JP2016028181A - Concrete void member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a concrete void member capable of facilitating a bar arrangement work of void holding reinforcement rods and an installation work void member while ensuring the holding property.SOLUTION: A void member 3 is embedded in a concrete structure 1. An upper plane 20 or a lower plane 30 of the void member 3 forms three or more grooves 21, 31 or a single groove 22, 32. An arrangement area of the grooves expands in a central area and both side areas in a direction along the groove width in the planes 20 and 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a void member embedded in a concrete structure such as a concrete slab, and more particularly to a void member embedded in concrete while being held by a void holding reinforcing bar.

In a concrete structure such as a concrete slab, it is known to embed a void member in order to reduce the amount of concrete placed and reduce the weight.
For example, the void member of Patent Document 1 is sandwiched from both upper and lower sides by void holding reinforcing bars so as not to be displaced due to the flow pressure at the time of placing concrete. A fitting groove is formed on the upper surface or the lower surface of the void member, and a void holding reinforcing bar is fitted into the fitting groove.

Japanese Patent No. 5259465 ([0074], FIG. 26)

In the above-mentioned Patent Document 1, the fitting groove and the void holding reinforcing bar are accurately aligned and fitted one-on-one. Therefore, the work of arranging the void holding reinforcing bars and the work of installing the void member are complicated. On the other hand, it is necessary to hold the void member to such an extent that it can withstand the fluid pressure at the time of placing concrete.
In view of the circumstances described above, an object of the present invention is to facilitate the work of arranging the void holding rebar and the installation work of the void member and to secure the retention of the void member.

In order to solve the above problems, the present invention is a void member embedded in a concrete structure in a state of being held by a void holding reinforcing bar,
At least one surface of the upper surface and the lower surface is formed with three or more grooves or a single groove arranged in parallel, and the region where the grooves are arranged is the center in the direction along the width of the groove on the one surface It extends over the part and both sides.

  According to this void member, for example, the void member is held so as to be sandwiched from above and below by the void holding reinforcing bars paired vertically. The groove on the upper surface of the void member and the upper void holding reinforcing bar may be parallel to each other or may intersect (or be orthogonal). Similarly, the groove on the lower surface of the void member and the lower void holding reinforcing bar may be parallel to each other or may intersect (or be orthogonal). When parallel, the void holding reinforcing bars can be accommodated in any of the three or more grooves, or can be accommodated in any location in the width direction of the wide single groove. When crossed, a plurality of void holding reinforcing bars can be pressed against adjacent portions of the one side of the void member or both edges of the grooves, or the ribs of the void holding reinforcing bars can be locked into the grooves. As a result, it is possible to facilitate the reinforcement work of the void-retaining reinforcing bars and the installation work of the void member and to secure the retainability.

The three or more grooves are juxtaposed over almost the entire area of the one surface, each groove is formed in a V-shaped cross section, and a ridge having a triangular cross section is formed between adjacent grooves. It is preferable. As a result, even if the void member and the void holding rebar are not precisely aligned, the void holding rebar can be fitted into an arbitrary groove, or the void holding rebar can be crossed with a plurality of protrusions to each of the protrusions. It can be pressed. Even when two or more void holding reinforcing bars are arranged side by side, it is not necessary to set the interval between these void holding reinforcing bars strictly. Therefore, it is possible to facilitate the installation work of the void member and the bar arrangement work of the void holding rebar, or to secure the retainability.
The “substantially the entire area of the one surface” refers to an area of preferably 80% or more, more preferably 90% or more of the one surface (hereinafter agreed).

  The single groove is formed on the one surface, and the single groove has a pair of inclined surfaces that occupy almost the entire area of the one surface. It may incline so that it may be dented and may mutually cross | intersect in the center part of said one surface. Accordingly, the void holding rebar can be easily accommodated in the groove without strictly aligning the void member and the void holding rebar. Even when two or more void holding reinforcing bars are arranged side by side, it is not necessary to set the interval between these void holding reinforcing bars strictly. Therefore, the installation work of the void member and the bar placement work of the void holding rebar can be facilitated.

  It is preferable that the groove is formed on both the upper surface and the lower surface, and the extending direction of the groove on the upper surface and the extending direction of the groove on the lower surface are orthogonal to each other. In accordance with this, it is preferable that the direction in which the upper void holding rebar is laid and the direction in which the lower void holding rebar is laid perpendicular to each other. By doing so, the displacement of the void member can be regulated in directions orthogonal to each other on the upper surface side and the lower surface side. Further, the swinging of the void member can be restricted. This makes it possible to hold the void member more stably.

Two parallel wide grooves or four wide grooves having a well shape are formed on the other surface of the upper surface and the lower surface, and the width of each of the wide grooves is larger than the diameter of the void holding rebar. It can be large.
Thereby, even if the void holding reinforcing bar corresponding to the other surface is in a free state, the void holding reinforcing bar can be easily and reliably fitted into the wide groove.
The two parallel wide grooves are preferably orthogonal to the extending direction of the groove on the one surface.

The three or more grooves are juxtaposed over almost the entire area of the one surface, and two main grooves separated from each other among the three or more grooves are wider than the remaining preliminary grooves. preferable.
As a result, the void holding reinforcing bar corresponding to the one surface can be fitted in the main groove in principle, and the selection of the groove in which the void holding reinforcing bar should be fitted can be facilitated.

