Floor structure and construction method of floor structure

Abstract

To provide floor structure and a construction method of the floor structure, which can reduce floor thickness and easily construct the same.SOLUTION: A floor structure has a RC slab 2 provided as a structural body of a structure, and a CLT panel 3 that is a non-structural body and provided along an undersurface of the RC slab. Truss reinforcements 22 are used as reinforcements of the RC slab. The floor structure also has shear keys 5B provided between the CLT panel and the RC slab. The shear keys are formed in a U-shape from steel material, and serve as spacers for the truss reinforcements of the RC slab.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a floor structure and a method for constructing the floor structure. [Background technology]

[0002] CLT (Cross Laminated Timber), which is made by laminating and gluing alternately planks so that their grain directions are perpendicular to each other, is a thick panel-shaped wooden material that is used as a structural material for buildings (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-78307 [Patent Document 2] Japanese Patent Application Publication No. 2019-138053 Summary of the Invention [Problem to be solved by the invention]

[0004] When using wooden structures for the main structural parts of a fire-resistant structure, the wooden materials must be covered with fire-resistant covering material. For this reason, when CLT panels are used as structural materials for the floor of a fire-resistant structure, the CLT panels are covered with fire-resistant covering material. In such floor structures, finishing materials are applied to the finished surface to cover the fire-resistant covering material, which increases the floor thickness and increases the number of construction steps, making construction more complicated.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a floor structure and a floor structure construction method that can reduce floor thickness and can be easily constructed. [Means for solving the problem]

[0006] In order to achieve the above object, the floor structure of the present invention comprises an RC slab that is provided as a structural element of a structure, and a CLT panel that is a non-structural element and is provided along the underside of the RC slab, wherein truss bars are used for the reinforcing bars of the RC slab, and further comprises a shear key provided between the CLT panel and the RC slab, the shear key being formed into a U-shape from steel and also serving as a spacer for the truss bars of the RC slab.

[0007] In this invention, by installing RC slabs as the structural components of the structure, CLT panels can be installed as vibration-damping materials, sound-proofing materials, and finishing materials rather than as the main structural components of the structure. Because the CLT panels are not the main structural components of the structure, there is no need to install fire-resistant covering materials on the CLT panels, even in the case of fire-resistant structures. Furthermore, because the CLT panels are not covered with fire-resistant covering materials, they can be installed in an exposed state as a finishing material with an exposed finish. In this way, by not requiring fire-resistant covering materials, the floor thickness can be reduced and the floor can be easily constructed. In addition, by having a shear key between the CLT panel and the RC slab, it is possible to improve the vibration-damping and sound-insulating performance of not only the CLT panel but also the composite floor in which the CLT panel and the RC slab are integrated. Furthermore, because the shear key also serves as a spacer for reinforcing the RC slab, there is no need to provide a separate spacer for reinforcing the RC slab, making construction easier and reducing the number of parts, making management easier. [Effects of the Invention]

[0008] According to the present invention, the floor thickness can be reduced and construction can be easily carried out. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a vertical cross-sectional view showing a floor structure according to a first embodiment. [Figure 2] FIG. 2 is a partially enlarged view of FIG. [Figure 3]FIG. 10 is a vertical cross-sectional view showing a floor structure according to a second embodiment. [Figure 4] FIG. 4 is a cross-sectional view taken along line AA in FIG. [Figure 5] FIG. 10 is a vertical cross-sectional view showing a floor structure according to a third embodiment. [Figure 6] FIG. 10 is a vertical cross-sectional view showing a floor structure according to a fourth embodiment. [Figure 7] FIG. 10 is a vertical cross-sectional view showing a modified example of the floor structure according to the fourth embodiment. [Figure 8] FIG. 10 is a vertical cross-sectional view showing another modified example of the floor structure according to the fourth embodiment. [Figure 9] FIG. 10 is a vertical cross-sectional view showing a floor structure according to a fifth embodiment. [Figure 10] FIG. 1 is a diagram showing a reverberation chamber used in a measurement test of floor impact sound insulation performance. [Figure 11] FIG. 1 is a plan view of the upper reverberation chamber. [Figure 12] FIG. 1 is a plan view of the lower reverberation chamber. [Figure 13] This is a diagram of the measurement equipment system for the measurement test of the deck impedance / natural frequency. [Figure 14] FIG. 1 is a diagram illustrating the concept of response impedance within impact time. [Figure 15] FIG. 1 is a side view illustrating loading in a static deflection measurement test and a shear key shear test. [Figure 16] FIG. 10 is a plan view illustrating loading in a static deflection measurement test and a shear key shear test. [Figure 17] 1 is a table showing an overview of the test specimens used in the sound insulation performance measurement test, static deflection measurement test, and shear key shear test. [Figure 18] (a) is a plan view of specimen 1-3, (b) is a cross-sectional view of (a) taken along line XX', (c) is a cross-sectional view of (a) taken along line YY', and (d) is an elevation (side view) of specimen 1-3. [Figure 19] (a) is a plan view of the test specimen 4, (b) is a cross-sectional view of (a) taken along line XX', (c) is a cross-sectional view of (a) taken along line YY', and (d) is an elevation (side view) of the test specimen 4. [Figure 20](a) is a plan view of the test specimen 5, (b) is a cross-sectional view taken along line XX' of (a), (c) is a cross-sectional view taken along line YY' of (a), and (d) is an elevation (side view) of the test specimen 5. [Figure 21] FIG. 10 is a diagram showing shear key allocation pattern A of specimen 1. [Figure 22] FIG. 10 is a diagram showing shear key allocation pattern B of specimen 2. [Figure 23] FIG. 10 is a diagram showing shear key allocation pattern C of specimen 3. [Figure 24] FIG. 10 is a diagram showing shear key allocation pattern D of specimen 4. [Figure 25] (a) is a side view of the shear key CLC8×160, (b) is a side view showing the shear key CLC8×160 set at a 90° angle to the test specimen, (c) is a plan view of (b), (d) is a side view showing the shear key CLC8×160 set at a 45° angle to the test specimen, and (e) is a plan view of (d). [Figure 26] (a) is a side view of the shear key of the lag screw bolt, (b) is a side view showing the test specimen in (a) set at a 90° angle, (c) is a plan view of (b), and (d) is a side view of the lag screw bolt M16. [Figure 27] (a) is a plan view showing the deflection measurement positions common to specimens 1b-4b, (b) is a side view, and (c) is a front view. [Figure 28] (a) is a diagram showing the measurement position of the impedance common to test specimens 1b-3b, (b) is a side view, (c) is a diagram showing the measurement position of the impedance common to test specimen 4b, and (d) is a side view. [Figure 29] This is a table showing the results of the sound insulation performance measurement test and static deflection measurement test (LH (heavy floor impact sound), deflection amount) for each test specimen. [Figure 30] 10 is a table showing the stiffness and strength of each shear key. [Figure 31](a) is an image showing the state of the shear key after the CLC8-90 (90°) test, (b) is an image showing the state of the shear key after the CLC8-45,135 (45°, 135°) test, (c) is an image showing the state of the shear key after the LSM12-90 (90°) test, and (d) is an image showing the state of the shear key after the LSM16-90 (90°) test. [Figure 32] 10 is a graph showing the relationship between the octave band center frequency and the floor impact sound level for each test specimen. [Figure 33] 10 is a graph showing the relationship between displacement and load for each shear key. [Figure 34] This is a floor plan of the second floor of the building where the sound insulation performance measurement test (bare concrete surface) will be conducted. [Figure 35] This is a floor plan of the first floor of the building where the sound insulation performance measurement test (bare concrete surface) will be conducted. [Figure 36] 1 is a table showing the heavy floor impact sound insulation performance and impact impedance for each measurement number in the sound insulation performance measurement test (bare concrete surface). [Figure 37] This is the result of measurement No. 1 of the sound insulation performance measurement test (bare concrete surface). [Figure 38] This is the measurement result of measurement No. 2 of the sound insulation performance measurement test (bare concrete surface). [Figure 39] This is the result of measurement No. 3 of the sound insulation performance measurement test (bare concrete surface). [Figure 40] These are the results of measurement No. 4 of the sound insulation performance measurement test (bare concrete surface). [Figure 41] This is a floor plan of the second floor of the building where the sound insulation performance measurement test (finished surface) will be conducted. [Figure 42] This is a table showing the heavy floor impact sound insulation performance and impact impedance for each measurement number in the sound insulation performance measurement test (finish surface). [Figure 43] This is the result of measurement No. 1 of the sound insulation performance measurement test (bare finish). [Figure 44] This is the result of measurement No. 2 of the sound insulation performance measurement test (bare finish). [Figure 45]This is the result of measurement No. 3 of the sound insulation performance measurement test (bare finish). [Figure 46] These are the results of measurement No. 4 of the sound insulation performance measurement test (bare finish). DETAILED DESCRIPTION OF THE INVENTION

