JP6915801B2 - Structural floor and its construction method - Google Patents

Description

The present disclosure relates to floors that reduce floor impact noise in building structures such as apartment houses and hotels.

In a building structure such as an apartment house or a hotel, when the floor of the upper floor is impacted by a person walking or the like, the floor vibrates, and the floor impact sound transmitted to the lower floor as a sound becomes a problem. Conventionally, various measures against floor impact noise have been proposed.

In the double floor where the floor is installed on the concrete floor slab via the support legs, a means for increasing the mass of the floor itself to reduce the floor impact noise is implemented. In addition, in a double ceiling in which a ceiling board is attached under a floor slab (ceiling slab) via a ceiling base material, a container containing granules is installed between the floor slab and the ceiling board, and the granules are containers. A means for attenuating vibration energy by moving within and reducing floor impact noise has been proposed (for example, Patent Document 1). In addition, in a floor slab in which voids (hollow parts) are formed using steel pipes, a bag filled with sand is loaded in the steel pipes, and the energy of vibration is converted into frictional heat of sand to reduce floor vibrations. Means have been proposed (eg, Patent Document 2). Further, a means for installing a dynamic vibration absorber (TMD) having a mass body and a coil spring on the floor has been proposed (for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2014-37678 Japanese Unexamined Patent Publication No. 2015-113964 Japanese Unexamined Patent Publication No. 2006-161388

However, the means for increasing the mass of the floor cannot be used for the directly stretched floor, and there is a problem that the cost of the material is high. Further, the means for installing the container containing the granular material between the floor slab and the ceiling board cannot be used on the direct ceiling, and there is a problem that it takes time and effort to install the container and the labor cost increases. Further, the means for loading a bag filled with sand in a void formed of a steel pipe also has a problem that it takes time and effort to load the bag into the void and labor cost increases. Further, in the means for installing the dynamic vibration absorber described in Patent Document 3, it is necessary to attach a dynamic vibration absorber provided with a mass body and a coil spring between the floor and the underfloor structure, so that it takes time and labor to install. There was a problem that the cost increased.

In view of such a background, an object of the present invention is to provide a floor of a structure capable of reducing floor impact noise and having good workability, and a method for constructing the floor.

At least some embodiments of the present invention are substantially the floor (1) of the structure, consisting of a concrete floor slab (2) having voids (11) and elastic foam plastic, as described above. A void formwork (5,41,61,81,101,111) arranged along the inner surface of the void and a weight (14) elastically supported by the void formwork so as to vibrate in the vertical direction. , 62, 82, 102, 112), and the void formwork material and the weight form a dynamic vibration absorber (3,47,63,83,103,113). Here, when the void formwork material is "substantially" changed from elastic foamed plastic, it is not only when it is entirely made of foamed plastic, but also when other materials such as a reinforcing material are partially used as long as the elasticity is not impaired. It means that it includes the case where it is mixed.

According to this configuration, since the void formwork material is used as a spring of the dynamic vibration absorber, the work of installing the void formwork material becomes a part of the work of installing the dynamic vibration absorber, and the work of installing the dynamic vibration absorber is used. It requires less effort than a conventional structural vibration absorber for floors. It can also be used for both double floors and straight floors, as well as double ceilings and straight ceilings.

In at least some embodiments of the present invention, in the above configuration, the weight has a plate shape extending in the horizontal direction, and the void formwork member has a lower member (12, 42, 66, 86, 105). , The lower body portion (15, 45, 68,) which has an upper member (13,43,67,87,106) arranged above the lower member, and the lower member abuts on the lower surface of the void. 88) and one or more lower protrusions (16, 64, 84) that project upward from the lower body and elastically support the weight, and the upper member is an upper surface of the void. An upper body portion (17,46,69,89) that abuts on the upper body portion, and one or a plurality of upper body protrusions (18,65,85) that project downward from the upper body portion and elastically support the weight. It is characterized by having.

According to this configuration, the lengths of the lower protrusion and the upper protrusion, and the contact area between the lower protrusion and the upper protrusion and the weight can be adjusted, so that the natural frequency of the dynamic vibration absorber is adjusted to a predetermined value. be able to.

In at least some embodiments of the present invention, in the above configuration, the lower body portion is provided at a first upper surface (31, 50, 72, 93) and a position recessed below the first upper surface. It has a second upper surface (32, 51, 73, 94) on which the lower protrusion protrudes, and the upper main body portion has a first lower surface (33, 52, 75, 95) and more than the first lower surface. It has a second lower surface (34, 53, 76, 96) provided at a position recessed upward and the plurality of upper protrusions project, and the first upper surface of the lower main body and the upper main body. Each of the first lower surfaces is characterized in that the void formwork member is deformed so as to be able to partially come into contact with the weight.

According to this configuration, even if a worker is placed on the void formwork material and the void formwork material is deformed at that portion between the time when the void formwork material is installed and the time when the concrete is placed, the void formwork material is deformed. When the first upper surface and the first lower surface come into contact with the weight, it is possible to prevent the lower protrusion and the upper protrusion from being excessively deformed and damaged. Therefore, the worker can be placed on the void formwork material to perform the reinforcing bar arrangement work and the like.

In at least some embodiments of the present invention, in the above configuration, the lower protrusion (64,84) and the upper protrusion (65,85) are, in plan view, from the center of gravity of the weight to the contour of the weight. The distance from a predetermined line passing through the center of gravity of the weight to the contour of the weight in a direction orthogonal to the predetermined line inside the frame connecting the points indicating 3/5 of the distance or in a plan view. It is characterized in that the weight is supported inside the two lines connecting the points indicating 3/5 of the above.

According to this configuration, the lower protrusion and the upper protrusion that function as springs support the center side of the weight in a plan view, so that the locking frequency becomes smaller than the natural frequency of the dynamic vibration absorber. Therefore, it is possible to avoid a reduction in the effect of the dynamic vibration absorber that occurs when the locking frequency and the natural frequency are close to each other.

In at least some embodiments of the present invention, in the above configuration, the weight (62,82) has through holes (78,92) provided along the vertical direction, and the lower member (66,86). ) And the upper members (67, 87) are provided with upper and lower surfaces so as to be in contact with each other at positions aligned with the through holes in the vertical direction, respectively, and a lower connecting portion (74, 97) and an upper connecting portion. It is characterized by having a part (77,98).

According to this configuration, the through hole locks the lower connecting portion and / or the upper connecting portion, so that the weight can be prevented from being displaced in the horizontal direction. Further, even if a worker rides on the upper member during construction, the upper surface of the lower connecting member and the lower surface of the upper connecting member are in contact with each other, so that the Boyt formwork material is prevented from bending. .. Therefore, it is possible to prevent damage to the lower protrusion and the upper protrusion and deviation of the spring constant caused by the consolidation of the lower protrusion and the upper protrusion.

In at least some embodiments of the present invention, in the above configuration, one side surface of the connecting portion (79,99) including the lower connecting portion and the upper connecting portion and the penetrating portion extends along the vertical direction. The other side surface of the connecting portion and the through hole is characterized in that it is partially inclined or curved toward the one side surface in the vertical direction and is locked to the one side surface.

According to this configuration, since the contact area between the through hole and the connecting portion becomes small, the frictional force between the through hole and the connecting portion when the weight vibrates up and down becomes small, and the through hole and the connecting portion become smaller. It is possible to suppress the interference of the vibration of the weight caused by the contact.