An interval between adjacent grooves on the one surface is narrow at both side portions including the main grooves, is wide at a central portion between the two side portions, and a flat portion is formed between adjacent grooves at the central portion. It is preferable that
By narrowing the groove spacing on both sides including the main groove, when the void holding rebar corresponding to the one surface is slightly shifted from the main groove, it is ensured that the spare groove near the main groove is in the spare groove. Can be fitted. In addition, by providing a flat portion at the central portion far from the main groove, the pointed portion between adjacent grooves, that is, the portion that tends to be lost can be reduced, and the void member can be suppressed or prevented from being lost.

  ADVANTAGE OF THE INVENTION According to this invention, while the reinforcement work of a void holding | maintenance reinforcing bar and the installation work of a void member can be facilitated, the retainability of a void member is securable.

FIG. 1 shows a concrete void member according to the first embodiment of the present invention. FIG. 1 (a) is a plan view taken along line Ia-Ia of FIG. 2 (a), and FIG. FIG. 3 is a bottom view taken along the line Ib-Ib in FIG. Fig.2 (a) is a front view of the said void member which follows the IIa-IIa line | wire of Fig.1 (a). FIG.2 (b) is a side view of the said void member which follows the IIb-IIb line | wire of Fig.2 (a). FIG. 3 is a perspective view of the void member, and shows the void holding reinforcing bars by phantom lines. FIG. 4 is a plan sectional view showing a concrete slab including the void member and taken along line IV-IV in FIG. 5. FIG. 5 is a front cross-sectional view of the concrete slab along the line V-V in FIG. 4. FIG. 6 is a side cross-sectional view of the concrete slab along the line VI-VI in FIG. 4. FIG. 7 is a perspective view showing the void member for concrete according to the second embodiment of the present invention, and shows the void holding reinforcing bars by phantom lines. FIG. 8 is a perspective view showing the void member for concrete according to the third embodiment of the present invention, and shows the void holding reinforcing bars by phantom lines. FIG. 9 is an enlarged cross-sectional view of a contact portion between the upper void holding reinforcing bar and the void member in the third embodiment. FIG. 10: is a perspective view which shows the void member for concrete which concerns on 4th Embodiment of this invention, and shows a void holding | maintenance reinforcement with a virtual line. FIG. 11 shows a concrete void member according to a fifth embodiment of the present invention, where FIG. 11 (a) is a plan view and FIG. 11 (b) is a bottom view. Fig.12 (a) is a front view of the void member of the said 5th Embodiment which follows the XIIa-XIIa line | wire of Fig.11 (a). FIG.12 (b) is a side view of the void member of the said 5th Embodiment which follows the XIIb-XIIb line | wire of Fig.12 (a). FIG. 13 shows a concrete void member according to a sixth embodiment of the present invention, where FIG. 13 (a) is a plan view and FIG. 13 (b) is a bottom view.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 6 show a first embodiment of the present invention. As shown in FIGS. 4 to 6, the concrete slab 1 (concrete structure) is used as a floor of a building, for example, and includes a concrete 2 and a reinforcing bar assembly 4. A rebar assembly 4 is embedded in the concrete 2. The reinforcing bar assembly 4 includes a main bar 40 and a distribution bar 41. The main bar 40 and the distribution bar 41 extend in directions orthogonal to each other. Here, the direction along the main bar 40 is referred to as “A direction”, and the direction along the distribution bar 41 is referred to as “B direction”. As shown in FIG.5 and FIG.6, the main reinforcement 40 and the distribution bar 41 are two steps | paragraphs in the up-down direction (thickness direction of the concrete slab 1), respectively.

  As shown in FIG. 4, the reinforcing bar assembly 4 further includes an upper void holding reinforcing bar 42 and a lower void holding reinforcing bar 43. As shown in FIGS. 5 and 6, the upper void holding reinforcing bar 42 is arranged on the upper stage of the reinforcing bar assembly 4, extends in the A direction in parallel with the upper main reinforcing bar 40, and intersects with the distributing bars 41. . The lower void retaining reinforcing bar 43 is arranged at the lower stage of the reinforcing bar assembly 4, intersects with the lower main reinforcing bar 40, and extends in the B direction in parallel with the distribution bar 41. Therefore, the spanning direction of the upper void retaining reinforcing bar 42 and the spanning direction of the lower void retaining reinforcing bar 43 intersect (orthogonal) each other.

  Further, a plurality of concrete void members 3 (hereinafter referred to as “void members 3”) are embedded in the concrete 2 for weight reduction. The void member 3 is made of a material having a lighter specific gravity than the concrete 2, and is preferably made of a foamed resin such as polystyrene foam. As shown in FIGS. 4 to 6, the plurality of void members 3 are arranged in the vertical and horizontal directions in the concrete slab 1. Between the adjacent void members 3 and 3, the main reinforcing bar 40 and the reinforcing bar 41 of the reinforcing bar assembly 4 are arranged. Further, each void member 3 is sandwiched from above and below by the two upper void holding rebars 42 and 42 and the two lower void holding rebars 43 and 43.

  As shown in FIGS. 1 to 3, each void member 3 has a block shape in which the horizontal cross section is substantially square (quadrangle) and the length of one side in the horizontal direction is larger than the height. Two opposite horizontal sides of the void member 3 are along the B direction, and the other two horizontal sides perpendicular to the void member 3 are along the A direction. Further, the upper part and the lower part of the middle part in the vertical direction of the void member 3 each have a quadrangular pyramid shape. Therefore, the outer surface of the void member 3 includes four side surfaces 11 in the middle portion in the vertical direction, four upper inclined surfaces 12 on the upper side, four lower inclined surfaces 13 on the lower side, an upper surface 20 and a lower surface 30. Including. Further, the corners at the four corners of the upper surface 20 and the lower surface 30 of the void member 3 are cut obliquely to form triangular notches 20e and 30e.