[0010] (First embodiment) A floor structure and a construction method for the floor structure according to a first embodiment of the present invention will be described below with reference to Figs. 1 and 2. As shown in Fig. 1, the floor structure 1 according to the first embodiment has an RC slab 2 and a CLT panel 3 installed along the underside of the RC slab 2. In this embodiment, the RC slab 2 is supported by RC beams 4. The CLT panel 3 is a CLT (Cross Laminated Timber) panel made by stacking and bonding slats alternately so that their fiber directions are perpendicular to each other. The CLT panel 3 is installed between horizontally adjacent beams 4.

[0011] In the floor structure 1 of this embodiment, the RC slab 2 is provided as a main structural component that supports vertical loads and separates floors, and the CLT panel 3 is provided as a vibration-proofing material and a sound-insulating material that isolates vibrations and sounds. 、 The CLT panels 3 are not a main structural part, do not support the load of the structure, and do not separate the floors. The underside 3c of the CLT panels 3 is exposed downward as a bare finish.

[0012] As shown in Figure 2, in this embodiment, a cutout 41 into which the end of the CLT panel 3 is fitted is formed in the beam 4. The underside 3c of the CLT panel 3 near the edge 3a is covered with the concrete of the beam 4, and the central portion 3e other than the edge 3a is exposed downward as a bare finish.

[0013] A shear key 5 is provided between the CLT panel 3 and the RC slab 2. The shear key 5 is, for example, a lag screw or structural screw, and its lower side is inserted into the CLT panel 3 from above, and its upper side protrudes above the top surface of the CLT panel 3 and is fixed to the concrete 21 of the RC slab 2. The structural screw may be inserted into the CLT panel 3 from an oblique direction.

[0014] A construction method for a floor structure according to this embodiment will now be described. The construction method for a floor structure according to this embodiment comprises a CLT panel installation process for installing CLT panels 3, an RC slab installation process for constructing RC slabs 2, and a shear key installation process for installing shear keys 5. The CLT panel installation process is carried out prior to the RC slab installation process. The shear key installation process may be carried out before the CLT panel installation process, i.e., before the CLT panels 3 are installed in their installation positions, or it may be carried out after the CLT panel installation process, i.e., after the CLT panels 3 are installed in their installation positions.

[0015] In the CLT panel installation process, the edge 3a of the CLT panel 3 is fitted into the cutout 41 of the beam 4, and the CLT panel 3 is installed at the installation position. Temporary supports for supporting the CLT panel 3 may be provided.

[0016] The RC slab construction process includes a reinforcement process in which reinforcing bars 27 of the RC slab 2 are installed above the CLT panels 3, and a concrete pouring process in which concrete 21 for the RC slab 2 is poured after the reinforcement process. In the RC slab construction process, the CLT panels 3 are used as formwork for the underside of the RC slab 2. The floor structure is constructed by carrying out the reinforcement process and concrete pouring process and then curing the concrete for a predetermined period of time. The shear key installation process may be carried out before or after the reinforcement process.

[0017] The functions and effects of the floor structure 1 and the floor structure construction method according to the first embodiment will be described. In the floor structure 1 according to the present embodiment, the RC slab 2 is provided as a structural component of the structure, so the CLT panels 3 can be provided as vibration-damping materials, sound-proofing materials, or finishing materials rather than as a main structural component of the structure. Because the CLT panels 3 are not a main structural component of the structure, there is no need to provide fire-resistant covering materials on the CLT panels 3, even in the case of a fire-resistant structure. Furthermore, because the CLT panels 3 are not covered with fire-resistant covering materials, they can be installed in an exposed state as a finishing material with an exposed finish. In this way, the elimination of the need for fire-resistant covering materials allows the floor thickness to be reduced, and the floor structure 1 can be easily constructed.

