JP5351576B2 - Spacer for floor slab - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently construct a floor slab, wherein the floor slab includes a concrete body and the block having a specific gravity smaller than that of a concrete and arranged inside the body, by reducing labor needed to prevent floating of the block when the body is formed by placing concrete. <P>SOLUTION: This spacer is used for the floor slab which includes the body made of the concrete, the block arranged in the body and having the specific gravity smaller than that of the concrete, and at least one reinforcement arranged inside the body at an interval above the block and elongated in the horizontal direction. The spacer for maintaining the space between the block and the reinforcement comprises: a body which is composed of a pair of opposed sides provided at an interval and a top portion positioned between the sides, and which can receive the reinforcement; and at least one protrusion which is provided on each of the sides of the body and protruding downward from the side, and which can pierce through the block. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a spacer used for a floor slab.

  Conventionally, some floor slabs of a building include a plate-like main body made of concrete and a block disposed inside the main body and having a specific gravity smaller than that of concrete (see Patent Document 1). By arranging the block inside the main body, the weight of the floor slab can be reduced, and the amount of concrete used in the floor slab can be reduced.

  The floor slab has a through hole provided in the block and extending vertically through the block, a rod having the lower end fixed to the bottom of the main body, and attached to the upper end of the rod. And a horizontal plate in contact with the block.

  When constructing the floor slab, first, the lower end of the rod is fixed to a plate-shaped formwork. Next, the block is disposed above the mold so that the through hole is penetrated by the rod. Thereafter, the plate is attached to the upper end portion of the rod so that the plate contacts the block. Thereafter, concrete is cast on the mold to a height higher than the height of the top of the block to form the main body.

  By the way, when placing the concrete, buoyancy is applied to the block, and the block tends to rise. At this time, the plate prevents the block from moving upward. As a result, the block can be prevented from being lifted, and the block can be accurately placed inside the main body.

JP 2004-263516 A

  However, it takes much time to provide the through hole in the block, to fix the lower end of the rod to the mold, and to attach the plate to the upper end of the rod. For this reason, the floor slab cannot be efficiently constructed. Moreover, since the said through-hole is provided in the said block, the volume of the said block is small compared with the case where the said through-hole is not provided in the said block. For this reason, an increase in the weight of the floor slab and the amount of concrete used is caused.

  The block may receive a horizontal force from the concrete when the concrete is placed. The plate only touches the block and cannot prevent the block from moving in the horizontal direction. For this reason, there is a possibility that the block is moved by receiving the horizontal force, and there is a possibility that the block cannot be accurately arranged inside the main body.

  An object of the present invention is to provide a floor slab including a main body made of concrete and a block having a specific gravity smaller than that of the concrete disposed inside the main body, and when the main body is formed by placing concrete. It is to make it possible to construct the floor slab efficiently by reducing the effort required to prevent the block from floating. Another object of the present invention is to prevent an increase in the weight of the floor slab and the amount of concrete used by preventing the block from lifting without providing a through hole in the block. is there. Furthermore, another object of the present invention is to prevent the block from receiving a horizontal force from the concrete and to move, so that the block can be arranged inside the main body with higher accuracy.

  The present invention includes the floor slab including at least one reinforcing bar spaced upward from the block, wherein the floor slab maintains at least one spacing between the block and the reinforcing bar. A spacer is used, the spacer comprising a pair of spaced apart opposing sides and a top located between the sides, the body part capable of receiving the rebar, and each side of the body part And at least one protrusion that protrudes downward from the side portion and can pierce the block, and prevents the block from being lifted by the spacer. Thereby, the main part is pressed against the reinforcing bar from above the reinforcing bar so that the spacer can be prevented from being lifted by attaching the spacer to the reinforcing bar, and the labor required to prevent the lifting of the block is reduced. The floor slab can be efficiently constructed. In addition, the volume of the block is not reduced by the through hole as in the conventional case where the block is provided with a through hole, and the weight of the floor slab and the amount of concrete used are not increased. To do. In addition, the main body portion of the spacer receives the reinforcing bar, and the protrusions pierce the block, thereby preventing the block from moving due to the horizontal force and allowing the block to move inside the main body with higher accuracy. So that it can be placed in

  The spacer according to the present invention is a plate-shaped main body made of concrete, a block disposed inside the main body, having a specific gravity smaller than that of concrete, and disposed inside the main body with an interval upward from the block, Used for floor slabs including at least one rebar extending in the horizontal direction, to maintain the spacing between the block and the rebar. The spacer is provided on each side of the main body part, the main body part having a pair of opposed side parts and a top part between the side parts, the main body part being capable of receiving the reinforcing bar, And at least one protrusion projecting downward from the side portion and capable of piercing the block.

  When constructing the floor slab, first, the block is placed above the formwork. Next, the reinforcing bars are arranged at intervals from the block, and the spacers are attached to the reinforcing bars. At this time, the main body portion of the spacer is pressed against the reinforcing bar from above the reinforcing bar. Thereby, the said main-body part receives the said reinforcing bar, and the said protrusion pierces the said block. After the spacer is attached to the reinforcing bar, concrete is placed on the formwork to form the main body.