  As shown in FIGS. 5 and 6, the upper surface 20 of the void member 3 is positioned at substantially the same height as the upper main bar 40 and the distribution bar 41. Further, the lower surface 30 of the void member 3 is positioned at substantially the same height as the lower main muscle 40 and the distribution bar 41. By arranging the upper and lower side surface portions of the void member 3 to be inclined to form the inclined surfaces 12 and 13, it is possible to easily secure the arrangement space for the main reinforcement 40 and the distribution reinforcement 41.

  The length of one side of the void member 3 in the horizontal direction is, for example, about 100 mm to 500 mm, and preferably about 300 mm. The vertical dimension (height) of the void member 3 is, for example, about 50 mm to 300 mm. Preferably it is about 150 mm.

  As shown in FIG. 1A, the upper surface 20 (one surface) of the void member 3 has three or more grooves 21, 21,. In the figure, the number of grooves 21 is 9, but it may be 3 to 8, or 10 or more. As shown in FIGS. 3 and 4, each groove 21 extends in the A direction, and extends along the direction in which the upper void holding rebar 42 is bridged. As shown in FIG. 1A, the grooves 21, 21... Are continuously arranged at regular intervals over almost the entire surface of the upper surface 20 from one end in the B direction to the other end of the upper surface 20. Therefore, the arrangement region of the groove 21 extends over the central portion and both end portions of the upper surface 20 in the B direction (the direction along the width of the groove 21).

  As shown in FIG. 2A, the cross section perpendicular to the extending direction (A direction) of the groove 21 is V-shaped. As shown in FIG. 1A, both ends of each groove 21 reach the upper inclined surfaces 12 on both sides in the A direction (up and down in FIG. 1A). A ridge 23 is formed between adjacent grooves 21. The ridge 23 has a triangular cross section and extends in the A direction. The grooves 21 and the ridges 23 are alternately arranged in the B direction. Therefore, the cross section orthogonal to the A direction of the upper surface 20 has a triangular wave shape. Moreover, the upper edge of the upper inclined surface 12 on both sides in the A direction has a triangular wave shape.

  The pitch of the grooves 21 is, for example, about 10 mm to 30 mm, and preferably about 10 mm. Moreover, the depth of the groove | channel 21 is about 3 mm-20 mm, for example, Preferably it is about 5 mm.

  As shown in FIG. 1B, three or more grooves 31, 31... Are formed on the lower surface 30 (the other surface) of the void member 3. In the figure, the number of grooves 31 is 9, but it may be 3 to 8, or 10 or more. Each groove 31 extends in the B direction, and is along the spanning direction of the lower void holding reinforcing bar 43. Therefore, the extending direction of the upper groove 21 and the extending direction of the lower groove 31 are orthogonal to each other. Further, the grooves 31, 31... Are continuously arranged at regular intervals over almost the entire area of the lower surface 30 from near one end of the lower surface 30 in the A direction to near the other end. Therefore, the arrangement region of the groove 31 extends over the center and both ends of the lower surface 30 in the A direction (the direction along the width of the groove 31).

  As shown in FIG. 2B, the cross section perpendicular to the extending direction (B direction) of the groove 31 is V-shaped. As shown in FIG. 1B, both end portions of the groove 31 reach the lower inclined surfaces 13 on both sides in the B direction (left and right in FIG. 1B). A ridge 33 is formed between adjacent grooves 31. The ridge 33 has a triangular cross section and extends in the B direction. The grooves 31 and the ridges 33 are alternately arranged in the A direction. Therefore, the cross section orthogonal to the B direction of the lower surface 30 has a triangular wave shape. Moreover, the upper edge of the lower inclined surface 13 on both sides in the B direction has a triangular wave shape.

  The parallel pitch of the grooves 31 is, for example, about 10 mm to 30 mm, and preferably about 10 mm. Moreover, the depth of the groove | channel 31 is about 3 mm-20 mm, for example, Preferably it is about 5 mm.

  As shown in FIGS. 5 and 6, the two upper void holding rebars 42, 42 are fitted and locked in arbitrary two grooves 21, 21 on the upper surface 20 of each void member 3. Further, two lower void holding rebars 43 and 43 are fitted and locked in arbitrary two grooves 31 and 31 on the lower surface 30 of each void member 3. The concrete 2 has entered the remaining grooves 21 and 31 of the void member 3.

  The distance between the two upper void holding rebars 42 and 42 is preferably an integral multiple of the parallel pitch of the grooves 21. Further, the interval between the two lower void holding reinforcing bars 43, 43 is preferably an integral multiple of the parallel pitch of the grooves 31.

  When constructing the reinforcing bar assembly 4 and thus constructing the concrete slab 1, the lower void holding reinforcing bar 43 is bridged in the B direction and supported by the lower main reinforcing bar 40. Then, each void member 3 is placed on the two lower void holding reinforcing bars 43, 43. By doing so, the two lower void holding reinforcing bars 43 and 43 can be easily fitted into any two grooves 31 and 31 of the void member 3. It is not necessary to strictly align the specific groove 31 and the lower void holding reinforcing bar 43. Further, it is not necessary to set the interval between the two lower void holding reinforcing bars 43, 43 strictly.