In at least some embodiments of the present invention, in the above configuration, the lower protrusion (64) and the upper protrusion (65) each exhibit a frame shape surrounding the through hole (78) in a plan view. It is characterized in that it faces each other with the weight in between. Further, in at least some embodiments of the present invention, in the above configuration, the lower protrusion (84) and the upper protrusion (85) are each present in plurality, and each of them is along the through hole (92). It is characterized by being arranged.

According to these configurations, it becomes relatively easy to prepare the void formwork material.

In at least some embodiments of the present invention, in the above configuration, the weight (102) is a protrusion received by a recess (107) provided in the lower member (105) and / or the upper member (106). The concave portion has a portion (104) and is inclined so that the side surface of the convex portion becomes thinner toward the tip end, so that the concave portion abuts on the base portion of the convex portion.

According to this configuration, the convex portion is locked to the concave portion, so that the weight can be prevented from being displaced in the horizontal direction. Further, since the contact area between the convex portion and the concave portion becomes small, the frictional force between the through hole and the connecting portion when the weight vibrates up and down becomes small, which is caused by the contact between the through hole and the connecting portion. It is possible to suppress the obstruction of the vibration of the weight.

In at least some embodiments of the present invention, in the above configuration, the convex portion is provided on either the upper surface or the lower surface of the weight, and the weight is the convex portion on either the upper surface or the lower surface. It is characterized by having a weight concave portion having a shape corresponding to or larger than that of the convex portion, which is provided at a position aligned with the vertical direction.

According to this configuration, when a plurality of weights are stacked and stored, one convex portion of the two stacked weights is received by the other concave portion, so that the stacked weights are not bulky.

In at least some embodiments of the present invention, in the above configuration, there are a plurality of the lower protrusions (16) and the upper protrusions (18), each of which faces each other in the vertical direction with the weight in between. However, they are arranged in a grid pattern (see FIGS. 2 and 3). Further, in at least some other embodiments of the present invention, in the above configuration, the lower protrusion (16) and the plurality of upper protrusions (18) face each other in the vertical direction with the weight interposed therebetween. Each is arranged in a staggered pattern (see FIGS. 7 and 8).

According to these configurations, the weight can be supported in a well-balanced manner.

In at least some embodiments of the present invention, in the first configuration described above, the weight (112) has a plate shape extending in the horizontal direction, and a bulge in which the central portion in the horizontal direction bulges up and down. The void type frame material (111) has a lower member (114) and an upper member (115) arranged above the lower member, and the lower member is said to have the portion (118). While abutting on the lower surface of the void, the lower end of the bulging portion of the weight is elastically supported, the upper member abuts on the upper surface of the void, and the upper end of the bulging portion of the weight is elastic. It is characterized by spontaneous support.

According to this configuration, since there are few irregularities inside the void formwork material, it becomes easy to create the void formwork material.

In at least some embodiments of the present invention, in the above configuration, the weight of the weight placed in the void is 4-10% of the weight of the floor slab in the region defining the bearing area of the void. It is characterized by.

According to this configuration, the vibration of the floor can be efficiently absorbed.

At least some embodiments of the present invention are methods of constructing the floor (1) of a structure, which is a void formwork (5,41,61,81,101, substantially made of elastic foam plastic. 111) and the step of arranging the weights (14, 62, 82, 102, 112) arranged inside the void formwork material on the upper surface of the lower concrete slab (4), the void formwork material and the weight. The step of arranging the slab upper end reinforcement (6) above the lower concrete slab on which the slab upper end reinforcement is installed, and the concrete (7) being placed on the lower concrete slab on which the slab upper end reinforcement is arranged. The void formwork material is provided with a step of manufacturing the floor slab (2) having the void (11), and the weight is elastically supported by the void formwork material so as to be viable in the vertical direction. And the weight constitutes a dynamic vibration absorber (3,47,63,83,103,113).

According to this configuration, since the void formwork material is used as a spring of the dynamic vibration absorber, it takes less time and effort to install the dynamic vibration absorber as compared with the conventional method of constructing the floor of a structure having a dynamic vibration absorber. A construction method can be provided.

In at least some embodiments of the present invention, in the above configuration, the weight has a plate shape extending in the horizontal direction, and the void formwork member (5,41,61,81,101) is a lower member (5,41,61,81,101). 12, 42, 66, 86, 105) and an upper member (13, 43, 67, 87, 106) arranged above the lower member, and the lower member defines the lower surface of the void. The lower main body (15, 45, 68, 88) formed and one or more lower protrusions (16, 64, 84) protruding upward from the lower main body to elastically support the weight. The upper member has an upper main body portion (17, 69, 89) that defines the upper surface of the void, and one or a plurality of upper main body portions that project downward from the upper main body portion and elastically support the weight. The lower member and the upper member have upper protrusions (18, 65, 85), and after the step of manufacturing the floor slab, the lower member and the upper member are vertically oriented by the weight of the concrete. It is characterized in that it is configured to be compressed in.

The weight can be reliably and elastically supported by compressing the lower and upper protrusions, but according to this configuration, the work can be performed by placing the upper concrete. It is possible to suppress the increase in the work required to install the vibration absorber.

In at least some embodiments of the present invention, in the above configuration, the outer peripheral portion (19) of the lower member is the outermost outer peripheral surface (25) of the lower member facing upward and the first outer peripheral surface (25). It has a second lower member outer peripheral surface (26) that is located inside the lower member outer peripheral surface and is located above the first lower member outer peripheral surface and faces upward. The outer peripheral surface of the first upper member (28), which is located on the outermost side and faces downward and faces the outer peripheral surface of the first lower member, and the outer peripheral surface of the first upper member, which is located inside the outer peripheral surface of the first upper member. It has a second upper member outer peripheral surface (29) that is located above the surface and faces downward and faces the second lower member outer peripheral surface, and the second lower member outer peripheral surface is the first upper member. It is characterized in that it is arranged above the outer peripheral surface.

According to this configuration, even if the lower member and the upper member are configured to be separated from each other in the vertical direction with the weight in between, the concrete cast on the lower concrete slab is a void formwork. It is prevented from flowing into the inside of the material.

In at least some embodiments of the present invention, in the above configuration, the step of installing the void formwork and the weight is performed in a factory, and the step of arranging the upper end reinforcement of the slab is the void formwork. It is characterized in that it is performed after the lower concrete slab on which the weight is installed is placed on the floor portion of the structure.

According to this configuration, the work at the construction site is substantially the same as the construction method of the void slab by the conventional half precast method, so that the increase in the work at the construction site can be suppressed.

According to the present invention, it is possible to provide a floor of a structure capable of reducing floor impact noise and having good workability, and a method for constructing the floor.

Longitudinal sectional view of the floor of the structure according to the first embodiment Vertical cross-sectional view showing a void formwork material and a weight according to the first embodiment. Top view showing the lower member of the void formwork material which concerns on 1st Embodiment Bottom view showing the upper member of the void formwork material according to the first embodiment. Explanatory drawing which shows construction procedure of floor of structure which concerns on 1st Embodiment A vertical sectional view showing a void formwork material and a weight according to the second embodiment. Top view showing the lower member of the void formwork material which concerns on 2nd Embodiment Bottom view showing the upper member of the void formwork material according to the second embodiment. Top view showing a dynamic vibration absorber according to a third embodiment XX sectional view in FIG. Top view showing a dynamic vibration absorber according to a fourth embodiment XII-XII sectional view in FIG. XIII-XIII sectional view in FIG. Top view showing a moving vibration absorber according to a fifth embodiment XIV-XIV sectional view in FIG. Top view showing a dynamic vibration absorber according to a sixth embodiment XVI-XVI sectional view in FIG. Graph showing the frequency characteristics of the dynamic vibration absorber according to the first embodiment ((A) before loading, (B) after loading) The figure which shows the shape and the dimension of the dynamic vibration absorber which concerns on Example 2. Vibration spectrum and phase difference of the weight in the dynamic vibration absorber according to the second embodiment

Hereinafter, embodiments of the floor of the structure according to the present invention will be described in detail with reference to the drawings.

