JP6958889B2 - Manufacturing method of loading member for graben and precast concrete plate - Google Patents

Description

The present invention relates to a method for manufacturing a precast concrete (hereinafter, also simply referred to as “PC”) board to which tiles are attached in advance, and a joint groove loading member to be loaded in a gap portion between tiles in the process of manufacturing a PC board.

As a method for manufacturing a PC plate to which tiles T, T ... Are attached in advance, as shown in FIG. 6, first, on the surface of a plurality of tiles T, T ... arranged with a predetermined (corresponding to a joint) gap, for example, paper is used. The sheet 100 is attached to form the tile unit 101, then the tile unit 101 is set on the bottom of the mold 102 so that the back surface of the tile T faces upward, and then the tile unit is placed on the mold 102 in that state. Concrete is cast so that 101 is buried and cured under predetermined conditions, and then the PC plate is demolded to remove the sheet 100 on the surface of the tile unit 101, and finally the PC plate is washed to cover the tile T surface. For example, Patent Documents 1 and 2 describe a method for removing stains and stains on joints.

In the method of manufacturing a PC board to which the tile T is attached in advance, liquid cement paste may adhere to the surface of the tile T and harden at the time of curing, and such the hardened cement paste is washed from the PC board. It has been conventionally known that the work of removing the tile requires extra effort.
Then, in Patent Documents 1 and 2, in order to solve such a problem, concrete curing delay is applied to the adhesive 103 for bonding the tile T applied to the sheet 100 (for example, a mixture of acrylic ester resin and starch paste). An appropriate amount of an agent (for example, lignin sulfonate) is blended, and the action of the concrete hardening retarder delays the hardening of the cement paste adhering to the tile T so that it can be easily removed by washing after demolding. ing.

Japanese Unexamined Patent Publication No. 48-29821 Japanese Unexamined Patent Publication No. 8-118325

As described above, when a concrete hardening delaying agent is mixed with the tile bonding adhesive 103 applied to the sheet 100 and the hardening of the cement paste is delayed by the action of the concrete hardening delaying agent, the adhesive is used. Since the concrete hardening retarder mixed with 103 may adversely affect the performance of the adhesive 103, the adhesive 103 that can be used is limited. Further, since the adhesive 103 containing the concrete hardening retarder is applied to the entire surface of the sheet 100, the amount of the concrete hardening retarder used is unnecessarily large.

The present invention has been made in view of the above, and an object of the present invention is to facilitate removal of cement paste by a concrete hardening retarder by using an existing sheet for forming a tile unit as it is or without using a sheet. To do.

As described in claim 1,
A loader with a shape that can be loaded into the gaps of multiple tiles that are installed with gaps in the formwork for precast concrete plate molding.
E Bei and a retardative layer containing concrete retarders,
The loading body is
A main member having a shape that can be loaded into the gap portion of a plurality of tiles,
It has a sheet-like swelling member that is attached to the surface of the main member facing the side surface of the tile and absorbs a liquid such as water to increase the thickness at least.
The curing delay layer is
Provided is a joint groove loading member in which the concrete curing retarder is mixed with an ink having a color different from the color of the swelling member and applied to one side or both sides of the swelling member.
When concrete is cast into a formwork having a plurality of tiles and the above-mentioned joint groove loading member loaded in the gap portion of the tiles, the cement paste leaking to the surface of the tiles is the tile and the loader. Since it always touches the hardening delay layer when passing between them, the hardening is delayed due to the influence of the concrete hardening retarder.

Further, according to mow th Graben for loading member or swelling member thicker to absorb sprayed liquid in advance, thereby a gap tiles and eye Rift for loading member is clogged most cement paste tiles Although it is difficult to leak to the surface, the cement paste may still leak to the surface of the tile, and even in such a case, the hardening of the leaked cement paste is delayed and can be easily removed by washing. Therefore, the shielding effect of the swelling member of the graben loading member and the antifouling effect of the curing delay layer act synergistically to efficiently produce a clean PC plate with less dirt due to cement paste.
Further, when the swelling member absorbs the pre-sprayed liquid to increase the thickness, the curing retarder of the curing delay layer naturally mixes with the liquid, so that if the cement paste invades the inside of the swelling member, the cement paste invades. Even if it is mixed with the above liquid, the cement paste is hard to cure due to the action of the curing retarder. Therefore, even if the debris of the swelling member mixed with the cement paste adheres to the graben after demolding and remains, it can be easily removed by washing.

Further, a hardening retarder layer, by a a mixture of concrete set retarder ink color different from the color of the swelling member, is clear at a glance that the set retarding layer is formed on the swelling member .. Further, when the swelling member having the curing delay layer formed on one surface is attached to the main member, there is no possibility that the orientation is mistaken.