  When placing the concrete, buoyancy is applied to the block, and the block tends to rise. At this time, the spacer prevents the block from moving upward by maintaining a distance between the block and the reinforcing bar. This prevents the block from being lifted.

  In order to prevent the block from lifting up, the spacer may be attached to the reinforcing bar by pressing the main body portion of the spacer against the reinforcing bar from above the reinforcing bar, which is necessary to prevent the block from lifting up. There is relatively little effort. For this reason, the rod having a lower end fixed to the formwork through the through hole provided in the block, and a plate attached to the upper end of the rod and preventing the block from moving upwards Providing the through hole in the block, fixing the lower end of the rod to the mold, and attaching the plate to the upper end of the rod as in the conventional case of preventing the block from lifting up. This is not necessary, and much effort is not required to prevent the block from being lifted. Thereby, the said floor slab can be constructed efficiently. In addition, since the through hole provided in the block is not required as in the conventional case, the volume of the block is not reduced by the through hole, and the weight of the floor slab and the amount of concrete used are reduced. There will be no increase.

  The block may receive a horizontal force in a direction perpendicular to the reinforcing bar from the concrete when the concrete is placed. Since the main body portion of the spacer receives the reinforcing bar and the protrusion pierces the block, when the block receives the horizontal force, the block receives a reaction force from the reinforcing bar through the spacer. The movement of the block is prevented. Thereby, it can prevent that the said block receives the said horizontal force, and moves with respect to the said reinforcing bar, and can arrange | position the said block inside the said body more accurately.

  Each side portion of the main body portion may have a thickness that gradually increases downward from the top portion. Each side portion of the main body portion has a lower end surface that contacts the block when the main body portion receives the reinforcing bar.

  By gradually increasing the thickness of each side portion of the main body portion downward from the top portion, the area of the lower end surface of each side portion of the main body portion can be increased, and each side portion of the main body portion can be increased. The contact area between the block and the block can be increased. Thereby, it can prevent that the said block receives the force from this concrete at the time of placement of the concrete, and rotates with respect to the said spacer.

  The block may have an arcuate top surface protruding downward in the longitudinal section. In this case, the main body portion of the spacer has a circular shape in which the lower end surface of one side portion has a center in the vicinity of the top portion or above the top portion when viewed in a plane perpendicular to the width direction of the side portion. The lower end surface of the other side part forms another part of the circular shape, and the lower end surface of each side part of the block of the block when the main body part receives the reinforcing bar. Touch the top. Thereby, when the block receives a force from the concrete when the concrete is placed, the block can easily receive a horizontal reaction force from the spacer. For this reason, it can prevent that the said block shifts | deviates to a horizontal direction with respect to the said spacer at the time of placement of the said concrete.

  Each side portion of the main body portion is provided with an elastic arm portion extending from the side portion toward the other side portion. The arm portion is elastically deformed in contact with the reinforcing bar when the main body portion receives the reinforcing bar, and the elastic deformation is released when the main body portion receives the reinforcing bar, and the main body portion becomes the reinforcing bar. To prevent it from coming off.

  When the spacer is attached to the reinforcing bar, the arm part comes into contact with the reinforcing bar and is elastically deformed while the main body part is receiving the reinforcing bar. When the main body portion has received the reinforcing bar, the arm portion is released from elastic deformation and restored to the state before elastic deformation. The restored arm portion prevents the main body portion from coming off the reinforcing bar.

  The distal end portion of the arm portion has a lower bending strength than the boundary portion between the arm portion and the side portion of the main body portion, and the distal end portion of the arm portion is elastically deformed when the arm portion contacts the reinforcing bar. The portion is bent and deformed, and the boundary portion is not bent and deformed. For this reason, when the said arm part contacts the said reinforcing bar and elastically deforms, bending deformation does not reach to each side part of the said main-body part. Thereby, when the main body portion receives the reinforcing bar, the interval between the side portions of the main body portion is not changed, and the protrusion of the protrusion into the block is not prevented, and the reinforcing bar of the spacer is not disturbed. Can be attached smoothly.

  The reinforcing bar has a plurality of nodes provided on the outer surface of the reinforcing bar at intervals in the axial direction of the reinforcing bar, each extending in the circumferential direction of the reinforcing bar. A lower surface that presents an upwardly projecting arc when viewed in a plane perpendicular to the width direction, the lower surface being in contact with the outer surface of the reinforcing bar when the main body portion receives the reinforcing bar, and provided on the lower surface, At least one groove extending in a direction, wherein the body portion engages one of the nodes when receiving the reinforcing bar.

  By engaging the groove with one of the nodes, the block is prevented from receiving a horizontal force in the axial direction of the reinforcing bar from the concrete and moving with respect to the reinforcing bar when the concrete is placed. Can do. Thereby, the said block can be arrange | positioned inside the said main body more accurately.