<< First Embodiment >>
FIG. 1 shows the floor 1 of the structure according to the first embodiment of the present invention. The floor 1 is provided in a building structure such as an apartment house or a hotel where reduction of floor impact noise is required. The floor 1 includes a floor slab 2 made of reinforced concrete, and a member functioning as a dynamic vibration absorber 3 is arranged on the floor slab 2. The floor 1 may be a double floor or a straight floor, and the ceiling of the lower floor may be a double ceiling or a straight ceiling.

The floor slab 2 is formed by a half precast method, and is arranged above the lower concrete slab 4 made of a precast concrete slab, the void formwork 5 arranged on the lower concrete slab 4, and the void formwork 5. The slab upper end bar 6 extending horizontally along the vertical direction (direction orthogonal to the paper surface of FIG. 1) and the horizontal direction (horizontal direction of FIG. 1), and the void formwork 5 and the slab upper end bar 6 are embedded so as to be embedded. It is provided with a cast upper concrete 7.

The lower concrete slab 4 has a lower concrete 8, a slab lower end bar 9 extending horizontally in the lower concrete 8 along the vertical and horizontal directions, and a truss bar 10. The truss bars 10 are a set of two bottom bars 10a embedded in the lower concrete 8 so as to extend horizontally along the vertical direction, and a set of bottom bars above the bottom bars 10a and a set of two bottoms. In the separation direction (lateral direction) of the streaks 10a, the top streaks 10b arranged at an intermediate position and extending parallel to the bottom streaks 10a, and a pair of wavy lattice streaks 10c are provided. A set of two lattice muscles 10c abuts on the top streaks 10b and the corresponding bottom streaks 10a near the apex of the wave shape, respectively, and the abutting positions coincide with each other in the separation direction (lateral direction) of the bottom streaks 10a. is doing.

The void formwork 5 is an embedded formwork for forming a void 11 (hollow portion) in the floor slab 2, and is made of elastic foamed plastic such as beaded polystyrene foam. The void formwork 5 may contain other materials such as a reinforcing material. The void formwork member 5 has a lower member 12 and an upper member 13 arranged above the lower member 12, and the lower member 12 and the upper member 13 cooperate with each other to form a flat plate-shaped weight 14 from the vertical direction. I'm holding it. The void formwork 5 and the weight 14 constitute a tuned mass damper 3.

FIG. 2 is a vertical cross-sectional view showing a void formwork member 5 and a weight 14 in a state before the upper concrete 7 is cast, FIG. 3 is a plan view of the lower member 12, and FIG. 4 is an upper view. It is a bottom view of the member 13. The lower member 12 has a lower main body portion 15 having a surface defining a void 11 and a plurality of lower main body portions 16 projecting upward from the lower main body portion 15 and abutting on a weight 14 at the tip thereof. Reference numeral 15 denotes a shape in which irregularities are provided on the upper surface of a flat plate having a rectangular shape in a plan view. Further, the upper main body 13 has an upper main body portion 17 having a surface defining a void 11 and a plurality of upper main body portions 18 projecting downward from the upper main body portion 17 and abutting on the weight 14 at the tip thereof. The portion 17 has a shape in which irregularities are provided on the lower surface of a flat plate having a rectangular shape in a plan view. The bottom surface of the lower body portion 15 is a plane defining the bottom surface of the void 11 of the floor slab 2, and the upper surface of the upper body portion 17 is a plane defining the upper surface of the void 11 of the floor slab 2. The side surface of the portion 15 and the side surface of the upper main body portion 17 are planes that collaborate to define the side surface of the void 11. The upper surface of the lower main body portion 15 has an outer peripheral portion 19, two accommodating portions 20 for accommodating the weight 14, and a dividing portion 21 for dividing the accommodating portion 20 into two. The lower surface of the upper main body 17 has an outer peripheral portion 22, two accommodating portions 23 for accommodating the weight 14, and a dividing portion 24 for dividing the accommodating portion 23 into two, and the outer peripheral portion 22 of the upper member 13 is accommodated. The portion 23 and the partition portion 24 are provided at positions that are aligned and opposed to the outer peripheral portion 19, the accommodating portion 20, and the partition portion 21 of the lower member 12, respectively, in the vertical direction. The facing surfaces of the dividing portion 21 of the lower member 12 and the dividing portion 24 of the upper member 13 may be a flat surface, a curved surface, or may be bent.

The outer peripheral portion 19 of the lower member 12 is located inside the first lower member outer peripheral surface 25 and the first lower member outer peripheral surface 25, which are located on the outermost side and face upward and have a rectangular frame shape in a plan view. The second lower member outer peripheral surface 26, which is located above the first lower member outer peripheral surface 25 and faces upward and has a rectangular frame shape in a plan view, the first lower member outer peripheral surface 25, and the second lower member outer peripheral surface. It has a lower step surface 27 that connects the steps between the 26 and faces the outside in the horizontal direction. The outer peripheral portion 22 of the upper member 13 is located on the outermost side and faces downward, faces the first lower member outer peripheral surface 25 at a distance of about 1 to 3 mm so as to be aligned in the vertical direction, and is a rectangular frame when viewed from the bottom. The outer peripheral surface 28 of the first upper member and the outer peripheral surface 28 of the first upper member, which exhibit a shape, are located inside the outer peripheral surface 28 of the first upper member, are located above the outer peripheral surface 28 of the first upper member and face downward, and the outer peripheral surface 26 of the second lower member. The outer peripheral surface 29 of the second upper member, the outer peripheral surface 28 of the first upper member, and the outer peripheral surface of the second upper member, which face each other at a distance of about 1 to 3 mm so as to be aligned in the vertical direction and have a rectangular frame shape when viewed from the bottom. It has an upper step surface 30 that connects the steps between 29 and faces inward in the horizontal direction. As will be described later, the outer peripheral portion 19 of the lower member 12 and the outer peripheral portion 22 of the upper member 13 are separated from each other in the vertical direction, but the lower step surface 27 and the upper step surface 30 are in contact with each other and are on the inner peripheral side. Since the second lower member outer peripheral surface 26 and the second upper member outer peripheral surface 29 facing each other are higher than the first lower member outer peripheral surface 25 and the first upper member outer peripheral surface 28 facing each other on the outer peripheral side. When the upper concrete 7 is placed, the concrete is prevented from flowing into the void formwork member 5. Further, the lower protrusion 16 and the upper protrusion 18 are compressed by the weight of the concrete, so that the outer peripheral surface 25 of the first lower member and the outer peripheral surface 28 of the first upper member, and the outer peripheral surface 26 of the second lower member and the outer circumference of the second upper member are compressed. The surfaces 29 are in contact with each other to prevent the concrete void formwork 5 from flowing into the inside. Further, since the lower step surface 27 of the lower member 12 comes into contact with the upper step surface 30 of the upper member 13 so as to surround it, the upper member 13 is prevented from being displaced horizontally with respect to the lower member 12. .. The outer peripheral surface 25 of the first lower member, the outer peripheral surface 26 of the second lower member, the outer peripheral surface 28 of the first upper member, and the outer peripheral surface 29 of the second upper member may be flat or curved. Further, the lower step surface 27 and the upper step surface 30 may be a flat surface or a curved surface that at least partially abuts against each other.