[0018] The floor structure 1 according to the present embodiment has a shear key 5 provided between the CLT panel 3 and the RC slab 2. This configuration improves vibration-proofing and sound-insulating performance as a composite floor that integrates not only the CLT panel 3 but also the CLT panel 3 and the RC slab 2. It is also expected to have the effect of suppressing long-term deflection of the RC slab 2.

[0019] In the floor structure 1 according to the present embodiment, the ends of the CLT panels 3 are fitted into cutouts 41 formed in the beams 4 that support the RC slab 2. This configuration allows the ends of the CLT panels 3 to be supported by the RC slab 2. Furthermore, because the ends of the CLT panels 3 are not exposed, the design can be improved.

[0020] Furthermore, in the floor structure construction method according to the first embodiment, the CLT panels 3 installed in the CLT panel installation process are used as formwork in the RC slab construction process. This makes it easier to install and remove the formwork for the RC slab 2.

[0021] (Other embodiments) Next, other embodiments will be described based on the accompanying drawings. Components and parts that are the same as or similar to those in the first embodiment described above will be designated by the same reference numerals, and their explanation will be omitted. Configurations that differ from the first embodiment will be described.

[0022] (Second embodiment) As shown in Figures 3 and 4, in the floor structure 1B according to the second embodiment, truss reinforcement 22 is used as the reinforcing bars of the RC slab 2. The truss reinforcement 22 includes two bottom reinforcement bars 23 located on the lower side, a top reinforcement bar 24 located on the upper side, and two lattice reinforcement bars 25 connected to the bottom reinforcement bars 23 and the top reinforcement bars 24. The two bottom reinforcement bars 23 are arranged parallel to each other with a horizontal gap between them. The top reinforcement bar 24 is arranged parallel to the two bottom reinforcement bars 23 and is located above the approximate center of the two bottom reinforcement bars 23. The lattice reinforcement bars 25 are corrugated reinforcing bars and are arranged in a truss shape between one bottom reinforcement bar 23 and the top reinforcement bar 24, and between the other bottom reinforcement bar 23 and the top reinforcement bar 24. A plurality of truss reinforcement bars 22 are arranged in the RC slab 2.

[0023] The shear key 5B is made of rebar or rod-shaped steel and is bent into a U-shape. The shear key 5B is positioned so that the U-shape opens downward. The lower side of the shear key 5B is inserted into the CLT panel 3 from above. The shear key 5B is designed so that its vertical dimension is larger than that of the truss reinforcement 22. Furthermore, the shear key 5B is designed so that the length from the top surface to the upper end of the CLT panel 3 when inserted into the CLT panel 3 is larger than the vertical length of the truss reinforcement 22.

[0024] The truss reinforcement 22 is placed overlapping the shear key 5B installed on the CLT panel 3. In other words, the shear key 5B also serves as a spacer for the reinforcement (truss reinforcement 22) of the RC slab 2. The top reinforcement 24 of the truss reinforcement 22 overlaps the corner 51 at the upper end of the shear key 5B, and the two bottom reinforcement reinforcement 23 of the truss reinforcement 22 are placed so as to sandwich the shear key 5B from both sides. The bottom reinforcement 23 is placed above the CLT panel 3 with a gap between them.

[0025] The floor structure 1B according to the second embodiment described above has the same effects as the first embodiment. In the floor structure 1B according to the second embodiment, the shear keys 5B also serve as spacers for reinforcing bars (truss bars 22) of the RC slab 2. This configuration eliminates the need to separately provide spacers for reinforcing bars of the RC slab 2, facilitating construction and reducing the number of parts, making management easier.

[0026] (Third embodiment) As shown in Figure 5, in the floor structure 1C according to the third embodiment, the CLT panel 3 is configured to be removable from the RC slab 2. An insert 26 is embedded in the RC slab 2. In Figure 5, the reinforcing bars of the RC slab 2 are omitted. The CLT panel 3 is fixed to the RC slab 2 with bolts 61 that screw into the insert 26. The CLT panel 3 can be removed from the RC slab 2 by removing the bolts 61. Furthermore, after removing the CLT panel 3 from the RC slab 2, a new CLT panel 3 can be attached to the RC slab 2. That is, in the floor structure 1C according to the second embodiment, the CLT panel 3 is detachable from the RC slab 2.

[0027] The CLT panel 3 has a hole 31 that penetrates vertically and through which a bolt 61 is inserted. The hole 31 has a straight portion 32 located on the upper side and a tapered portion 33 located on the lower side. The straight portion 32 is a circular hole that extends vertically and has the same diameter throughout the entire length. The tapered portion 33 is a hole that extends vertically and gradually increases in diameter from top to bottom. An opening 33a at the upper end of the tapered portion 33 is the same circular shape as the round hole of the straight portion 32, and an opening 33b at the lower end of the tapered portion 33 is larger in circle than the opening 33a at the upper end. The tapered portion 33 is formed in a truncated cone shape. A sealing material 64 that seals the hole 31 is provided at the lower end of the hole 31. The sealing material 64 is made of wood, for example, and has a finished bottom surface.

[0028] When the CLT panel 3 is fixed to the RC slab 2, the upper side of the bolt 61 is threaded into the insert 26 of the RC slab 2, and the lower side is disposed in the hole 31 of the CLT panel 3. The lower end of the bolt 61 is located in the tapered portion 33. A washer 62 is attached to the bolt 61 from below, and a nut 63 is fastened to the washer 62 from below. The outer shape of the washer 62 is formed in a truncated cone shape whose diameter gradually increases from top to bottom. The outer shape of the washer 62 corresponds to the tapered portion 33. The washer 62 can be fitted into the tapered portion 33. When the washer 62 is fitted into the tapered portion 33, the outer surface of the washer 62 comes into surface contact with the inner surface of the tapered portion 33. When the nut 63 is fastened to the bolt 61, the outer surface of the washer 62 presses against the inner surface of the tapered portion 33, compressing the CLT panel 3. At this time, a compressive force is generated as the washer 62 pushes the CLT panel 3 upward toward the RC slab 2. The friction force proportional to this compressive force plays the same role as a shear key, transmitting shear force when the CLT panel 3 and the RC slab 2 slip.

