JP5409225B2 - Curing jig for precast concrete products and curing method - Google Patents

Description

  The present invention relates to a curing jig for a precast concrete product. In particular, when it is attached to a peripheral edge portion of a precast concrete product during thermal curing, the peripheral portion is thermally damaged to cause damage such as cracks. The present invention relates to a curing jig for a precast concrete product that can prevent the above-described problem, and a curing method using the curing jig.

  When producing precast concrete products such as concrete slabs and concrete segments used in shield tunnels, if the concrete is cast with a large amount of cement, the amount of heat generated during air curing after demolding will increase. Thus, the temperature of the precast concrete product is considerably higher than the outside air temperature. In addition, when steam curing is performed, the temperature difference between the precast concrete product and the outside air is further increased. And when the temperature difference between the precast concrete product after demolding and the outside air is large in this way, the temperature of the peripheral edge portion with good heat dissipation of the precast concrete product is higher than the temperature of the center portion during the air curing. It drops early, and cracks are likely to occur especially at the edges and corners. Thus, in order to prevent the occurrence of cracks, when precast concrete products are cured in the air, the products are wrapped in a heat insulating sheet and kept in the air while being kept warm.

  However, if the entire precast concrete product is wrapped in a heat insulating sheet and kept warm, the temperature of the entire product will hardly decrease, and it will take a considerable amount of time to move to the next process, resulting in a decrease in production efficiency. Will end up. For this reason, conventionally, as shown in, for example, Patent Document 1 below, when precast concrete products are cured in air, the corners are covered with a heat insulating material to locally keep the part warm. A curing method has been proposed in which a primary curing process for curing and a secondary curing process for curing by removing the heat insulating sheet are performed.

JP 2000-290087 A

By the way, as a heat insulating material used at the time of air curing of precast concrete products, heat insulating sheets are generally used. However, the heat insulating sheets are wound around peripheral edge portions such as corners of precast concrete products, and adhesive tapes are used. The work of mounting and fixing with the work is very troublesome and time-consuming, and it is very difficult to perform by one worker, and therefore requires a plurality of personnel.
Moreover, even if it folds after the said heat insulation sheet peeled, there existed a problem that it became bulky and it took time and effort to clean up.

  The present invention has been made in view of the problems as described above, and its purpose is to cover the peripheral edge of the precast concrete product with an insulating layer and keep it warm during the air curing of the precast concrete product. In preventing the occurrence of cracks, a curing tool for precast concrete products that can be easily detached and attached to the peripheral edge by one person, and can be reused repeatedly and does not require any disposal. And providing a curing method using the curing jig.

In order to achieve such an object, the invention shown in claim 1 is a detachable, which is mounted along the peripheral edge of the precast concrete product and heat-insulated and warms the peripheral edge when the precast concrete product is cured in air. A curing jig, comprising: a covering that covers the surface of the peripheral edge; and a heat insulating layer interposed between the covering and the peripheral edge, the covering being the peripheral edge And the covering is formed in a U-shaped cross-section, and is pressed against the surface of the pre-cast product along both edges of the open end of the U-shaped cross-section. A space partition member for partitioning and forming an air layer as the heat insulating layer is provided between the peripheral edge surface of the cover and the inner surface of the covering .

The invention shown in claim 2 is the curing jig for the precast concrete product according to claim 1, wherein the covering is formed of a synthetic resin .

The invention shown in claim 3 is a curing jig for a precast concrete product according to claim 2 , wherein the space partition member is integrally formed of the same synthetic resin as the covering.

The invention shown in claim 4 is a curing jig for a precast concrete product according to any one of claims 1 to 3 , wherein when the precast concrete product is attached to the precast concrete product, the covering body facing the end surface of the product is provided. The inner surface is provided with a separation member that abuts against the end surface and maintains a separation dimension with the covering body at a predetermined value.

