JP7141719B2 - Formwork, Concrete Product Manufacturing Method and Concrete Product - Google Patents

Description

TECHNICAL FIELD The present invention relates to a formwork, a method for manufacturing a concrete product, and a concrete product. More specifically, the present invention relates to a formwork capable of suppressing the appearance of irregularities due to traces of air pockets on the surface of the inner surface of a concrete product, a method for manufacturing a concrete product, and a concrete product.

Concrete products are made by first mixing cement, sand, gravel, water and an admixture to produce ready-mixed concrete (concrete before hardening). It is formed by solidifying along the inner shape of the frame.

During the production of this ready-mixed concrete and when it is poured into the formwork, air is easily mixed into the ready-mixed concrete, forming air bubbles that rise to the surface of the ready-mixed concrete. It often accumulates. When the ready-mixed concrete is solidified while the air pockets remain, irregularities are formed on the surface of the concrete product. In this case, the appearance of the concrete product is spoiled, and although there is no problem with the strength, the commercial value of the concrete product is lowered, and it takes time and effort to repair it.

Therefore, the invention "Method for manufacturing concrete products" shown in Patent Document 1 has been proposed. This invention manufactures a concrete product by pouring ready-mixed concrete into an outer formwork and then submerging the inner formwork in the ready-mixed concrete. This is because it is easy to remove.

JP-A-2004-34377

However, although the "method for manufacturing a concrete product" described in Patent Document 1 can remove air bubbles on the surface of the ready-mixed concrete around the inner mold, when the ready-mixed concrete solidifies, the inside of the ready-mixed concrete It is not possible to suppress the generation of air bubbles that gradually rise from the

That is, in Patent Document 1, in paragraph number [0012] of the specification, "Air bubbles at the bottom sandwiched between the outer formwork and the inner formwork, especially air bubbles adhering to the surface of the formwork at the bottom and the surface of the reinforcing bar are also removed. However, in fact, it is possible to easily remove the air bubbles that gradually rise from the inside of the ready-mixed concrete between the ready-mixed concrete poured into the outer formwork and the bottom surface of the inner formwork. not a thing

The present invention has been devised in view of the above points, and provides a formwork, a method for manufacturing a concrete product, and a concrete product that can suppress the appearance of irregularities due to traces of air pockets on the surface of the inner surface of the concrete product. intended to provide

In order to solve the above-mentioned problems, the formwork of the present invention comprises: an outer formwork which has an opening and forms an outer surface of a concrete base which is an object to be molded; and at least one of the openings of the outer formwork. an inner mold base body arranged to close a part; and a covering member detachably attached to the inner mold base body in a posture substantially facing a base surface located on the opposite side of the opening of the outer mold frame. and an inner formwork that forms an inner surface of the concrete base.

Here, since the outer formwork has an opening, ready-mixed concrete can be poured into the outer formwork through the opening.

The outer formwork forms the outer surface of the concrete base, which is the object to be molded, and the inner formwork forms the inner surface of the concrete base. A patterned concrete base is formed.

In addition, since the inner mold has an inner mold base that closes at least a part of the opening of the outer mold, the inner mold base is arranged in the vicinity of the opening edge of the opening of the outer mold. can do. As a result, a casting space is formed between the inner formwork base and the outer formwork, into which ready-mixed concrete can be poured.

In addition, by having the covering member attached to the inner formwork substrate in a posture substantially facing the base surface located on the opposite side of the opening of the outer formwork, a space for placing the outer formwork and the inner formwork is formed. When the concrete is cast, the ready-mixed concrete solidifies together with the covering member while contacting the surface of the covering member on the side substantially opposite to the base surface located on the opposite side of the opening of the outer formwork. .

At this time, in the process of solidifying the ready-mixed concrete to form the concrete base, uneven portions are formed due to traces of air pockets between the concrete base and the covering member, but these uneven portions are covered with the covering member. Therefore, it is possible to suppress the irregularities from appearing on the surface of the concrete product.

