JP4179414B2 - Method for forming joint part of embedded formwork - Google Patents

Description

The present invention relates to a method for forming a joint portion of an embedded formwork, and more particularly to a method for forming a joint portion that reliably prevents leakage of cast concrete from the joint portion provided between precast concrete embedded formwork .

  When building a concrete structure, it hardens integrally with the concrete placed in the formwork and eliminates the need to remove the formwork, thereby streamlining the concrete work and improving the exterior design and durability of the structure. For the purpose of improvement, various precast concrete embedded forms have been developed (see Patent Document 1).

  FIG. 7 is a perspective view schematically showing a state in which a conventional general precast concrete embedded form 50 is pre-assembled. As shown in the figure, each embedded mold 50 is fixedly supported on a mold support by a fastening jig or the like (not shown) and assembled along a predetermined outer shape of the structure, and concrete 52 is placed in the mold. It is set up. At this time, since the reticulated reinforcing steel panel 51 is exposed on the inner surface side of the embedded formwork, the placed concrete 52 (hereinafter, internal concrete 52) and the embedded formwork 50 are integrated, and the internal concrete is formed. If 52 hardens | cures, as shown in FIG. 8, the embedding formwork 50 and the internal concrete 52 will become an integral structure. At this time, by using highly durable concrete such as resin concrete for the panel portion of the embedded formwork 50, high durability can be obtained as a concrete structure. For the sake of explanation, the illustration of the formwork support is omitted in FIG.

  Each drawing in FIG. 9 shows an example of a joint portion 53 (shown by enlarging a circle in FIG. 9) between the respective embedded molds in a state where the internal concrete 52 is placed in the embedded mold 50. It is an enlarged view. For example, in the invention described in Patent Document 1, an epoxy resin layer 54 and a polymer cement mortar layer 55 are formed on the joint portion 53 having a predetermined slit width so as to cover the joint from the inside of the mold. Further, a back-up material 56 is fitted, and joint processing (not shown) with a sealing material or the like is performed from the outer surface side of the mold after the concrete is placed, so that the joint portion 53 is configured. Also, in FIG. 6B, there is a joint portion 53 that is directed to the joint portion 53 by a joint outer mold frame 57 supported by a support (not shown) and prevents the concrete mortar paste from leaking from the slit. It is shown.

JP-A-7-229222.

By the way, in the joint part structure shown in FIG. 9A, prior to the concrete placing work, for example, an epoxy resin layer or the like is formed on the inner surface side of the mold and the joint part is closed by providing a backup material in the slit. There is a need to do. Further, a joint processing operation for filling the sealing material from the outer surface of the mold is required. Further, the joint structure shown in FIG. 5B requires additional steps such as assembling of the outer mold and demolding work. For this reason, the increase in material cost, the extension of the process, and the increase in construction cost have been problems. It is an object of the present invention to solve the problems of the prior art described above, prior to concreting, joints you allow the task of closing the assembly at the same time easily and quickly joints buried formwork It is in providing the formation method .

In order to achieve the above object, the present invention assembles an embedded form having a groove-like portion on the side surface of the mold so that the groove-like portion faces each other across a slit corresponding to a predetermined joint width. An elastic joint closing member having a tip portion with a bifurcated tip corresponding to the cross-section of the shape portion is elastically deformed so as to narrow the width of the tip portion, and the tip portion becomes the groove-like portion. Until it reaches, and the forked portion is engaged with the opposing groove-shaped portion, and the slit is closed with a plate-like portion continuous with the tip of the elastic joint closing member, It is characterized in that the concrete placed on the wall is prevented from leaking from the slit .

It is preferable that the joint closing member has a bifurcated shape having a front end having a semi-cylindrical tip that can be engaged with the groove-like portions facing each other with the slit interposed therebetween .

  The joint closing member is preferably removed from the slit after the concrete is hardened, and the slit is filled with a sealing material.

  According to the present invention, in a concrete structure work performed by assembling an embedded formwork, a joint closing member made of an inexpensive molded part can be easily and quickly attached to the joint slit between the embedded formwork, and the concrete is hardened. Since the joint closing member can be easily removed later, it is possible to reduce the cost and to perform quick and safe formwork.