Invention of Claim 5 is the curing method of the precast concrete product using the curing jig of the precast concrete product in any one of Claims 1-4 , Comprising: At the time of demolding of this precast concrete product, this product An attaching step of continuously attaching the curing jigs formed in a divided manner along the peripheral edge of the first and a primary curing the precast concrete product for a predetermined time after the curing jigs are attached. It has a curing step, a step of removing the curing jig after completion of the air curing, and a secondary curing step of curing the precast concrete product after removal of the curing jig.

  According to the present invention, at the time of primary curing in the air of a precast concrete product, the peripheral edge is covered with a heat insulating layer and kept warm, thereby preventing the occurrence of cracks in the part. Provides a curing tool for precast concrete products that can be easily detached and attached by one person, and can be reused repeatedly, and does not require time for disposal, and a curing method for precast concrete products using the curing jig can do.

It is a figure which shows the state which applied and applied the curing jig which concerns on this invention to the peripheral edge part of a flat precast concrete product, (a) is the top view, (b) is the front view, (c) These are sectional views taken along the line cc in FIG. It is a perspective view which shows 1st Embodiment of the curing jig which concerns on this invention, (a) shows the curing jig piece with which the straight part of a precast concrete product is mounted | worn, (b) is mounted | worn with a corner part. A curing jig piece is shown. It is a perspective view which shows 2nd Embodiment of the curing jig which concerns on this invention, (a) shows the curing jig piece with which the straight part of a precast concrete product is mounted | worn, (b) is mounted | worn with a corner part. A curing jig piece is shown. It is a perspective view which shows 3rd Embodiment of the curing jig which concerns on this invention, (a) shows the curing jig piece with which the straight part of a precast concrete product is mounted | worn, (b) is mounted | worn with a corner part. A curing jig piece is shown. It is a side view which shows 4th Embodiment of the curing jig which concerns on this invention, (a) shows the curing jig piece with which the straight part of a precast concrete product is mounted | worn, (b) is mounted | worn with a corner part. A curing jig piece is shown. It is a figure which shows the state which applied and attached the curing jig which concerns on this invention to the peripheral edge part of the precast concrete product formed in the curved plate shape as a segment for shield tunnels, (a) is the top view , (B) is a front view thereof.

  Hereinafter, a curing jig for a precast concrete product according to the present invention and a curing method using the curing jig will be described in detail with reference to the accompanying drawings.

  First, as shown in FIGS. 1 (a), (b), and (c), the curing jig 2 of the present invention basically has a peripheral edge of the precast concrete product A when the precast concrete product A is cured in air. By being detachably mounted along the portion Aa and thermally insulating and keeping the peripheral edge portion Aa, the peripheral edge portion Aa is prevented from being cracked.

  Here, the precast concrete product A in the figure is illustrated as a rectangular flat plate used for a floor slab or the like. The precast concrete product A is formed by placing concrete in a mold, although not shown. Then, when the product A is removed from the formwork, the curing jig 2 is detachably attached to the peripheral edge Aa along the entire circumference, and the curing jig 2 is used for precast concrete. A peripheral side portion composed of three surfaces of upper and lower surfaces Aa1, Aa2 and end surface Aa3 in the peripheral edge portion Aa of the product A is thermally insulated and kept locally over the entire circumference. Then, the precast concrete product A is primarily cured in the air for a predetermined time in a state in which the peripheral side portion composed of the three surfaces at the peripheral edge portion Aa is thermally insulated and kept locally. In addition, after the completion of the primary curing, the curing jig 2 is removed, and after the removal, the precast concrete product A is subjected to secondary curing. For the secondary curing, air curing, water curing, or the like can be adopted.

  Here, the curing jig 2 includes a covering 6 that covers the surface of the peripheral edge Aa of the precast concrete product A, and a heat insulation interposed between the covering 6 and the peripheral edge of the precast concrete product A. The curing jig 2 having the layer 8 and made of the covering 6 and the heat insulating layer 8 is divided into a predetermined length along the peripheral edge Aa of the product A. That is, the curing jig 2 is composed of a large number of divided curing jig pieces 4, and the straight part curing jig pieces 4 a and the corner portions that cover the four straight sides forming a rectangular shape in plan view. And a curing jig piece 4b for corners that covers the corners. Each of the straight part curing jig pieces 4a and the corner curing jig pieces 4b is precast concrete in which the end portions thereof are in close contact with each other to form a continuous annular state. It is attached to the peripheral edge Aa of the product A. In addition, each curing jig piece 4a, 4b is divided and formed in a predetermined length so that an operator can carry it alone.

