JP2016065397A - Precast concrete slab with rib for synthetic floor slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily execute blocking-up form installation work at a job site for blocking up mutual ribs under a precast concrete slab end part with the rib.SOLUTION: A precast concrete slab with a rib for a synthetic floor slab is provided by integrally projecting a rib 13 toward the extension direction on an undersurface of a precast concrete slab body 12 forming a plate shape, and blocking-up forms 14 and 15 are integrally molded toward the extension direction in an end part of the precast concrete slab body 12 for closing a space under a precast concrete slab body side edge part between mutual ribs and/or from the ribs, and the blocking-up form is bent to the lower side from a boundary part with the precast concrete slab body 12, so that the end part of the space under the precast concrete slab body side edge part is closed between the mutual ribs and/or from the ribs.SELECTED DRAWING: Figure 1

Description

  TECHNICAL FIELD The present invention relates to a ribbed precast concrete plate used for a synthetic floor slab composed of a precast concrete plate with ribs and cast-in-place concrete placed thereon.

  Conventionally, when building floors of buildings, precast concrete slabs created at production yards near factories and sites are spanned between beams built on the floor support or between cast beam components. There is a well-known method of making a composite slab by placing cast-in-place top concrete on top.

  The precast concrete plate used for this type of composite floor slab is composed of an RC member or a PC member, and as shown in FIGS. A rib-shaped precast concrete plate 3 that is integrally provided with ribs 2 and 2 (small beams) in a T-section arrangement on the lower surface is often used (for example, Patent Document 1).

  The synthetic floor slab using this type of precast concrete plate 3 with ribs is one in which a construction portion 4 having no ribs on the lower surface is integrally formed in an extended arrangement at the end of the precast concrete plate main body 1.

  When the beam for supporting the ribbed precast concrete plate 3 is made of steel, as shown in FIG. 13, the supporting portion 4 is supported on the upper surface of the steel beam 5, and When the beam is a cast-in-place concrete beam, as shown in FIG. 14, with the beam 6 and the top concrete 7 for floor slabs placed in the upper portion of the beam 6, the erection part 4 is beamed. The bearing structure penetrated into No.6.

  However, the precast concrete plate provided with the erection part 4 that extends the precast concrete slab main body as described above needs to form a portion without a rib on the lower surface of the erection part 4, and the upper surface of the erection part is locally There is a problem that the cost becomes high due to factors such as the need for a reinforcing overlay 8 to cope with stress and the need for a large amount of man-hours during manufacturing.

  Therefore, in recent years, as shown in FIG. 15, a precast concrete plate 3 with ribs having no ribs on the lower surface and having ribs formed over the entire length is used, and cast-in-place concrete is used as shown in FIG. A support structure in which the rib 2 is penetrated with respect to the beam 6 and a support structure in which the lower surface of the rib 2 is supported on the upper surface of the steel beam (not shown) are employed.

JP 62-296039 A

  When trying to directly support the end of the rib shown in FIG. 15 and FIG. 16 on the steel beam or in the concrete beam, between the ribs on the lower surface of the end of the precast concrete plate or from the rib to the precast concrete plate main body. As shown in FIGS. 16 and 17, it is necessary to perform a mold work to close the space between the side edges by a cover mold 9 such as a face door plate. Since it has a thin taper shape or a shape that is rounded on the outer surface of the root, that is, the outer surface of the boundary portion between the precast concrete plate main body and the ribs, the cover mold frame for closing these spaces is used. Installation work becomes troublesome.

  In view of such a conventional problem, the present invention provides a rib for a synthetic floor slab that makes it easier to install a formwork in the field for closing the space between the ribs under the end of the precast concrete slab with ribs than before. It was made for the purpose of providing precast concrete slabs.

  According to a first aspect of the present invention for achieving the above object, ribs extending in the bridging direction are integrally projected on the lower surface of the flat-cast precast concrete plate main body, and both ends are for floor support. In the precast concrete slab with ribs for synthetic floor slab, which is constructed by placing cast-in-place concrete on the upper surface, spanning between the beams, between the ribs and / or ribs at the end of the precast concrete slab body A closing mold for closing the space under the side edge of the precast concrete plate main body is integrally formed in the extending direction, and the blocking mold is bent downward from the boundary portion with the precast concrete plate main body. The space between the ribs and / or from the ribs below the side edge of the precast concrete plate body by the cover mold In the end has to be closed.

  According to a second aspect of the present invention, in addition to the configuration of the first aspect, a connecting bar is embedded across the cover mold and the precast concrete plate main body, and the concrete in the boundary portion is broken to This is because the connecting bars are bent.

  According to a third aspect of the present invention, in addition to the configuration of the first or second aspect, a concave groove having an inverted V-shaped cross section is formed on the lower surface of the boundary portion, and the inverted V-shaped is formed by the bending. This is because the concave groove is closed and the cover mold is bent at a predetermined downward angle.

