JPH0752860Y2 - Base material for construction and ▲ body structure using the base material - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention, regardless of the material of the finishing material stretched on the upper surface of the concrete structure when it is laid on the inner surface of the body, especially on a horizontal slab, The present invention relates to a building base material that exhibits excellent effects of light impact sound and heavy shock sound insulation and pressure resistance, and a structure of a structure using the base material.

[Conventional technology]

Conventionally, as an example of a frame structure in a concrete-based building, for example, a floor structure, a base material made of a plate-shaped expanded synthetic resin body is laid on the horizontal slab, and then a finishing material made of a wood-based material is placed on the upper surface of the base material. It is known to be stretched.

[Problems to be solved by the device]

However, with such a floor structure, shock noise from the upper floor to the lower floor,
Especially, light impact sound is easily transmitted, and noise is a problem. However, noise is not a problem when the finishing material disposed on the base material is a soft material such as a carpet. It is considered that this is because hard wood-based materials have high rigidity, and the foaming synthetic resin body that is the base material also has high rigidity, so the cushioning effect and the vibration isolation effect are small, and the sound insulation performance deteriorates. To be

[Means for Solving the Problems]

In consideration of these conventional problems, the present inventors have conducted various experiments. As a result, in addition to the fact that soft finishing materials do not cause deterioration of sound insulation performance as is conventionally known, when the bending rigidity of the base material is small, not only the sound insulation performance of lightweight impact sound but also weight It was discovered that the sound insulation performance of impact sound is also improved. This has been found as a result of an experiment in which the thickness of a base material made of a foamed synthetic resin body was sequentially changed.

It was also found that light impact sound is excellent in sound insulation performance by using a relatively soft material for the base material. However, with respect to pressure resistance due to furniture placement, walking, and sound insulation performance against heavy impact sound, when a soft material is used, the amount of distortion becomes too large and the performance deteriorates. That is, there is a contradictory relationship between the sound insulation performance of light impact sound and the pressure resistance performance or the sound insulation performance of heavy impact sound.

With this in mind, when laid on the inner surface of the concrete building, especially on a horizontal slab, the sound insulation performance of lightweight impact sound and heavy impact sound is irrespective of the material of the finishing material stretched on the upper surface. In addition, the inventors of the present invention have earnestly studied for the purpose of exerting an excellent effect on the pressure resistance performance, and as a result, have arrived at the present invention.

The base material for construction according to claim 1 has a plurality of receiving projections on the upper surface of the base substrate, with the upper surface of the base substrate being substantially flush with the upper surface of the base substrate. The cushioning material is provided between the support portions such that the upper surface thereof protrudes from the support portion upper surface and the whole thereof is elastically deformable.

According to a second aspect of the present invention, there is provided a base material for construction in which a plurality of receiving protrusions are scattered on the upper surface of the base substrate between the support parts with the upper surface of the base substrate being substantially flush with the upper surface. A cushioning material, which is received from below via the plurality of receiving projections, is arranged between the support portions such that the upper surface thereof protrudes from the upper surface of the support portion and the whole is elastically deformable. A top plate is provided on the upper side.

Here, as in claim 3, the base substrate is formed of a foamed synthetic resin body, and as in claim 4, the base substrate and the top plate are formed of a foamed synthetic resin body, and
7. As described above, the mounting member made of a low-foam synthetic resin body or a wood-based material is embedded in the upper surface plate with its surface substantially flush, and the finishing material is fixed to this mounting member. In addition, it is a preferred embodiment that the support portion is erected under the attachment member attached to the top plate.

In addition, as described in claim 7, the interval between the centers of the support portions is
It is set within the range of 15 to 60 cm, the width of the support portion is set to 10 cm or less as described in claim 8, and the protrusion height of the cushioning material upper surface from the support portion upper surface is set as described in claim 9. Sa is 0.
Within the range of 5 to 5 mm, or according to claim 10, the 5% strain compressive strength of the cushioning material is set within the range of 0.05 to 0.15 kg / cm ² , or according to claim 11, The compressive elastic modulus of the cushioning material is 1.
It may be set within the range of 0 to 3.0 kg / cm ² .

Further, as described in claim 12, urethane foam is used as the cushioning material, or as described in claim 13, the receiving area of the cushioning material is set to 50% or more of the area of the base substrate, As described above, it is possible to provide the receiving projections on the surface of the top plate facing the cushioning material in a scattered manner.