  Hereinafter, various embodiments of the curing jig 2 to be mounted on the precast concrete product A will be sequentially described by specifically illustrating the curing jig piece 4.

=== First Embodiment ===
FIG. 2 shows the curing jig 102 (= curing jig 2) of the precast concrete product according to the first embodiment of the present invention, and the sectional view shown in FIG. 1 (c) is also the one according to the first embodiment. It has become. That is, in the curing jig 102 of the first embodiment, the covering 106a of the straight part curing jig piece 104a shown in FIG. 2A and the corner part curing shown in FIG. The covering body 106b of the jig piece 104b is formed of an elastic material such as synthetic resin in a U-shaped cross section, and the heat insulating layer 8 is formed over the entire inner surface of the U-shaped cross section. A heat insulating material 108 that press-contacts the surface of the precast concrete product is provided.

  That is, the upper and lower plate portions 110 of the coverings 106a and 106b are formed so that the distance between them is sufficiently larger than the thickness of the precast concrete product A, and the opposing surfaces of the heat insulating materials 108 provided on the inner opposing surfaces. The interval between them is set slightly smaller than the thickness of the precast concrete product A. For this reason, when the coverings 106a and 106b are attached to the peripheral edge portion Aa of the precast concrete product A, the heat insulating material 108 is compressed and brought into pressure contact with the surfaces Aa1 and Aa2 of the precast concrete product A. Here, as the heat insulating material 108, various materials such as a foam cushioning sheet, a foamed resin-related material such as foamed polyurethane and polystyrene, a heat insulating material such as glass wool, and an air bag can be applied.

  Further, as shown in FIG. 2 (b), the corner-curing jig piece 104b has a cover plate that closes the U-shaped cross section on one end side in the longitudinal direction of the covering body 106b. 112 is provided, and a heat insulating material 108 for forming a heat insulating layer is also provided on the inner surface side of the cover plate 112. Here, the cover plate 112 is formed so as to be separated from each other by, for example, cutting lines being inserted into the upper and lower plate portions 110 forming a U-shaped cross section, and the upper and lower plate portions 110 are elastic. It does not hinder the deformation and the opening on the protruding end side from expanding. Similarly, the heat insulating material 108 provided inside the plate portions 110 and 112 is also formed so as to be free from each other.

The straight portion curing jig piece 104a and the corner portion curing jig piece 104b configured as described above are shown in FIG. 1 (a) when the precast concrete product is removed from the mold. As shown, the end portions are attached to each other along the peripheral edge portion Aa of the precast concrete product A, and are continuously attached in a state of being in close contact with each other. It is formed. In addition, at the time of this attachment, the peripheral edge part Aa of the precast concrete product A is expanded while expanding the opening part on the protruding end side of the upper and lower plate parts 110 of the coverings 106a and 106b made of an elastic material and elastically deforming the opening part. Is fitted and mounted so as to be inserted inside. (Installation process of curing jig)
Then, after the attachment of the curing jig 102 is completed, the precast concrete product A is subjected to primary curing in the air for a predetermined time (primary curing process), and after completion of the primary curing, the straight part curing jig piece 104a. And the corner curing piece 104b are sequentially removed (curing jig removing step), and after dripping, the precast concrete product A is immersed in water for a predetermined time or left in the air for a predetermined time. Secondary curing (secondary curing process). In the present embodiment, the case where the secondary curing is performed by immersing in water for a predetermined time or leaving in the air for a predetermined time after the primary curing has been described. However, the secondary curing is limited to these. However, other curing methods such as sealing and wrap curing may be used.

  Therefore, according to the present embodiment configured as described above, the straight portion curing jig piece 104a and the corner portion curing jig piece 104b, which are divided and formed in a size that can be carried by a single worker, are used. Since these are successively attached to the peripheral edge Aa of the precast concrete product A one after another and assembled into the annular curing jig 102 (= 2), assembly work of the curing jig 102 is performed. And the dismantling / removing work can be easily performed by one worker.

