JP2018094838A - Manufacturing method of division type concrete products and division type concrete products - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of division type concrete products that can manufacture with high accuracy a junction of each segment block of division type concrete products and to provide division type concrete products.SOLUTION: A mold frame 4 is for placement of concrete and manufacturing division type concrete products. The mold frame 4 is constituted such that it is partitioned by partition plates 5 with constant thickness at positions being junctions of the division type concrete products, and concrete is placed at the same time into multiple zones 4A, 4B inside the mold frame 4 that is partitioned by the partition plates 5.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for manufacturing a split concrete product including a plurality of segment blocks such as a split box culvert and a split concrete product.

  Conventionally, for example, what has been constructed with cast-in-place concrete has been replaced with concrete products (precast concrete (PC)) pre-manufactured in the factory, thereby shortening the construction time. However, there is a limit to the size of the concrete product because there is a transportation problem due to the shape and weight of the concrete product produced in the factory. The problem of transportation is that when a large concrete product such as a box culvert is transported to the site by a large truck, it is necessary to obtain permission to use the road at night and to use a trailer, which increases the transportation cost. .

  Therefore, when the height is 3 m, 4 m, or more, a split type or half precast type box culvert is selected. In the half precast type, the left and right side walls are made of concrete, the bottom plate is made of cast-in-place concrete, the top plate is slabed, and only the left and right corners are made of cast-in-place concrete to construct a large-section box culvert. The split type box culvert is, for example, one in which segment blocks divided into upper and lower parts are tension-integrated with PC steel.

  The two- or four-divided box culvert and the half-precast type box culvert are appropriately selected depending on the width or height. For example, the division type is selected up to a width of 5 m, and the half-precast type is selected when the width exceeds that. Is done. In the half precast method, as a method for integrating the segment blocks, for example, as described in Patent Document 1, loop bars protruding at the joint portions of the segment blocks are joined and integrated by in-situ concrete.

  On the other hand, in the case of a split type box culvert, for example, in an upper and lower split concrete product, an upper segment block and a lower segment block are separately manufactured and integrated on site. The method of integration is performed by, for example, integration by connecting plates and bolts, or by vertically tensioning with a PC steel rod (see, for example, Patent Documents 2 and 3).

JP 2011-127363 A Japanese Utility Model Publication No. 60-18182 Japanese Patent No. 5914624

  However, in the case of the upper and lower divisions, the upper segment block and the lower segment block manufactured separately cause a slight difference in product dimensions due to the problem of manufacturing accuracy. For this reason, this slight difference in product dimensions is accumulated during construction, and especially when the construction extension becomes long, the vertical and horizontal deviations become large. In order to solve this, fine adjustment work is required when constructing one by one, which takes time and labor, and worsens the joints. In addition, the bar used for fine adjustment causes problems such as scratches on the product. In addition, a slight unevenness of the joint end surfaces of the upper and lower segment blocks causes an uneven load, resulting in problems such as cracking of the product after integration or during the integration operation.

  Then, in this invention, it aims at providing the manufacturing method of a split-type concrete product and the split-type concrete product which can manufacture the junction part of each segment block of a split-type concrete product with high precision.

  The method for producing a split concrete product according to the present invention is a formwork for manufacturing a split concrete product by placing concrete, and the position of the joint portion of the split concrete product is divided by a partition plate having a constant thickness. It comprises forming a formwork and placing concrete simultaneously into a plurality of sections in the formwork divided by a partition plate.

  According to the method for producing a split concrete product of the present invention, the concrete is simultaneously placed in a plurality of sections in a formwork in which positions where the split concrete product is joined are partitioned by a partition plate having a constant thickness. Therefore, even if the partition plate is slightly displaced or bent when placing concrete, these slight displacements and deflections are transferred to each other's joints with the partition plate having a certain thickness in between. As a result, it is possible to obtain a highly accurate segment block in which the subtle dimensional deviation of the joint and the subtle unevenness of the joint surface are matched.

  Here, it is desirable that the partition plate is a pair of joining keys for joining the first and second segment blocks constituting the split concrete product so as to sandwich the partition plate. Thereby, a segment block embedded with the pair of joining keys positioned in the first and second segment blocks with the partition plate in between is obtained.

  Further, it is desirable that the partition plate is attached with a connecting member for integrating the first and second segment blocks constituting the split concrete product so as to sandwich the partition plate. As a result, a segment block embedded in a state where the connecting member for integrating the first and second segment blocks is positioned in the first and second segment blocks with the partition plate interposed therebetween is obtained.