  Further, the upper void holding reinforcing bars 42 are bridged in the A direction and supported by the upper power distribution bars 41. Then, the two upper void holding reinforcing bars 42 and 42 are pressed against the upper surface 20 of each void member 3. By doing so, the two upper void holding reinforcing bars 42 and 42 can be easily fitted into any two grooves 21 and 21 of the void member 3. It is not necessary to strictly position the specific groove 21 and the upper void holding reinforcing bar 42. Further, it is not necessary to strictly set the interval between the two upper void holding rebars 42, 42.

  Thereby, the void member 3 can be easily incorporated into the reinforcing bar assembly 4. The void member 3 can be stably disposed inside the reinforcing bar assembly 4 by sandwiching the void member 3 from above and below by the upper and lower void holding reinforcing bars 42 and 43. In addition, since the groove 21 on the upper surface 20 and the groove 31 on the lower surface 30 are orthogonal to each other, and the upper void holding reinforcing bar 42 and the lower void holding reinforcing bar 43 are orthogonal to each other, the void member 3 can be held more stably. . That is, the contact between the upper void holding reinforcing bar 42 and the inner surface of the groove 21 can prevent the void member 3 from being translated in the B direction (displacement) and rotated around the axis along the B direction (swing). Further, the contact between the lower void holding reinforcing bar 43 and the inner surface of the groove 31 can prevent the void member 3 from being translated (displaced) in the A direction and rotated (oscillated) around the axis along the A direction.

Subsequently, a formwork is installed around the rebar assembly 4 and concrete 2 is placed. At this time, even if the flow pressure of the concrete 2 acts on the void member 3, the void member 3 can be prevented from being displaced by holding the void member 3 from above and below by the void holding reinforcing bars 42 and 43. . Moreover, since the grooves 21 and 31 are directed in a direction orthogonal to each other and the void holding rebars 42 and 43 are directed in a direction orthogonal to each other, it is possible to reliably prevent displacement and swinging of the void member 3. be able to.
Even if the void member 3 is displaced in the B direction, the upper void retaining bar 42 can be locked in the adjacent groove 21. Further, even if the void member 3 is displaced in the A direction, the lower void holding reinforcing bar 43 can be locked in the adjacent groove 31. Therefore, it is possible to prevent the void member 3 from being greatly displaced.

  In this way, the reinforcing bar assembly 4 and the void member 3 are embedded in the concrete 2 to produce the concrete slab 1. By embedding the void member 3, it is possible to reduce the amount of the concrete 2 to be placed.

Next, another embodiment of the present invention will be described. In the following embodiments, the same reference numerals are attached to the drawings for the same configurations as those described above, and the description is simplified.
FIG. 7 shows a void member 3A according to the second embodiment of the present invention. In the void member 3 </ b> A of this embodiment, a wide single groove 22 is formed on the upper surface 20, and a wide single groove 32 is formed on the lower surface 30.

  The groove 22 of the upper surface 20 extends in the A direction with the width direction facing the B direction, and is provided over almost the entire surface of the upper surface 20. Therefore, the arrangement region of the groove 22 extends over the center and both sides of the upper surface 20 in the B direction (the direction along the width of the groove 22). The groove 22 has a pair of inclined surfaces 22a, 22a and has a V-shaped cross section. The inclined surfaces 22a and 22a are arranged on both sides of the upper surface 20 in the B direction, and are inclined so as to be recessed downward as they approach each other, and intersect at the center of the upper surface 20 in the B direction. An intersecting portion 22c between the slopes 22a and 22a extends linearly in the A direction. Further, the outer end portion in the B direction of each inclined surface 22a (the end portion opposite to the intersecting portion 22c) reaches the end portion in the B direction of the upper surface 20, and both end portions in the A direction of each inclined surface 22a are A It reaches the inclined surfaces 12 on both sides of the direction. Accordingly, almost the entire upper surface 20 is occupied by the pair of inclined surfaces 22 a and 22 a of the groove 22.

Further, the groove 32 of the lower surface 30 extends in the B direction with the width direction facing the A direction, and is provided over almost the entire surface of the lower surface 30. Therefore, the arrangement region of the groove 32 extends over the center and both sides of the lower surface 30 in the A direction (the direction along the width of the groove 32). The groove 32 has a pair of slopes 32a and 32a and has a V-shaped cross section. The inclined surfaces 32a and 32a are arranged on both sides of the lower surface 30 in the A direction, and are inclined so as to be recessed upward as they approach each other, and intersect at the central portion of the lower surface 30 in the A direction. An intersecting portion 32c between the inclined surfaces 32a and 32a extends linearly in the B direction. Further, the outer end portion in the A direction of each inclined surface 32a (the end portion opposite to the intersecting portion 32c) reaches the end portion in the A direction of the lower surface 30, and both end portions in the B direction of each inclined surface 32a are B It reaches the inclined surfaces 13 on both sides of the direction. Therefore, almost the entire area of the lower surface 30 is occupied by the pair of inclined surfaces 32 a and 32 a of the groove 32.
As in the first embodiment, the extending direction of the upper groove 22 and the extending direction of the lower groove 32 are orthogonal to each other.

  Two upper void holding rebars 42 and 42 are accommodated in the groove 22. The spanning direction of these upper void holding rebars 42 is parallel to the extending direction (A direction) of the groove 22. One upper void holding reinforcing bar 42 hits one slope 22a, and the other upper void holding reinforcing bar 42 hits the other slope 22a.

  Further, two lower void holding rebars 43, 43 are accommodated in the groove 32. The spanning direction of these lower void holding reinforcing bars 43 is parallel to the extending direction (B direction) of the grooves 32. One lower void holding reinforcing bar 43 hits one inclined surface 32a, and the other lower void holding reinforcing bar 43 hits the other inclined surface 32a.