[0029] In the third embodiment, the beam 4 has a cutout 41 similar to that in the first embodiment, but the edge 3a of the CLT panel 3 is not fitted into the cutout 41. A fixing timber 7 is fitted into the cutout 41. The end face 7a of the fixing timber 7 facing the CLT panel 3 is gradually tapered upward from the bottom toward the CLT panel 3. The lower end of the fixing timber 7 facing the CLT panel 3 is located directly above the side face of the beam 4, and as it extends upward from the bottom, it gradually protrudes toward the CLT panel 3 beyond the side face of the beam 4. In the third embodiment, the end face 3f of the CLT panel 3 is tapered and corresponds to the end face 7a of the fixing timber 7 facing the CLT panel 3. The end face 3f of the CLT panel 3 is gradually tapered upward from the bottom toward the center in a plan view. The edge 3a of the CLT panel 3 is fixed to the fixing timber 7 with fasteners 71 such as mounting nails. At this time, because the end face 3f of the CLT panel 3 and the end face 7a of the fixing timber 7 are tapered, tightening the nut 63 generates an axial force between the end face 3f of the CLT panel 3 and the end face 7a of the fixing timber 7 in a direction along the surface of the CLT panel 3 (horizontal direction), and a friction force proportional to this compressive force can be expected to have the effect of compensating for the fixing device 71.

[0030] A method for replacing a CLT panel 3 in the floor structure 1C of the third embodiment will be described. First, the nuts 63 are loosened to remove the bolts 61 from the inserts 26, and the bolts 61, nuts 63, and washers 62 are removed from the CLT panel 3, and the fasteners 71 are also removed. Next, the CLT panel 3 is removed from the RC slab 2. At this time, the fastening timbers 7 are also removed from the RC slab 2 along with the CLT panel 3. Next, new fastening timbers 7 are installed in the cutouts 41 of the beams 4. Next, the new CLT panel 3 is placed below the RC slab 2, and the CLT panel 3 is fixed to the fastening timbers 7. The bolts 61, nuts 63, and washers 62 are then attached to fix the CLT panel 3 to the RC slab 2. The CLT panel 3 is replaced in this manner.

[0031] The floor structure 1C according to the third embodiment achieves the same effects as the first embodiment. In the floor structure 1C according to the third embodiment, the insert 26 can function as a shear key 5B. In the floor structure 1C according to the third embodiment, the CLT panel 3 is configured to be detachable from the RC slab 2. With this configuration, if the CLT panel 3 is damaged due to an earthquake, fire, or the like, the CLT panel 3 can be easily replaced. Furthermore, even if the CLT panel 3 is damaged, the performance of the CLT panel 3 (such as vibration-damping and sound-insulating performance) can be maintained by replacing the CLT panel 3.

[0032] Furthermore, if the fixing wood 7 itself is not damaged and the position of the fixing device 71 that secures the newly installed CLT panel 3 can be shifted from the original position, it can be reused without replacement.

[0033] (Fourth embodiment) As shown in FIG. 6, a floor structure 1D according to the fourth embodiment is employed when the beams 4D are steel beams. In the floor structure 1D according to the fourth embodiment, the upper surfaces 3b of the CLT panels 3D are located at the same height as the upper end surfaces 4a of the beams 4D, and the lower surfaces 3c of the CLT panels 3D are located at the same height as the vertical middle of the beams 4D. An RC slab 2 is placed on the beams 4D and the CLT panels 3D. The steel beams in this embodiment are H-shaped steel beams. The upper surfaces 3b of the CLT panels 3D are located at the same height as the upper surfaces of the upper flanges 42 of the steel beams. The lower surfaces 3c of the CLT panels 3D are located at the same height as the vertical middle of the webs 43 of the beams 4D. In this embodiment, the height of the upper surfaces 3b of the CLT panels 3D is the same as the upper end surfaces 4a of the beams 4D, but as shown in FIG. 7, the height of the upper surfaces 3b of the CLT panels 3D may be different from that of the upper end surfaces 4a of the beams 4D.

[0034] The upper side of the beam 4D is embedded in concrete in the height range where the CLT panel 3D is provided. The concrete in which the upper side of the beam 4D is embedded is referred to as beam concrete 45. and The upper end of the concrete beam 45 is at the same height as the upper end surface 4a (upper end surface of the upper flange 42) of the beam 4D. An RC slab 2 is provided on the concrete beam 45.

[0035] A CLT panel 3D is placed to the side of the concrete beam 45. The side of the concrete beam 45 and the edge 3a of the CLT panel 3D face each other. The upper side of the edge 3a of the CLT panel 3D protrudes more to the side (towards the concrete beam 45) than the lower side. The protruding portion on the upper side of the edge 3a of the CLT panel 3D is called a protrusion 34. A cutout 41D is formed in the concrete beam 45, into which the protrusion 34 at the end of the CLT panel 3D is fitted. In the fourth embodiment, the protrusion 34 at the edge 3a of the CLT panel 3D is covered by the concrete of the beam 4D. The underside 3c of the CLT panel 3D is exposed downward as a bare finish. A fire-resistant covering material (not shown) is provided on the lower side of the beam 4D that is not covered by the concrete beam 45.

[0036] In the floor construction method according to the fourth embodiment, in the CLT panel installation step, a formwork for the lower side of the concrete beam 45 is installed. The formwork 81 for the lower side of the concrete beam 45 may be supported by the beam 4D (steel beam). In FIG. 6, the formwork 81 for the lower side of the concrete beam 45 is shown on only one side of the web 43. The CLT panel 3D is installed so as to be continuous with the formwork 81 for the lower side of the concrete beam 45. In this embodiment, the edge 3a of the CLT panel 3D is used as the formwork on the side of the concrete beam 45. Temporary supports 82 are provided to support the CLT panel 3D. Next, the beam concrete construction step is performed, in which the concrete beam 45 is poured. Next, the RC slab construction step is performed.