That is, the irregularities due to the traces of air pockets formed on the surface of the concrete base are formed as follows. First, in the process of solidifying the ready-mixed concrete, the air bubbles contained inside gradually move toward the inner formwork, forming air pockets between the ready-mixed concrete and the covering member. When the ready-mixed concrete solidifies in a state in which the air pockets remain, irregular irregularities are formed in the concrete base due to traces of the air pockets. It should be noted that the air reservoir is not limited to one having a certain area, and includes fine air bubbles appearing on the surface of the concrete base.

Moreover, since the covering member is detachably attached to the inner formwork base, the covering member can be removed from the inner formwork base after the ready-mixed concrete has solidified to form the concrete base. That is, the covering member attached to the inner formwork base is formed integrally with the concrete base in the process of solidifying the ready-mixed concrete. An embedded concrete product is produced. At this time, since the uneven portion due to the traces of air pockets formed on the concrete base is covered with the covering member removed from the inner formwork base, the uneven portions due to traces of air pockets are formed on the surface of the inner surface of the concrete product. You can prevent it from appearing.

Further, when the surface of the covering member to be attached to the inner form base is smooth, the covering member not only covers the uneven portions of the concrete product, but also the concrete product is integrated with the covering member. When formed, the smooth side of the covering member can be placed on the surface side of the concrete product.

In addition, when a concave portion into which ready-mixed concrete can enter is formed on the side of the covering member, the anchoring effect of the concrete that has penetrated into the concave portion and solidified forms the covering member more firmly and integrally with the concrete base. can do.

In order to solve the above-mentioned problems, the method for manufacturing a concrete product according to the present invention provides an inner mold frame to which a covering member for covering at least a part of the inner surface of a concrete base, which is an object to be molded, is detachably attached. The covering member closes at least a part of the opening of the outer formwork in a posture substantially facing the base surface located on the opposite side of the opening of the outer formwork forming the outer surface of the concrete base. a placing step of arranging the inner formwork at the position where the inner formwork is placed, a placing step of placing ready-mixed concrete in the space between the inner formwork and the outer formwork placed in the inner formwork arranging step, and the placing a step of removing the covering member formed integrally with the concrete base from the inner form when the poured ready-mixed concrete solidifies, and removing the concrete base from the outer form. Prepare.

Here, an inner formwork to which a covering member for covering at least a part of the inner surface of a concrete base, which is a molding object, is detachably attached, is provided with an outer mold in which the covering member forms the outer surface of the concrete base. The opening of the outer formwork is arranged in a position that closes at least a part of the opening of the outer formwork in a posture substantially facing the base surface located on the opposite side of the opening of the outer formwork. An inner mold base can be placed near the opening edge of the part. As a result, a casting space is formed between the inner formwork base and the outer formwork, into which ready-mixed concrete can be poured.

Also, at this time, the covering member is arranged between the outer formwork and the inner formwork substrate in a posture substantially facing the base surface located on the opposite side of the opening of the outer formwork. As a result, when the ready-mixed concrete is placed in the space for placing the outer and inner forms in the subsequent placing process, uneven portions are formed due to traces of air pockets between the ready-mixed concrete and the covering member. However, since the uneven portion is covered with the covering member, it is possible to prevent the uneven portion from appearing on the surface of the concrete product.

In addition, since the covering member is detachably attached to the inner formwork, it is attached to the inner formwork until it is formed integrally with the concrete base. can be removed from the

In addition, the ready-mixed concrete is placed in the space between the inner formwork and the outer formwork arranged in the inner formwork arrangement process, and the ready-mixed concrete is placed in the opening of the outer formwork of the covering member. It solidifies together with the covering member while being in contact with the surface on the side substantially opposite to the base surface located on the opposite side. At this time, since the covering member covers the irregularities formed on the concrete base, it is possible to suppress the appearance of irregularities due to traces of air pockets on the inner surface of the concrete product.

In addition, in the casting process, when the ready-mixed concrete solidifies, the covering member formed integrally with the concrete base is removed from the inner formwork, and the concrete base is removed from the outer formwork by a formwork removal process. , a concrete product is manufactured in which the concrete base and the covering member are integrally formed.