  In the second embodiment, since the groove 22 is wide, the upper void holding rebars 42, 42 can be easily arranged in the groove 22 by addressing the void member 3 </ b> A to the two upper void holding rebars 42, 42 from below. Can be accommodated. Further, since the groove 22 is V-shaped, the upper void holding rebars 42 and 42 are surely brought into contact with the corresponding inclined surface 22a regardless of the distance between the two upper void holding rebars 42 and 42. it can. And the position shift to the B direction of 3 A of void members can be prevented by contact | abutting with these upper side void holding | maintenance reinforcing bars 42 and 42 and slope 22a, 22a.

Similarly, since the groove 32 is wide, the lower void holding rebars 43, 43 can be easily accommodated in the groove 32 by placing the void member 3A on the two lower void holding rebars 43, 43. In addition, since the groove 32 is V-shaped, the lower void holding rebars 43 and 43 are securely attached to the corresponding slope 32a regardless of the distance between the two lower void holding rebars 43 and 43. Can contact. And the position shift of the void member 3A in the A direction can be prevented by the contact between the lower void holding reinforcing bars 43, 43 and the inclined surfaces 32a, 32a.
Furthermore, the swinging direction of the void member 3A can be prevented by the crossing directions of the upper and lower void holding rebars 42, 43 being orthogonal to each other.
Thereby, the reinforcement work of the void holding rebars 42 and 43 and the installation work of the void member 3A can be facilitated, and the retention of the void member 3A can be secured.

  8 and 9 show a third embodiment of the present invention. As shown in FIG. 8, in the third embodiment, the void member 3 is oriented in a direction rotated 90 ° around the vertical line with respect to the first embodiment. Accordingly, the grooves 21 on the upper surface 20 extend in the B direction and are aligned in the A direction. The grooves 31 on the lower surface 30 extend in the A direction and are arranged in the B direction.

The upper void holding rebar 42 crosses the grooves 21, 21,... As shown in FIG. 9, the upper void holding reinforcing bars 42 are pressed against the ridges 23, 23... At a plurality of locations in the longitudinal direction. Further, a rib 42 b is formed on the outer periphery of the upper void holding reinforcing bar 42, and this rib 42 b enters the groove 21, is caught on the edge of the groove 21, or is pressed against the ridge 23. .
The rib 42b may be spiral (the same applies to the lower void holding reinforcing bar 43).

  Further, as shown in FIG. 8, the lower void holding rebar 43 crosses the grooves 31, 31... Although detailed illustration is omitted, the lower void holding reinforcing bars 43 are pressed against the ridges 33, 33... At a plurality of locations in the longitudinal direction. In addition, the outer peripheral rib of the lower void holding reinforcing bar 43 enters the groove 31, is caught on the edge of the groove 31, or is pressed against the ridge 33.

  In 3rd Embodiment, since the parallel direction of the groove | channel 21 is along the spanning direction of the upper void holding reinforcement 42, even if it does not align the void member 3 and the upper void holding reinforcement 42 exactly | strictly, a void member 3 can be made to intersect with the protrusions 23, 23..., And the rib 42 b can be locked to the groove 21. In addition, since the parallel direction of the grooves 31 is along the spanning direction of the lower void holding rebar 43, the void member 3 can be lowered even if the void member 3 and the lower void holding rebar 43 are not strictly aligned. The plurality of portions of the lower void holding reinforcing bar 43 and the ridges 33, 33... Intersect with each other and the ribs of the lower void holding reinforcing bar 43 can be locked in the groove 31 by simply placing the ribs on the side void holding reinforcing bars 43. it can. Thereby, the installation work of the void member 3 can be simplified, and the retainability can be secured.

FIG. 10 shows a fourth embodiment of the present invention.
Three grooves 24 are formed on the upper surface 20 of the void member 3B of the fourth embodiment. The number of grooves 24 may be four or more. These grooves 24 extend in the B direction and are arranged in the A direction. Therefore, the arrangement region of the groove 24 extends over the center portion and both side portions in the A direction (the direction along the width of the groove 24) on the upper surface 20. The cross section perpendicular to the extending direction (B direction) of the groove 24 is substantially rectangular.

  The upper void holding rebar 42 is pressed against the upper surface 20 while crossing the three grooves 24, 24, 24 by being bridged in the A direction. Although not shown in detail, the outer peripheral rib 42 b of the upper void holding reinforcing bar 42 is strongly pressed against the upper surface 20, enters the groove 24, or is caught on the edge of the groove 24.

  Further, three grooves 34 are formed in the lower surface 30 of the void member 3B. The number of grooves 34 may be four or more. These grooves 34 extend in the A direction and are arranged in the B direction. Therefore, the arrangement region of the groove 34 extends over the center portion and both side portions in the B direction (the direction along the width of the groove 34) on the lower surface 30. The cross section orthogonal to the extending direction of the groove 34 is a quadrangle.

  The lower void holding reinforcing bar 43 is crossed with the three grooves 34, 34, 34 by being bridged in the B direction, and is pressed against the lower surface 30. Although not shown in detail, the outer peripheral ribs of the lower void holding rebar 43 are strongly pressed against the lower surface 30, entered into the groove 34, or caught on the edge of the groove 34.