In the frame structure according to claim 15, the supporting portion is provided upright with the upper surface of the underlying substrate substantially flush with the underlying substrate, and a plurality of receiving convex portions are provided on the upper surface of the underlying substrate between the supporting portions. , A base material having a cushioning material that is received from below via a plurality of receiving convex portions, the upper surface of which is projected from the upper surface of the support portion, and the entire base material is elastically deformable, and is provided between the support portions. Is laid on a horizontal slab and then a finishing material is arranged on the upper surface thereof.

In the frame structure according to claim 16, the support portion is provided upright with the upper surface of the base substrate substantially flush with the space therebetween, and a plurality of receiving convex portions are provided on the upper surface of the base substrate between the support portions in a scattered manner. , A cushioning material, which is received from below via the plurality of receiving convex portions, is arranged between the supporting portions such that the upper surface thereof protrudes from the upper surface of the supporting portion and the whole thereof is elastically deformable, and further above these. A base material provided with an upper surface plate is laid on a horizontal slab of a concrete skeleton, and then a finishing material is stretched on the upper surface.

[Action]

Thus, by using such an architectural base material, a concrete structure as a floor structure is provided on the inner surface side of a concrete building, for example, on a horizontal slab, which has excellent sound insulation performance for light weight impact sound and heavy impact sound and pressure resistance. The following is how to implement it. First, a base material is laid on a horizontal slab by using an adhesive or a mortar dumpling, or by using both together, with the cushioning material side facing the upper surface and the base substrate side facing the lower surface. Then, a finishing material made of a wood-based material is stretched on the upper surface. The load of furniture, which is not relatively large per unit area, is supported in the state of a kind of floating floor structure through cushioning materials, and in some cases, such as walking pressure due to human walking, comparison per unit area The moving load, which is significantly larger, shrinks the cushioning material by the thickness of the protruding part from the upper surface of the supporting part and brings the top plate of the finishing material or the base material into contact with the supporting part standing upright from the base substrate of the base material. The floor is supported with a small amount of strain. Further, since the cushioning material is arranged on the plurality of receiving convex portions, the elastic deformation of the cushioning material corresponding to the receiving convex portions is promoted, and the propagation of the lightweight impact sound is further effectively suppressed.

In addition to this, such a base material may be provided on the inner surface side of the wall of a concrete building to embody as a wall structure a structure having excellent sound insulation of impact sound.

〔Example〕

The details of the architectural base material and the frame structure using the base material according to the present invention will be further described with reference to the accompanying drawings.

FIG. 1 shows a floor structure having a foundation material according to the present invention laid on a horizontal slab, which is the body of a concrete building, and having excellent sound insulation performance for light weight impact sound and heavy impact sound and pressure resistance. A vertical cross-sectional view of a state embodied as is shown.

In the figure, 1 is a horizontal slab, 2 is a substantially plate-shaped, and a base material laid on the horizontal slab 1 using an adhesive or a mortar dumpling (not shown), or a combination of both, 3 is this base It is a finishing material composed of a natural wood composite flooring stretched on the material 2 by nailing 4 or by using it together with an adhesive.

As shown in detail in FIGS. 2 (a) and 2 (b), the base material 2 is made of expanded polystyrene, or a foamed synthetic resin of the same type as other conventional base materials, or a base substrate 5 made of a fiber-based heat insulating material. A support portion 6 whose upper surface is substantially flush across the outer circumference and the lengthwise direction is equally erected from the underlying substrate 5 so that the four rectangular shapes are arranged side by side. The outer surface of the supporting member 6 is elastically deformable so that a gap is formed between the supporting member 6 and the supporting member 6. 5
Of the cushioning material 7 is fixed on the upper surface of the receiving convex portion 8 having a square shape in a plan view provided by being scattered on the disposing surface of the cushioning material 7, and the same type as the base substrate 5 is formed on the upper surface of the cushioning material 7. Alternatively, the upper surface plate 9 made of a different kind of foamed synthetic resin body is fixed by using an adhesive. Reference numeral 10 in the drawing denotes a mounting member for fixing the nail 4 to the finishing material 3 made of a low-foam synthetic resin body or a wood-based material, which is buried on the surface side of the upper surface plate 9 so that its surface is flush. In the illustrated example, the support portion 6 is positioned below the mounting member 10 provided on the upper surface plate 9. Then, the base substrate 5, the supporting portion 6 and the top plate 9
For example, a 40-fold molded product of polystyrene foam and a double-molded product of the polystyrene foam are suitable for the mounting member 10. However, as materials for the base substrate 5, the supporting portion 6 and the upper surface plate 9, there are various foaming ratios of polythylene foam suitable for the application of the base material 2 and other foaming ratios of other foamed synthetic resin bodies. Molded articles or fiber insulation can be used. Moreover, as the mounting member 10, a wood-based material can be used as described above.

