JP2015108273A - Concrete void slab - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete void slab with excellent vibration performance, at the same time reducing its weight.SOLUTION: In this two-way concrete void slab, a void mold 40 made of foam resin is placed in a grid-form small space S between an upper reinforcement 2 and a lower reinforcement 3. Several light-weight void molds of different sizes and forms are prepared beforehand for the void mold, and the largest void mold among those with a size and form that fit in the small space S is placed. This way, a void mold that reduces the slab weight to the extent possible may be placed in each small space, while maintaining section rigidity of the slab. Thus, the slab weight may be reduced. Also, by reducing the size of a small space at the slab edge and placing a small void mold in the small space, the amount of concrete becomes larger at the slab edge compared to the slab center, thereby increasing the area of concrete cross-section. As such, a virtually arch-shaped slab may be formed while keeping the upper and lower surfaces of the slab flat, enhancing the vibration performance and flexibility.

Description

  The present invention relates to a concrete void slab in which a lightweight void form is disposed between upper and lower reinforcement bars and a method for constructing the same.

As a concrete void slab of this type, for example, as shown in FIG. 9, the upper form 2 is arranged in a grid pattern on the floor mold 1, and the bottom line 3 is also arranged in a grid form. There is a structure in which a lightweight void formwork (embedding material) 4 made of foamed resin or the like is disposed therein and concrete C is placed therein (see Patent Document 1 FIG. 1 and Patent Document 2 FIG. 5).
This concrete void slab is constructed as a floor slab of an RC (Reinforced-Concrete) building, and the lightweight void form 4 is embedded to reduce the weight of the slab while maintaining the cross-sectional rigidity of the slab.

JP-A-9-250196 JP 2006-9363 A

  In the small space S of the conventional concrete void slab, a single (same size and shape) void form 4 is arranged. For this reason, the void mold frame 4 is not arranged in the small space S in which the void mold frame 4 cannot be disposed (cannot be entered), and the concrete C is placed in the entire area in the small space S. Even if the void form 4 is arranged, the fact that the cross section rigidity of the slab can be maintained, the fact that the void form 4 is not arranged means that the slab becomes heavy and the whole building becomes heavy. This is disadvantageous in terms of strength.

  This invention makes it a subject to provide the concrete void slab excellent in vibration performance, aiming at the weight reduction of a slab under the above actual condition.

In order to achieve the above object, the present invention prepares a plurality of lightweight void molds having different sizes and shapes in advance, and within the small space S, the size and shape that can be accommodated in the small space S, The largest void formwork prepared was arranged.
If it does in this way, as long as the cross-sectional rigidity of a slab can be maintained, the void type | mold frame which can make the weight of a slab lightest most can be arrange | positioned in each small space. In addition, lightweight means that density is lower than concrete (light weight).

  As a specific configuration of the present invention, the lattice-shaped lower end bars are provided in parallel with a space in the vertical direction like the lattice-shaped upper end bars, and a lightweight void form frame is disposed between the upper and lower end bars, and the concrete is In the placed concrete void slab, a plurality of objects having different sizes and shapes are prepared for the void formwork, and the prepared void type is formed in a lattice-like small space composed of the upper end and the lower end. It is possible to adopt a configuration in which the largest object that fits in this small space is arranged.

In this configuration, the small space has the same length in at least one direction (for example, the left-right direction) in the front-back, left-right direction in the plan view of the slab, and the plurality of prepared voids are the same in the small space. The lengths of the portions corresponding to the lengths may be the same.
In this way, if only the other length (width) of the void mold is changed, the void mold can be arranged in all small spaces, so that the preparation (preparation) of the void mold is easy. Become. In addition, the void formwork corresponding to each small space can be appropriately selected and arranged by selecting the void formwork corresponding to the width of each small space. There is no restriction on the number of reinforcing bars, the degree of freedom in selecting the reinforcing bar diameter and the number of reinforcing bars is increased, and the small space in which the void formwork is not disposed is reduced as much as possible, so that an economical design is possible.

  Also, by reducing the small space at the end of the slab and placing a small void formwork in the small space, the amount of concrete at the end of the slab will be larger than that at the center of the slab, and the concrete cross section at the end will be reduced. Can be increased. For this reason, it is possible to form a substantially arched slab while keeping the upper and lower surfaces of the slab flat (planar), and the vibration performance and the bending performance are improved. For example, in an apartment house or the like, when a floor impact sound with respect to the lower floor becomes a problem, a small lightweight void form is uniformly embedded in a small space of the part including the end. In this way, by partially increasing the concrete density, it is possible to satisfy a place where vibration performance is required, for example, floor impact sound demand performance (vibration demand performance) of a living room or the like.

As the shape of the above-mentioned void form, various types have been proposed in the past, and they can be used. A shape that is inclined outward toward the side surface can be employed.
If it does in this way, it will become easy to perform rebar fastening work near the side central part of a void form by the above-mentioned inclined surface. In addition, when viewed from above (when viewed from above), when the shape is a quadrangle, the lattice-shaped small space is also the same square shape, and therefore, a lightweight void formwork can be arranged in the small space with a minimum gap, For this reason, the amount of concrete placed in the small space can be minimized, and the weight of the slab can be easily reduced.