  In the fourth embodiment, even if the void member 3B and the void holding rebar 42 are not strictly aligned, the upper void holding rebar 42 is 3 by simply passing the upper surface of the void member 3B to the void holding rebar 42. It can be made to intersect the groove 24 at a location. Further, the lower void holding reinforcing bar 43 can intersect with the groove 34 at three places only by placing the void member 3B on the lower void holding reinforcing bar 43. Thereby, the installation work of the void member 3B can be simplified, and the retainability can be secured.

11 and 12 show a fifth embodiment of the present invention.
As shown in FIG. 11A and FIG. 12A, in the void member 3C of the fifth embodiment, three or more grooves 25 and 26 are formed over almost the entire upper surface 20 (one surface). . These grooves 25 and 26 extend in the A direction (direction along the main reinforcement 40 (see FIG. 4)) and are arranged in the B direction (direction along the distribution bar 41 (see FIG. 4)). The cross section orthogonal to the A direction of the upper surface 20 has a substantially wave shape.

The width, pitch, cross-sectional shape and the like of the grooves 25 and 26 are irregular.
Specifically, as shown in FIG. 11A, two main grooves 25, 25 apart from each other among the grooves on the upper surface 20 are wider than the remaining preliminary grooves 26, 26. That is, the width W ₂₅ of the main groove 25 is larger than the width W ₂₆ of the preliminary groove 26 (W ₂₅ > W ₂₆ ). The two main grooves 25, 25 are arranged on both side portions 20d, 20d of the upper surface 20 in the B direction (groove width direction). As shown in FIG. 12A, the cross section of each main groove 25 is trapezoidal. On the other hand, the cross section of each preliminary groove 26 is V-shaped. The preliminary grooves 26 are arranged outside the main groove 25 on the upper surface 20 in the B direction and between the two main grooves 25, 25.

Further, as shown in FIGS. 11 (a) and 12 (a), the distance between adjacent grooves 25, 26 and 26, 26 on both sides 20d of the upper surface 20 is narrow, and the center between both sides 20d, 20d is narrow. The interval between the adjacent preliminary grooves 26 and 26 in the portion 20c is wide. Preferably, adjacent grooves 25, 26 and 26, 26 on both side portions 20 d are closely attached to each other, and a ridge 23 (a sharp point) having a triangular cross section is formed between these grooves 25, 26 and 26, 26. Part) is formed. On the other hand, a ridge 27 having a trapezoidal cross section is formed between adjacent grooves 26 and 26 in the central portion 20c. The upper end surface of the ridge 27 is a flat portion 27a. The width W ₂₇ of the flat portion 27a is smaller than the width W ₂₆ of the preliminary groove 26 (W ₂₇ <W ₂₆ ). However, the invention is not limited thereto _and may be a _{W 27} ≧ _{W 26.}

As shown in FIGS. 11B and 12B, two wide grooves 35, 35 having a semicircular cross section are formed in parallel on the lower surface 30 (the other surface) of the void member 3C. The wide groove 35 extends in the B direction (direction along the power distribution line 41 (see FIG. 4)). Therefore, the extending direction of the wide groove 35 is orthogonal to the extending direction of the grooves 25 and 26 on the upper surface 20. The two wide grooves 35 and 35 are disposed away from each other on both sides of the lower surface 30 in the A direction (up and down in FIG. 11B). The width W ₃₅ of the wide groove 35 is equal to or larger than the width W ₂₅ of the main groove 25 (W ₃₅ ≧ W ₂₅ ), and is sufficiently larger than the diameter D _{43 of} the lower void holding reinforcing bar 43. Here, the diameter D ₄₃ of the lower void holding rebar 43 refers to the diameter of the real part excluding the ribs and fuzz of the lower void holding rebar 43. Preferably, the width W ₃₅ of the wide groove 35 is about 1.5 to 5 times the diameter D ₄₃ of the lower void holding reinforcing bar 43. Specifically, the width _{W 35} of the wide groove 35 _is approximately W 35 = 10 mm to 30 mm, preferably _W 35 = 20 mm approximately. The depth _{H 35} of the wide groove 35 is, for example, _H 35 = 3 mm to 10 mm approximately, preferably _H 35 = 6 mm approximately.
The cross-sectional shape of the wide groove 35 is not limited to a semicircular shape, and may be a quadrangle or a V shape. Width _{W 35} of the wide groove 35 may be not more than the width _{W 25} of the main groove _{25 (W 35 ≦ W 25)} .

  As shown in FIGS. 11B and 12B, the lower void holding reinforcing bars 43 are fitted in the wide grooves 35. The lower void retaining reinforcing bar 43 is in a free state. That is, the lower void holding reinforcing bar 43 is merely placed on the main bar 40 (see FIG. 6) and is not fixed to the main bar 40 by binding or the like.

The void member 3C of the fifth embodiment is particularly suitable when the lower void holding reinforcing bar 43 is in a free state. That is, if the lower surface 30 has a number of grooves like the upper surface 20 and has a wave shape, it is difficult for the operator to know which groove the lower void holding rebar 43 should be fitted into. In particular, since the lower surface 30 is difficult to see, it is not easy to select a groove to be fitted. Moreover, the position of the lower void holding reinforcing bar 43 in the free state is inaccurate and does not serve as an index, and because it is unstable, if the groove is narrow, it is easy to come off even if it is once fitted.
On the other hand, by using only two wide grooves 35, the grooves into which the lower void holding reinforcing bars 43 should be fitted can be clarified. Further, by sufficiently larger than the diameter D ₄₃ of the lower void holding rebar 43 width W ₃₅ of the wide groove 35 can easily fit the lower void held rebar 43 in the wide groove 35, and the lower void holding rebar 43 and the void member 3C can be tolerated to some extent, and the free void lower reinforcing bar 43 can be stably fitted. Further, by making the cross-sectional shape of the groove 35 semicircular, the lower void holding rebar 43 can be naturally guided to the center portion in the width direction of the wide groove 35. Furthermore, by fitting the lower void holding reinforcing bars 43 into the two wide grooves 35, the distance between the two lower void holding reinforcing bars 43, 43 can be regulated to a desired size.