Hereinafter, as the best mode for carrying out the method for forming a joint part of an embedded mold according to the present invention, the following examples will be described with reference to the accompanying drawings.

FIG. 1 is a perspective view showing a joint closing member 10 used in an embodiment of a method for forming a joint part of an embedded mold according to the present invention. In the operation of forming the joint between the embedded molds according to the present invention, the joint closing member 10 mounted so as to close the slits 2 serving as the vertical joints between the embedded molds 1 assembled adjacently is used. The joint closing member 10 is composed of two semicylindrical tip portions 10a having the same shape formed by cracking into two branches, and a plate-like portion 10b having a width slightly smaller than the width of the slit 2 of the embedded mold 1. It consists of a long plate-like synthetic rubber molded product having a length equal to the height of the embedded mold 1. In this embodiment, butadiene rubber having excellent alkali resistance is used as the material. As other rubber materials, various rubber materials can be employed as long as they are alkali-resistant rubbers, regardless of whether they are diene rubbers or non-diene rubbers. For example, natural rubber, isoprene rubber, styrene butadiene rubber, chloroprene rubber can be used for the diene rubber, and butyl rubber, ethylene / propylene rubber, urethane rubber, silicone rubber, acrylic rubber, etc. can be used for the non-diene rubber. Further, foamed polyurethane can be used as a sponge-like soft synthetic resin having appropriate rigidity, and polyurethane elastomer or the like can be used as an elastomer exhibiting rubbery properties.

  Further, a groove portion having a semicircular cross section is formed on the side surface of the embedded mold 1 along the height direction of the embedded mold 1, and as shown in FIG. 1, as shown in FIG. When the distal end portion 10 a is mounted in the slit 2 between the embedded molds 1, it is engaged with the cross-sectional shape of the semicircular groove-shaped portion 4. At this time, the plate-like portion 10b is set to a width that is slightly smaller than the slit width between the adjacent embedded molds 1 (usually set to 2 to 5 cm) and is in contact with the side surface 1a of the embedded mold 1.

  As shown in FIG. 2, the joint closing member 10 has a width slightly smaller than the slit width between the two semicylindrical tip portions 10 a having the same shape formed by bifurcating the fork and the embedded formwork. It consists of the rubber material which consists of the plate-shaped part 10b which has and is elastically deformable. For this reason, even if the tip portion 10a is wider than the slit width between the embedded molds 1 in the initial shape, as shown in FIGS. Then, it can be elastically deformed so as to be narrowed to about the slit width and sandwiched in the slit 2 for mounting. And as shown in FIG. 1, when the front-end | tip part 10a reaches the groove-shaped part 4 of the side surface 1a of the embedded formwork 1, the elastic deformation of the front-end | tip part 10a which was compressed is released, and it returned to the initial shape. In this state, the entire joint closing member 10 is securely held in the slit 2 between the embedded molds.

  Next, with reference to FIG. 3, the process from mounting the joint closing member 10 in the slit 2 between the embedded molds, placing the internal concrete 3 in the molds, and finally performing the joint treatment work will be described with reference to FIG. 3. I will explain. First, the width of the slit 2 between the embedded molds is secured by a predetermined amount (2 to 5 cm), and the embedded mold 1 is arranged and fixed along the outer shape of the planned structure by a mold support not shown (see FIG. a)). Insert the joint closing member 10 with the width of the tip 10a narrowed into the slit 2 until the tip 10a reaches the position of the groove-like portion 4, and the elastic deformation is released at that position and the groove is formed in the initial shape. It engages and attaches to the shape part 4 (the figure (b)-(c)). Next, the inner concrete 3 is placed in the embedded mold 1. At this time, it is preferable to perform vibration compaction with a vibrator or the like so that the inside of the slit 2 is sufficiently filled with the mortar portion of the concrete ((d) in the figure). After a predetermined curing period, a small hole 15 is drilled by a cone or the like along the plate-like portion 10b of the joint closing member 10 from the outside of the mold frame to provide an air hole. In this way, the joint closing member 10 can be easily pulled out in the direction of the arrow by communicating between the surface of the mortar and the tip 10a of the joint closing member 10 with the outside air ((e) in the figure). Thereafter, the joint gap is filled with mortar 5 as a sealing material as a joint processing work ((f) in the figure). Thereby, a joint part with high water-tightness can be formed between the embedded molds. In addition to the mortar, it is also preferable to use various synthetic resin sealing materials excellent in waterproofness and weather resistance as the sealing material.