  The spacer has a plurality of second pierced blocks that protrude downward from the lower end surface of each side portion of the main body portion and have a length shorter than the length of the first protrusion. A protrusion may be provided. Each second protrusion pierces the block, so that when the block receives a horizontal force from the concrete in a direction perpendicular to the reinforcing bar, a frictional resistance generated between each side portion of the main body portion and the block is generated. Can be increased. Thereby, it can prevent more reliably that the said block receives the said horizontal force, and moves with respect to the said reinforcing bar.

  According to the present invention, a main body made of concrete, a block disposed in the main body and having a specific gravity smaller than that of the concrete, and disposed in the main body at an interval upward from the block, extend in the horizontal direction. A spacer for use in a floor slab including at least one reinforcing bar and maintaining a spacing between the block and the reinforcing bar is between a pair of spaced apart side portions and the side portions And a main body portion that can receive the reinforcing bar, and at least one protrusion that protrudes downward from the side portion and can pierce the block. Accordingly, the spacer can be attached to the reinforcing bar by pressing the main body portion from above the reinforcing bar, and the spacer attached to the reinforcing bar forms concrete by placing concrete. When doing so, the space between the block and the reinforcing bar is maintained to prevent the block from being lifted. For this reason, in order to prevent the block from being lifted, the spacer may be attached to the reinforcing bar by pressing the main body portion against the reinforcing bar from above the reinforcing bar, which is necessary for preventing the block from lifting. There is relatively little effort.

  Thus, the rod having a lower end fixed to the formwork through the through hole provided in the block, and a plate attached to the upper end of the rod and preventing the block from moving upwards Providing the through hole in the block, fixing the lower end of the rod to the mold, and attaching the plate to the upper end of the rod as in the conventional case of preventing the block from lifting up. This is not necessary, and much effort is not required to prevent the block from being lifted. For this reason, the floor slab can be efficiently constructed. Further, since the through hole provided in the block is not required unlike the conventional case, the volume of the block is not reduced by the through hole. For this reason, the increase in the weight of the floor slab and the amount of concrete used is not caused.

  Further, since the main body portion receives the reinforcing bar and the protrusion pierces the block, when the block receives a horizontal force in a direction perpendicular to the reinforcing bar from the concrete when the concrete is placed, the block is The block is prevented from moving by receiving a reaction force from the reinforcing bar through the spacer. Thereby, it can prevent that the said block receives the said horizontal force, and moves with respect to the said reinforcing bar, and can arrange | position the said block inside the said body more accurately.

The longitudinal cross-sectional view of a floor slab . The front view of an upper spacer . The perspective view of an upper spacer . The front view of a lower spacer. The perspective view of a lower spacer. The front view of the block before attaching an upper spacer to a reinforcing bar. The front view of the block after attaching an upper spacer to a reinforcing bar. The front view of the upper spacer when the main-body part of the upper spacer has received the reinforcing bar. The front view of the upper spacer when the main-body part of an upper spacer receives a reinforcing bar. The longitudinal cross-sectional view of the floor slab which concerns on 1st Example of this invention. The front view of the upper spacer which concerns on 1st Example of this invention. The perspective view of the upper spacer which concerns on 1st Example of this invention. The longitudinal cross-sectional view of the floor slab which concerns on 2nd Example of this invention. The front view of the upper spacer which concerns on 2nd Example of this invention. The perspective view of the upper spacer which concerns on 2nd Example of this invention. FIG. 14 is a longitudinal sectional view of the upper spacer taken along line 16 in FIG. 13.

  As shown in FIG. 1, a building floor slab 10 is constructed. The floor slab 10 includes a plate-like main body 12 made of concrete, a block 14 disposed inside the main body, and an interior of the main body 12 spaced upward from the block, and at least one extending horizontally. It includes a rebar 16 of the book and at least one spacer (upper spacer) 18 that is disposed inside the body 12 and maintains the spacing between the block 14 and the rebar 16.

  The block 14 is made of a material having a specific gravity smaller than that of concrete, such as polystyrene foam, plastic, wood, and the like. By arranging the block 14 inside the main body 12, the weight of the floor slab 10 can be reduced, and the amount of concrete used in the floor slab can be reduced. The block 14 is a hexahedron and has a substantially rectangular planar shape. Each of the top surface 20 and the bottom surface 22 of the block 14 is flat.

  The block 14 has a bottom 24 spaced upwardly from the lower surface 26 of the body 12 and the floor slab 10 has at least one that maintains a spacing between the bottom 24 of the block 14 and the lower surface 26 of the body 12. A lower spacer 28 is included. In the example shown in FIG. 1, the floor slab 10 includes four lower spacers 28 disposed at the corners of the block 14. The number of the lower spacers 28 may be one instead of the example shown in FIG.

  The main body 12 has a substantially rectangular planar shape, and the reinforcing bars 16 are parallel to one side of the rectangle. In the example shown in FIG. 1, the reinforcing bar 16 extends in the vertical direction of the rectangle (the depth direction in FIG. 1). The distance between the block 14 and the reinforcing bar 16 corresponds to the concrete covering thickness required around the reinforcing bar. In the example shown in FIG. 1, the diameter of the reinforcing bar 16 is about 12 mm, and the distance between the block 14 and the reinforcing bar 16 is about 20 mm.