  According to a fourth aspect of the present invention, in addition to the structure of any one of the first to third aspects, a concave groove for bending is formed on the upper surface of the boundary portion.

  In the present invention, as described in claim 1, a ribbed precast concrete plate for a synthetic floor slab in which ribs extending in the bridging direction are integrally projected on the lower surface of a flat-cast precast concrete plate main body. A sealing mold for closing the space between the ribs and / or from the rib to the side of the precast concrete plate main body side edge is integrally formed at the end of the precast concrete plate main body in the extending direction. By bending the formwork downward from the boundary portion with the precast concrete plate main body, the end of the space between the ribs and / or from the rib below the side edge of the precast concrete plate main body is closed by the cover formwork. As a result, the fusing formwork is integrally formed during the manufacture of precast concrete plates with ribs. It is easy to keep, and when using the precast concrete plate with ribs, the space between the ribs that can be formed at the end can be closed by folding the cover mold, which has been done in the past There is no need for formwork such as installation of doorboards, and field work can be reduced.

  In the present invention, as described in claim 2, a connecting bar is embedded between the cover mold and the precast concrete plate main body, and the connecting bar is bent by breaking the concrete at the boundary portion. As a result, it is easy to integrate the cover formwork into the precast concrete plate body, and the connecting bar acts as a hinge, so there is no need to have a special folding member, and it is inexpensive. Can be manufactured.

  According to the present invention, as in the invention described in claim 3, a concave groove having an inverted V-shaped cross section is formed on the lower surface of the boundary portion, and the inverted V-shaped concave groove is closed by the bending. Since the cover formwork is bent at a predetermined angle downward, the gap after the folded part becomes smaller, and the work for filling the gap becomes unnecessary or less, and the gap filling work is done manually. Is labor-saving.

  According to the present invention, as in the invention described in claim 4, since the concave groove for bending is formed on the upper surface of the boundary portion, the thickness of the concrete portion destroyed at the time of bending is reduced, and the bending is thereby performed. Work becomes easy.

It is a top view of the edge part of the precast concrete plate with a rib for synthetic floor slabs concerning the present invention. It is a side view same as the above. It is the same front view. It is a perspective view from the diagonally lower side. It is a perspective view from the slanting lower side which shows the state which bent the cover form of the precast concrete plate with a rib for synthetic floor slabs shown in FIG. It is a fragmentary sectional view of the state before bending a cover mold form. It is sectional drawing which shows the state which bent the cover formwork It is a partial front view of the other example of the precast concrete board with a rib for synthetic floor slabs concerning this invention. It is the same top view. It is a top view of an example of the conventional precast concrete plate with a rib for synthetic floor slabs. It is the same side view. It is the same front view. It is sectional drawing which shows an example of the use condition of the precast concrete board with a rib for synthetic floor slabs shown in FIG. It is sectional drawing which shows the other example of the same use condition. It is a perspective view from the diagonally lower side which shows the other example of the conventional precast concrete plate with a rib for synthetic floor slabs. It is a vertical side view which shows an example of a use condition same as the above. It is the longitudinal section front view.

  Next, embodiments of the present invention will be described with reference to the drawings. 1 to 7 show an example of a precast concrete plate with ribs for a synthetic floor slab according to the present invention. This ribbed precast concrete plate 11 (hereinafter referred to as “ribbed PCa plate 11”) has a rectangular plate-shaped precast concrete plate main body (hereinafter referred to as “PCa plate main body”) 12 and a full length on the lower surface of the PCa plate main body 12. Are formed integrally with ribs 13 and 13, and cover molds 14, 14 and 15 which are integrally formed at the end of the PCa plate main body 12 in the extending direction thereof. The cover molds 14, 14, 15 are integrated with the end portions of the PCa plate main body 12 without the ribs 13, 13.

  In the PCa plate main body 12 and the ribs 13 and 13, reinforcing bars of an amount necessary for the necessary arrangement are respectively embedded, and the upper surface of the PCa plate main body 12 is a gibber bar for integration with top concrete described later. (Not shown) is provided as required.

  As shown in FIGS. 6 and 7, a connecting reinforcing bar 17 straddling the PCa plate body 12 is embedded in each of the cover molds 14, 14, 15. The connecting reinforcing bar 17 is formed by lengthening a part of the reinforcing bar facing in the longitudinal direction in the PCa plate main body 12 and embedding the reinforcing bar in the PCa plate main body 12. 14 and 15 and the PCa plate main body 12 may be arranged, and apart from the reinforcing bar for the PCa plate main body 12, a smaller dedicated connection may be used.

  The cover molds 14 and 14 have a shape that matches the cross-sectional shape of the space below the PCa plate main body side edge from the rib 13 on the lower surface of the PCa plate main body 12, and the cover mold 15 is formed between the ribs 13 and 13. The shape matches the cross-sectional shape of the space.