[0037] After the beam concrete installation process, a fire-resistant covering process is carried out in which a fire-resistant covering material is provided on the lower side of the beam 4D that is not covered by the beam concrete 45. In this embodiment, the beam concrete 45 is provided between the CLT panel 3D and the beam 4D, and the CLT panel 3D and the beam 4D are not in contact with each other. This prevents the CLT panel 3D from affecting the fire resistance certification. In the fire-resistant covering process, after the beam concrete 45 has hardened and the formwork 81 and temporary supports 82 have been removed, a fire-resistant covering material is provided on the lower side of the beam 4D that is not covered by the beam concrete 45.

[0038] In the floor construction method according to the fourth embodiment, the concrete of the RC slab 2 and the concrete beam 45 may be poured together. Also, as shown in Fig. 8, the formwork 81 and temporary support 82 below the concrete beam 45 may be integrated so that they can be used interchangeably.

[0039] The floor structure 1D according to the fourth embodiment has the same effects as the first embodiment, even when the beams 4D are steel beams.

[0040] (Fifth embodiment) As shown in Figure 9, a floor structure 1E according to the fifth embodiment is employed when the beams 4E are steel beams. In the floor structure 1E according to the fifth embodiment, CLT panels 3E are placed on top of the beams 4E. The beams 4E are covered with fire-resistant covering material 48, and the CLT panels 3E are placed on top of fire-resistant covering material 48a that covers the top surfaces of the beams 4E. An RC slab 2 is placed on top of the CLT panels 3E.

[0041] A stud 46 is joined to the upper flange 42 of the beam 4E so as to protrude upward. No CLT panel 3E is placed around the stud 46, and concrete is provided. The concrete provided around the stud 46 on the upper flange 42 is called beam concrete 47. The beam concrete 47 is provided integrally with the concrete of the RC slab 2. The stud 46 is provided as a shear key between the beam 4E and the RC slab 2. By providing the stud 46, it is possible to expect a composite effect between the beam 4E (steel beam) and the RC slab 2.

[0042] In the floor structure construction method according to the fifth embodiment, in the CLT panel installation step, a CLT panel 3E is installed so that its edge 3a is placed on a beam 4E. The end face 3d of the CLT panel 3E also serves as the formwork for the side of the concrete on the beam 47. Next, the RC slab construction step is carried out. After the reinforcement of the RC slab 2 is arranged, the concrete of the RC slab 2 and the concrete on the beam 47 are poured together.

[0043] The floor structure 1E according to the fifth embodiment achieves the same effects as the first embodiment, even when the beams 4E are steel beams. Furthermore, in the floor structure construction method according to the fourth embodiment, it is necessary to provide a fire-resistant covering material on the lower side of the beams 4D that is not covered by the beam concrete 45 after the beam concrete 45 is constructed. In contrast, the floor structure construction method according to the fifth embodiment differs from the fourth embodiment in that the fire-resistant covering material is constructed prior to the construction of the beam-top concrete 47. As a result, the floor structure construction method according to the fifth embodiment allows the CLT panels 3E to be directly supported on the beams 4E before concrete is poured, eliminating the need to provide temporary supports 82 (see FIG. 6) as in the fourth embodiment.

[0044] For the floor structure having the RC slab and CLT panel of the present invention, we conducted a sound insulation performance measurement test, a static deflection measurement test, a shear key shear test, a floor impact sound insulation measurement test, and a sound insulation performance measurement test in an actual building where the structure was installed. Each measurement test is explained below. In the following description, the term "floor slab" and "test floor slab" refers to the floor slab of the floor structure of the present invention.

[0045] (Sound insulation performance measurement test) In the sound insulation performance measurement test, floor impact sound insulation performance and floor slab impedance / natural frequency were measured.

[0046] (Floor impact sound insulation performance measurement test) The floor impact sound insulation performance measurement test was carried out at the General Building Research Corporation of Japan (Suita City, Osaka Prefecture). As shown in Figure 10, the upper reverberation chamber (second reverberation chamber, V = 178.5 m) was placed above the other chamber. 2 ), the lower reverberation chamber (4th reverberation chamber, V=134.2m 2 ) and placed a test specimen with the floor structure of the present invention in the opening between the two reverberation chambers to conduct the test. Figure 11 shows a plan view of the upper reverberation chamber. S1 to S5 in the figure are excitation points, located at five diagonal points. Figure 12 shows a plan view of the lower reverberation chamber. R1 to R5 are sound receiving points (measurement points). Figure 12 also shows the heights of the sound receiving points from the floor.

[0047] Tests were conducted on the light floor impact sound insulation performance (tapping machine) and the heavy floor impact sound insulation performance (tire impact source).

[0048] (1) Lightweight floor impact sound insulation performance The test is based on ISO10140-3 "Acoustics - Laboratory measurement of sound insulation of building elements - Part 3: Measurement of impact sound insulation," and involves measuring normalized floor impact sound levels using a standard light impact source (tapping machine) (see Figures 11 and 12 for excitation and measurement points). The measurement equipment system is as follows: The excitation device is a standard light impact source (tapping machine, B&K Type-3204). The receiving devices are a microphone (Ono Sokki MI-1233), a preamplifier (Ono Sokki MI-3110), a multi-channel signal analyzer (Ono Sokki DS-2100), and a control PC (Toshiba DynaBook).

[0049] The normalized light floor impact sound level is calculated using the following procedure. (a) The test deck is vibrated at each excitation point using a tapping machine, and the equivalent sound pressure level is measured at five receiving points set up in the fourth reverberation room. (b) Energy average the equivalent sound pressure level values ​​obtained at the five sound receiving points. (c) Using the above steps (a) and (b), calculate the average energy value for each of the five excitation points. Calculate the arithmetic mean of these values ​​to calculate the light floor impact sound level. (d) Calculate the equivalent sound absorption area of ​​the fourth reverberation room from the reverberation time of the room, and use the standard equivalent sound absorption area (10 m 2 ) and calculate the standardized lightweight floor impact sound level. The measurement frequency is a 1 / 3 octave band with a center frequency of 50 to 500 Hz, and the values ​​for an octave band with a center frequency of 63 to 4 kHz are calculated from the results.