  The floor slab 10 includes lattice-shaped lower end bars 30 and 32 disposed inside the main body 12, and lattice-shaped upper end bars 16 and 34 disposed inside the main body 12 with an interval upward from the lower end lines. 36. The block 14 is spaced from the lower stripes 30, 32, and the bottom 24 of the block 14 is located at approximately the same height as the lower stripes 30, 32.

  Each of the lattice-shaped lower end bars 30 and 32 extends in the longitudinal direction, and each of the first lower end bars 30 is spaced apart from each other in the lateral direction of the square (left and right direction in FIG. 1). A plurality of second lower end bars 32 that are orthogonal to the lower end bars and spaced in the longitudinal direction. The lattice-shaped upper end bars 16, 34, and 36 are a reinforcing bar (first upper end bar) 16 and a plurality of second upper end bars 34 that are parallel to the first upper end bar and spaced apart in the lateral direction. And a plurality of third upper end bars 36 that are perpendicular to the first upper end line 16 and the second upper end line 34 and that are spaced apart in the longitudinal direction.

  As shown in FIGS. 2 and 3, the upper spacer 18 used in the floor slab 10 includes a body portion 42 comprising a pair of opposed side portions 38 and a top portion 40 between the sides, An elastic arm portion 44 provided on each side portion 38 of the main body portion and extending from the side portion toward the other side portion 38, and provided on each side portion 38 of the main body portion 42. And at least one protrusion 46 protruding downward.

  The body portion 42 can receive the first upper end muscle 16. Each side portion 38 of the main body portion 42 has a height dimension substantially equal to the distance between the block 14 and the reinforcing bar 16, that is, the concrete covering thickness required around the first upper end reinforcing bar 16. Each side portion 38 of the main body portion 42 has a substantially constant thickness and has a lower end surface 48. The lower end surface 48 contacts the block 14 when the main body portion 42 receives the first upper end stripe 16.

  The top portion 40 of the body portion 42 has a thickness dimension that is smaller than the height dimension of the side portion 38. In the example shown in FIG. 2, the thickness of the top 40 is about 1/3 of the height of the side 38. The top portion 40 of the main body portion 42 has a lower surface 50 that presents an upwardly projecting arc when viewed in a plane perpendicular to the width direction of the top portion (the depth direction in FIG. 2). The lower surface 50 contacts the first upper end line 16 when the main body portion 42 receives the first upper end line 16.

  The arm portion 44 is elastically deformed in contact with the first upper end muscle when the main body portion 42 receives the first upper end muscle 16, and is elastically deformed when the main body portion 42 receives the first upper end muscle 16. The main body portion 42 is released from the first upper end muscle 16 and is released. The arm portion 44 is inclined with respect to the side portion 38 of the main body portion 42, and the tip portion 52 of the arm portion 44 is higher than the height of the boundary portion 54 between the arm portion 44 and the side portion 38 of the main body portion 42. Located in.

  The distal end portion 52 of the arm portion 44 has a lower bending strength than the boundary portion 54 between the arm portion 44 and the side portion 38 of the main body portion 42. When the arm portion 44 comes into contact with the first upper end muscle 16 and elastically deforms, the distal end portion 52 of the arm portion 44 is bent and deformed, and the boundary portion 54 between the arm portion 44 and the side portion 38 of the main body portion 42 is not bent and deformed. .

  The protrusion 46 is provided on the lower end surface 48 of each side portion 38 of the main body portion 42 and can pierce the block 14. The protrusion 46 is tapered, and its thickness gradually decreases downward from the side portion 38 of the main body portion 42. In the example shown in FIGS. 2 and 3, each side portion 38 of the main body portion 42 is provided with a plurality of protrusions 46 spaced in the width direction of the side portion (the depth direction in FIG. 2). Instead of the example shown in FIGS. 2 and 3 in which a plurality of protrusions 46 are provided on each side portion 38 of the main body portion 42, one protrusion 46 may be provided on each side portion 38 of the main body portion 42.

  As shown in FIG. 1, in the floor slab 10, the main body portion 42 of the upper spacer 18 receives the first upper end reinforcement 16, and the lower end surface 48 of each side portion 38 of the main body portion 42 is in contact with the block 14. The lower surface 50 of the top portion 40 of the main body portion 42 is in contact with the first upper end stripe 16. The arm portion 44 prevents the main body portion 42 from coming off the first upper end muscle 16, and the protrusion 46 pierces the block 14. The upper spacer 18 is made of plastic. The upper spacer 18 may be made of metal instead of the above example made of plastic.