  Moreover, the curing jig 102 removed and disassembled into the individual curing jig pieces 104a and the corner curing jig pieces 104b can be reused repeatedly in the air of other precast concrete products A. Since it can be diverted at the time of primary curing, no waste material is generated, and the time and effort of the disposal process is eliminated.

  Furthermore, since the curing jig 102 is divided and formed into a large number of curing jig pieces 104a and 104b, even when it is necessary to move the precast concrete product A to another place with a crane or a forklift during air curing, Only by temporarily removing the curing jig piece 104a at the position corresponding to the portion supported by the crane, forklift or the like, the movement can be performed easily and quickly.

=== Second Embodiment ===
FIG. 3 shows a curing jig 202 (= curing jig 2) for precast concrete products according to the second embodiment of the present invention. Even in the curing jig 202 of the second embodiment, the basic configuration is the same as that of the first embodiment described above, and therefore the differences will be described in detail below.

  That is, in the curing jig 202 of the precast concrete product according to the second embodiment, the covering 206a of the linear part curing jig piece 204a shown in FIG. 3A and the corner shown in FIG. The covering 206b of the corner curing jig piece 204b is formed in an U-shaped cross section with an elastic material such as synthetic resin, and at least the U-shaped inner surface is formed on the inner surface of the U-shaped cross section. A space partition member 214 is provided along both edges of the opening end that expands, that is, along at least the protruding end edges of the upper and lower plate portions 210. And this space division member 214 press-contacts the surface of a precast concrete product, and secures the air layer 216 as the said heat insulation layer 8 between the peripheral edge part surface of a precast concrete product, and the inner surface of the said coverings 206a and 206b. A space to be formed is formed. In the embodiment shown in FIG. 3, the space partition member 214 is provided substantially continuously along the outer peripheral edge of the inner side surface of the coverings 206a and 206b in an annular shape over the entire length thereof. Yes. In the figure, reference numeral 212 denotes a cover plate.

  The space partition member provided on the inner surface of the covering 206 facing the end surface Aa3 of the precast concrete product A, that is, the side plate portion 211 that connects the upper and lower plate portions 210 to each other when the precast concrete product A is mounted. When attaching the divided curing pieces 204a and 204b, 214 abuts against the end surface Aa3 of the precast concrete product A and keeps the distance from the coverings 206a and 206b at a predetermined value, and the heat insulating air layer 216 is placed on the part. What is necessary is just to function at least as the separating member 218 for ensuring the above. In other words, the space partition member 214 provided at the site may be easily positioned at the time of attachment, and the space partition member 214 is not necessarily provided at the site. In other words, in the case where it is provided only to function as the separation member 218, it may be in the shape of a rod or the like that protrudes inward from the side plate portion 211 by a predetermined length. A book may be provided.

  Further, the space partition member 214 presses against the surface of the precast concrete product A to suppress the air flow, thereby partitioning and forming a space of the air layer 216 (= heat insulation layer 8) that can ensure a predetermined heat insulation property. Therefore, the material is not particularly limited. However, considering the adhesion and stability at the time of pressure contact with the surface of the precast concrete product A, for example, a resin-based elastic material such as neoprene rubber is used. It is preferred to use.

  The configuration other than the above is the same as that of the first embodiment described above, and the attachment / detachment procedure at the time of detachment to the precast concrete product and the curing method thereof are the same as those of the first embodiment, and the operation thereof. The effect is equivalent.