[0050] (2) Heavy floor impact sound insulation performance (tire impact source) The test was conducted in accordance with ISO10140-3 "Acoustics - Laboratory measurement of sound insulation of building elements - Part 3: Measurement of impact sound insulation," and involved measuring the heavy-duty floor impact sound level using a standard heavy-duty floor impact source (tire impact source) with impact force characteristics (1) specified in JIS A1418-2:2000 "Methods for measuring floor impact sound insulation performance of buildings - Part 2: Method using standard heavy-duty impact limits" (see Figures 11 and 12 for excitation and measurement points). The measurement equipment system consisted of the following: the excitation device was a standard light-duty impact source (tire impact source, Satsuki Seisakusho T-type). The sound receiving devices were a microphone (Ono Sokki MI-1233), a preamplifier (Ono Sokki MI-3110), a multi-channel signal analyzer (Ono Sokki DS-2100), and a control PC (Toshiba DynaBook).

[0051] The heavy floor impact sound level is calculated using the following procedure. (a) The test deck is vibrated by a tire impact source at each excitation point, and the maximum sound pressure level (dynamic characteristic F) is measured at five sound receiving points set up in the fourth reverberation chamber. (b) The maximum sound pressure levels obtained at the five receiving points are energy averaged. (c) Using the above steps (a) and (b), calculate the average energy value for each of the five excitation points. Calculate the heavy floor impact sound level by arithmetically averaging these values. The measurement frequency is a 1 / 3 octave band with a center frequency of 20 to 630 Hz, and the values ​​for the octave band with a center frequency of 31.5 to 500 Hz are calculated from the measurement results.

[0052] (Deck slab impedance / natural frequency measurement test) The measurement tests for the floor slab's impedance / natural frequency were carried out at the General Building Research Corporation of Japan (Suita City, Osaka Prefecture). As with the measurement tests for floor impact sound insulation performance, the tests were carried out using the second and fourth reverberation chambers, which are located above and below each other, with the test specimen placed in the opening between the two chambers.

[0053] The measurement equipment system diagram for the test to measure the deck slab's impedance / natural frequency is shown in Figure 13. In this test, the impact hammer was PCB 0860D20, the IPC POWER UINIT was PCB MODEL 480E09, the vibration acceleration pickup was Ono Sokki NP-2130, the charge amplifier was Ono Sokki CH-1200, the multi-channel signal analyzer was Ono Sokki DS-2100, and the control PC was Toshiba DynaBook.

[0054] The impedance / natural frequency is calculated using the following procedure. (a) An acceleration pickup is fixed to the test deck, and the vicinity of it is vibrated with an impact hammer. The excitation force output from the impact hammer and the acceleration generated in the test deck are measured. The impact hammer used is PCB 086D20, with a medium head (impact frequency approximately 200Hz). (b) The excitation force and acceleration are input into the analyzer, and the following two analyses are performed to determine the impedance. The sampling frequency for the analysis is 12.8 kHz, and the frame length is 1.28 seconds.

[0055] -Shock time response impedance The concept of response impedance within impact time is shown in Figure 14. The impact time range shown in Figure 14 is the target. The square root of the ratio of the squared integral values ​​of the excitation force and vibration velocity time waveforms within the impact time is taken, and the common logarithm is multiplied by 20 to determine the response impedance within impact time. Three measurements are taken for each excitation point, and the results are arithmetically averaged. Due to the calculation method, the response impedance within impact time shows a constant value regardless of frequency, and is mainly used to examine floor impact sound. - Total time response impedance / natural frequency The time waveforms of the excitation force and vibration velocity are Fourier transformed, and the excitation force is divided by the vibration velocity in the frequency domain to determine the impedance. The impedance level is then determined by dividing it by the reference impedance, taking the logarithm, and multiplying by 20. Three measurements are taken and the average is calculated. The total time response impedance has frequency characteristics, and it is possible to observe the modal characteristics of the slab. From the characteristics of the total time response impedance, the position of the clear dip at the lowest frequency is determined to be the natural frequency.

[0056] (Static deflection measurement test, shear key shear test) In the static deflection measurement test, as shown in Figure 15, a test deck 101, which serves as the test specimen, is erected on a support 102, and a loading plate is placed on the test deck 101. In Figure 15, the load applied by the loading plate is indicated by the reference symbol 103. Reference symbol 104 in the figure indicates an angle. After loading, the displacement of the support 102 alone and the displacement of the support 102 and the entire test specimen are measured, and the displacement of the test specimen alone is measured by subtracting the displacement of the support 102 alone from the displacement of the support 102 and the entire test specimen. Figure 16 shows the displacement measurement positions (X1-X5). The squares on both sides of the displacement measurement positions indicate the loading plate 103, and the H-shapes indicate the angles. The loading plate was created when the concrete for the RC slab was poured. The loading plate measures 600mm x 600mm x 100mm and weighs 83kg. Six load plates will hold 500 kg, and 12 plates will hold 1,000 kg. A hoisting device is attached to the load plate, and the plate is placed on top of the test specimen using a crane.

[0057] Figure 17 shows specimen 1-5 used in the sound insulation performance measurement test, static deflection measurement test, and shear key shear test. In the tests, two configurations were tested for each specimen: one supported on four sides and one supported on two sides. Shear keys will be discussed later.

[0058] Figure 18(a) shows a plan view of specimen 1-3, Figure 18(b) shows a cross-sectional view taken along line XX' in Figure 18(a), Figure 18(c) shows a cross-sectional view taken along line YY' in Figure 18(a), and Figure 18(d) shows an elevation (side view) of specimen 1-3.

[0059] Fig. 19(a) shows a plan view of the test specimen 4. Fig. 19(b) shows a cross-sectional view taken along line XX' in Fig. 19(a), Fig. 19(c) shows a cross-sectional view taken along line YY' in Fig. 19(a), and Fig. 19(d) shows an elevation view (side view) of the test specimen 4.

[0060] Fig. 20(a) shows a plan view of the test specimen 5. Fig. 20(b) shows a cross-sectional view taken along line XX' in Fig. 20(a), Fig. 20(c) shows a cross-sectional view taken along line YY' in Fig. 20(a), and Fig. 20(d) shows an elevation view (side view) of the test specimen 5.