  The distance between the first upper end reinforcement 16 and the upper surface of the main body 12 corresponds to the concrete covering thickness required around the first upper end reinforcement 16. Since the height dimension of the side portion 38 of the main body portion 42 is substantially equal to the concrete covering thickness and the thickness dimension of the top portion 40 of the main body portion 42 is smaller than the height dimension of the side portion 38, The thickness dimension is smaller than the concrete covering thickness, and the top portion 40 of the main body portion 42 does not protrude upward from the upper surface of the main body 12.

  As shown in FIGS. 4 and 5, the lower spacer 28 used in the floor slab 10 is provided on the main body portion 56 disposed between the bottom 24 of the block 14 and the lower surface 26 of the main body 12, and the main body portion. And a protrusion 58 protruding upward from the main body portion 56. The main body portion 56 has an upper end surface 60 that contacts the bottom portion 24 of the block 14 when the main body portion 56 is disposed between the bottom portion 24 of the block 14 and the lower surface 26 of the main body 12. The protrusion 58 is provided on the upper end surface 60 of the main body portion 56 and can pierce the block 14. The protrusion 58 is tapered, and its thickness gradually decreases upward from the main body portion 56.

  As shown in FIG. 1, in the floor slab 10, the main body portion 56 of the lower spacer 28 is disposed between the bottom 24 of the block 14 and the lower surface 26 of the main body 12, and the upper end surface 60 of the main body portion 56 is a block. 14 is in contact with the bottom 24 of the 14, and the protrusion 58 pierces the block 14. The lower spacer 28 is fixed to the bottom portion 24 of the block 14 by the protrusion 58 piercing the block 14. The lower spacer 28 is fixed to the bottom 24 of the block 14 by adhering the upper end surface 60 of the main body portion 56 to the bottom 24 of the block 14 instead of the example shown in FIG. It may be a thing. In this case, the lower spacer 28 may not have the protrusion 58.

  When constructing the floor slab 10, as shown in FIG. 6, first, the lattice-shaped lower end bars 30 and 32 are disposed upwardly from the substantially square plate-shaped formwork 62. Next, the block 14 and at least one lower spacer 28 fixed to the bottom 24 of the block are prepared. Thereafter, the block 14 is arranged at a distance from the mold 62 upward by the lower spacer 28. At this time, the block 14 is spaced from the lower end bars 30 and 32. The preparation of the block 14 and the lower spacer 28 is performed in place of the above example in which the lower end bars 30 and 32 are arranged after being spaced apart from the mold frame 62, and the lower end bars 30 and 32 are replaced with the mold frame 62. May be carried out before being spaced apart from the top.

  After the block 14 is spaced upward from the mold 62, the lattice-shaped upper stripes 16, 34, 36 are spaced upward from the lower stripes 30, 32. At this time, at least one first upper end stripe 16 parallel to one side of the quadrilateral is arranged at an interval upward from the block 14. Thereafter, as shown in FIG. 7, at least one upper spacer 18 is attached to the first upper end stripe 16. At this time, the upper spacer 18 maintains the space between the block 14 and the first upper end reinforcement 16.

  When the upper spacer 18 is attached to the first upper end stripe 16, as shown in FIG. 8, the main body portion 42 is pressed against the first upper end stripe from above the first upper end stripe 16 (the direction in which the main body portion 42 is pressed in FIG. 8). Is indicated by arrow 64). As a result, as shown in FIG. 9, the main body portion 42 receives the first upper end muscle 16, the lower end surface 48 of each side portion 38 of the main body portion 42 is in contact with the block 14, and the protrusion 46 pierces the block 14. Since the upper spacer 18 can be attached to the first upper end 16 only by pressing the main body portion 42 from above the first upper end 16 to the first upper end 16, The attachment work to 16 is relatively easy.

  While the main body portion 42 is receiving the first upper end muscle 16, as shown in FIG. 8, the arm portion 44 comes into contact with the first upper end muscle 16 and is elastically deformed (the arm portion 44 is elastic in FIG. 8). The direction of deformation is indicated by arrow 66). Thereby, the space | interval between the arm part 44 provided in the one side part 38 of the main-body part 42 and the arm part 44 provided in the other side part 38 of the main-body part 42 spreads. At this time, the distal end portion 52 of the arm portion 44 is bent and deformed, and the boundary portion 54 between the arm portion 44 and the side portion 38 of the main body portion 42 is not bent and deformed. When the main body portion 42 has received the first upper end muscle 16, the elastic deformation of the arm portion 44 is released as shown in FIG. As a result, the arm portion 44 is restored to the state before elastic deformation (in FIG. 9, the direction in which the arm portion 44 is restored is indicated by an arrow 68). The restored arm portion 44 presses the first upper end muscle 16 against the top 40 of the main body portion 42 and prevents the main body portion 42 from coming off the first upper end muscle 16.

  When the elastic deformation of the arm portion 44 is released, the arm portion 44 is completely restored to the shape before the elastic deformation in the example shown in FIG. 9, but instead, it is completely restored to the shape before the elastic deformation. The shape before elastic deformation is such that the arm portion 44 does not restore the shape and the arm portion 44 presses the first upper end muscle 16 against the top 40 of the main body portion 42 to prevent the main body portion 42 from coming off the first upper end muscle 16. You may restore it.