The dividing portion 21 of the lower member 12 is a strip-shaped flat surface or curved surface facing upward, and the dividing portion 24 of the upper member 13 facing the partition portion 24 in the vertical direction is a strip-shaped flat surface or curved surface facing downward. Is. The lower member 12 and the upper member 13 are arranged so that the tip of the lower protrusion 16 and the tip of the upper protrusion 18 abut on the lower surface and the upper surface of the weight 14, respectively, and do not receive a force in the vertical direction from other members. When, the first lower member outer peripheral surface 25, the second lower member outer peripheral surface 26, and the partition portion 21 of the lower member 12 are separated from the first upper member outer peripheral surface 28, the second upper member outer peripheral surface 29, and the partition portion 21, respectively. It is preferable that the portion 24 is separated from the portion 24 in the vertical direction, and the separation distance is preferably about 1 to 3 mm. When such a separation distance is provided, in a state where the upper concrete 7 is cast and the floor slab 2 is completed, the lower protrusion 16 and the upper protrusion 18 are the first lower member outer peripheral surface 25 and the first lower member 12 of the lower member 12. 2 By the weight of the upper concrete 7 so that the lower member outer peripheral surface 26 and the partition portion 21 approach or abut on the first upper member outer peripheral surface 28, the second upper member outer peripheral surface 29, and the partition portion 24 of the upper member 13, respectively. In order to compress, the lower protrusion 16 and the upper protrusion 18 surely cooperate with each other to elastically support the weight 14 even if there is some dimensional error or the like. In addition, instead of the own weight of the upper concrete 7, or in addition to the own weight, the first lower member outer peripheral surface 25, the second lower member outer peripheral surface 26, and the partition portion 21 of the lower member 12 are separated by a fixture such as a clip. The lower protrusion 16 and the upper protrusion 18 may be compressed by approaching or abutting the first upper member outer peripheral surface 28, the second upper member outer peripheral surface 29, and the partition portion 24 of the upper member 13, respectively.

The accommodating portion 20 of the lower member 12 has a first upper surface 31 and a second upper surface 32 that is provided at a position recessed below the first upper surface 31 and projects the lower protrusion 16. In the housing portion 20 of one section separated by the outer peripheral portion 19 and the dividing portion 21, the first upper surface 31 is formed in a single connection, and a plurality of second upper surfaces 32 are formed. Each second upper surface 32 exhibits a square congruent to each other, and one lower protrusion 16 projects from the center of each. The second upper surface 32 and the lower protrusion 16 are arranged in a state in which those close to each other are arranged along the vertical and horizontal directions, that is, in a grid pattern. The first upper surface 31 is located below the tip of the lower protrusion 16, and the difference is preferably about 5 to 8 mm.

The accommodating portion 23 of the upper member 13 is provided at a position recessed above the first lower surface 33 with the first lower surface 33 facing the first upper surface 31 so as to be aligned in the vertical direction, and the upper protrusion 18 is projected. , A second lower surface 34 facing the second upper surface 32 so as to be aligned in the vertical direction. In the accommodating portion 23 of one section separated by the outer peripheral portion 22 and the dividing portion 24, the first lower surface 33 is formed in a single connection, and a plurality of second lower surface 34s are formed. Each of the second lower surfaces 34 exhibits a square congruent with each other, and one upper protrusion 18 projects from the center of each of the second lower surfaces 34. The second lower surface 34 and the upper protrusion 18 are arranged in a grid pattern, respectively. The first lower surface 33 is located above the tip of the upper protrusion 18, and the difference is preferably about 2 to 6 mm.

The lower protrusion 16 and the upper protrusion 18 have a square columnar shape, and the tips thereof are flat. It is preferable that the lower protrusion 16 and the upper protrusion 18 have the same shape as each other. The shapes of the lower protrusion 16 and the upper protrusion 18 may be changed to a pyramid or a truncated cone, or the tip thereof may be curved so that the weight 14 side is convex. When a force that partially compresses the void formwork member 5 in the vertical direction is applied, the lower protrusion 16 and the upper protrusion 18 in the vicinity of the region where the force is applied are weighted by the first upper surface 31 and the first lower surface 33, respectively. It can be compressed until it comes into contact with 14.

The total weight of the weights 14 arranged in one void 11 is preferably 4-10% of the weight of the floor slab 2 in the region defining the load area of the voids 11 in which the weights 14 are housed. Here, the region defining the load area of the void 11 is, in a plan view, in the direction in which the other voids are adjacent to each other, up to the center line between the wall surfaces of the two voids adjacent to each other, in the direction in which the other voids are not adjacent to each other. Refers to the area up to the end of the floor slab 2 in that direction. Further, although the weight 14 is made of a concrete slab, it may be made of another material such as a steel material, or may be a mixed material thereof. The side surface of the weight 14 is preferably separated from the void formwork 5 so as not to receive frictional resistance from the void formwork 5 when the weight 14 vibrates up and down. A part of the weight 14 may be locked with a stopper (not shown) in order to restrict the weight 14 from moving in the horizontal direction.

Since the lower protrusion 16 and the upper protrusion 18 made of elastic foamed plastic elastically support the weight 14, the weight 14 is elastically supported from the vertical direction with a predetermined spring force. Therefore, the void formwork 5 and the weight 14 form a dynamic vibration absorber 3 and absorb the vibration energy of the floor 1 to reduce the floor impact sound. The natural frequency of the dynamic vibration absorber 3 is adjusted by the contact area between the lower protrusion 16 and the upper protrusion 18 and the weight 14, the protrusion length of the lower protrusion 16 and the upper protrusion 18, the foaming ratio of the foamed plastic, and the like. The larger the contact area between the lower protrusion 16 and the upper protrusion 18 and the weight 14, the shorter the protrusion length of the lower protrusion 16 and the upper protrusion 18, and the smaller the foaming ratio of the foamed plastic, the lower the natural frequency. It gets higher. It is preferable to adjust the natural frequency so that the center frequency in the octave band falls within the band of 63 Hz so as to mainly reduce the heavy floor impact sound generated by a person walking or jumping.

The construction method of the floor 1 according to the first embodiment will be described with reference to FIG. As shown in FIG. 5A, in a precast concrete manufacturing factory, a lower member 12 is installed on a lower concrete slab 4, a weight 14 is accommodated in an accommodating portion 20 of the lower member 12, and an upper member 13 is accommodated. The upper member 13 is arranged on the lower member 12 and the weight 14 so that the portion 23 covers the weight 14. It is preferable that the lower member 12 is fixed to the lower concrete slab 4 by using a nail or the like after shaping the lower concrete slab 4 and before it hardens. The lower concrete slab 4 on which the void formwork 5 and the weight 14 are arranged is transported to the construction site of the floor 1.