(1) A formwork in which concrete is cast to produce a split concrete product, and the formwork is formed by dividing the position of the joint portion of the split concrete product by a partition plate of a certain thickness. By placing concrete in multiple sections in a divided formwork at the same time, it is highly accurate to match subtle irregularities in the joints and subtle irregularities in the joints across the partition plate with a certain thickness. Since segment blocks can be obtained, fine adjustment work is not required during construction on site, and construction speed is greatly improved. In addition, the product can be prevented from being scratched or cracked during construction.

(2) By using a partition plate attached so as to sandwich a pair of joining keys for joining the first and second segment blocks constituting the split concrete product, the first and second sandwiching the partition plate Since a segment block embedded with a pair of joint keys positioned on the two segment blocks is obtained, when the product is assembled and integrated, positioning is easily performed by this pair of joint keys, and the construction speed is reduced. Further improve.

(3) By using the partition plate attached so that the connecting member that integrates the first and second segment blocks constituting the split concrete product is sandwiched, the connecting member is positioned across the partition plate. As a result, a segment block embedded in a heated state can be obtained, so that assembly and integration of products can be facilitated and construction speed can be further improved.

It is a front view of the division | segmentation type box culvert in embodiment of this invention. It is II-II sectional drawing of FIG. It is a top view of the mold which manufactures the division | segmentation type box culvert 1 of FIG. It is the IV section expanded sectional view of FIG. It is a top view which shows the connection member arrange | positioned in the formwork. It is a longitudinal cross-sectional view of the connection member of FIG. It is a top view which shows another example of the connection member arrange | positioned in the formwork. It is a longitudinal cross-sectional view of the connection member of FIG. It is the elements on larger scale of the junction part of the state which divided | segmented the segment block after mold removal. It is a partial expanded sectional view of the junction part of the segment block after product assembly integration. It is the perspective view which looked at the 1st segment block from the joined part side.

  1 is a front view of a split box culvert according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a plan view of a mold for manufacturing the split box culvert of FIG. 4 is an enlarged sectional view of a portion IV in FIG. 3, FIG. 5 is a plan view showing a connecting member disposed in the mold, and FIG. 6 is a longitudinal sectional view of the connecting member in FIG.

  As shown in FIG. 1, a split box culvert 1 as a split concrete product in the embodiment of the present invention is composed of first and second segment blocks 1A and 1B which are divided into two parts. Further, as shown in FIG. 2, a pair of joining keys 3 for joining the segment blocks 1A and 1B is embedded in the joining part 2 of the segment blocks 1A and 1B. In addition, about the connection member 10 (refer FIG. 5 and FIG. 6) for connecting the segment blocks 1A and 1B mentioned later, other members, etc., illustration is abbreviate | omitted in FIGS.

  As shown in FIG. 3, the mold 4 is for manufacturing the whole of the segment blocks 1A and 1B integrated at the site at a time. In the mold 4, the position where the segment blocks 1 </ b> A and 1 </ b> B are joined 2 is divided by a partition plate 5 having a constant thickness of 5 to 10 mm. As shown in FIG. 4, a pair of joining keys 3 are attached to the partition plate 5 so as to sandwich the partition plate 5.

  The joining key 3 includes a female first key 6 embedded in one segment block 1A and a male second key 7 embedded in the other segment block 1B. The female first key 6 includes a flange 60 for preventing the segment block 1A from coming off, a recess 61 in which the male second key 7 is fitted, and a through hole 62 communicating with the recess 61. Have.

  The male second key 7 includes a collar 70 for preventing the segment block 1B from coming off, a convex 71 that fits into the female concave 61, and a bolt provided at the tip of the convex 71. 72. The bolt 72 is screwed into a female screw portion 73 formed at the center of the convex portion 71. The joining key 3 is attached so as to be sandwiched between the female first key 6 and the male second key 7 through the through hole 5A formed in the partition plate 5. At this time, the first key 6 and the second key 7 are formed by tightening a nut 75 having a diameter smaller than that of the through hole 62 to the bolt 72 via a resin washer 74 having a diameter larger than that of the through hole 62. Fixed to.

  Further, as shown in FIGS. 5 and 6, a connecting member 10 for integrating the segment blocks 1 </ b> A and 1 </ b> B in the field is attached in the mold 4 so as to sandwich the partition plate 5. In FIG. 5, illustration of the above-described joining key 3 and the like is omitted.