=== Third Embodiment ===
FIG. 4 shows a precast concrete product curing jig 302 (= curing jig 2) according to a third embodiment of the present invention. In the precast concrete product curing jig 302 of the third embodiment, FIG. 4 (a), the covering 306a of the straight part curing jig 304a and the covering 306b of the corner curing jig 304b shown in FIG. 4 (b) are both made of an elastic material such as a synthetic resin. A space partition member 314 is provided on the inner side surface of the U-shaped cross section along at least both edges of the open end that expands in the U-shape. The member 314 is integrally formed of the same elastic material as the covering bodies 306a and 306b. The space partition member 314 is continuously provided in an annular shape on the inner side surfaces of the covering bodies 306a and 306b along the entire outer peripheral edge. Here, the space partition members 314 formed on the both side edges in the longitudinal direction of the upper and lower plate portions 310 and the both side edges in the longitudinal direction of the side plate portions 311 connecting the upper and lower plate portions 310 to each other are U-shaped. If the upper and lower plate portions 310 are unfolded if they are integrally formed in a continuous shape, the U-shaped corners are cut into each other by inserting cut lines or the like. Leave it free. In addition, 312 in a figure is a cover board.

  That is, the third embodiment corresponds to a configuration in which the space partition member 214 in the second embodiment described above is integrally formed of the same elastic material as the coverings 206a and 206b. In other words, the third embodiment is described as follows. The coverings 306a and 306b are formed of an elastic material such as a synthetic resin so as to have a C-shaped cross section, and the opening of the C-shaped cross section is in pressure contact with the surface of the precast concrete product A. An air layer 316 in a space defined by the inner surfaces of the covering bodies 306a and 306b functions as the heat insulating layer 8.

  Similarly to the second embodiment, the space partition member 314 contacts the end surface Aa3 of the precast concrete product A when the divided curing pieces 304a and 304b are attached, and is separated from the coverings 306a and 306b. Is maintained at a predetermined value, and functions as at least a separation member 318 for securing an air layer 316 (= heat insulating layer 8) in the portion, so that the positioning at the time of attachment can be easily performed. It is not always necessary to provide a space partition member at the site. In the case where it is provided to function only as the separating member 318, it may be in the form of a rod or the like protruding inward from the side plate portion 311, and a plurality of formation positions are provided near the central portion of the side plate portion 311. You may do it.

  The configuration other than the above is the same as that of the first embodiment described above, and the attachment / detachment procedure at the time of detachment to the precast concrete product and the curing method thereof are the same as those of the first embodiment, and the operation thereof. The effect is equivalent.

== Fourth Embodiment ===
FIGS. 5A and 5B show a curing jig 402 (= curing jig 2) for a precast concrete product according to the fourth embodiment of the present invention, and FIG. 404a is shown, and (b) shows a corner curing jig piece 404b. Here, in the curing jig 402 for the precast concrete product according to the fourth embodiment, the configuration of the first embodiment described above is assumed to be the prerequisite configuration, and is different from the first embodiment in the following points. ing.

  That is, each of the coverings 406a and 406b has a side plate portion 411 connecting the upper and lower plate portions 410 facing each other at the end face Aa3 of the precast concrete product A when the side plate portion 411 is attached to the precast concrete product A. In 411, the curing jig pieces 404a and 404b are each divided into two vertically. The upper covering bodies 406a-1 and 406b-1 and the lower covering bodies 406a-2 and 406b-2 of the curing jig pieces 404a and 404b divided into the upper and lower parts are arranged on the outer surface side of the side plate portion 411. The hinges 420 are connected to each other so as to be opened and closed.

  Further, on the outside of the side plate portion 411, an urging means 422 for urging the upper covering bodies 406a-1, 406b-1 and the lower covering bodies 406a-2, 406b-2 in the closing direction is provided. . In the illustrated example, the hinge 420 is formed of a spring plate, and the hinge 420 also serves as the urging means 422. In the figure, reference numeral 412 denotes a cover plate.

  That is, when the upper cover bodies 406a-1 and 406b-1 and the lower cover bodies 406a-2 and 406b-2 are opened and closed through the hinge 420 in this manner, Since the plate portion 410 can be greatly expanded, fitting and mounting to a precast concrete product can be performed more easily. In addition, when such an opening / closing mechanism is provided, the curing jig pieces 404a and 404b can be mounted even if the coverings 406a and 406b are not elastically deformed, so that the material of the coverings 406a and 406b is used. May not necessarily use an elastic material such as a synthetic resin.