Next, as shown in FIG. 5B, the lower concrete slab 4 in which the void formwork 5 and the weight 14 are arranged is arranged in a portion where the floor 1 at the construction site is to be manufactured. The lower concrete slab 4 is supported from below by the support 35. The lower concrete slab 4 is arranged so that its side surface abuts on the beam 36. The beam 36 has a beam main bar 37 and a stirrups 38, and concrete 39 has already been cast only in the lower portion (concrete may have been cast in the entire beam 36). The lower concrete slab 4 is arranged so that the upper surface of the lower concrete slab 4 and the upper surface of the cast concrete 39 of the beam 36 are aligned with each other, and the upper surface of the lower concrete slab 4 and the cast concrete 39 of the beam 36 are arranged. Reinforcing bars 40 are installed so as to bridge the upper surface. Further, the slab upper end muscle 6 extending in the lateral direction is bridged so as to be orthogonal to the top muscle 10b, and the slab upper end muscle 6 extending in the vertical direction extends in the lateral direction. Reinforcement is arranged so that 6 is bridged. The end of the slab upper end muscle 6 is overlapped with the stirrups 38. At this time, even if the worker steps on the void formwork 5 and the void formwork is deformed in the vicinity thereof, the first upper surface 31 of the lower member 12 and the first lower surface 33 of the upper member 13 hit the weight 14. The contact prevents the lower protrusion 16 and the upper protrusion 18 from being excessively deformed and damaged, or being compacted to change the spring constant.

Next, a formwork (not shown) for placing the upper concrete 7 is installed, and the upper concrete 7 is placed integrally with the concrete above the beam 36. Due to the weight of the cast upper concrete 7, the lower protrusion 16 and the upper protrusion 18 have the first lower member outer peripheral surface 25, the second lower member outer peripheral surface 26, and the partition portion 21 of the lower member 12, respectively. 13 is compressed so as to be close to or in contact with the outer peripheral surface 28 of the first upper member, the outer peripheral surface 29 of the second upper member, and the partition portion 24. As a result, the lower protrusion 16 and the upper protrusion 18 elastically support the weight 14. When the formwork and the support 35 are dismantled, the floor 1 is completed as shown in FIG. 5 (C).

Since the work at the construction site is substantially the same as the half precast method of the floor slab in which measures against floor impact noise are not taken, the floor 1 that reduces the floor impact noise can be constructed without deteriorating the workability at the site.

<< Second Embodiment >>
Next, a second embodiment according to the present invention will be described with reference to FIGS. 6, 7 and 8. In the description, the configurations common to the first embodiment are designated by the same reference numerals without the description thereof (the same applies to the third to sixth embodiments). Further, the construction method is the same as that of the first embodiment (the same applies to the third to sixth embodiments) unless otherwise specified. The second embodiment is different from the first embodiment in the internal shape of the void formwork 41.

The void formwork 41 has a lower member 42 and an upper member 43, and the lower member 42 and the upper member 43 cooperate with each other to sandwich the flat plate-shaped weight 14 from above and below. FIG. 6 is a vertical cross-sectional view of the void formwork member 41 and the weight 14, FIG. 7 is a plan view of the lower member 42, and FIG. 8 is a bottom view of the upper member 43.

Similar to the first embodiment, the lower member 42 has a lower main body portion 45 and a lower protrusion 16, and the upper member 43 has an upper main body portion 46 and an upper protrusion 18. The upper surface of the lower main body 45 has an outer peripheral portion 19, an accommodating portion 48 for accommodating the weight 14, and a dividing portion 21 for dividing the accommodating portion 48, and the lower surface of the upper main body portion 46 has the outer peripheral portion 22 and the weight. It has an accommodating portion 49 for accommodating 14 and a dividing portion 24 for partitioning the accommodating portion 49, and these are provided with three accommodating portions 48 of the lower main body portion 45 and three accommodating portions 49 of the upper main body portion. It differs from the first embodiment in that two dividing portions 21 and 24 are provided to separate them.

The outer peripheral portion 19 of the lower member 42 and the outer peripheral portion 22 of the upper member 43 have the same stepped shape as in the first embodiment, so that when the upper concrete 7 (see FIG. 1) is placed, the concrete is formed. It is prevented from flowing into the void formwork member 41, and the upper member 43 is prevented from being displaced in the horizontal direction with respect to the lower member 42.

Further, by placing the upper concrete 7 from the state shown in FIG. 6, the first upper member outer peripheral surface 28, the second upper member outer peripheral surface 29, and the partition portion 24 of the upper member 43 are respectively formed of the lower member 42. The first lower member outer peripheral surface 25, the second lower member outer peripheral surface 26, and the partition portion 21 are brought close to or in contact with each other, and the lower protrusion 16 and the upper protrusion 18 are in a compressed state, so that the dynamic vibration absorber 47 is formed and the weight 14 is formed. It is the same as the first embodiment in that both the lower protrusion 16 and the upper protrusion 18 can elastically support the weight 14 even if the weight 14 vibrates up and down.

The accommodating portion 48 of the lower member 42 has a first upper surface 50 and a second upper surface 51 provided at a position recessed below the first upper surface 50 and projecting the lower protrusion 16. , The first lower surface 52 provided in the accommodating portion 49 of the upper member 43 and the second lower surface 53 provided at a position recessed above the first lower surface 52 and projecting the upper protrusion 18 are aligned in the vertical direction. They are facing each other. However, unlike the first embodiment, the second upper surface 51 and the lower protrusion 16, and the second lower surface 53 and the upper protrusion 18 are each removed from the grid-like arrangement every other time in the vertical and horizontal directions, and along the diagonal direction. They are aligned, that is, staggered.

<< Third Embodiment >>
A third embodiment according to the present invention will be described with reference to FIGS. 9 and 10. 9 and 10 show a plan view and a vertical cross-sectional view of the void formwork member 61 and the weight 62. From the state shown in FIGS. 9 and 10, the dynamic vibration absorber 63 is configured by applying a compressive force in the vertical direction to the void formwork member 61. The Tuned Mass Damper 63 according to the third embodiment is different from the first and second embodiments in that the lower protrusion 64 and the upper protrusion 65 that function as springs are provided near the center of the weight 62 in a plan view. do.

The void formwork 61 has a lower member 66 and an upper member 67. The lower member 66 has a lower main body portion 68 and one lower protrusion 64 that projects upward from the lower main body portion 68 and abuts on the weight 62 at the tip. The upper member 67 has an upper main body portion 69 and one upper protrusion 65 that projects downward from the upper main body portion 69 and abuts on the weight 62 at the tip. The upper surface of the lower main body portion 68 has an outer peripheral portion 19 and one accommodating portion 70 for accommodating the weight 62. The lower surface of the upper main body portion 69 has an outer peripheral portion 22 and one accommodating portion 71 for accommodating the weight 62.

The accommodating portion 70 of the lower member 66 has a first upper surface 72 and a second upper surface 73 arranged inside the first upper surface 72 in a plan view and recessed downward. From the second upper surface 73, a lower protrusion 64 having a quadrangular frame shape in a plan view projects upward. Further, a rectangular lower connecting portion 74 projects upward from a portion inside the lower projection 64 of the second upper surface 73 in a plan view. The accommodating portion 71 of the upper member 67 has a first lower surface 75 and a second lower surface 76 which is arranged inside the first lower surface 75 in a plan view and is recessed upward. From the second lower surface 76, an upper protrusion 65 having a quadrangular frame shape in a plan view projects downward. Further, a rectangular upper connecting portion 77 projects downward from a portion inside the second lower surface 76 in a plan view from the upper protrusion 65. The lower end of the upper protrusion 65 faces the upper end of the lower protrusion 64 in the vertical direction with the weight 62 interposed therebetween. Further, a through hole 78 is provided in the center of the plate-shaped weight 62, and the protruding ends of the lower connecting portion 74 and the upper connecting portion 77 plunge into the through hole 78, respectively, and the upper surface and the upper surface of the lower connecting portion 74 respectively. The lower surface of the connecting portion 77 faces each other with a distance of about 1 to 3 mm.