[0061] There are four shear key layout patterns as shown in Figures 21-24. The shear key layout pattern in Figure 21 is shear key layout pattern A for specimen 1. The shear key layout pattern in Figure 22 is shear key layout pattern B for specimen 2. The shear key layout pattern in Figure 23 is shear key layout pattern C for specimen 3. The shear key layout pattern in Figure 24 is shear key layout pattern D for specimen 4. Specimen 4 is a form in which a cutout is provided in specimen 1. Specimen 5 does not have a CLT panel.

[0062] Figure 25 shows the shear key, CLC8x160, used for specimen 3. In specimen 3, the shear key is provided at an angle (-45°, -135°) as shown in Figures 25(d) and 25(e). Figure 26 shows the shear key of the lag screw bolt. Figure 26(d) shows the shear key and lag screw bolt M16 used for specimens 1 and 2.

[0063] Figure 27 shows the natural frequency and strain measurement positions common to test specimens 1b-4b. In Figure 27(c), a loading plate 103 weighing a total of 1000 kg is placed on top of the RC slab 2. Figure 28(a) shows the measurement positions for impact impedance common to test specimens 1b-3b, and Figure 28(b) shows the measurement positions for impact impedance of test specimen 4b.

[0064] Figure 29 shows the results of the sound insulation performance measurement test and static deflection measurement test (LH (heavy floor impact sound), deflection amount) for each test specimen, Figure 30 shows the stiffness and strength for each shear key, and Figure 31 shows the state of the shear key after the test. The graph in Figure 32 shows the relationship between the octave band center frequency and floor impact sound level for each test specimen, and the graph in Figure 33 shows the relationship between displacement and load for each test specimen.

[0065] Figures 29 and 32 show that installing CLT panels (150mm) can reduce LH (heavy floor impact sound) by 5db. Figure 29 shows that installing CLT panels (150mm) can reduce the amount of deflection. As shown in Figures 30, 31 and 33, installing shear keys makes it possible to understand the shear stiffness and strength of the joints between the RC slab and CLT panels.

[0066] (Sound insulation performance measurement test in a building where the floor structure of the present invention was actually installed) The tests were carried out on the first and second floors of a building (a residential house). The second floor of the building has an area with a floor slab (a composite floor of RC slab and CLT panel) of the floor structure of the present invention, and an area with an FR composite floor (RC slab and precast concrete plate). A temporary wall was installed on the first floor directly below. Heavy impact sound impacts and light impact sound impacts were carried out on the second floor of the building, and measurements were taken on the first floor directly below.

[0067] In the same building, two sound insulation performance tests were conducted: one in which impact sound was applied to the bare concrete surface of the second floor (top surface of the RC slab), and the other in which impact sound was applied to the finished surface of the second floor. The finished surface of the second floor is the top surface of the dry double floor installed on the RC slab on the second floor.

[0068] (1) Sound insulation performance measurement test using impact sound on the bare concrete surface of the second floor In the following, the sound insulation performance measurement test in which impact sound impacts were performed on the bare concrete surface of the second floor will be referred to as the "sound insulation performance measurement test (bare concrete surface)." In the sound insulation performance measurement test (bare concrete surface), heavy impact sound impacts are performed to measure sound insulation performance.

[0069] Fig. 34 shows a plan view of the second floor of the building where the sound insulation performance measurement test (bare concrete surface) will be conducted, and Fig. 34 shows a plan view of the first floor. Of the floors on the second floor shown in Fig. 34, floor slabs of the floor structure of the present invention (composite floor of RC slab and CLT panel) are installed in the range between centerlines 1 to 3 and between centerlines A to C, and FR composite floors (RC slab and precast concrete panel) are installed in the rest of the area.

[0070] The location of the heavy impact sound is indicated by a white circle on the second floor plan in Figure 34. The location of the temporary wall construction is shown on the first floor plan in Figure 35. Measurements were taken in the assembly room on the first floor directly below. Measurements were taken in four areas (Measurement No. 1 to Measurement No. 4).

[0071] For Measurement No. 1, the sound source room (the room where the heavy impact sound was struck) was a living room on the second floor, and the sound receiving room (the room where the measurements were taken) was the meeting hall on the first floor directly below it. The floor of the second floor for Measurement No. 1 was a slab of reinforced concrete (RC) slab (150 mm thick) and CLT panels (150 mm thick).

[0072] Measurement No. 2 was performed in a second-floor living room (different from Measurement No. 1), with the sound source room being the meeting hall on the first floor directly below it, which was the sound receiving room. The second-floor floor of Measurement No. 2 was made of RC slab (150 mm thick) and CLT panel (150 mm thick) floor slab.

[0073] For Measurement No. 3 and Measurement No. 4, the sound source room was a second-floor living room different from Measurement No. 1 and Measurement No. 2, and the living room directly below it on the first floor was the sound receiving room. The measurement area for Measurement No. 3 was smaller than that of Measurement No. 4. The second-floor floor for Measurement No. 3 and Measurement No. 4 was a RC slab (200 mm) and a precast concrete slab (FR composite floor), and measurements were taken to compare with Measurement No. 1 and Measurement No. 2.

[0074] If the measurement area is connected to other areas and becomes part of a larger space, it is expected that the impact sound will spread over a wide area and the measured value will be small, so a temporary wall was set up around the first floor areas for Measurement No. 1 and Measurement No. 2. The temporary wall is indicated by a dashed line and reference number 105 in Figure 35.

[0075] (Heavy floor impact sound insulation performance) A test of heavy floor impact sound insulation performance (tire impact source) will be conducted. Measurement of heavy floor impact sound insulation performance (tire impact source) will be carried out in the same manner as (2) Heavy Floor Impact Sound Insulation Performance (tire impact source) in the floor impact sound insulation performance measurement test above. Vibration from the tire impact source will be applied to the floor slab on the second floor, and the maximum sound pressure level (dynamic characteristic F) will be measured at five sound receiving points set up on the second floor.

[0076] (Deck slab impedance / natural frequency measurement test) The measurement test of the deck impedance / natural frequency is carried out in the same manner as the measurement test of the deck impedance / natural frequency described above.

[0077] Figure 36 shows the heavy floor impact sound insulation performance and impact impedance for each measurement number. Figure 37 shows the results of measurement No. 1, Figure 38 shows the results of measurement No. 2, Figure 39 shows the results of measurement No. 3, and Figure 40 shows the results of measurement No. 4.