  In addition, the lower surface of the void form frame may have a cross-shaped groove for receiving an auxiliary muscle, and may be an inclined surface that does not have a horizontal plane toward the center outer side (lower side) in the longitudinal direction. . If the lower surface has such a shape, the lower surface does not have a horizontal surface, and the concrete smoothly flows from the inclined surface to the lower surface of the void formwork, so that the concrete placement failure can be suppressed. Further, if the void form frame is roughly placed on the auxiliary muscle and pushed lightly from above (if a load is applied), the auxiliary muscle can be guided into the groove along the inclined surface, and the construction becomes easy. The inclined surface may be linear (flat inclined surface) or curved (curved surface).

  The slab may be constructed by the same construction (construction) method as in the past, for example, on the floor formwork, the upper and lower streaks are arranged in a lattice pattern, and in each lattice-like small space, The concrete C can be placed after placing the largest object that fits in each small space among the prepared void molds having different sizes and shapes.

  Since the present invention is configured as described above and can reduce the weight of the slab as long as the cross-sectional rigidity of the slab can be maintained, the concrete void slab having excellent vibration performance while reducing the weight of the slab. It can be.

Schematic perspective view of one embodiment The same embodiment is shown, (a) is a cut partial front view, (b) is a partial plan view. An example of the lightweight void formwork of the embodiment is shown, (a) is a perspective view, (b) is a front view, (b) is a side view. The other example of the lightweight void formwork of the embodiment is shown, (a) is a top view, (b) is a front view, (b) is a side view. The still another example of the lightweight void formwork of the embodiment is shown, (a) is a plan view, (b) is a front view, and (b) is a side view. The still another example of the lightweight void formwork of the embodiment is shown, (a) is a plan view, (b) is a front view, and (b) is a side view. The still another example of the lightweight void formwork of the embodiment is shown, (a) is a plan view, (b) is a front view, and (b) is a side view. The still another example of the lightweight void formwork of the embodiment is shown, (a) is a plan view, (b) is a front view, and (b) is a side view. Conventional light-weight void formwork layout schematic perspective view

As shown in FIGS. 1 and 2, according to an embodiment of the present invention, as shown in FIG. 1 and FIG. A concrete void slab in which a lightweight void mold 40 is disposed between the upper and lower reinforcing bars 2 and 3 and concrete C is placed therein.
In this concrete void slab, the void form frames 40a, 40b, 40c, 40d, 40e, and 40f (hereinafter generically referred to as 40) shown in FIGS. It arrange | positions suitably in the formed small space S. FIG. As the material of the void form frame 40, a lightweight material similar to the conventional one may be used as appropriate, but for example, a polystyrene foam is used.

As shown in FIG. 3 and the like, the void form frame 40 has upper and lower surfaces 41a and 41b and side surfaces 42a, 42b, 42c and 42d, and all of the side views from four directions are substantially octagonal. Viewed (viewed from above), presents a rectangle.
The upper and lower surfaces 41a and 41b are oval with both ends cut in a plan view, and are connected to the side surfaces 42a, 42b, 42c and 42d by inclined surfaces 43a and 43b. As described above, the side view from four directions is an octagon, a plan view, an ellipse with both ends cut, and inclined surfaces 43a and 43b. It can be said that it is a substantially flat oval shape composed of sides and arcs.

  In addition, grooves 44a and 44b for receiving the fixing auxiliary muscles 5 are formed in the upper and lower surfaces 41a and 41b. The groove 44b of the lower surface 41b has a cross shape. The lower surface 41b has a horizontal surface at the center, but the center portion gradually rises along the longitudinal groove 44a and is connected to the inclined surface 43b without having a horizontal surface (the lower edge of the vertical cross section is Curve). At this time, the curved surface may be a flat slope (the lower edge of the longitudinal section is a straight line).

The length L, the same width W, and the same height H (see FIG. 3 etc.) of the lightweight void mold 40 are set to be just within the small space S. For this reason, when the amount of reinforcing bars in the place to be arranged is large, the small space S is correspondingly reduced, so the void form 40 having a reduced length and width is used.
For example, the void form 40a shown in FIG. 3: front left and right length L = 380 mm, plane width W = 230 mm, height H = 245 mm, void form 40b shown in FIG. 4: same L = 340 mm, same W = 190 mm, H = 150 mm, void form 40c shown in FIG. 5: L = 300 mm, W = 190 mm, H = 150 mm, void form 40d shown in FIG. 6: L = 380 mm, W = 230 mm, H = 150 mm, void form 40e shown in FIG. 7: L = 300 mm, W = 190 mm, H = 245 mm, void form 40f shown in FIG. 8: L = 340 mm, W = 190 mm, H = 245 mm Etc.