  After the upper spacer 18 is attached to the first upper end reinforcement 16, concrete is placed on the formwork 62 to a height higher than the height of the upper end reinforcements 16, 34, 36 to form the plate-like main body 12. After the concrete has hardened, the formwork 62 is removed from the main body 12.

  When the concrete is placed, buoyancy is applied to the block 14 and the block tends to float. At this time, the upper spacer 18 prevents the block 14 from moving upward by maintaining the space between the block 14 and the first upper end reinforcement 16. As a result, the block 14 can be prevented from being lifted, and the block 14 can be accurately placed inside the main body 12.

  In order to prevent the block 14 from being lifted by the upper spacer 18 that maintains the distance between the block 14 and the first upper end stripe 16, the upper spacer 18 is attached to the first upper end stripe 16 in order to prevent the block 14 from rising. What is necessary is that relatively little effort is required to prevent the block 14 from being lifted. For this reason, the rod having a lower end fixed to the formwork through the through hole provided in the block, and a plate attached to the upper end of the rod and preventing the block from moving upwards Providing the through hole in the block, fixing the lower end of the rod to the mold, and attaching the plate to the upper end of the rod as in the conventional case of preventing the block from lifting up. This is not necessary, and much effort is not required to prevent the block from being lifted. Thereby, the floor slab 10 can be constructed efficiently.

  Further, since the through hole provided in the block is not required unlike the conventional case, the volume of the block is not reduced by the through hole. For this reason, the increase in the weight of the floor slab 10 and the amount of concrete used is not caused.

  By the way, the 1st upper end reinforcement 16 arrange | positioned at intervals from the block 14 may bend by dead weight. When the first upper end line 16 is bent, the first upper end line 16 cannot be accurately arranged inside the main body 12, and the interval between the block 14 and the first upper end line 16 becomes narrow, and the block 14 A necessary concrete covering thickness cannot be ensured between the first upper end reinforcement 16 and the first upper end reinforcement 16. The upper spacer 18 maintains the distance between the block 14 and the first upper end stripe 16 to prevent the first upper end stripe 16 from being bent, and the distance between the block 14 and the first upper end stripe 16 is reduced. Prevent narrowing. For this reason, the 1st upper end reinforcement 16 can be accurately arrange | positioned inside the main body 12, and the said concrete covering thickness can be ensured between the block 14 and the 1st upper end reinforcement 16 reliably.

  When the concrete is placed, the block 14 may receive a horizontal force in a direction perpendicular to the first upper end reinforcement 16 from the concrete. Since the main body portion 42 of the upper spacer 18 receives the first upper end stripe 16 and the projection 46 pierces the block 14, when the block 14 receives the horizontal force, the block 14 passes through the upper spacer 18 and the first upper end stripe 16. In response to the reaction force from the muscle 16, the movement of the block 14 is prevented. Accordingly, the block 14 can be prevented from moving with respect to the first upper end muscle 16 due to the horizontal force, and the block 14 can be arranged inside the main body 12 with higher accuracy.

  When the arm portion 44 of the upper spacer 18 comes into contact with the first upper end muscle 16 and elastically deforms, the tip portion 52 of the arm portion 44 is bent and deformed, whereas the arm portion 44 and the side portion 38 of the main body portion 42 Since the boundary portion 54 of the main body portion 42 is not bent and deformed, the side portion 38 of the main body portion 42 is not bent and deformed (FIG. 8). For this reason, the space between the side portions 38 of the main body portion 42 does not change when the main body portion 42 receives the first upper end muscle 16, and the piercing of the protrusion 46 into the block 14 is not hindered. The 18 can be smoothly attached to the first upper end muscle 16.

  When the arm portion 44 comes into contact with the first upper end muscle 16 and elastically deforms, the distal end portion 52 of the arm portion 44 is bent and deformed, and the intermediate portion of the arm portion 44, that is, the distal end portion 52 and the boundary portion 54 The portion located between them may be bent and deformed, or only the tip portion 52 of the arm portion 44 may be bent and deformed, and the intermediate portion of the arm portion 44 may not be bent and deformed. Further, instead of the above example in which the distal end portion 52 of the arm portion 44 is bent and deformed, only the intermediate portion of the arm portion 44 may be bent and deformed without bending the distal end portion 52 of the arm portion 44. However, even when the intermediate portion of the arm portion 44 is bent and deformed, the boundary portion 54 between the arm portion 44 and the side portion 38 of the main body portion 42 is not bent and deformed, and the side portions 38 of the main body portion 42 are bent and deformed. Never reach.

  Instead of the example shown in FIG. 1 in which the first upper end bars 16 extend in the longitudinal direction, the first upper end bars 16 may extend in the lateral direction. In this case, the lattice-shaped upper end bars 16, 34, and 36 are spaced apart from the block 14 and extend in the lateral direction, and the first upper end bars 16 are orthogonal to the first upper end bars 16. A plurality of second upper end bars 34 spaced apart in the lateral direction, and a plurality of the plurality of spaced apart in the longitudinal direction, each parallel to the first upper end line 16 and perpendicular to the second upper end line 34 A third upper end line 36. The number of the first upper end bars 16 is one in the example shown in FIG. 1, but may be two or more instead.