  The construction in which the upper covering bodies 406a-1, 406b-1 and the lower covering bodies 406a-2, 406b-2 are opened and closed via the hinge 420 in the fourth embodiment is the same as the second embodiment described above. The present invention can also be applied to the embodiment and the third embodiment.

=== Fifth Embodiment ===
6A and 6B show a curing jig 502 (= curing jig 2) for a precast concrete product according to the fifth embodiment of the present invention. The precast concrete product curing jig 502 of the fifth embodiment is different from the first to fourth embodiments described above in that the precast concrete product A ′ to be mounted is a segment used for a shield tunnel. It is only that there is.

  That is, since the precast concrete product A ′ as a segment has a plate shape curved in an arc shape, the curved portion curing jig piece 504c attached to the curved peripheral edge portion A′c has the curvature thereof. Only the points that are curved are different, and in other points, the curing jig pieces 104a, 204a, 304a, 404a for straight portions of the curing jigs described in the first to fourth embodiments described above and The same configuration as the corner curing jig pieces 104b, 204b, 304b, 404b can be obtained. In addition, among the illustrated bending portion curing jig pieces 504c, those disposed at both end portions are configured for corner portions.

  Moreover, since the peripheral edge part A'a along the generatrix of the cylindrical surface in the precast concrete product A 'is substantially linear, each linear part in the first to fourth embodiments described above is included in the part. The same curing jig pieces 104a, 204a, 304a, 404a can be used.

  And even if it exists in the curing jig of the precast concrete product of the said 5th Embodiment, the effect equivalent to 1st Embodiment-4th Embodiment mentioned above is acquired.

A, A 'Precast concrete product Aa, A'a, A'c Peripheral edge 2 Curing jig 4 Curing jig piece 4a Curing jig piece 6 for straight part Covering body 8 Heat insulation layers 102, 202, 302, 402, 502 Curing jig 104a, 204a, 304a, 404a Curing jig piece for straight part 104b, 204b, 304b, 404b Curing jig piece for corner part 106a, 206a, 306a, 406a Cover (curing jig piece for straight part )
106b, 206b, 306b, 406b Cover (curing jig piece for corner portion)
108,408 Thermal insulation (heat insulation layer)
214, 314 Space partition members 216, 316 Air layer (heat insulation layer)
218, 318 Separating member 504c Curing jig piece for bending portion

Claims (5)

A removable curing jig that attaches along the peripheral edge of the precast concrete product during the air curing of the precast concrete product and insulates and heats the peripheral edge,
A covering that covers the surface of the peripheral edge; and a heat insulating layer interposed between the covering and the peripheral edge, the covering being divided into a predetermined length along the peripheral edge Formed ,
The covering is formed in a U-shaped cross section, and presses against the surface of the precast product along both edges of the open end of the U-shaped cross section, so that the peripheral end surface of the precast concrete product and the covering A space partition member for partitioning the air layer as the heat insulating layer is provided between the inner side surface and the inner surface ,
Curing jig for precast concrete products. A curing jig for precast concrete products according to claim 1,
The covering is formed of a synthetic resin;
Curing jig for precast concrete products. A curing jig for precast concrete products according to claim 2 ,
The space partition member is integrally formed of the same synthetic resin as the covering body,
Curing jig for precast concrete products. A curing jig for precast concrete products according to any one of claims 1 to 3 ,
At the time of mounting on the precast concrete product, a separation member is provided on the inner surface of the covering body that faces the end face of the product and abuts against the end face to maintain a separation dimension with the covering body at a predetermined value.
Curing jig for precast concrete products. A curing method for a precast concrete product using the curing jig for a precast concrete product according to any one of claims 1 to 4 ,
At the time of demolding the precast concrete product, an attaching step of continuously attaching the curing jig formed by dividing along the peripheral edge of the product;
After only taken with the Ri of該養students jig, and the primary curing step of curing in the air the precast concrete products for a predetermined time,
Removing the curing jig after the air curing is completed;
A secondary curing process for curing the precast concrete product after removing the curing jig;
A curing method for a precast concrete product, characterized by comprising:

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