefinic plastic film or the like.

The cylindrical body (1) is made as follows. That is,
The strip-shaped composite sheet forming the inner lining (6) on the peripheral surface of the mandrel, the five strip-shaped paperboards (5) and the strip-shaped composite sheet forming the outer lining (7) are arranged in the above-mentioned order with mutual adhesives. The material is spirally wound to form a long cylindrical material. At this time, it is preferable to leave a slight gap so that the side edges of the strips (5) are not adhered to each other. Then, the cylindrical member is cut into a predetermined length, and one end is bent into an arc shape to form a cylindrical body.
(1) is created.

FIG. 6 to FIG. 8 show the manufacturing process of the specimen using the above mold.

In order to manufacture a test piece, first, paraffin is applied to the inner surface of the body (1), and then concrete is poured into the mold (see FIG. 6) to naturally cure the concrete. Next,
Finish the top surface of concrete flat (capping).

After this, at the position corresponding to the mark (9), insert a spatula (10) between the barrel (1) and the solidified concrete, and remove the barrel (1).
To push outward (see Fig. 7). Instead of the spatula (10), it may be pulled and spread with pliers or the like. Then, at the winding end of the strip paper (5), the lining (6) is first broken, and then the seams (8A) to (8E) of all the strip papers (5) are the innermost strips (5). From the seam (8A) of the
(7) is broken. As a result, the core body (4) is disassembled along the seams (8A) to (8E) while the strip-shaped papers (5) are bonded to each other (see FIG. 8). Then, the body (1) is stripped along the seams (8A) to (8E), and the specimen is taken out from the mold. Thus, the test piece is manufactured.

Effect of the Invention According to the mold for producing a specimen for concrete strength test of the present invention, the tubular body is composed of a spirally wound two-layer structure including a tubular body and a lid closing the lower end opening of the body. It is equipped with a core made of the above strips of paper, and the spiral butt seams between the side edges of each strip of paper are stepwise in cross section, so that the concrete that has been cast into the formwork has solidified. When taking this out, remove the joints of all the strips of paper that make up the core of the cylindrical body in order from the joints of the innermost strip of paper, so that the strips of paper remain bonded together. The body can be stripped off along the seam in this state.
Therefore, the sample can be taken out of the mold with a simple operation.

Further, according to the mold of the present invention, since the barrel is provided with the core body made of two or more layers of band-shaped paper, it is lighter and easier to handle than the conventional metal casting mold. In addition, since the price is lower than that of the conventional one, it can be disposable, and the maintenance and management do not require cost and labor unlike the conventional one.

[Brief description of drawings]

FIG. 1 is a partial sectional perspective view showing an embodiment of the present invention, and FIG.
The figure is also a longitudinal sectional view, FIG. 3 is a perspective view, FIG. 4 is a partial sectional view showing a modified example of the body, FIG. 5 is a partial longitudinal sectional view showing another modified example of the case, and FIG. Partially cutaway front view showing the step of driving concrete into the formwork, FIG. 7 is a perspective view showing how to take out from the formwork after the concrete has solidified, and FIG. 8 is a partial cross-section showing how to strip the barrel. FIG. 9 is an exploded perspective view showing a conventional example. (1) …… Cylinder body, (4) …… Core body, (5) …… Bandboard, (8A)
~ (8E) …… Spiral butt seam.

Continuation of the front page (56) References Japanese Unexamined Patent Publication No. 52-37177 (JP, A) Actual development No. 52-169384 (JP, U) Actual publication No. 37-21841 (JP, Y1)

Claims (1)

[Scope of utility model registration request] 1. A tubular body and a lid for closing a lower end opening of the barrel, wherein the tubular body has a core body made of two or more layers of spirally wound strip paper, and each strip paper. Formwork for the production of specimens for concrete strength testing, in which the spiral butt joint between the side edges of is made stepwise in cross section.