The lower protrusion 64 and the upper protrusion 65 cooperate in a plan view inside a frame connecting points indicating 3/5, preferably 1/2, of the distance from the center of gravity of the weight 62 to the contour of the weight 62. The weight 62 is elastically supported. By placing the upper concrete 7 (see FIG. 1) from the state shown in FIG. 10, the first upper member outer peripheral surface 28, the second upper member outer peripheral surface 29, and the upper connecting portion 77 of the upper member 67 are respectively. The lower member 66 comes close to or abuts on the first lower member outer peripheral surface 25, the second lower member outer peripheral surface 26, and the lower connecting portion 74. At this time, the lower protrusion 64 and the upper protrusion 65 are in a compressed state, and the dynamic vibration absorber 63 is configured. Even if the weight 62 vibrates up and down, both the lower protrusion 64 and the upper protrusion 65 always use the weight 62. Can be supported elastically.

Since the weight 62 has a plate shape, locking occurs. When the lower protrusion 64 and the upper protrusion 65 that function as springs of the dynamic vibration absorber 63 are arranged in a dispersed manner, the natural frequency of the dynamic vibration absorber 63 and the locking frequency become close to each other, and the effect of suppressing the floor vibration noise by the dynamic vibration absorber 63. May be reduced. In the present embodiment, the lower protrusion 64 and the upper protrusion 65 that function as springs are arranged near the center of the weight 62 in a plan view to lower the locking frequency so as not to approach the natural frequency of the dynamic vibration absorber 63. did.

Further, since the pillar-shaped connecting portion 79 composed of the lower connecting portion 74 and the upper connecting portion 77 penetrates through the through hole 78 provided in the weight 62, the inner surface of the through hole 78 is the connecting portion 79. By abutting on the side surface, the weight 62 is restricted from being displaced in the horizontal direction. Further, since the inner side surface of the through hole 78 is inclined or curved inward as the inner surface of the through hole 78 is reduced so that the upper end side of the through hole 78 is reduced, the contact area between the connecting portion 79 and the through hole 78 is reduced. Therefore, when the weight 62 vibrates, the frictional force between the connecting portion 79 and the through hole 78 becomes small, and the influence on the action of the dynamic vibration absorber 63 can be suppressed.

Further, even if the worker steps on the void formwork 61 during construction, the lower connecting portion 74 and the upper connecting portion 77 come into contact with each other in the central portion, so that the void formwork 61 is suppressed from being deformed. On the edge side, the first upper surface 72 of the lower member 66 and the first lower surface 75 of the upper member 67 come into contact with the weight 62, so that the deformation of the void formwork 61 is suppressed. This prevents the lower protrusion 64 and the upper protrusion 65 from being excessively deformed and damaged, or being compacted to change the spring constant.

Further, since the shape of the inner surface of the void formwork 61 is not finer than that of the first and second embodiments, it is relatively easy to manufacture the void formwork 61 made of foamed plastic.

The shapes of the lower protrusion 64 and the upper protrusion 65 may be changed to other ring shapes in a plan view. The vertical position at which the upper surface of the lower connecting portion 74 and the lower surface of the upper connecting portion 77 come into contact with each other may be changed. For example, the lower connecting portion 74 may be a part of the second upper surface 73, the lower surface of the upper connecting portion 77 may be brought into contact with the surface, and the connecting portion 79 may be formed by substantially only the upper connecting portion 77. The upper connecting portion 77 may be a part of the second lower surface 76, the upper surface of the lower connecting portion 74 may be brought into contact with the surface thereof, and the connecting portion 79 may be formed substantially only by the lower connecting portion 74. The shape for reducing the contact area between the through hole 78 and the connecting portion 79 to reduce the frictional force may be provided so that the inclination or curvature of the through hole 78 is reduced at the lower end side or the intermediate portion. The inner surface of the through hole 78 may be vertical and the side surface of the connecting portion 79 may be at least partially inclined or curved.

<< Fourth Embodiment >>
A fourth embodiment according to the present invention will be described with reference to FIGS. 11 to 13. 11 to 13 show a plan view and a vertical cross-sectional view of the void formwork member 81 and the weight 82. From the state shown in FIGS. 11 to 13, the dynamic vibration absorber 83 is configured by applying a compressive force in the vertical direction to the void formwork member 81. The Tuned Mass Damper 83 according to the fourth embodiment is similar to the third embodiment in that the lower protrusion 84 and the upper protrusion 85 that function as springs are provided on the central side of the weight 82 in a plan view. Its shape is different.

The void formwork 81 has a lower member 86 and an upper member 87. The lower member 86 has a lower main body 88 and two lower protrusions 84 that project upward from the lower main body 88 and abut on the weight 82 at the tip. The upper member 87 has an upper main body 89 and two upper protrusions 85 that project downward from the upper main body 89 and come into contact with the weight 82 at the tip. The upper surface of the lower main body portion 88 has an outer peripheral portion 19 and one accommodating portion 90 for accommodating the weight 82. The lower surface of the upper main body portion 89 has an outer peripheral portion 22 and one accommodating portion 91 for accommodating the weight 82.

The weight 82 is provided with a rectangular through hole 92 in a plan view. Two lower protrusions 84 are provided so as to sandwich the through hole 92, and each of them extends along the longitudinal direction of the through hole 92 and exhibits a rectangular shape in a plan view. Two upper protrusions 85 are provided at positions aligned with the lower protrusion 84 in the vertical direction. The lower protrusion 84 and the upper protrusion 85 are directed from a predetermined line passing through the center of gravity of the weight 82 (line XII-XII in FIG. 11) to a direction orthogonal to this line (vertical direction on the paper surface in FIG. 11) in a plan view. Inside the two lines connecting the points indicating 3/5, preferably 1/2 of the distance to the contour of the weight, the weight 82 is elastically supported in cooperation. This lowers the locking frequency and prevents the locking frequency from becoming close to the natural frequency of the Tuned Mass Damper 83. Further, since the shape of the inner surface of the void formwork 81 is not finer than that of the first and second embodiments, it is relatively easy to manufacture the void formwork 81 made of foamed plastic.

The first upper surface 93 and the second upper surface 94 formed in the accommodating portion 90 of the lower member 86, and the first lower surface 95 and the second lower surface 96 formed in the accommodating portion 91 of the upper member 87 have first contours in a plan view. Although different from those of the third embodiment, the positions and functions in the vertical direction are the same as those of the first to third embodiments. Further, the lower connecting portion 97 protruding upward from the second upper surface 94 of the lower member 86 and the upper connecting portion 98 protruding downward from the second lower surface 96 of the upper member 87 are rectangular shapes corresponding to the through holes 92 in a plan view. And functions in the same manner as in the third embodiment. The inner surface of the through hole 92 is inclined or curved so as to reduce friction with the connecting portion 99 composed of the lower connecting portion 97 and the upper connecting portion 98, as in the third embodiment.

The number of the lower protrusion 84 and the upper protrusion 85 and the shape in a plan view may be changed as long as the weight 82 is provided in a well-balanced manner so as not to tilt. The shape for reducing the contact area between the through hole 92 and the connecting portion 99 to reduce the frictional force may be changed in the same manner as in the modified example in the third embodiment.