  A bent portion 20 is formed at a boundary portion between the cover molds 14, 14, 15 and the PCa plate main body 12 so that the concrete at the portion can be broken and bent.

  The bent portion 20 includes a concave groove (notch) 21 having an inverted V-shaped cross section formed on the lower surface of the boundary portion and a concave groove (notch) 22 formed on the upper surface of the boundary portion. The V-shaped angle of the groove 21 on the side is 90 degrees.

  In either case, the concave grooves 21 and 22 are formed to a depth that does not reach the connecting reinforcing bar 17, and a thin portion in which the connecting reinforcing bar 17 is passed between the concave grooves 21 and 22 is formed. The lower concave groove 21 may be formed to a depth that reaches the connecting reinforcing bar 17.

  The precast concrete slab 11 with ribs for a composite floor slab constructed in this way is shown in FIG. 16 and FIG. 17 when it is bridged over a cast-in-place concrete beam 6 part for supporting a slab or a steel beam. 5. As shown in FIG. 7, the cover molds 14, 14, 15 are bent downward from the respective bent portions 20.

  As a result, the space under the PCa plate body side edge and the space between the ribs 13 and 13 from the rib 13 on the lower surface of the PCa plate body 12, that is, the space under the end of the PCa plate body 12 corresponding to the height of the ribs 13 and 13 are closed. This eliminates the need to close the space between the ribs by the mold work.

  In addition, the gap between the outer surface of the rib 13 and the lower surface of the PCa plate body 12 and the cover molds 14, 14, 15 is filled with an appropriate joint material to prevent leakage of mortar components when placing the top concrete. To do.

  In this manner, the end portion of the ribbed PCa plate 11 is inserted into the beam frame 31 as in the conventional example shown in FIG. A top concrete 7 that is continuous with the portion is placed to form a composite floor slab.

  In this example, the so-called swallowing type in which the end portion of the ribbed PCa plate 11 is embedded in the beam 6 has been described. May be.

  Further, in the above-described example, the case where the cast-in-place concrete is supported on the beam 6 is shown. However, in the case where the steel beam is supported, the cover molds 14, 14, 15 are similarly moved downward from the bent portions 20. Bending and closing the space under the PCa plate main body side edge and the space between the ribs 13 and 13 from the rib 13 on the lower surface of the PCa plate main body 12, that is, the space under the end of the PCa plate main body 12 corresponding to the height of the ribs 13 and 13. Can be used as

  In the above-described example, the case where the cross-sectional shape of the ribs 13 and 13 is an inverted trapezoid is shown. However, as shown in FIGS. 8 and 9, a concave shape is formed between the side surfaces of the ribs 13 and 13 and the bottom surface of the PCa plate body 12. In the case of the curved surface (R) 40, a convex curved surface 41 that fits the concave curved surface 40 is formed on the side surfaces of the cover frames 14, 14, 15 corresponding to the curved surface 40 when bent. As a result, the space between the ribs 13 and 13 below the end of the PCa plate body 12 can be closed as described above.

11 Precast concrete plate with ribs (PCa plate with ribs)
12 Precast concrete plate body (PCa plate body)
13 Ribs 14 and 15 Fuzzy formwork 17 Reinforcing bars 20 Bending parts 21 and 22 Concave groove 31 Formwork 32 Supporting work 40 Concave curved surface 41 Convex curved surface

Claims (4)

Synthetic floor slabs with ribs facing in the direction of the bridge are integrally projected on the lower surface of the flat-cast precast concrete plate body, both ends are spanned between beams for floor support, and cast-in-place concrete is cast on the upper surface In the precast concrete slab with ribs for synthetic floor slabs
At the end of the precast concrete plate main body, a cover mold for closing the space between the ribs and / or from the rib under the side edge of the precast concrete plate main body is integrally formed in the extending direction,
The end of the space between the ribs and / or from the rib to the side of the precast concrete plate main body side is closed by bending the cover mold form downward from the boundary with the precast concrete plate main body. A precast concrete plate with ribs for synthetic floor slabs.   The rib for a composite floor slab according to claim 1, wherein a connecting bar is embedded between the cover mold and the precast concrete plate body, and the connecting bar is broken by breaking the concrete at the boundary portion. Precast concrete plate with.   A concave groove having an inverted V-shaped cross section is formed on the lower surface of the boundary portion, and the inverted V-shaped concave groove is closed by the bending, so that the cover mold is bent at a predetermined downward angle. The ribbed precast concrete slab for synthetic floor slab according to claim 1 or 2.   The precast concrete plate with ribs for synthetic floor slabs according to any one of claims 1 to 3, wherein a concave groove for bending is formed on the upper surface of the boundary portion.

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