In addition, before the inner mold frame arranging step, the covering member manufacturing process for manufacturing the covering member having a smooth surface on the side attached to the inner mold frame causes the smooth surface to be formed in the inner mold frame arranging step, which is a later process. A covering member is attached to the inner formwork so as to face the inner formwork. Thereby, since the smooth surface of the covering member is arranged on the surface side of the concrete base, the appearance of the surface of the concrete product is not spoiled.

Further, in order to solve the above-mentioned problems, the concrete product of the present invention includes a concrete base having uneven portions due to traces of air pockets on the surface of the inner surface, and the concrete base covering the uneven portions of the concrete base. and a covering member which is formed integrally with the concrete base and has a smooth surface appearing on the surface side of the concrete base when formed integrally with the concrete base.

Here, the concrete base having uneven portions due to traces of air pockets on the surface of the inner surface, and the covering member formed integrally with the concrete base by covering the uneven portions of the concrete base, the covering member is the uneven portion of the concrete base. Since it is formed integrally with the concrete base part while covering the , it is possible to suppress the appearance of irregularities due to traces of air pockets on the surface of the inner surface of the concrete product.

In addition, since the smooth surface of the covering member is arranged on the surface side of the concrete base by the covering member whose surface is arranged on the surface side of the concrete base when integrally formed with the concrete base is a smooth surface, the concrete product does not impair the appearance of the surface of the

The formwork, the method for manufacturing a concrete product, and the concrete product according to the present invention are capable of suppressing the appearance of irregularities due to traces of air pockets on the surface of the inner surface of the concrete product, the method for manufacturing a concrete product, and the concrete product. It has become.

BRIEF DESCRIPTION OF THE DRAWINGS It is exploded explanatory drawing of the formwork and concrete product which concern on embodiment of this invention. It is an explanatory view showing a state in which the outer formwork and the inner formwork according to the embodiment of the present invention are combined. FIG. 3(a) is a side view of the inner mold according to the embodiment of the present invention, and FIG. 3(b) is a front view of the inner mold. FIG. 4(a) is a perspective view of a mold used in manufacturing the covering plate according to the embodiment of the present invention, and FIG. 4(b) is a covering plate according to the embodiment of the present invention. is an explanatory view for explaining a state in which the is removed from the mold. It is explanatory drawing which shows the manufacturing method of the concrete product which concerns on embodiment of this invention. FIG. 4 is an explanatory view showing another form of the covering plate of the present invention; It is explanatory drawing which shows the manufacturing process of the concrete product which concerns on embodiment of this invention.

The mold A of the present invention will be described below with reference to FIGS. 1 to 4 for understanding of the present invention.

The formwork A consists of a box-shaped outer formwork A1 with an open top and an inner formwork A2 arranged at a predetermined position inside the outer formwork A1. By overlapping the outer mold frame A1 and the inner mold frame A2, a space SA is generated inside as shown in FIG. Ready-mixed concrete (concrete before hardening) is placed in this space SA to form the concrete base 2 . At this time, the covering plate 1 attached to the inner formwork A20 of the inner formwork A2 is integrated with the concrete base 2 to form the concrete product P. As shown in FIG.
Details will be described below.

[About formwork A]
The outer frame A1 is surrounded by a pedestal A10, side plates A11, A11, and end plates A12, A12, and has a hollow and substantially quadrangular shape in a plan view with an opening A16 formed at the top. The side plates A11, A11 and the end plates A12, A12 are attached to the base A10 so as to be rotatable and fixed at the closed position as shown in FIG.

The end plates A12, A12 of the outer formwork A1 are provided with clamp members A13a, A13a, which are engaged with the clamp receiving members A13b, A13b provided on the inner formwork A2 to move the inner formwork A2 to the outer formwork. It can be fixed to the frame A1.

Specifically, the inner formwork A2 is composed of the inner formwork base A20 and the cover plate 1, and is partially closed to cover the upper opening of the outer formwork A1. It is detachably attached to the outer formwork A1 by A13b.