As shown in FIGS. 11A and 12A, the upper void holding reinforcing bar 42 is fitted in the main groove 25 in principle among the grooves 25 and 26 of the upper surface 20. Since the main groove 25 is wider than the spare groove 26, it is easy to determine in which groove the upper void holding rebar 42 should be fitted.
When the upper void holding reinforcing bar 42 and the main groove 25 are displaced, the upper void holding reinforcing bar 42 can be fitted into the preliminary groove 26. Usually, since the deviation is small, the upper void holding reinforcing bar 42 can be securely fitted in the preliminary groove 26 near the main groove 25 by narrowing the interval between the grooves 25 and 26 on both side portions 20d.
On the other hand, by providing the flat portion 27a in the central portion 20c far from the main groove 25, it is possible to prevent or suppress the lack of a part of the void member 3C.

In addition, although the upper void holding | maintenance reinforcement 42 is bound to the power distribution bar 41 (refer FIG. 4), it is good also as a free state, without being bound.
The void member 3C may be used upside down. The wide groove 35 may be formed on the upper surface 20, and the grooves 25 and 26 may be formed on the lower surface 30. Then, the upper void holding reinforcing bar 42 may be fitted into the wide groove 35 and the lower void holding reinforcing bar 43 may be fitted into the main groove 25 (or the spare groove 26).

FIG. 13 shows a sixth embodiment of the present invention.
The void member 3D of the sixth embodiment relates to a modification of the void member 3C of the fifth embodiment. On the lower surface 30 of the void member 3D, four wide grooves 35, 35, 36, and 36 having a semicircular cross section are formed. These wide grooves 35 and 36 are arranged in a well shape. That is, the two wide grooves 35 and 35 extend in the A direction and are spaced apart from each other in the B direction. The remaining two wide grooves 36 and 36 extend in the B direction and are spaced apart from each other in the A direction. The wide groove 35 and the wide groove 36 intersect at a right angle.
The extending direction of the wide groove 35 is orthogonal to the extending direction of the grooves 25 and 26 on the upper surface 20.
The extending direction of the wide groove 36 is parallel to the extending direction of the grooves 25 and 26 on the upper surface 20.
The width W ₃₆ of the wide groove ₃₆ is substantially equal to the width W ₃₅ of the wide groove 35 (W ₃₅ ≈W ₃₆ ). The widths W ₃₅ and W _{36 of the} wide grooves ₃₅ and ₃₆ may be different from each other.

According to the void member 3D, as shown in FIG. 13, when the lower void holding reinforcing bar 43 is orthogonal to the upper void holding reinforcing bar 42, the lower void holding reinforcing bar 43 is fitted into the wide groove 35, and The upper void retaining bar 42 can be fitted into the main groove 25 (or the spare groove 26). Alternatively, the void member 3D is rotated by 90 ° from the posture shown in FIG. 13 with respect to the void holding reinforcing bars 42 and 43, the lower void holding reinforcing bar 43 is fitted into the wide groove 36, and the grooves 25 and 26 on the upper surface 20 are set to the upper voids. It can also be arranged perpendicular to the holding rebar 42 (see the third embodiment (FIG. 8)).
Although illustration is omitted, when the upper and lower void holding reinforcing bars 42 and 43 are parallel, the lower void holding reinforcing bar 43 is fitted into the wide groove 36 and the upper void holding reinforcing bar 42 is inserted into the main groove 25 (or the spare groove 26). Can be fitted. Alternatively, the lower void holding rebar 43 is fitted in the wide groove 35, and the grooves 25 and 26 on the upper surface 20 are arranged perpendicular to the upper void holding rebar 42 (see the third embodiment (FIG. 8)). it can.
The void member 3D may be used upside down. Wide grooves 35 and 36 may be formed on the upper surface 20, and grooves 25 and 26 may be formed on the lower surface 30. Then, the upper void holding reinforcing bar 42 may be fitted into the wide groove 35 and the lower void holding reinforcing bar 43 may be fitted into the main groove 25 (or the spare groove 26). Alternatively, the upper void holding reinforcing bar 42 may be fitted into the wide groove 36 and the lower void holding reinforcing bar 43 may intersect with the grooves 25 and 26.

The present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the horizontal cross sections of the void members 3, 3 </ b> A, 3 </ b> B, 3 </ b> C, and 3 </ b> D are not limited to squares, but may be other squares such as rectangles.
Of the upper surface 20 and the lower surface 30 of the void members 3, 3 </ b> A, 3 </ b> B, a groove may be formed only on the upper surface 20, or a groove may be formed only on the lower surface 30.
The upper void holding rebar 42 may be parallel to the distribution bar 41 and the lower void holding rebar 43 may be parallel to the main bar 40.
The spanning direction of the upper void retaining rebar 42 and the spanning direction of the lower void retaining rebar 43 may be parallel to each other.
The extending direction of the upper grooves 21, 22, 24, 25, 26 of the void members 3, 3A, 3B, 3C and the extending direction of the lower grooves 31, 32, 34, 35 may be parallel to each other. .
The cross-sectional shape of the grooves 21, 22, 24, 25, 26 is not limited to a V shape or a square shape, and may be a semicircular shape.