  The connecting member 10 includes a sheath pipe 11 embedded in the upper (first) segment block 1A, a PC steel rod 12 embedded in the lower (second) segment block 1B, and an upper end portion (partition) of the PC steel rod 12. The coupler 13 is provided at the end of the plate 5, and the fixing plate 14 is provided at the lower end of the PC steel rod 12. The coupler 13 is threaded on the inside.

  Concave forming molds 15 </ b> A and 15 </ b> B are respectively provided at the upper end portion and the lower end portion (end portion on the partition plate 5 side) of the sheath pipe 11. The concave molding die 15A is for forming a space for accommodating a nut fastened to a PC steel rod inserted into the sheath pipe 11 when the segment blocks 1A and 1B are integrated. The recess molding die 15B has a space (a recess 80 (see FIG. 11)) into which the coupler 13 can enter when the lower end portion of the PC steel rod inserted into the sheath pipe 11 is fastened to the coupler 13 and is tensioned. It is for forming.

  The sheath pipe 11 and the recess forming molds 15A and 15B are fixed to the coupler 13 with the lower end portion sandwiched by the partition plate 5 by the PC steel rod 16 inserted into the sheath pipe 11B, and the upper end portion is fixed to the mold frame 4. The The upper end and the lower end of the PC steel bar 16 are threaded, the lower end is fastened to the coupler 13, and the upper end is fastened to the mold 4 by a nut 17.

  The fixing plate 14 is a square steel plate. A nut 18 is welded to the lower surface side of the fixing plate 14. The upper end and lower end of the PC steel rod 12 are threaded, the upper end is fastened to the coupler 13, the fixing plate 14 is screwed into the lower end by a nut 18, and a fixing bracket 19 whose inner side is threaded is further provided. Screwed in and fastened from the outside of the mold 4 by T-bolts 20.

  The split type box culvert 1 in this embodiment is manufactured by simultaneously placing concrete in the respective sections 4A and 4B in the mold 4 divided by the partition plate 5 after the mold 4 is configured. . In addition, the concrete placement is not limited to the case where concrete is placed simultaneously in the sections 4A and 4B as the wording, but the concrete is alternately placed in the sections 4A and 4B so that excessive pressure is not applied to the partition plate 5. Including the case of setting. In short, concrete is placed in each of the sections 4A and 4B to simultaneously manufacture the segment blocks 1A and 1B.

  Then, after curing, the mold is removed and the partition plate 5 is removed. In the divided box culvert 1 manufactured in this way, concrete is simultaneously applied to the respective sections 4A and 4B in the mold 4 in which the positions where the joint portions 2 of the segment blocks 1A and 1B are divided by the partition plate 5 having a constant thickness. By being driven, both surfaces of the partition plate 5 are transferred to the joint surfaces of the segment blocks 1A and 1B, respectively. That is, in the obtained segment blocks 1A and 1B, even if the partition plate 5 is slightly displaced or bent at the time of placing the concrete, the delicate displacement and deflection of the partition plate 5 having a certain thickness can be obtained. The material is transferred to the joint portion 2 with the pinch interposed therebetween, and the subtle dimensional deviation of the joint portion 2 and the fine unevenness of the joint surface 2 are highly accurate.

  Therefore, in the split type box culvert 1 in the present embodiment, when the product is assembled and integrated, the joint portions 2 of the segment blocks 1A and 1B exactly match each other. Construction speed is greatly improved. It is also possible to prevent the product from being scratched or cracked during construction.

  Moreover, in the manufacturing method of the split type box culvert 1 in the present embodiment, the first key 6 and the second key 7 are fixed to the partition plate 5, but when the segment blocks 1A and 1B are separated after demolding. When the resin washer 74 is broken, the nut 75 having a smaller diameter than the through hole 62 passes through the through hole 62. FIG. 7 is a partially enlarged cross-sectional view of the joint portion 2 in a state where the segment blocks 1A and 1B are divided after demolding. Thereafter, the bolt 72 is removed from the female screw portion 73.

  Thus, in the split type box culvert 1 in the present embodiment, the pair of joining keys 3 composed of the first key 6 and the second key 7 and the partition plate 5 attached so as to sandwich the connecting member 10 are used. Thus, the segment blocks 1A and 1B embedded in a state in which the pair of joining keys 3 and the connecting member 10 are positioned in the first and second segment blocks 1A and 1B with the partition plate 5 interposed therebetween are obtained.