Next, a concrete void slab construction method using the void form 40 will be described.
First, as in the prior art, the upper end stripes 2 are arranged in a lattice pattern on the floor mold 1, and the lower end stripes 3 are also arranged in a lattice pattern. At this time, in the portion where the slab stress increases, for example, at the end of the slab (at the end of the beam), the upper end reinforcement 2 is increased in amount. Since the reinforcing bars (upper and lower bars 2, 3) need to be spaced apart from each other, the arrangement space (small space S) of the void form frame 40 is reduced only at a location (end portion) where the amount of the upper reinforcing bar 2 is increased. (The width of the space S is reduced).
Next, the auxiliary muscles 5 are arranged in a cross shape between the lower end muscles 3 and the void form frame 40 is placed thereon so that the auxiliary muscles 5 enter the grooves 44b. At this time, since the lower surface of the void form 40 is an inclined surface 43b whose whole circumference rises toward the central portion, the auxiliary muscle 5 is formed along the inclined surface 43b when it is pushed lightly from above (when a load is applied). Can be guided to the groove 44b.

Further, the auxiliary muscle 5 is disposed so as to enter the groove 44a on the upper surface of the void mold 40, and the auxiliary muscle 5 is fixed to the floor mold 1 with a U-shaped hook (not shown). At this time, since there is an inclined surface 43a at the upper surface edge of the void mold 40, the void mold 40 does not interfere with the work of the auxiliary muscle 5 and the U-shaped hook. In particular, the binding of the auxiliary muscles 5 is performed in the central portion of the small space S formed by the upper end muscles 2 (distribution muscles). Its existence secures the work space.
The upper bar 2, the lower bar 3, and the auxiliary bar 5 may be bound together by a wire or the like, and supported on the floor mold 1 by a support member (not shown) such as the U-shaped hook (see Patent Document 2). 4 etc.).

When the arrangement of the reinforcing bars 2, 3, 5 and the void mold 40 is completed, the concrete C is placed on the floor mold 1. At this time, since the periphery of the lower surface of the void mold 40 is an upward inclined surface 43b from the outside toward the center, the concrete C smoothly enters (wraps around) the lower surface of the void mold 40 and there is no placement failure. There is little fear of it occurring.
With such arrangement of reinforcement bars 2, 3, 5 and void formwork 40, the concrete cross section increases only at the beam, so the upper and lower surfaces of the cast concrete layer (slab) are kept flat while being substantially flat. Arched slabs can be formed. This arch shape improves the vibration performance and deflection performance of the slab.

  In addition, the said embodiment is each examples of arrangement | positioning of the upper reinforcement 2 and the lower reinforcement 3, the number, the arrangement and number of the reinforcement reinforcement 5, the size of the void formwork 40, etc., and this invention is a one-way concrete slab. Of course, it can be adopted in either of two-way concrete slabs. Therefore, it should be considered that the embodiments disclosed herein are illustrative and non-restrictive in every respect, and the scope of the present invention is defined by the claims, and It is of course intended to include all modifications within the meaning and scope equivalent to the above.

DESCRIPTION OF SYMBOLS 1 Floor form frame 2 Top bar 3 Bottom bar 4, 40, 40a, 40b, 40c, 40d, 40e, 40f Void frame 5 Auxiliary bar 41a Void frame upper surface
41b Void frame lower surface 42a, 42b, 42c, 42d Void frame side surfaces 43a, 43b Void frame inclined surfaces 44a, 44b Auxiliary reinforcement groove C Concrete S Lattice-like small space

Claims (6)

Like the lattice-shaped upper end line (2), the lattice-shaped lower end line (3) is provided in parallel in the vertical direction with a light-weight void frame (40) between the upper end line (2) and the lower end line (3). In the concrete void slab where the concrete (C) is placed and placed,
A plurality of objects having different sizes and shapes are prepared for the void formwork (40), and the preparation is provided in a lattice-like small space (S) composed of the upper end stripe (2) and the lower end stripe (3). A concrete void slab in which the largest object that fits in the small space (S) is arranged in the void formwork (40).   The small space (S) has the same length in at least one of the two directions, and the plurality of void form frames (40) correspond to the same length of the small space (S). The concrete void slab according to claim 1, wherein the lengths of the portions are the same.   The concrete void slab according to claim 1 or 2, wherein the amount of concrete at the end of the slab is larger than that at the center of the slab.   The void form frame (40) has a quadrangular shape in plan view and has four side surfaces (42a, 42b, 42c, 42d), and an outwardly inclined surface from the top and bottom surfaces (41a, 41b) toward the side surfaces. The concrete void slab according to any one of claims 1 to 3, wherein the concrete void slab is (43a, 43b).   The lower surface (41b) of the void form (40) has a cross-shaped groove (44b) for receiving the auxiliary muscle (5), and is inclined toward the center. The concrete void slab according to any one of 1 to 4.   The method for constructing a concrete void slab according to any one of claims 1 to 5, wherein the upper end bars (2) and the lower end bars (3) are arranged in a grid pattern on a floor formwork (1). In the lattice-shaped small spaces (S), after placing the largest object that fits in the small spaces (S) among the prepared void forms (40) having different sizes and shapes, concrete A method for constructing a concrete void slab characterized by placing (C).

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