Further, as described in claim 3 , the ink provides the joint groove loading member according to claim 1 or 2 , which has the same color as or similar to that of concrete.
According to such an invention, even if the debris of the swelling member is mixed with the cement paste and remains in the joint groove as described above, the debris is dyed in the same color as or similar to that of concrete by the ink, so that it is not noticeable.

Further, as described in claim 4 , a plurality of tiles arranged face down and the joint groove loading member according to any one of claims 1 to 3 loaded in the gap portion of the tiles. Provided is a method for manufacturing a PC plate in which concrete is cast into a mold in which at least the above is set and cured, and after the mold is removed, the loading member for the joint groove is removed and cleaned.
According to such a manufacturing method, a PC board having almost no or almost no conspicuous stain due to leakage of cement paste can be efficiently manufactured.

As described above, according to the present invention, by providing the hardening delay layer in the loading member for the joint groove, the existing sheet for forming the tile unit can be used as it is, or cement by the concrete hardening delay agent can be used without using the sheet. The paste can be easily removed. Therefore, it is possible to reduce the waste of the concrete hardening retarder as compared with the case where the adhesive containing the concrete hardening retarder is applied to the entire surface of the sheet, and the cement paste can be surely brought into contact with the concrete hardening retarder. Therefore, it is possible to efficiently delay the curing of the cement paste.

It is a perspective view of the loading member for a graben which shows a part in a cross section. (A) to (c) are cross-sectional views showing a manufacturing process of a tile unit. It is a top view of the jig which shows the state which the tile and the loading member for a joint groove are fitted. FIG. 2C is an enlarged cross-sectional view of a main part centered on the graben loading member of FIG. 2C. (A) is a cross-sectional view of a main part showing a state in which a tile unit is set on the bottom of a formwork, and (b) is a cross-sectional view of a main part showing a state in which concrete is poured into the formwork. It shows the manufacturing method of the conventional PC board, and is the perspective view of the main part which shows the state which the tile unit is set in the formwork.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The graben loading member 1 of the embodiment is a long square bar-shaped loading body 3 formed to have substantially the same width as the width of the gap portion 2 (later graben) between the tile T and the tile T, and the loading body 3 thereof. It is provided with a hardening delay layer 4 formed on both side surfaces by a concrete hardening retarder.

[Loading body]
The loading body 3 has a main member 5 that constitutes most of the loading body 3, and a swelling member 7 that is attached to both side surfaces of the main member 5 with a thermosetting adhesive 6, and the swelling body 3 thereof. The curing delay layer 4 is provided on one side (outer surface) of the member 7 on the opposite side of the main member 5 side. Although not shown, the curing delay layer 4 may be provided on one side (inner surface) of the swelling member 7 on the main member 5 side or on both sides of the swelling member 7.

[Loading body-main member]
The main member 5 of the loading body 3 is a foam such as polyethylene, urethane, or styrene, and has appropriate elasticity. It should be noted that the fact that the main member 5 has elasticity is advantageous in terms of work because it is appropriately deformed when it is fitted into the gap portion 2 between the tiles T. The color of the main member 5 is, for example, gray, which is the same color as or similar to that of concrete C.

[Loading body-swelling member]
The swelling member 7 of the loading body 3 may be anything as long as it absorbs a liquid (water, an alkaline aqueous solution, etc.) to increase the thickness. For example, the normal thickness before water absorption is 0.05 mm to 0.25 mm. It is a commercially available water-soluble paper whose thickness increases by 15 to 20 times by absorbing water, or an insoluble synthetic resin having swelling property.
An example of the latter is an insoluble acrylic resin that absorbs water and swells. Then, when such an acrylic resin is applied to both the front and back surfaces of the water-soluble sheet as the core and dried, the sheet-shaped swelling member 7 is formed. Some of the existing swelling members 7 made of synthetic resin contain water and swell 100 to 300 times in thickness.

The swelling member 7 is attached to both side surfaces of the main member 5 with a thermosetting adhesive 6, but the thermosetting adhesive 6 does not melt under heating conditions when the concrete is heat-cured. Anything is acceptable as long as it is equipped with. For example, 75 to 80% by weight of natural rubber or synthetic rubber, 10 to 20% by weight of fluororesin as a heat-resistant resin, 5 to 15% by weight of zincated or titanium oxide as a filler (filler), and several weights of isocyanate as a cross-linking agent. When synthesized at a ratio of%, a thermosetting adhesive 6 that cures at a temperature of 100 ° C. or lower and exhibits heat resistance of 130 ° C. or higher can be obtained. Currently, concrete is generally heat-cured by continuously heating it at a temperature of 100 ° C. to 120 ° C. for 5 to 10 hours using steam, and the thermosetting pressure-sensitive adhesive 6 synthesized as described above is used. It cures under such heating conditions and does not melt during heat curing.