In the present invention, the load of furniture or the like, which is not relatively large per unit area, is supported in a state of a kind of floating floor structure through the cushioning material 7, and depending on the case such as walking pressure due to walking by a person, Is a relatively large moving load per unit area. The entire load is shrunk by the thickness of the protruding portion of the cushioning material 7 from the supporting portion 6, and the upper surface plate 9 is brought into contact with the supporting portion 6 to distort the floor. Is supported in a small state. Due to this, when such a base material 2 is laid on the horizontal slab 1, the shock generated in the upper floor is absorbed by the cushioning material 7 regardless of the material of the finishing material stretched on the upper surface of the horizontal support slab 6. The impact sound is reduced by contracting by the thickness of the protruding portion to reduce the impact sound, and at the same time, the upper plate 9 is brought into contact with the upper surface of the support portion 6 to reduce the amount of strain on the floor and improve the walking feeling. It is something to do.

Next, an evaluation test of the floor structure will be described.

A first floor structure in which various dimensions are changed in the sectional structure shown in FIG. 2B, and a second floor structure in which the mounting member 10 is provided on the cushioning member 7 in the sectional structure shown in FIG. The floor impact sound performance was inspected using three types of floor structures, that is, the third floor structure including the base material without using the cushioning material 7, and the results shown in Table 1 were obtained. Incidentally, No. 1 and No. 2 of the first floor structure are the best modes.

The receiving area of the upper surface plate 9 composed of the entire supporting portion 6, that is, the area of the upper surface of the supporting portion 6 is 50% or less, preferably 15 to 25% of the area of the underlying substrate 5 on which it is erected. It is set. When the receiving area is 50% or more, the sound insulation performance of heavy impact sound is deteriorated as in No. 4 of the first floor structure in Table 1. Further, the supporting portion 6 shown as a in FIG.
The distance between the centers of the is within the range of 15-60 cm, preferably 30-45
It is set within the range of cm. When the distance between the centers of the support portions 6 is 15 cm or less, the sound insulation performance of heavy impact sound is deteriorated as shown in the second floor structure of Table 1, and when it is 60 cm or more, the floor distortion is caused when walking. The amount becomes large and the walking feeling becomes poor. Further, it is preferable that the width of the supporting portion 6, which is also shown as b in FIG. 2 (a), is formed to be 10 cm or less.
When the width of the support portion 6 is 10 cm or more, the sound insulation performance of heavy impact sound is deteriorated as in No. 3 of the first floor structure in Table 1. Further, the height of protrusion of the upper surface of the cushioning material 7 from the upper surface of the support portion 6 when no load is applied from above, which is shown as c in FIG. 2B, is formed within the range of 0.5 to 5 mm. preferable. When the height of protrusion of the upper surface of the cushioning material 7 from the upper surface of the support portion 6 is 0.5 mm or less, as shown in No. 5 of the first floor structure in Table 1, the sound insulation performance of the lightweight impact sound and the heavy impact sound is reduced. There is no improvement. When the protruding height is 5 mm or more, the amount of strain on the floor becomes too large during walking, and a good walking feeling cannot be obtained.

The 5% strain compressive strength of the cushioning material 7 is preferably set within the range of 0.05 to 0.15 kg / cm ² . This 5% strain compression strength is
When it is less than 0.05kg / cm ² , the sound insulation performance of heavy impact sound becomes worse as No. 9 of the first floor structure in Table 1, and 0.15kg / cm ²
In the above cases, as in No. 8 of the first floor structure in Table 1, the effect of improving the sound insulation performance of the lightweight impact sound becomes small. Furthermore, the compressive elastic modulus of the cushioning material 7 is preferably in the range of 1.0 to 3.0 kg / cm ² .