  In the divided box culvert 1 obtained in this way, the segment blocks 1A and 1B, as described above, match the subtle irregularities of the joint 2 and the subtle irregularities of the joint 2 and also assemble and integrate the products. In addition, it is possible to easily perform positioning with this pair of joining keys 3, and the construction speed is further improved. FIG. 8 is a partially enlarged cross-sectional view of the joint portion 2 of the segment blocks 1A and 1B after product assembly integration.

  In the split box culvert 1 in this embodiment, when the first segment block 1A and the second segment block 1B are integrated, a PC steel rod is inserted into the sheath pipe 11B of the first segment block 1A. Then, the lower end portion is fastened to the coupler 13 of the second segment block 1B, the upper end portion is tensioned with a jack, and when the tension reaches a fixing load, the nut is fastened with a nut. At this time, the coupler 13 is pulled toward the first segment block 1A due to the tension of the PC steel bar. As shown in FIG. 11, the first segment block 1A has a recess 80 formed by the recess forming die 15B. Since the coupler 13 does not enter the recess 80 and the coupler 13 does not interfere with the first segment block 1A, the PC steel rod is made up of the first segment block 1A and the second segment. Tension is evenly distributed over block 1B.

  In the present embodiment, the example in which the sheath pipe 11 is embedded in the first segment block 1A and the PC steel rod 12 is embedded in the second segment block 1B has been described. FIG. 7 and FIG. As described above, the sheath pipe 21 may be embedded in the second segment block 1B. The aforementioned PC steel rod 12 is inserted into the sheath pipe 21. A coupler sheath 22 is provided at the upper end of the sheath pipe 21 so as to cover the PC steel rod 12 and the coupler 13.

  Moreover, in the said embodiment, although the division type box culvert 1 of the upper and lower divisions was demonstrated to the example as a division | segmentation type concrete product, there is no restriction | limiting in a division | segmentation number and it can apply even if what division. Further, the present invention is not limited to the split box culvert 1 and can be applied to any split concrete product including a plurality of segment blocks.

  INDUSTRIAL APPLICABILITY The present invention is useful as a method for manufacturing a split concrete product composed of a plurality of segment blocks such as a split box culvert, and in particular, it is possible to manufacture a joint portion of each segment block of a split concrete product with high accuracy. It is suitable as a method for producing a simple split concrete product.

DESCRIPTION OF SYMBOLS 1 Division type box culvert 1A, 1B Segment block 2 Joining part 3 Joining key 4 Formwork 5 Partition plate 6 1st key 7 2nd key 10 Connecting member 11 Sheath pipe 12, 16 PC steel rod 13 Coupler 14 Fixing plate 15A, 15B Recess molding die 17, 18 Nut 19 Fixing bracket 20 T bolt 21 Sheath pipe 22 Coupler sheath 80 Recess

Claims (6)

A formwork for producing a split concrete product by placing concrete, and forming a formwork in which the position to be a joint of the split concrete product is divided by a partition plate having a certain thickness,
A method for producing a split concrete product, comprising simultaneously placing concrete in a plurality of sections in the formwork divided by the partition plate.   2. The division according to claim 1, wherein a pair of joining keys for joining the first and second segment blocks constituting the split concrete product is attached to the partition plate so as to sandwich the partition plate. Method for manufacturing concrete products.   The said partition plate is attached so that the connection member for integrating the 1st and 2nd segment block which comprises the said split-type concrete product may be inserted | pinched between the said partition plate. A method for producing a split concrete product as described in 1.   The connecting member includes a sheath pipe embedded in the first segment block, a recess molding die disposed at an end of the sheath pipe on the partition plate side, and PC steel embedded in the second segment block. The split concrete product according to claim 3, further comprising: a rod and a coupler disposed at an end portion of the PC steel rod on the partition plate side, wherein the partition plate is sandwiched between the concave mold and the coupler. Manufacturing method. A split concrete product comprising first and second segment blocks produced by placing concrete in a mold,
Both surfaces of a partition plate having a certain thickness arranged at positions where the first and second segment blocks of the mold are to be joined are transferred to the joining surfaces of the first and second segment blocks, respectively. Split concrete products. The second segment block is a PC steel rod to be integrated with the first segment block, and a PC steel rod in which a coupler is disposed at an end of the joint surface side with the first segment block. Is embedded,
The first segment block is embedded with a sheath pipe into which a PC steel rod for integration with the second segment block is inserted, and the joint surface of the sheath pipe with the second segment block 6. The split concrete product according to claim 5, wherein a concave portion into which the coupler can enter is formed at a side end portion.