  The floor slab 10 may not include the lower spacer 28 instead of the example illustrated in FIG. 1 including the lower spacer 28. In the floor slab 10, for example, at least one auxiliary muscle (not shown) parallel to one of the lower end bars 30, 32 is fixed to the lower end bars 30, 32, and the block 14 is placed on the auxiliary bars. Can be.

  By the way, the position of the lower end bars 30 and 32 may deviate from the position determined in design due to the lower end bars 30 and 32 being bent by their own weight or due to an error in installation. When the block 14 is placed on the auxiliary muscle, the position of the block 14 changes depending on the positions of the lower end bars 30 and 32, and therefore there is a possibility that the block 14 cannot be arranged at a position determined by design. is there. On the other hand, when the block 14 is arranged at an interval upward from the mold 62 by the lower spacer 28, the position of the block 14 is determined with reference to the mold 62. It does not change according to the position of 32. For this reason, the block 14 can be reliably arrange | positioned in the position decided on design.

  In the example shown in FIGS. 10 to 12, the body portion 42 of the upper spacer 18 is replaced with the example shown in FIG. 1 in which the thickness of each side portion 38 is substantially constant. It gradually increases downward. The lower end surface 48 of each side portion 38 is flat.

  The thickness of each side portion 38 of the main body portion 42 gradually increases downward from the boundary portion 70 between the side portion and the top portion 40, thereby increasing the area of the lower end surface 48 of each side portion 38 of the main body portion 42. The contact area between each side portion 38 of the main body portion 42 and the block 14 can be increased. This prevents the block 14 from rotating with respect to the upper spacer 18 due to the force from the concrete when the concrete is placed.

  In the example shown in FIGS. 13 to 15, the main body portion 42 of the upper spacer 18 is replaced with the width direction of the side portion 38 (in FIG. 13) instead of the example shown in FIG. 10 where the lower end surface 48 of each side portion 38 is flat. When viewed in a plane perpendicular to the depth direction, the lower end surface 48 of one side 38 forms a part of a circle, and the lower end 48 of the other side 38 forms another part of the circle. The circular shape is on a straight line extending vertically between the side portions 38 of the main body portion 42, and is substantially the same height as the height of the boundary portion 70 between the side portion 38 and the top portion 40, or higher than the height of the boundary portion 70. It has a center located at the height. That is, the circle has the center in the vicinity of the top 40 or above the top 40.

  The block 14 has an arcuate top surface 20 projecting downward in the longitudinal section of the block. A lower end surface 48 of each side portion 38 of the main body portion 42 of the upper spacer 18 has a shape corresponding to the shape of the top surface 20 of the block 14 and is in contact with the top surface 20. Thereby, when the block 14 receives a force from the concrete when placing the concrete, the block 14 can easily receive a horizontal reaction force from the upper spacer 18. For this reason, it can prevent that the block 14 shifts | deviates to a horizontal direction with respect to the upper spacer 18 at the time of placement of the said concrete.

  As shown in FIG. 13, the lower end surface 48 of each side portion 38 of the main body portion 42 of the upper spacer 18 has a curvature of the lower end surface 48 equal to the curvature of the top surface 20 of the block 14, and the entire lower end surface 48 is blocked. 14 in contact with the top surface 20. Note that the lower end surface 48 of each side portion 38 of the main body portion 42 of the upper spacer 18 is replaced with an example of the lower end surface 48 instead of the example shown in FIG. 13 in which the entire lower end surface is in contact with the top surface 20 of the block 14. The portion may be in contact with the top surface 20 of the block 14. The lower end surface 48 of each side portion 38 of the body portion 42 of the upper spacer 18 is replaced with the above example in which the curvature of the lower end surface is equal to the curvature of the top surface 20 of the block 14, and the curvature of the lower end surface 48 is the top of the block 14. It may be different from the curvature of the surface 20. In this case, a part of the lower end surface 48 of each side portion 38 of the main body portion 42 of the upper spacer 18 is in contact with the top surface 20 of the block 14.

  A groove 72 extending in a direction perpendicular to the longitudinal section is provided on the bottom surface 22 of the block 14, and the groove receives the first lower end stripe 30. The inner surface of the groove 72 is spaced from the first lower bar 30 and the distance between the inner surface of the groove 72 and the first lower bar 30 is the concrete covering thickness required around the first lower bar. Equivalent to. For this reason, even when the first lower end bar 30 exists below the block 14, the height of the bottom 24 of the block 14 can be made substantially the same as the height of the first lower end bar 30. 14 can be wide in the vertical direction, and the weight of the floor slab 10 can be reduced and the amount of concrete used can be reduced.