Further, as shown in the figure, if the support portion 6 is located under the mounting member 10 provided on the top plate 9, the effect of improving the sound insulation performance for heavy impact sound is great as in the second floor structure of Table 1. It became clear as a result of the experiment.

Next, the base substrate 5 and the top plate 9 have higher rigidity than the cushioning material 7 and are hard or semi-hard, and their 5% strain compression strength is within the range of 0.5 to 5 kg / cm ² , for example. Further, those having a compressive elastic modulus in the range of, for example, 10 to 200 kg / cm ² can be suitably used.

As the cushioning material 7, urethane foam, or polyolefin resin foam such as polypropylene foam or polyethylene foam, vinyl chloride resin foam, and further natural rubber, synthetic rubber, natural rubber foam, synthetic rubber foam. The body etc. can be used. Further, as the base substrate 5, the support portion 6 and the upper surface plate 9, as described above, in addition to polystyrene foam or the like, fiber type heat insulating materials such as glass wool and rock wool can be used.

Such a base material 2 has, for example, a width of 600 mm and a length of 900 mm,
Generally, the entire thickness is formed within the range of 50 to 120 mm. Of these, the upper surface plate 9 has a poor sound insulation performance for light weight impact sound and heavy impact sound as the thickness thereof increases. Therefore, if the mounting member 10 is embedded within 40 mm or less and the sound insulation performance is improved, it is 20 It can be said that it is a preferable embodiment to form within a range of up to 30 mm. The mounting member 10 embedded in this is generally formed to have a width of about 40 mm and a thickness of about 20 mm. The mounting member 10 has a rectangular cross section as shown in FIGS. Alternatively, it may be formed in an I-shape as shown in FIG. 3, or may be formed in a trapezoidal shape or another suitable shape (not shown).

In addition, the compression elastic modulus is 2.0 kg / cm ² on a horizontal slab with a thickness of 150 mm.
A cushioning material 7 is used to form a base material as shown in FIGS. 2 (a) and 2 (b), which is laid, and a natural wood composite flooring is stretched thereon as a finishing material 3. As a result of experiments using various thicknesses, it was found that the thicker the cushioning material 7, the better the sound insulation performance. According to this experimental result, when the thickness of the cushioning material 7 is 10 mm, L _L −
_{60, L H -55, L L} -55 when the thickness is 40 mm, L _H -55 next by increasing its thickness, it is know that improves the sound insulation performance of lightweight impact sound. However, considering the thickness of the floor of a general house, the thickness of the cushioning material 7 is 10-
About 50mm is suitable.

Then, the floor structure is constructed on the horizontal slab 1 of the concrete building by using the base material 2 as follows. First, the base material 2 is laid on the horizontal slab 1 by using an adhesive, mortar dumpling, or both in combination with the upper surface plate 9 side facing the upper surface and the base substrate 5 side facing the lower surface. Then, as shown in FIG. 3, the finishing material 3 made of natural wood composite flooring is stretched by fixing it to the attachment member 10 of the base material 2 with the nail 4 at the portion 11 of the actual hollow structure provided at the side end thereof. At this time, an adhesive may be used together for fixing the finishing material 3 to the base material 2.

Here, in the base material 2 shown in FIGS. 2A and 2B, the receiving projection 8 having a square shape in plan view as shown in FIG. 4A is provided on the surface of the base substrate 5 on which the cushioning material 7 is provided. Are provided in a scattered manner, and the lower surface of the cushioning material 7 is fixed to this upper surface. When such a receiving convex portion 8 is provided, a smaller receiving area with the cushioning material 7 is, for example, within a range of 10 to 30% of the area of the lower surface of the cushioning material 7,
It is particularly preferable that the contact is about 20%. When it is 10% or less, the sound insulation performance of heavy impact sound is deteriorated as in No. 6 of the first floor structure in Table 1, and when it is 30% or more, it is No. 1 of the first floor structure in Table 1. As in .7, the sound insulation performance of light impact sound is deteriorated. It has been found that when such a receiving convex portion 8 is provided, the sound insulation performance of the lightweight impact sound is improved by about L _L 3 to 5. If the height of the receiving projection 8 is set to 2 mm or more,
Since the amount of strain on the floor increases during walking and the feeling of walking becomes poor, 2 mm or less is preferable. Regarding the shape, as shown in FIG. 4 (b), a hexagonal shape in plan view, a circular shape in plan view as shown in (c), or a top surface as shown in FIG. 5 (a). And make the bottom surface the same size,
Further, as shown in (b), the upper surface can be made smaller than the lower surface.