<< Fifth Embodiment >>
A fifth embodiment according to the present invention will be described with reference to FIGS. 14 and 15. 14 and 15 show a plan view and a vertical cross-sectional view of the void formwork 101 and the weight 102. From the state shown in FIGS. 14 and 15, the dynamic vibration absorber 103 is configured by applying a compressive force in the vertical direction to the void formwork member 101. The Tuned Mass Damper 103 according to the fifth embodiment is different from the third embodiment in that it does not have a through hole 78 and a connecting portion 79, and that the plate-shaped weight 102 has a convex portion 104 and the like. The lower member 105 and the upper member 106 constituting the void formwork 101 have the same shape and operation as those of the third embodiment except that the lower connecting portion 74 and the upper connecting portion 77 (see FIG. 10) are not provided. Has an effect.

The convex portion 104 is provided in the center of the upper surface of the weight 102, and is received by the concave portion 107 defined by the inner side surface of the frame-shaped upper protrusion 65 and the second lower surface 76. It is preferable that the convex portion 104 has a pyramidal trapezoidal shape so that the contact area with the inner surface of the concave portion 107 is small, and abuts on the inner surface of the concave portion 107 only at the base portion thereof. Since the contact area is small, the frictional force between the convex portion 104 and the concave portion 107 when the weight 102 vibrates becomes small, and the influence of the vibration of the weight 102 on the action of the dynamic vibration absorber 103 can be suppressed. Further, it is desirable that a concave portion 108 having a shape corresponding to or larger than the convex portion 104 is provided in the center of the lower surface of the weight 102. By providing the recess 108 in the weight 102, when a plurality of weights 102 are stacked and stored, the convex portion 104 of the lower weight 102 is received by the recess 108 of the upper weight 102, so that the weight 102 is not bulky.

The combination of the convex portion 104 and the concave portion 108 of the weight 102 and the concave portion 107 of the void formwork member 101 may be turned upside down. Further, the convex portions 104 may be provided on the upper and lower surfaces of the weight 102, and the concave portions 107 may be provided on both the lower member 105 and the upper member 106.

<< 6th Embodiment >>
A sixth embodiment according to the present invention will be described with reference to FIGS. 16 and 17. 16 and 17 show a plan view and a vertical cross-sectional view of the void formwork member 111 and the weight 112. From the state shown in FIGS. 16 and 17, the dynamic vibration absorber 113 is configured by applying a compressive force in the vertical direction to the void formwork member 111.

The Tuned Mass Damper 113 according to the sixth embodiment has a void formwork 111 having a lower member 114 and an upper member 115, and a weight 112. The upper surface 116 inside the outer peripheral portion 19 of the lower member 114 is a horizontal flat surface, and the lower surface 117 inside the outer peripheral portion 22 of the upper member 115 is a horizontal flat surface.

The weight 112 has a plate shape and has a bulging portion 118 whose central portion bulges up and down. The two bulges are preferably in the shape of a pyramid or a truncated cone, and the tips of the two bulges 118 are horizontal flat surfaces, respectively, at the center and above of the upper surface 116 of the lower member 114. It abuts on the central portion of the lower surface 117 of the member 115. Since the lower member 114 and the upper member 115 are made of elastic foamed plastic such as beaded polystyrene foam, the central portion of the lower member 114 and the upper member 115 in the horizontal direction also has elasticity. Therefore, the bulging portion 118 of the weight 112 is elastically supported by the horizontal central portion of the lower member 114 and the upper member 115, and the other portion of the weight 112 is in contact with the lower member 114 and the upper member 115. do not have. Therefore, the weight 112 can vibrate up and down, and the void type frame member 111 and the weight 112 constitute the dynamic vibration absorber 113. The support portion of the bulging portion 118 of the weight 112 in the void formwork member 111 may be a recess.

Since the weight 112 is supported by the void formwork 111 by the bulge 118 provided in the center, the locking frequency is smaller than the natural frequency of the central part of the void formwork 111 that functions as a spring. It is possible to prevent a reduction in the effect of the dynamic vibration absorber 113 that occurs when the frequencies are close to each other. Further, since the shape of the inner surface of the void formwork 111 is less uneven, the void formwork 111 can be easily manufactured.

When the upper end of the slab is laid, it is assumed that the worker will rest on the void formwork. It was predicted that the natural frequency would fluctuate due to the creep of the lower and upper protrusions compressed at this time. Therefore, a test was conducted to confirm the fluctuation range.

The shape of the void formwork used in the test conformed to the first embodiment and was as follows. The lower protrusions and the upper protrusions were arranged in a grid pattern in three vertical rows and four horizontal rows. The distance between the centers of each protrusion was 80 mm in length and 62 mm in width. Each protrusion had a rectangular parallelepiped shape of 15 mm in length × 15 mm in width × 18 mm in height. The second upper surface and the second lower surface on which each protrusion protrudes were 35 mm in length × 35 mm in width, respectively. The difference in vertical height between the tip of the lower protrusion and the first upper surface was 6 mm, and the difference in vertical height between the tip of the upper protrusion and the first lower surface was 3 mm. As the material of the void formwork material, a bead method polystyrene foam having a foaming ratio of 65 times was used. A dynamic vibration absorber was composed of such a void formwork material and a weight (7.6 kg), and changes in the natural frequency were measured before and after loading a load assuming a person. The measurement result is shown in FIG.

The frequency at which the vibration acceleration is maximized, that is, the natural frequency, was in the early 70 Hz before loading and in the early 50 Hz after loading. All were within the octave band center frequency 63 Hz (about 44 Hz to about 88 Hz).

In order to examine the influence of the arrangement of the lower protrusion and the upper protrusion on the locking frequency, the vibration spectra of the weights of the test body a corresponding to the fifth embodiment and the test body b corresponding to the first embodiment are shown. Measurements were made for the phase difference.

FIG. 19A shows the dimensions of the test body a in which the lower protrusion and the upper protrusion are arranged in the center. FIG. 19B shows the dimensions of the test body b in which the lower protrusion and the upper protrusion are dispersedly arranged. In each of the test specimens, the material of the void formwork material was a beaded polystyrene foam having a foaming ratio of 65 times, and the weight was 7.6 kg.

The measurement results are shown in FIG. 20 (Fig. A shows the results of the test body a, and Fig. b shows the results of the test body b). The locking frequency was about 90 Hz in the test body b in which the lower protrusion and the upper protrusion were dispersedly arranged, whereas in the test body a in which the lower protrusion and the upper protrusion were arranged in the center, the locking frequency was about 90 Hz. Was about 30 Hz. When setting the natural frequency of a vibration absorber in the octave band range where the center frequency is 63 Hz, it is better to arrange the lower protrusion and the upper protrusion in the center so that the lower protrusion and the upper protrusion are arranged in a dispersed manner. Compared to the case, the locking frequency is farther from the natural frequency. Therefore, it is advantageous to arrange the lower protrusion and the upper protrusion in the center.

Although the description of the specific embodiment is completed above, the present invention can be widely modified without being limited to the above embodiment. The floor slab may be full precast concrete or cast-in-place concrete. The number of weights received by a set of void formwork members may vary. Before placing the upper concrete, the lower member and the upper member that have received the weight may be fixed to each other by nails, clips, or the like so that the outer peripheral portions and the dividing portions of the upper members are in contact with each other. The shapes of the weight and the void formwork may be changed as long as the portion of the void formwork that supports the weight functions as a spring.