  Here, the state of the distal end portion 10a of the joint closing member 10 at the time of placing the concrete and the state at the time of removing the joint closing member 10 will be described with reference to FIGS. FIG. 4 shows a state where the space between the buried molds 1 is filled with mortar when the inner concrete 3 is placed. As shown in the figure, the side pressure generated by the mortar portion that has not yet hardened acts on one surface of the tip end portion 10 a that opens at an obtuse angle of the joint closing member 10. In the figure, when a uniform lateral pressure as shown by an arrow acts on the tip portion 10a, the tip portion 10a of the joint closing member 10 made of an elastic member such as synthetic rubber engaged with the groove-like portion 4 is laterally moved. It is deformed so as to expand and is sufficiently in close contact with the groove-like portion 4. Thereby, it can prevent reliably that the mortar part which is not yet hardened at the time of concrete placement leaks from a joint part.

  FIG. 5 shows a state in which the joint closing member 10 is removed after the concrete is hardened. As shown in the figure, the cured mortar and the tip 10a of the joint closing member 10 are in close contact with each other, but a small hole 15 is drilled in the plate-like part 10b of the joint closing member 10 with a cone or the like. By providing the air holes, the boundary surface between the mortar surface and the distal end portion 10a of the joint closing member 10 is communicated with the outside air. When the joint closing member 10 is pulled in the arrow direction in this state, air flows into the gap and elastically deforms so that the width of the distal end portion 10a is narrowed, and the joint closing member 10 is peeled off from the mortar surface and easily pulled out. be able to.

  FIG. 6 is a schematic plan view showing a modification of the shape of the distal end portion 10 a of the joint closing member 10. As shown in FIG. 6A, in the case of the joint closing member 10 having the tip portion 10a having a polygonal column shape in which the overall planar shape is substantially Y-shaped, By providing the V-shaped groove 4 as shown in FIG. By setting it as such a planar shape, the joint blockage member 10 can be hold | maintained in the more stable state between the embedment formwork 1.

The perspective view which showed typically the state which mounted | wore between the embedding formwork with the joint obstruction | occlusion member in the formation method of the joint part of the embedding formwork of this invention. The top view which showed the planar shape (at the time of an elastic deformation) of the joint closure member shown in FIG. The operation | movement sequence diagram which showed typically the procedure which mounts a joint blockage | closure member between embedding formwork, and forms a joint part in an embedding formwork . State explanatory drawing which showed the action state to the joint block member of concrete side pressure. State explanatory drawing which showed the removal state of the joint blockage member. The top view which showed the planar shape (initial shape, at the time of elastic deformation) of a joint block member (modification example). The perspective view which showed the assembly state of the embedded formwork. FIG. 8 is a perspective view illustrating a state in which internal concrete is placed in the embedded form shown in FIG. 7. The elements on larger scale which showed the joint part of the embedded formwork shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Embedded mold 2 Slit 3 Internal concrete 4 Groove-shaped part 5 Mortar 10 Joint closing member 10a Tip part 10b Plate-shaped part 15 Small hole

Claims (3)

Assembling an embedded mold form having a groove portion on the side surface of the mold frame so that the groove portion faces each other across a slit corresponding to a predetermined joint width, and corresponds to a cross section of the groove portion, An elastic joint closing member having a tip portion having a shape is elastically deformed so as to reduce the width of the tip portion, and is inserted into the slit until the tip portion reaches the groove-like portion. The slits are closed with plate-like portions that are continuous with the end portions of the elastic joint closing members, and the concrete placed in the embedded formwork is separated from the slits. A method for forming a joint part of an embedded formwork characterized by preventing leakage . The said joint obstruction | occlusion member makes | forms the front cracked bifurcated shape which has the same-shaped semi-cylindrical front-end | tip part which can each engage with the said groove-shaped part which opposes on both sides of the said slit. A method for forming a joint portion of an embedded formwork . The method for forming a joint portion of an embedded form according to claim 1 or 2, wherein after the concrete is hardened, the joint blocking member is removed from the slit, and the slit is filled with a sealing material .

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