Next, FIG. 6 shows another embodiment of the base material according to the present invention. The base material 2 shown here is one in which the support portion 6 is erected from the base substrate 5 in a state in which its side is open.

Furthermore, FIG. 7 shows still another embodiment of the base material according to the present invention. In this base material 2, the finishing material 3 is directly attached without providing the upper surface plate 9 on the upper surface of the cushioning material 7. The base material 2 is attached to the upper surface of the cushioning material 7 with an adhesive or the like in advance so that the base material 2 can be laid directly on the horizontal slab 1 together with the finish material 3.

In addition to the embodiment shown in the drawings, the base substrate 5 and the supporting portion 6 may be made of the same kind of material and separated from each other, or they may be formed of different materials and the supporting portion 6 may be attached to the base substrate 5 by means of adhesion or the like. It can also be installed upright. Further, the arrangement state of the support portions 6 can be appropriately set such that the support portions 6 are arranged in parallel according to the object of use. Further, the cushioning material 7 has its lower surface on the base substrate 5
It is also possible to dispose it in a state of simply placing it without adhering to the receiving convex portion 8 provided on the. If the entire cushioning material 7 can be compressed and deformed between the outer periphery of the cushioning material 7 and the support portion 6, it is not always necessary to form a gap. It is also possible to intersperse the receiving projections 8 on the surface of the top plate 9 facing the cushioning material 7.

Further, FIGS. 8 and 9 show other examples of finishing materials. The finishing material 3 shown in FIG. 8 is such that a soft foam synthetic resin body or a vibration isolator 13 made of a soft synthetic resin material is laminated on the lower surface of a surface material 12 made of a wood-based material, and the lower surface thereof is also made of a wood-based material. The back material 14 is laminated. Further, the finishing material 3 shown in FIG. 9 is one in which grooves 15 having an opening width are provided in a grid shape or a parallel shape on the back surface material 14 of the finishing material 3 shown in FIG. Finishing material 3 shown in FIGS. 8 and 9
By substituting on the base material 2 in place of the natural wood composite flooring shown in FIG. 1, the sound insulation performance of lightweight impact sound is further improved.

In addition to this, the base material 2 is provided on the inner surface side of the wall of the concrete building, and has a frame structure excellent in sound-insulating performance of impact sound,
It can also be embodied as a wall structure.

[Effect of device]

If a frame structure, especially a floor structure, is constructed in a concrete building using the building base material according to the present invention as described above, regardless of the material of the finishing material stretched on the upper surface,
By absorbing the shock generated in the upper floor by the amount of the thickness of the protruding part from the upper surface of the support part and absorbing it by the elasticity of the material, the sound insulation performance of impact sound, especially lightweight impact sound is improved, In addition, at this time, since the top plate of the finishing material or the base material is brought into contact with the support portion standing upright from the base substrate of the base material, the pressure resistance performance is improved and the amount of floor strain is reduced. Then, as a result of the amount of strain on the floor being reduced, the walking feeling is improved. In addition, a simple structure in which a plurality of receiving protrusions are provided on the upper surface of the base substrate and a cushioning material is arranged on the receiving protrusions prevents the base material from becoming thick and further improves the sound insulation performance of lightweight impact sound. It becomes possible.