[Curing Delay Layer]
The curing delay layer 4 of the embodiment provided on the outer surface of the swelling member 7, that is, the surface opposite to the main member 5 side is about 6 to 30% by weight of the printing ink having the same color as or similar to that of concrete. It is a mixture of a concrete hardening retarder of about 6 to 10% by weight, preferably about 6 to 10% by weight, and is applied by printing. When the curing delay layer 4 is provided on both sides of the swelling member 7, half the amount of the concrete curing delaying agent may be mixed with the printing ink and applied to each surface. By doing so, the total amount of the concrete hardening retarder becomes the same as that of one side of the embodiment.
The curing delay layer 4 may be applied uniformly, but when the absorption of the liquid into the swelling member 7 is delayed due to this, a so-called shaded state, which is a collection of fine dots, or a thin line An appropriate liquid passage space may be provided by applying the mixture to a so-called hatched state, which is an aggregate. As a result, the liquid absorption of the swelling member 7 can be quickly performed via the curing delay layer 4.

The concrete hardening retarder forming the hardening retarding layer 4 is known, for example, the lignin sulfonate exemplified in Patent Document 1 and (1) gluconic acid, tartrate acid, citric acid, exemplified in Patent Document 2. Oxycarboxylic acids such as malic acid, galactic acid or salts thereof and salts thereof, (2) ketocarboxylic acids such as pyruvate, (3) sugar alcohols such as sorbitol and arabitol, (4) glucose, mannose, saccharose and the like. (5) In addition, there are sodium silicate, magnesium silicate, lead nitrate, sodium phosphate, sodium iodide, sodium fumate, tannin, linseed oil and the like.

The joint groove loading member 1 of the embodiment has the above-described configuration, and then a method of manufacturing a PC plate using the same will be described.
First, the tile unit 9 is made using the box-shaped jig 8 shown in FIGS. 2 (a) and 3 (a). The jig 8 is a shallow box having a depth substantially equal to the thickness of the tile T, and is arranged on the bottom plate 10 so that a plurality of tiles T (six pieces shown in the figure) are aligned at intervals corresponding to joint grooves. Partition frames 11, 11 ... Are projected. The height of the partition frame 11 is smaller than the thickness of the tile T, and the gap portion 2 is set between the tile T and the tile T. Further, as shown in FIGS. 2A and 3, step frames 12 corresponding to the partition frame 11 are provided on two sides adjacent to each other with one corner of the jig 8 interposed therebetween.

Next, the tiles T are arranged on the jig 8 with the front side facing up as shown in FIG. 2 (b), and the partition frame 11 and the step frame 12 are as shown in FIG. 2 (c). The joint groove loading member 1 is fitted into the space. In this state, the curing delay layer 4 of the graben loading member 1 faces the side surface of the tile T.

Next, as shown by the alternate long and short dash line in FIG. 2C, all the tiles T and the graben loading member 1 are covered with a sheet 13 made of polypropylene, polyvinyl chloride, polyester or paper, and the sheet 13 is covered. The tile T and the graben loading member 1 are integrally bonded by an adhesive layer formed on the entire surface.

The tile units 9 formed as described above are arranged on the bottom of the mold 14 with the sheet 13 facing down as shown in FIG. 5A. In this state, the back surface of the tile T is facing upward. Note that FIG. 5A shows a part of each of the two tile units 9, and for the purpose of facilitating the distinction between the two tile units 9, only one tile unit 9 is inked. The other tile unit 9 is shown in white. Therefore, the boundary between the black tile T and the white tile T corresponds to the seam between the tile units 9.

Next, water is sprayed into the form 14 so that the swelling member 7 of the graben loading member 1 absorbs water. Then, the thickness (volume) of the swelling member 7 increases, and the width of the graben loading member 1 increases by that amount, so that the swelling member 7 comes into close contact with the side surface of the tile T. At this time, the concrete hardening retarder of the hardening delay layer 4 spreads over the entire swelling member 7 together with water, so that the swelling member 7 itself substantially constitutes the hardening delay layer 4.
Next, concrete C is placed in the formwork 14 as shown in FIG. 5 (b). At this time, since the gap portion 2 between the tiles T is closed by the joint groove loading member 1, the liquid such as cement paste is stopped there in principle.

Then, the concrete C is heat-cured with steam for 5 to 10 hours while being placed in the mold 14 to be cured. At this time, most of the cement paste is stopped by the joint groove loading member 1 and does not leak to the surface of the tile T as described above, but if by any chance the tile T is distorted or scratched, it is loaded for the joint groove. Even if the adhesion of the member 1 is insufficient and the cement paste leaks to the surface of the tile T, the cement paste always touches the curing delay layer 4 of the joint groove loading member 1 in the process of leakage, so that there. Hardening is delayed by the action of the contained concrete hardening retarder.