The number of upper void retaining bars 42 and the number of lower void retaining bars 43 applied to each of the void members 3, 3 </ b> A, 3 </ b> B, 3 </ b> C, 3 </ b> D is not limited to two, and may be one or three or more.
In the first embodiment (FIGS. 1 to 6), one upper void holding reinforcing bar 42 may be fitted into the groove 21 in the center of the upper surface 20 in the B direction, and one lower void holding reinforcing bar 43 may be placed on the lower surface. It may be fitted in the groove 31 in the center part of the 30 A direction.
In the second embodiment (FIG. 7), one upper void retaining bar 42 may be disposed at the intersection 22c of the upper surface 20, and one lower void retaining bar 43 may be disposed at the intersection 32c of the lower surface 30. May be.

A plurality of embodiments may be combined. For example, in the fourth embodiment (FIG. 10), the groove 24 and the upper void holding rebar 42 may be parallel, and the upper void holding rebar 42 may be accommodated in the groove 24. Further, the groove 34 and the lower void holding reinforcing bar 43 may be parallel, and the lower void holding reinforcing bar 43 may be accommodated in the groove 34.
In the fifth embodiment (FIGS. 11 and 12), as in the third embodiment (FIG. 8), the grooves 25 and 26 and the upper void holding rebar 42 may be orthogonal to each other, and the wide groove 35 and the lower side The void holding reinforcing bars 43 may be orthogonal to each other.
In the first embodiment (FIGS. 1 to 6) and the like, the widths and pitches of the grooves 21, 21... On the upper surface 20 and the grooves 31, 31. , 26 may be irregular.
The irregular grooves 25 and 26 on the upper surface 20 (one surface) of the void members 3C and 3D of the fifth and sixth embodiments (FIGS. 11 to 13) are the same as those of the first embodiment (FIGS. 1 to 6). Three or more regular grooves 21, 21... Or a single groove 22 in the second embodiment (FIG. 7) may be substituted.

The void holding reinforcing bars 42 or 43 may penetrate the void member 3.
The void holding rebar 42 or 43 penetrates the plurality of void members 3, 3... (3A, 3A...) (3B, 3B...) (3C, 3C...) (3D, 3D. 42 or 43 and a plurality of void members 3, 3... (3A, 3A...) (3B, 3B...) (3C, 3C...) (3D, 3D...) May be a unit.
By dividing the void members 3, 3A, 3B, 3C, 3D into two pieces, sandwiching the void holding reinforcing bars 42, 43 between the two pieces, and integrating these two pieces, the void holding reinforcing bars 42 and 43 may pass through the void members 3, 3A, 3B, 3C, and 3D.

  As a material of the void members 3, 3 </ b> A, 3 </ b> B, 3 </ b> C, 3 </ b> D, a material that can bear a part of the strength of the concrete slab 1 may be adopted. Then, since the surface area of the void members 3, 3A, 3B, 3C, 3D can be increased by the grooves 21-34 and the adhesion to the concrete 2 can be increased, the strength burden of the void members 3, 3A, 3B, 3C, 3D The power can be extracted effectively.

  The present invention can be applied to the construction of a reinforced concrete structure, for example.

1 Concrete slab (concrete structure)
2 Concrete 3, 3A, 3B, 3C, 3D Concrete void member 20 Upper surface (one surface)
20c Central part 20d Both side parts 21 Groove 22 Single groove 22a Slope 23 Projection line 24 Groove 25 Main groove 26 Preliminary groove 27a Flat part 30 Lower surface (the other surface)
31 groove 32 single groove 32a slope 33 ridge 34 groove 35, 36 wide groove 42 upper void retaining bar 43 lower void retaining bar

Claims (7)

A void member embedded in a concrete structure in a state of being held by a void holding reinforcing bar,
At least one surface of the upper surface and the lower surface is formed with three or more grooves or a single groove arranged in parallel, and the region where the grooves are arranged is the center in the direction along the width of the groove on the one surface A void member for concrete, characterized by extending over both sides and both sides.   The three or more grooves are juxtaposed over almost the entire area of the one surface, each groove is formed in a V-shaped cross section, and a ridge having a triangular cross section is formed between adjacent grooves. The void member for concrete according to claim 1, wherein:   The single groove is formed on the one surface, and the single groove has a pair of inclined surfaces that occupy almost the entire area of the one surface. 2. The void member for concrete according to claim 1, wherein the concrete void member is inclined so as to be recessed and intersects with each other at a central portion of the one surface.   The groove is formed in both the upper surface and the lower surface, and the extending direction of the groove on the upper surface and the extending direction of the groove on the lower surface are orthogonal to each other. The void member for concrete according to any one of the above.   Two parallel wide grooves or four wide grooves having a well shape are formed on the other surface of the upper surface and the lower surface, and the width of each of the wide grooves is larger than the diameter of the void holding rebar. The void member for concrete according to any one of claims 1 to 3, wherein the void member is large.   The three or more grooves are juxtaposed over almost the entire area of the one surface, and two of the three or more grooves that are separated from each other are wider than the remaining preliminary grooves. The void member for concrete according to claim 1 or 5 characterized by things.   An interval between adjacent grooves on the one surface is narrow at both side portions including the main grooves, is wide at a central portion between the two side portions, and a flat portion is formed between adjacent grooves at the central portion. The void member for concrete according to claim 6, wherein the void member is used for concrete.

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