The inner mold frame A2 is composed of an inner mold base body A20 that is elongated in the left-right direction in FIG. 1, and a covering plate 1 that is detachably attached to the lower surface A20a of the inner mold base body A20 and elongated in the left-right direction. Although the cover plate 1 is made of concrete in this embodiment, it is not limited to this, and it is also possible to use resin, wood, metal, rubber, or the like.

The cover plate 1 has a smooth upper surface 10 and a non-smooth lower surface 11 located on the opposite side of the upper surface 10. The smooth upper surface 10 faces the lower surface A20a of the inner mold base A20. It is attached to the inner mold base A20 by four fixing bolts A15a and four insert nuts A15b so as to be in contact with each other.

That is, when the cover plate 1 is removed from the inner formwork base body A20 after the concrete base 2 is integrally formed with the cover plate 1, the smooth upper surface 10 of the cover plate 1 is on the surface side of the concrete base 2. placed in Further, the non-smooth lower surface 11 is in contact with the inner bottom surface 20 formed by the surface modeled by the lower surface 11 of the covering plate 1 when the covering plate 1 is in contact with the concrete base 2 and integrally formed. It never appears on the surface of the concrete product P. Therefore, the appearance of the concrete product P is not spoiled.

When attaching the upper surface 10 to the lower surface A20a of the inner mold base A20, it is possible to interpose a rubber mat or the like in between so that the upper surface 10 is in close contact with the lower surface A20a. In this case, it is possible to prevent ready-mixed concrete from entering between the upper surface 10 and the lower surface A20a of the inner formwork base A20 and forming irregularities on the smooth upper surface 10. FIG.

In this embodiment, the cover plate 1 is attached to the inner mold base A20 by four fixing bolts A15a and four insert nuts A15b. The means for attaching the covering plate 1 to the inner mold base A20 is not limited to providing the insert nuts A15b on the upper surface 10, but any other means such as providing insert nuts on the side surfaces of the covering plate 1. can be used. Furthermore, when the insert nut A15b is attached to the cover plate 1, the insert nut A15b is attached to the upper surface 10 of the cover plate 1. The insert nut A15b can be closed flat with a known closing means such as a lid. Therefore, the upper surface 10 can be kept smooth.

Further, as shown in FIGS. 1, 2 and 3, between the end plates A12 and A12 of the outer formwork A1, both ends A20b and A20b of the inner formwork base A20 extend downward from the upper parts A12a and A12a. Notch portions A12b and A12b are formed so as to have a width that allows the fitting without any gaps. Both ends A20b, A20b of the inner mold base A20 are fitted into the cutouts A12b, A12b, whereby the inner mold base A20 is fixedly attached to the outer mold A1.

Clamp receiving members A13b and A13b that can be engaged with the clamp members A13a and A13a are attached to both longitudinal side faces A20c and A20c of the inner mold base A20. By engaging the clamp members A13a, A13a with the clamp receiving members A13b, A13b, the inner formwork A2 is fixed to the outer formwork A1 as shown in FIG. The means for fixing the outer mold frame A1 and the inner mold frame A2 is not limited to the clamp members, and other arbitrary means such as fixing with screws can be used.

As shown in FIGS. 3(a) and 3(b), grooves 12a, 12a are provided in the longitudinal side surfaces 12, 12 of the cover plate 1 in parallel with the longitudinal direction. Ready-mixed concrete is placed in the space SA and penetrates into the grooves 12a, 12a, and when the ready-mixed concrete solidifies to form the concrete base 2, the concrete base 2 is formed by the anchor effect of the penetrated portion. It becomes possible to form the cover plate 1 firmly and integrally.

[Regarding the concrete base 2]
As shown in FIG. 2, when the outer formwork A1 and the inner formwork A2 are put together, the concrete base 2 of the concrete product P is formed by pouring ready-mixed concrete into the space SA formed inside.