[0078] (2) Sound insulation performance measurement test using impact sound on the finishing surface of the second floor In the following, the sound insulation performance measurement test in which impact sound was struck on the finishing surface of the second floor is referred to as the "sound insulation performance measurement test." In the sound insulation performance measurement test (finished surface), light impact sound impacts and heavy impact sound impacts are performed to measure sound insulation performance.

[0079] Figure 41 shows the floor plan of the second floor of the building where the sound insulation performance measurement test (finished surface) was conducted. As mentioned above, the sound insulation performance measurement test (finished surface) was conducted in the same building as the sound insulation performance measurement test (bare concrete surface). On the second floor plan in Figure 41, the positions where light and heavy impact sounds were struck are indicated by open circles.

[0080] The measurement area for Measurement No. 3 is smaller than that for Measurement No. 4. The floor of the second floor for Measurement No. 3 and Measurement No. 4 was an RC slab (200 mm) and a precast concrete slab (FR composite floor), and measurements were taken to compare with Measurement No. 1 and Measurement No. 2.

[0081] (Lightweight floor impact sound insulation performance) Lightweight floor impact sound insulation performance (tapping machine) testing is conducted in the same manner as the (1) Lightweight floor impact sound insulation performance testing in the floor impact sound insulation performance measurement test above.

[0082] (Heavy floor impact sound insulation performance) Testing of heavy floor impact sound insulation performance (tire impact source) is carried out in the same way as the heavy floor impact sound insulation performance (tire impact source) test in the sound insulation performance measurement test (bare concrete surface).

[0083] (Deck slab impedance / natural frequency measurement test) The measurement test for the impedance / natural frequency of the deck slab is carried out in the same manner as the measurement test for the impedance / natural frequency of the deck slab in the sound insulation performance measurement test (bare concrete surface) described above.

[0084] Figure 42 shows the heavy floor impact sound insulation performance and impact impedance for each measurement number. Figure 43 shows the results of measurement No. 1, Figure 44 shows the results of measurement No. 2, Figure 45 shows the results of measurement No. 3, and Figure 46 shows the results of measurement No. 4.

[0085] The above describes embodiments of the floor structure and floor structure construction method according to the present invention, but the present invention is not limited to the above embodiments and can be modified as appropriate within the scope of the spirit thereof. For example, in the above embodiment, shear keys 5, 5B are provided between the CLT panel 3 and the RC slab 2. Shear keys 5, 5B do not have to be provided between the CLT panel 3 and the RC slab 2. Furthermore, in the above embodiment, the shear keys 5B also serve as shoring and spacers for the reinforcement of the RC slab 2, but they do not have to be used as shoring and spacers for the reinforcement of the RC slab 2. Furthermore, the shear keys 5B also serve as spacers for the truss reinforcement 22, but they may be used as spacers for reinforcement other than the truss reinforcement 22.

[0086] Furthermore, in the first and second embodiments described above, the edge 3a of the CLT panel 3 is fitted into the cutout 41 of the beam 4. However, the cutout 41 may not be formed in the beam 4, and the end face of the CLT panel 3E and the side surface of the beam 4 may face each other. [Explanation of symbols]

[0087] 1,1B~1E Floor structure 2 RC slab 3,3D,3E CLT panel 3b Top side 41 Cutout 5,5B Shear Key 22 Truss reinforcement (reinforcement)

Claims

1. an RC slab provided as a structural component of the structure; and a non-structural CLT panel provided along the underside of the RC slab; Truss bars are used as reinforcing bars for the RC slab, Further, a shear key is provided between the CLT panel and the RC slab, The shear key is a floor structure formed in a U-shape from steel and also serves as a spacer for the truss reinforcement of the RC slab.

2. The truss reinforcement is The structure has two bottom reinforcements located on the lower side, a top reinforcement located on the upper side, and a lattice reinforcement joined to the bottom reinforcement and the top reinforcement, The floor structure described in claim 1, wherein the lattice reinforcement is a reinforcing bar bent into a wave shape and arranged in the shape of a truss between one of the bottom reinforcement and the top reinforcement, and between the other of the bottom reinforcement and the top reinforcement.

3. an RC slab provided as a structural component of the structure; and a non-structural CLT panel provided along the underside of the RC slab; The beams are made of H-shaped steel beams, The upper surface of the CLT panel and the upper surface of the upper flange of the beam are located at the same height, The lower surface of the CLT panel is located at the height of the middle part of the web of the beam in the vertical direction, A protrusion is formed on the upper side of the edge of the CLT panel that protrudes more laterally than the lower side, A beam concrete is provided between the edge of the CLT panel and the beam, A floor structure in which the RC slab is provided on top of the CLT panels and concrete beams.

4. an RC slab provided as a structural component of the structure; and a non-structural CLT panel provided along the underside of the RC slab; The beams are made of H-shaped steel beams, The lower surface of the CLT panel and the upper surface of the upper flange of the beam are located at the same height, A protrusion is formed on the upper side of the edge of the CLT panel that protrudes more laterally than the lower side, A beam concrete is provided in a space surrounded by the edge of the CLT panel and the upper flange of the beam, A floor structure in which the RC slab is provided on top of the CLT panels and concrete beams.

5. an RC slab provided as a structural component of the structure; A CLT panel provided along the underside of the RC slab; A construction method for a floor structure having a steel beam made of H-shaped steel, a CLT panel installation process for installing the CLT panel; and an RC slab construction step of constructing the RC slab, In the CLT panel installation step, a lower formwork is installed to close the gap between the underside of the CLT panel and the steel beam, In the RC slab construction process, the CLT panels and the lower formwork installed in the CLT panel installation process are used as formwork to form concrete beams, and the RC slab is formed on the top surface of the CLT panels.

6. an RC slab provided as a structural component of the structure; and a non-structural CLT panel provided along the underside of the RC slab; The beams are made of H-shaped steel beams, A fire-resistant covering material is provided to cover the surface of the beam, The edge of the CLT panel is placed on top of the fire-resistant covering material provided on the upper surface of the upper flange of the beam, A stud protruding upward is joined to the upper flange of the beam; The concrete on the beam is provided in the space surrounded by the edge of the CLT panel and the upper flange of the beam, A floor structure in which the RC slab is provided on top of the CLT panels and the concrete on the beams.

Images