Furthermore, if the base substrate and top plate that make up the base material are made of foamed synthetic resin and the cushioning material is made of foam such as urethane foam, the weight of the base material can be reduced while ensuring sufficient rigidity. The construction work can be simplified, and the manufacturing cost of the base material can be reduced.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a concrete structure of the present invention embodied as a floor structure, and FIG. 2 (a) is a plan view showing an example of a base material of the present invention with a top plate removed. Figure, (b)
Is a vertical sectional front view of the base material, FIG. 3 is an enlarged vertical sectional view showing an essential part of FIG. 1, and FIGS. 4 (a), (b), and (c) are explanatory views showing the planar shape of the receiving projection. 5 (a) and (b) are explanatory views showing the shape of the side surface in the same manner, FIG. 6 is a longitudinal sectional view showing another embodiment of the base material, and FIG. 7 is still another embodiment of the base material. FIG. 8 is a vertical sectional view showing a state in which a finishing material is integrally laminated on its upper surface, and FIGS. 8 and 9 are vertical sectional views showing other embodiments of the finishing material. 1: Horizontal slab, 2: Base material, 3: Finishing material, 4: Nails, 5: Base substrate, 6: Support part, 7: Buffer material, 8: Receiving convex part, 9: Top plate, 10:
Mounting member, 11: Actual structure, 12: Surface material, 13: Anti-vibration material, 14: Back material, 15: Groove.

Claims (16)

[Scope of utility model registration request] 1. A support portion is provided upright on a base substrate with a top surface thereof substantially flush with each other, and a plurality of receiving convex portions are provided on the top surface of the base substrate in a space between the support portions. A construction base material in which a cushioning material that is received from below via a receiving convex portion is arranged between support portions such that the upper surface thereof protrudes from the upper surface of the support portion and the whole is elastically deformable. 2. A support portion is provided upright on the base substrate with a space therebetween so that the top surfaces thereof are substantially flush with each other, and a plurality of receiving convex portions are provided on the top surface of the base substrate in a space between the support portions. The cushioning material, which is received from below via the receiving convex portion, is arranged between the support portions such that the upper surface of the cushioning material protrudes from the upper surface of the support portion and the whole is elastically deformable, and the upper surface plate is provided on the upper side thereof. Foundation material for construction. 3. The construction base material according to claim 1, wherein the base substrate is formed of a foamed synthetic resin body. 4. The construction base material according to claim 2, wherein the base substrate and the top plate are formed of a foamed synthetic resin body. 5. A mounting member made of a low-foam synthetic resin body or a wood-based material is embedded in an upper surface plate so that its surface is substantially flush,
The construction base material according to claim 2 or 4, wherein a finishing material is fixed to the mounting member. 6. The construction base material according to claim 5, wherein a support portion is provided upright under a mounting member to be mounted on the top plate. 7. The base material for construction according to any one of claims 1 to 6, wherein the distance between the centers of the supporting portions is within a range of 15 to 60 cm. 8. The base material for construction according to any one of claims 1 to 7, wherein the width of the support portion is 10 cm or less. 9. The height of protrusion of the upper surface of the cushioning material from the upper surface of the support portion is
The base material for construction according to any one of claims 1 to 8 in which a utility model is registered within a range of 0.5 to 5 mm. 10. The 5% strain compressive strength of the cushioning material is 0.05 to 0.15 kg.
The construction base material according to any one of claims 1 to 9 in which the utility model is registered within the range of / cm ² . 11. The construction base material according to claim 1, wherein the cushioning material has a compressive elastic modulus within a range of 1.0 to 3.0 kg / cm ^2. Material. 12. The construction base material according to any one of claims 1 to 11, wherein the cushioning material is urethane foam. 13. The receiving area of the cushioning material is 50 times the area of the base substrate.
% Or more, the architectural base material according to any one of claims 1 to 12 in the utility model registration claim. 14. A construction for construction according to claim 2, claim 4, claim 5, or claim 6, wherein the receiving projections are provided on the surface of the upper surface plate facing the cushioning material in a scattered manner. Base material. 15. A support part is provided upright on the base substrate with a space therebetween so that its upper surface is substantially flush with each other, and a plurality of receiving convex parts are provided on the top face of the base substrate in a space between the support parts. On the horizontal slab of the concrete skeleton, the cushioning material that is received from below via the receiving convex portion The structure of the skeleton, which is laid on the top of which is then placed a finishing material on the top surface. 16. A support portion is provided upright on the base substrate so that the top surface is substantially flush with the base substrate, and a plurality of receiving convex portions are provided on the top surface of the base substrate in a space between the support portions. The cushioning material, which is received from below via the receiving convex portion, is arranged between the support portions such that the upper surface of the cushioning material protrudes from the upper surface of the support portion and the whole is elastically deformable, and the upper surface plate is provided on the upper side thereof. A base structure in which a base material is laid on a horizontal slab of a concrete structure, and then a finishing material is stretched on the upper surface.