Specifically, by placing ready-mixed concrete in the space SA between the outer formwork A1 and the inner formwork A2, the shape of the inner surface A14 of the outer formwork A1 and the outer peripheral surface A21 of the inner formwork A2 is formed. A concrete base 2 having a substantially "U"-shaped cross section is formed.

Here, before the concrete base 2 solidifies, the air bubbles contained inside the ready-mixed concrete gradually rise and come into contact with the lower surface 11 of the covering plate 1 attached to the inner formwork A2 and the lower surface 11. An air reservoir 21 is formed between the concrete base 2 and the inner bottom surface 20, as shown in FIGS. 5(d) and 5(e). Since the air pool 21 is formed between the lower surface 11 and the inner bottom surface 20 of the concrete base 2, it is difficult to remove, and in many cases, the ready-mixed concrete solidifies with the air pool 21 remaining.

When the concrete base 2 solidifies in a state in which the air pool 21 remains without being removed, an uneven air pool trace 22 imitating the shape of the air pool 21 is formed on the inner bottom surface 20 of the concrete base 2. .

When the concrete base 2 is solidified, the air pockets 22 are covered by the cover plate 1 integrated with the concrete base 2 and do not appear on the surface of the concrete product P. can be prevented from being damaged.

[Regarding the cover plate 1]
The cover plate 1 is made of concrete in this embodiment and is formed by a formwork B. As shown in FIG. As shown in FIG. 4(a), the mold B has a hollow shape with an open top, and consists of a pedestal B1, side plates B2 and B2, and end plates B3 and B3. The side plates B2, B2 and the end plates B3, B3 are attached to the pedestal B1 so as to be rotatable and fixed in the closed position as shown in FIG. can be used to form the cover plate 1. The side plates B2, B2 and the end plates B3, B3 can be detached from the pedestal B1 and disassembled.

4(a) and 4(b), four bottomed cylindrical insert nuts A15b are attached to the pedestal B1 with their open ends A15c in contact with the pedestal B1. installed by When ready-mixed concrete is poured into the formwork B from the opening B4 in this state, when the ready-mixed concrete solidifies, the covering member 1 is formed with the four insert nuts A15b embedded therein. Since the open end A15c of the insert nut A15b appears on the back surface 1b side of the cover plate 1, the fixing bolt A15a can be screwed into the insert nut A15b from the open end A15c side.

Here, as shown in FIG. 4(b), on the surface 1a of the cover plate 1 exposed from the opening B4 of the formwork B, air bubbles in the ready-mixed concrete poured into the formwork B rise. As a result, an air reservoir 13 is formed. Since it is difficult to remove all of these air pockets 13, they remain, and when the ready-mixed concrete hardens, air pocket traces 14 are formed on the surface 1a, resulting in a non-smooth surface.

With this surface 1a as the lower surface 11, the lower surface 11 is in contact with the concrete base 2 when the covering plate 1 is attached to the inner formwork base body A20 so that the covering plate 1 and the concrete base 2 are integrally connected. Thereby, the lower surface 11 which is a non-smooth surface can be prevented from appearing on the surface of the concrete product P.

When attaching the cover plate 1 to the inner mold base A20, it is conceivable to interpose a rubber mat between them so that the cover plate 1 and the inner mold base A20 are in close contact with each other. In this way, when the fresh concrete is placed in the space SA, the fresh concrete enters between the upper surface 10 and the lower surface A20a of the inner formwork base A20, forming irregularities on the smooth upper surface 10. can prevent

On the other hand, the back surface 1b, which is the surface opposite to the front surface 1a, is in contact with the pedestal B1. Here, since the air bubbles move upward, they are not formed on the back surface 1b side, and the back surface 1b becomes a smooth surface. With this rear surface 1b as the upper surface 10, the inner mold base A20 is attached so as to face the lower surface A20a. As a result, when the concrete base 2 is formed, the upper surface 10 appears on the surface of the concrete base 2, and the covering plate 1 covers and hides the air pool traces 22 generated in the concrete base portion 2, so that the air pool traces 22 are formed. does not appear on the surface of the concrete product P, and the deterioration of the appearance of the concrete product P can be prevented.