Next, the solidified PC plate is removed from the mold 14. Then, first, the sheet 13 attached to the tile unit 9 is peeled off from the surface of the PC plate, then the joint groove loading member 1 is removed from the gap 2 between the tiles T, and finally the tile T and the joint groove loading member. Clean the joint groove formed in the removal mark of 1. At this time, as described above, even if there is a leaked cement paste on the surface of the tile T, the amount thereof is small in the first place due to the shielding effect of the swelling member 7 of the graben loading member 1. Secondly, since the hardening delay layer 4 is not completely hardened due to the action of the concrete hardening retarder, it can be easily removed by washing.
Further, when the swelling member 7 absorbs the pre-sprayed liquid to increase the thickness, the curing retarder of the curing delay layer 4 naturally mixes with the liquid, so that if the cement paste is tentatively formed inside the swelling member 7. Even if it invades and mixes with the previous liquid, the action of the concrete hardening retarder makes it difficult for the cement paste to harden. Therefore, even if the debris of the swelling member 7 mixed with the cement paste adheres to the graben after demolding and remains, it can be easily removed by washing.

The arrangement of the tiles T of the tile unit 9 can be freely set by changing the partition of the jig 8. Further, there is also a method of arranging the tile T and the graben loading member 1 directly in the formwork 14 without forming the tile unit 9 as described above. Of course, in such a case, the sheet 13 becomes unnecessary.

Printing ink (selecting almost the same color as concrete) mixed with a concrete hardening retarder in a predetermined ratio is printed (applied) on both sides of the swelling member 7 made of water-soluble paper, and it is applied to both sides of the main member 5. A loading member 1 for a joint groove was manufactured by sticking with a thermosetting adhesive 6.
Then, a PC plate was manufactured by the above-mentioned method using the joint groove loading member 1, and the state of the joint groove was visually confirmed after cleaning.
As a result, as the mixing ratio of the concrete hardening retarder becomes larger, the roughness of the joint groove (mainly near the corner portion of the groove bottom) becomes conspicuous although it is at an allowable level, and conversely, the removal of the swelling member 7 by cleaning is not possible. It's easier. As a result, it was confirmed that the hardening delay layer 4 of the graben loading member 1 affects the hardening of concrete.
As a result of such a test, when the curing delay layer 4 is provided on both sides of the swelling member 7, the concrete curing delay agent is applied to the printing ink by integrating the efficiency of the cleaning work and the state of the joint groove after cleaning. It is preferable to mix about 3 to 15% by weight, and preferably about 3 to 5% by weight. When the curing delay layer 4 is provided only on one side of the swelling member 7, the mixing ratio of the concrete curing delay agent may be doubled as described above.

Although the present invention has been described above with embodiments, the present invention is, of course, not limited to the above embodiments. For example, in the embodiment, the loading body 3 of the graben loading member 1 is formed by a combination of the main member 5 and the swelling member 7, but it is also possible to form the loading body 3 only by the main member 5. If the swelling member 7 is absent, the shielding function of the graben loading member 1 is lowered, and the amount of cement paste leaked to the tile T surface is increased by that amount, and the antifouling function of the curing delay layer 4 is insufficient. If there is a risk, the antifouling function may be enhanced by increasing the mixing ratio of the concrete hardening retarder to the hardening delay layer 4.
Further, in the embodiment, the concrete curing delay agent is mixed with the ink to form the curing delay layer, but the curing delay layer may be formed only with the concrete curing delay agent.

1 ... Loading member for graben 2 ... Gap 3 ... Loading body 4 ... Curing delay layer 5 ... Main member 7 ... Swelling member 14 ... Formwork T ... Tile C ... Concrete

Claims (4)

A loader with a shape that can be loaded into the gaps of multiple tiles that are installed with gaps in the formwork for precast concrete plate molding.
E Bei and a retardative layer containing concrete retarders,
The loading body is
A main member having a shape that can be loaded into the gap portion of a plurality of tiles,
It has a sheet-like swelling member that is attached to the surface of the main member facing the side surface of the tile and absorbs a liquid such as water to increase the thickness at least.
The curing delay layer is
A loading member for a joint groove, which is obtained by mixing the concrete hardening retarder with an ink having a color different from the color of the swelling member and applying the concrete curing retardant to one side or both sides of the swelling member. The graben loading member according to claim 1 , wherein the curing delay layer is applied to one side of the swelling member on the side opposite to the main member. The graben loading member according to claim 1 or 2 , wherein the ink has the same color as or similar to that of concrete. Concrete is placed in a formwork in which at least a plurality of tiles arranged face down and the graben loading member according to any one of claims 1 to 3 loaded in the gap portion of the tiles are set. A method for producing a precast concrete plate, characterized in that the concrete plate is cast and cured, and after the mold is removed, the loading member for the joint groove is removed and cleaned.

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