  As shown in FIGS. 14 and 15, the upper spacer 18 used for the floor slab 10 is provided on the lower end surface 48 of each side portion 38 of the main body portion 42 in addition to the protrusion (first protrusion) 46. A plurality of second protrusions 74 projecting downward from the lower end surface are provided. Each second protrusion 74 is shorter than the first protrusion 46 and can pierce the block 14.

  As shown in FIG. 13, in the floor slab 10, each second protrusion 74 pierces the block 14. For this reason, when the block 14 receives the said horizontal force from the said concrete, the frictional resistance which arises between the lower end surface 48 of each side part 38 of the main-body part 42 and the top surface 20 of the block 14 can be increased. Thereby, it can prevent more reliably that the block 14 receives the said horizontal force and moves with respect to the 1st upper end muscle 16.

  In the example shown in FIG. 16, the first upper end bars 16 are provided on the outer surface 76 of the first upper end bars at intervals in the axial direction of the first upper end bars 16. A plurality of nodes 78 extending in the direction. That is, the first upper end bar 16 is a deformed bar. The top portion 40 of the main body portion 42 of the upper spacer 18 has at least one groove 80 provided on the lower surface 50 having the circular arc extending in the direction of the circular arc. The bottom surface 50 of the top portion 40 of the main body portion 42 contacts the outer surface 76 of the first upper end muscle when the main body portion 42 receives the first upper end muscle 16, and the groove 80 has the main body portion 42 that connects the first upper end muscle 16. Engages with one of the nodes 78 when received.

  In the floor slab 10, the lower surface 50 of the top 40 of the main body portion 42 of the upper spacer 18 is in contact with the outer surface 76 of the first upper end bar 16, and the groove 80 is engaged with one of the nodes 78. Since the groove 80 is engaged with one of the nodes 78, the block 14 receives a horizontal force in the axial direction of the first upper end reinforcement 16 from the concrete when the concrete is placed, and is applied to the first upper end reinforcement. It can be prevented from moving. Thereby, the block 14 can be arrange | positioned inside the main body 12 more accurately.

10 Floor slab 12 Body 14 Block 16 Reinforcement 18 Spacer (Upper spacer)
20 Top surface 38 Side portion 40 Top portion 42 Main body portion 44 Arm portion 46 Projection (first projection)
48 Lower end surface 50 Lower surface 52 Front end portion 54 A boundary portion between the arm portion and the side portion of the main body portion 74 Second protrusion 76 Outer surface 78 Node 80 Groove

Claims (6)

A plate-shaped main body made of concrete, a block disposed in the main body and having a specific gravity smaller than that of the concrete, and at least one block disposed in the main body at an interval upward from the block and extending in the horizontal direction A spacer that is used for a floor slab including a reinforcing bar and maintains a distance between the block and the reinforcing bar,
A body portion capable of receiving the rebar comprising a pair of spaced apart side portions and a top portion between the side portions;
Wherein provided on each side of the body portion, projecting from said side portion downward, have at least one first protrusion pierceable said block,
Each of the side portions of the main body portion has a thickness that gradually increases downward from the top portion, and has a lower end surface that contacts the block when the main body portion receives the reinforcing bar. The block has an arcuate top surface protruding downward in the longitudinal section thereof,
The main body portion of the upper spacer is a part of a circular shape having the lower end surface of one side portion centered in the vicinity of the top portion or above the top portion when viewed in a plane perpendicular to the width direction of the side portion. And the lower end surface of the other side portion forms another part of the circular shape,
The spacer according to claim 1 , wherein the lower end surface of each side portion is in contact with the top surface of the block when the main body portion receives the reinforcing bar. Each side portion of the main body portion is provided with an elastic arm portion extending from the side portion toward the other side portion, and the arm portion is configured so that the main body portion receives the reinforcing bar. elastically deformed in contact with the iron muscle, the body portion said body portion elastic deformation is released when the receiving the reinforcing bar is prevented from deviating from the reinforcing bar, the spacer according to claim 1 or 2. The tip portion of the arm portion has a lower bending strength than the boundary portion between the arm portion and the side portion of the body portion,
The spacer according to claim 3 , wherein when the arm portion comes into contact with the reinforcing bar and elastically deforms, the tip portion of the arm portion is bent and deformed, and the boundary portion is not bent and deformed. The reinforcing bar is provided on the outer surface of the reinforcing bar at intervals in the axial direction of the reinforcing bar, each having a plurality of nodes extending in the circumferential direction of the reinforcing bar,
The top portion of the main body portion is a lower surface that exhibits an upwardly projecting arc when viewed in a plane perpendicular to the width direction of the top portion, and is a lower surface that contacts the outer surface of the reinforcing bar when the main body portion receives the reinforcing bar. And at least one groove provided in the lower surface and extending in the direction of the arc, wherein the body portion engages one of the nodes when receiving the reinforcing bar. Item 5. The spacer according to any one of Items 1 to 4 . A plurality of second protrusions that protrude downward from the lower end face and have a length shorter than the length of the first protrusion and can pierce the block are provided on the lower end face of each side portion of the main body portion. The spacer according to any one of claims 1 to 5 .

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