As shown in FIG. 4(b), air pockets 15 are formed not only on the surface of the covering plate 1 exposed from the opening B4 of the mold B, but also on the lower inner surface regions 12b, 12b of the grooves 12a, 12a. After that, it becomes an air pool trace 16 having an uneven shape. However, the air pockets 16 around the grooves 12a, 12a are covered with the concrete base 2 and do not appear on the surface of the concrete product P, so that the appearance of the concrete product P is not spoiled.

Also, other shapes of the cover plate are not particularly limited, and shapes other than the shape of the cover plate 1 as shown in FIGS. For example, the cover plate 1a shown in FIG. 6(a) has an air reservoir (not shown) formed near the lower surface 1a1 formed to protrude in a substantially arc shape. However, since this air pocket or the air pocket trace formed thereby is covered with the covering plate 1a, it does not appear on the surface of the concrete product P.

In addition, the cover plate 1b shown in FIG. 6(b) has a plurality of ridges 1b2 formed on its lower surface 1b1, and air pools (not shown) are formed in the grooves between these ridges 1b2. is formed. However, since this air pocket or the air pocket trace formed thereby is covered with the covering plate 1b, it does not appear on the surface of the concrete product P. As shown in FIG.

In addition, the cover plate 1c shown in FIG. 6(c) has a single protruding streak portion 1c2 formed substantially in the center of the lower surface 1c1, and an air reservoir (not shown) is formed around the protruding streak portion 1c2. ) is formed. However, since this air pocket or the air pocket trace formed thereby is covered with the covering plate 1c, it does not appear on the surface of the concrete product P. As shown in FIG.

In addition, the covering plate 1d shown in FIG. 6D has a single groove 1d2 cut in a semicircular shape on the lower surface 1d1 thereof. ) is formed. However, since this air pocket or the air pocket trace formed thereby is covered with the cover plate 1d, it does not appear on the surface of the concrete product P. As shown in FIG.

Moreover, the length and width of the cover plate are not particularly limited and can be set arbitrarily. Furthermore, the thickness of the cover plate 1 is preferably at least about 5 mm in order to give strength to the cover plate itself, but the thickness is not limited and can be set as appropriate.

Further, when forming the concrete base 2 integrally with the covering plate 1, interposing a wire mesh or the like as an anchor between the concrete base 2 and the covering plate 1 is conceivable. can. As a result, the cover plate 1 can be firmly attached to the concrete base 2 .

[About Concrete Product P]
As described above, the concrete product P consists of the concrete base 2 and the covering plate 1. As shown in FIG. By aligning the inner bottom surface 20 of the concrete base 2 and the lower surface 11 of the covering plate 1 to integrally form the concrete base 2 and the covering plate 1, the air trap marks 22 generated in the process of forming the concrete base 2 and the coating It is possible to prevent air pockets 14 generated in the process of forming the plate 1 from appearing on the surface of the concrete product P.

Moreover, when the concrete base 2 solidifies, the covering plate 1 is formed integrally with the concrete base 2 . After that, the inner formwork base body A20 is removed from the outer formwork A1, and a concrete product P comprising the concrete base 2 and the covering plate 1 is formed.

At this time, the air pockets 22 of the concrete base 2 are covered with the cover plate 1 and are not exposed on the surface of the concrete product P. In addition, since the covering plate 1 and the concrete base 2 are integrally formed in a state where the uneven portion formed on the surface 1a (lower surface 11) of the covering plate 1 itself is in contact with the concrete base 2, the lower surface 11 The formed irregularities do not appear on the surface of the concrete product P.

[Method for manufacturing concrete product P]
The concrete product P is manufactured by first manufacturing the covering plate 1 and then forming the concrete base 2 while integrating it with the covering plate 1 to form the concrete product P. As shown in FIG. Description will be made with reference to FIGS. 4 and 5. FIG.