1: Floor 2: Floor slab 3,47,63,83,103,113: Tuned mass damper 4: Lower concrete slab 5,41,61,81,101,111: Void formwork 6: Slab upper end bar 7: Upper concrete 11: Void 12, 42, 66, 86, 105, 114: Lower member 13, 43, 67, 87, 106, 115: Upper member 14, 62, 82, 102, 112: Weight 15, 45, 68, 88: Lower main body 16, 64, 84: Lower protrusions 17, 69, 89: Upper main body 18, 65, 85: Upper main body 19: Outer peripheral portion 22 (of lower member): Outer peripheral portion 25 (of upper member) : 1st lower member outer peripheral surface 26: 2nd lower member outer peripheral surface 28: 1st upper member outer peripheral surface 29: 2nd upper member outer peripheral surface 31, 50, 72, 93: 1st upper surface 32, 51, 73, 94: Second upper surface 33, 52, 75, 95: First lower surface 34, 53, 76, 96: Second lower surface 74, 97: Lower connecting portion 77, 98: Upper connecting portion 78, 92: Through hole 79, 99: Connecting Part 104: Convex 107: Concave (of void formwork) 118: Protruding

Claims (16)

The floor of the structure
Concrete floor slabs with voids and
Void formwork, which is substantially made of elastic foamed plastic and is arranged along the inner surface of the void.
It is equipped with a weight that is elastically supported by the void formwork material so that it can vibrate in the vertical direction.
The void form member and said weight with a configured dynamic vibration absorber,
The weight has a plate shape extending in the horizontal direction,
The void formwork has a lower member and an upper member arranged above the lower member.
The lower member has a lower main body portion that abuts on the lower surface of the void, and one or a plurality of lower main body protrusions made of foamed plastic that project upward from the lower main body portion and elastically support the weight. ,
The upper member has an upper main body portion that abuts on the upper surface of the void, and one or a plurality of upper body protrusions made of foamed plastic that project downward from the upper main body portion and elastically support the weight. The floor of the characteristic structure. The lower main body portion has a first upper surface and a second upper surface provided at a position recessed below the first upper surface and from which the lower protrusion protrudes.
The upper main body portion has a first lower surface and a second lower surface provided at a position recessed above the first lower surface and from which the upper protrusion protrudes.
The first upper surface of the lower main body and the first lower surface of the upper main body are each characterized in that the void formwork material is deformed so as to be able to partially abut on the weight. The floor of the structure according to claim 1. The lower protrusion and the upper protrusion of the weight are formed inside a frame connecting points indicating 3/5 of the distance from the center of gravity of the weight to the contour of the weight in a plan view, or in a plan view. It is characterized in that the weight is supported inside two lines connecting points indicating 3/5 of the distance from a predetermined line passing through the center of gravity to the contour of the weight in a direction orthogonal to the predetermined line. The floor of the structure according to claim 1 or 2. The weight has a through hole provided along the vertical direction.
The lower member and the upper member each have a lower connecting portion and an upper connecting portion provided so that upper and lower surfaces can come into contact with each other at positions aligned with the through hole in the vertical direction. The floor of the structure according to claim 3. One side surface of the connecting portion including the lower connecting portion and the upper connecting portion and the through hole extends along the vertical direction.
4. The fourth aspect of the invention is characterized in that the other side surface of the connecting portion and the through hole is partially inclined or curved toward the one side surface in the vertical direction and locked to the one side surface. The floor of the described structure. The structure according to claim 4 or 5 , wherein the lower protrusion and the upper protrusion each have a frame shape surrounding the through hole in a plan view and face each other with the weight in between. floor. The floor of the structure according to claim 4 or 5 , wherein a plurality of the lower protrusions and the upper protrusions are present, and each of them is arranged along the through hole. The weight has a convex portion that is received by a recess provided in the lower member and / or the upper member.
The invention according to any one of claims 1 to 3, wherein the side surface of the convex portion is inclined so as to become thinner toward the tip end, so that the concave portion abuts on the base portion of the convex portion. The floor of the structure. The convex portion is provided on either the upper surface or the lower surface of the weight.
The weight is provided at a position that is vertically aligned with the convex portion on either the upper surface or the lower surface, and has a weight concave portion having a shape corresponding to the convex portion or a shape larger than the convex portion. The floor of the structure according to claim 8. According to claim 1 or 2 , a plurality of the lower protrusions and the upper protrusions are present, and each of them faces each other in the vertical direction with the weight in between and is arranged in a grid pattern. The floor of the described structure. According to claim 1 or 2 , there are a plurality of the lower protrusions and the upper protrusions, each of which faces each other in the vertical direction with the weight in between, and is arranged in a staggered manner. The floor of the described structure. The floor of the structure
Concrete floor slabs with voids and
Void formwork, which is substantially made of elastic foamed plastic and is arranged along the inner surface of the void.
With a weight that is elastically supported by the void formwork material so that it can vibrate in the vertical direction
With
The void formwork material and the weight form a dynamic vibration absorber.
The weight has a plate shape extending in the horizontal direction, and has a bulging portion in which the central portion in the horizontal direction bulges up and down.
The void formwork has a lower member and an upper member arranged above the lower member.
The lower member abuts on the lower surface of the void and elastically supports the lower end of the bulging portion of the weight.
The floor of a structure, wherein the upper member abuts on the upper surface of the void and elastically supports the upper end of the bulging portion of the weight. The weight of the weight arranged in the void is 4 to 10% of the weight of the floor slab in the region defining the load area of the void according to any one of claims 1 to 12. The floor of the described structure. It is a construction method for the floor of a structure.
A void formwork material substantially made of elastic foamed plastic, and a step of arranging a weight arranged inside the void formwork material on the upper surface of the lower concrete slab.
A step of arranging the upper end reinforcement of the slab above the lower concrete slab on which the void formwork material and the weight are installed, and
A step of placing concrete on the lower concrete slab on which the upper end reinforcement of the slab is arranged to manufacture a floor slab having voids is provided.
The weight is by being elastically supported oscillatably the voids form member in the vertical direction, the voids form member and said weight with a configured dynamic vibration absorber,
The weight has a plate shape extending in the horizontal direction,
The void formwork has a lower member and an upper member arranged above the lower member.
The lower member has a lower main body portion that defines the lower surface of the void, and one or a plurality of lower protrusions made of foamed plastic that project upward from the lower main body portion and elastically support the weight. death,
The upper member has an upper body portion that defines the upper surface of the void, and one or a plurality of foamed plastic upper body protrusions that project downward from the upper body portion and elastically support the weight. ,
After the step of manufacturing the floor slab, the lower member and the upper member are characterized in that the lower protrusion and the upper protrusion are compressed in the vertical direction by the weight of the concrete. Construction method of the floor of the structure to be constructed. The outer peripheral portion of the lower member is located inside the outer peripheral surface of the first lower member and the outer peripheral surface of the first lower member, which is located on the outermost side and faces upward, and is above the outer peripheral surface of the first lower member. It has a second lower member outer peripheral surface that is positioned and faces upward.
The outer peripheral portion of the upper member is located on the outermost side and faces downward, and is located inside the outer peripheral surface of the first upper member facing the outer peripheral surface of the first lower member and the outer peripheral surface of the first upper member. It has a second upper member outer peripheral surface that is located above the outer peripheral surface of the first upper member and faces downward, and faces the second lower member outer peripheral surface.
The method for constructing a floor of a structure according to claim 14 , wherein the outer peripheral surface of the second lower member is arranged above the outer peripheral surface of the first upper member. The step of installing the void formwork and the weight is performed in the factory.
14. Construction method of the floor of the structure described in.

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