(ST1) First placing step As shown in FIGS. 4(a) and 4(b), ready-mixed concrete is poured from the opening B4 of the formwork B to form the covering plate 1 from the formwork B. . At this time, air bubbles contained in the ready-mixed concrete before solidification gradually rise and appear on the surface 1a of the cover plate 1, forming an air pocket 13 as shown in FIG. 4(b). When the covering plate 1 is solidified, the air pool 13 becomes an uneven air pool trace 14 . In this way, the surface 1a becomes a non-smooth surface with irregularities formed with air trap marks 14, and is integrated with the concrete base 2 as a lower surface 11, which will be described later.

In addition, as shown in FIG. 4B, the back surface 1b, which is located on the opposite side of the front surface 1a, is in contact with the pedestal B1 of the mold B, and is smooth because no air pool is formed. The concrete base 2 and the cover plate 1 are integrated and solidified so that the rear surface 1b is formed on the surface of the concrete base 2 as the upper surface 10 described later.

In addition, air pockets 15 are also formed in the lower inner surface regions 12b, 12b of the grooves 12a, 12a, and then air pool traces 16 having uneven shapes are formed. At this time, as shown in FIG. 4(b), the air pockets 16 around the grooves 12a, 12a are covered with the concrete base 2 and do not appear on the surface of the concrete product P. It does not spoil the appearance.

(ST2) Step of Removing Cover Plate 1 As shown in FIG.

(ST3) Step of attaching the covering plate 1 to the inner mold base A20 As shown in FIG. It is attached using a fixing bolt A15a and an insert nut A15b so as to be in contact with each other.

Specifically, the insert nuts A15b are embedded at four locations on the upper surface 10 side of the cover plate 1. As shown in FIG. In addition, the fixing bolts A15a are attached to the bottom plate A20d of the inner mold base A20 at positions corresponding to the embedded insert nuts A15b. Then, the upper surface 10 of the cover plate 1 and the bottom surface A20a of the inner mold base A20 are aligned, and the fixing bolts A15a are screwed into the insert nuts A15b to attach the cover plate 1 to the inner mold base A20. In this manner, the inner formwork base body A20 to which the covering plate 1 is attached is referred to as an inner formwork A2. In this embodiment, the insert nuts A15b are provided at four locations, but the number of insert nuts A15b is not limited to this, and the number of insert nuts to be provided can be determined arbitrarily.

Further, when the fixing bolt A15a is longer than the thickness of the covering plate 1, the covering plate 1 is attached to the inner formwork base body A20 with the tip of the fixing bolt A15a protruding from the lower surface 11 of the covering plate 1. mounted on. As a result, in the second placing step ST5, which will be described later, the contact area between the ready-mixed concrete and the covering plate 1 is increased, so that the covering plate 1 and the concrete base 2 are more strongly integrated.

(ST4) Mounting Process of Inner Formwork A2 As shown in FIG. 5(b), the inner formwork A2 is mounted to the outer formwork A1 using clamp members A13a, A13a and clamp receiving members A13b, A13b. Specifically, the clamp members A13a, A13a provided on the end plates A12, A12 of the form A and the clamp receiving members A13b, A13b provided on both side surfaces A20c, A20c of the inner form base A20 are engaged. As a result, the inner formwork A2 is fixed to the outer formwork A1.

(ST5) Second Placement Step As shown in FIG. 5(c), ready-mixed concrete is placed in the space SA formed between the outer formwork A1 and the inner formwork A2. At this time, as the ready-mixed concrete solidifies, the cover plate 1 attached to the inner formwork base A20 is formed integrally with the concrete base 2 to form a concrete product P.

(ST6) Step of Forming Concrete Product P Air bubbles contained in the ready-mixed concrete gradually rise to form an air pocket 21 between the inner bottom surface 20 of the concrete base 2 and the bottom surface 11 of the covering plate 1. be done. It is difficult to remove this air pool 21, and when the ready-mixed concrete hardens, an air pool trace 22 shaped like the air pool 21 is formed. In addition, since the B surface 11 is a non-smooth surface, the air pool 21 is difficult to move and can be prevented from rising along the side surface of the inner formwork base A20, and the air pool marks 22 are left on the upper surface of the concrete base 2 ( The surface exposed between the outer mold frame A1 and the inner mold frame A2 shown in FIG. 2) can also be suppressed from appearing.

Further, the covering plate 1 attached to the inner mold base A20 is solidified integrally with the concrete base 2 while covering the air trap marks 22, and the concrete product P is formed. At this time, since the upper surface 10 of the covering plate 1 is attached facing the inner formwork base A20, the upper surface 10 is arranged on the surface side of the concrete base 2 when the ready-mixed concrete hardens. As a result, the air pockets 22 formed on the inner bottom surface 20 of the concrete base 2 are less likely to appear on the surface of the concrete product P by being covered with the covering plate 1 . Therefore, the appearance of the concrete product P is not spoiled.

(ST7) Formwork removal process As shown in Figs. 5(d) and (e), the inner formwork A2 is removed from the outer formwork A1, and the concrete product P is die-cut from the outer formwork A1 to obtain a concrete product. P is completed.

By the above steps, the appearance of traces of air pockets on the surface of the inner surface of the concrete product P is suppressed, and the concrete product P without unevenness on the surface is formed. The concrete product P in the present embodiment is 900 mm long, 490 mm wide, and 300 mm high, and can be used as stacking blocks or box culverts that form the slope of a river. be. In this case, the piling blocks and the like are often different in shape from the concrete product P of this embodiment. It has a substantially U-shaped shape.

As described above, the formwork, the method for manufacturing a concrete product, and the concrete product according to the present invention are capable of suppressing the appearance of irregularities due to traces of air pockets on the surface of the inner surface of the concrete product, and the method for manufacturing a concrete product. and concrete products.

1 covering plate (covering member)
2 Concrete base A Formwork A1 Outer formwork A2 Inner formwork A10 Pedestal (base surface)
A16 Opening A20 Inner formwork base P Concrete product

Claims (6)

an outer formwork that has an opening and forms an outer surface of a concrete base that is an object to be molded;
The inner mold base, which closes at least a part of the opening of the outer mold, and the base surface of the outer mold, which is located on the opposite side of the opening of the outer mold, are substantially opposed to each other. an inner formwork having a covering member detachably attached to the frame base and forming an inner surface of the concrete base,
The covering member is made of concrete, and has a smooth surface on the side attached to the inner formwork, and a non-smooth surface on the side opposite to the side attached to the inner formwork due to formation of traces of air pockets. frame. The formwork according to claim 1, wherein a concave portion into which ready-mixed concrete can enter is formed in a side portion of the covering member. The formwork according to claim 2, wherein the inner surface of the recess is formed with an air pool mark. An inner formwork to which a covering member that covers at least a part of the inner surface of the concrete base, which is the object to be molded, is detachably attached; an inner formwork arranging step of arranging the inner formwork at a position that closes at least a part of the opening of the outer formwork in a posture substantially facing the base surface located on the opposite side of the part;
a placing step of placing ready-mixed concrete in the space between the inner formwork and the outer formwork arranged in the inner formwork arranging step;
In the casting step, the covering member formed integrally with the concrete base is removed from the inner form when the poured ready-mixed concrete solidifies, and the concrete base is removed from the outer form. and a removal step,
The covering member is made of concrete, and has a smooth surface on the side to be attached to the inner formwork, and a non-smooth side surface opposite to the side to be attached to the inner formwork due to formation of air pockets. Concrete How the product is made. 5. The method of manufacturing a concrete product according to claim 4, further comprising, prior to the inner mold frame arranging step, a covering member manufacturing step of manufacturing the covering member having a smooth surface on the side to be attached to the inner mold frame. a concrete base having uneven portions due to traces of air pockets on the surface of the inner surface;
a covering member formed integrally with the concrete base by covering the uneven portion of the concrete base, and having a smooth surface appearing on the surface side of the concrete base when formed integrally with the concrete base; with
A concrete product, wherein the covering member is made of concrete, and the side surface opposite to the smooth surface is non-smooth due to formation of traces of air pockets.

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