JPH03257240A - Hollow slab - Google Patents

Abstract

PURPOSE:To strengthen rigidity by link-juxtaposing a unit, formed by transversely bind-arranging a plurality of concrete cylindrical beams introduced with prestress, between beams, and thereafter placing after-place concrete on an upper part of total unit. CONSTITUTION:A unit U is formed by transversely arranging a cylindrical beam 1, in which prestress is introduced, with a plurality of the beams 1 as a single set, and tightening them into an integral unit by a steel plate-made tightening belt 2. Both ends of the beam 1 are closed by preblinding concrete. Next, the unit U is link-juxtaposed between beams of a building to embed pipes 7, 8 for electrical wiring in an upper surface part, and a slab S is formed by placing after-place concrete 4. The pipes 7, 8 and the beam 1 are arranged so that they are prevented from grade separation by positioning the pipes 7, 8 in a hollow part between the adjacent beams 1. Accordingly, rigidity can be increased by avoiding thin covering of the concrete.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hollow slab using concrete cylindrical beams.

[Prior Art] As a conventional hollow slab, there is, for example, something called spancrete, which is a type of precast concrete product that introduces prestress. It is provided with a hollow hole passing through it.

[Problem to be solved by the invention] When using the above-mentioned spancrete, in order to effectively transmit the horizontal force to the columns, beams, and load-bearing walls when the building receives horizontal force, it is necessary to It is necessary to place poured concrete c (topping concrete). Piping d for electrical wiring is buried in this post-cast concrete C, but it has been pointed out that the concrete cover is thinner in the areas where the pipes intersect, and furthermore, air conditioning equipment ducts must be installed separately. . Furthermore, it was believed that span cleats could not be used with large spans due to rigidity and other strength reasons.

The present invention was made in order to solve the problems of the conventional hollow slab, and the cover of post-cast concrete does not become thin at the intersection of electrical wiring piping, and there is no need to separately provide equipment ducts. The object of the present invention is to provide a hollow slab that has strong strength such as rigidity and can be sufficiently applied to large spans.

[Means for Solving the Problem] As a means for technically solving this problem, the present invention forms a unit by arranging and intertwining a plurality of prestressed concrete cylindrical beams, The gist of this project is to install these units in parallel across the beams and to integrate them by pouring post-cast concrete over the entire upper part.

[Function] Since the material is a cylindrical beam with co-prestress introduced, it is possible to bury electrical wiring piping using the valley between adjacent cylindrical beams to prevent the intersection from lifting up. , has significantly higher rigidity than conventional span cleats,
It can be fully applied to buildings with large spans, and the hollow part of the cylindrical beam can be used as space for equipment ducts, eliminating the need for separate installation.

[Embodiments] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

In FIG. 1, numeral 1 is a cylindrical beam into which prestress is introduced, and its outer peripheral surface 1a is formed in a finely uneven shape.
As shown in the figure, a plurality of belts (three on the open side) are arranged side by side in a set, and several places are tightened together with a steel plate tightening belt 2 as shown in Figure 5. Unit U is formed. Reference numeral 3 designates a tightening tool for the tightening belt 2, and as shown in FIG. Insert into the hole 2a12b of 2, and insert it into the hole 2a12b) 3c
The tightening belt 2 can be tightened by screwing and tightening.

The units U thus formed can be placed side by side across the beams of a building without gaps, and can be integrated into a slab S by pouring post-cast concrete 4 on the upper surface. At this time, as shown in FIG. 2, both ends of each cylindrical beam 1 are closed with packed concrete 5,
The post-cast concrete 4 is prevented from flowing into the inside of the cylindrical beam, except for the post-cast concrete 4 at the opening.
Leave a slight gap 6 so that it can fit in. The prepacked concrete 5 can resist the shearing force of the slab, and its length 1 is set to be larger than the outer diameter of the cylindrical beam 1 and about 1.5 times or less (D≦1≦1.5D). The reason why the outer circumferential surface 1a of each cylindrical beam 1 is formed into a finely uneven shape as described above is to improve the adhesion strength of the post-cast concrete 4.

In addition, when pouring concrete 4 is placed, electrical wiring pipes 7 and 8 are buried, but in this case, the pipes 8 parallel to the cylindrical beams 1 are located in the valley between adjacent cylindrical beams. Therefore, the intersection with the piping 7 does not become an overpass and lift upward, thereby preventing the cover of the post-cast concrete from becoming thin. Also,
An embedded box 9 for a socket can be provided on the upper surface of the post-cast concrete 4. lO is the ceiling material,
It can be attached via the ceiling base material 11 fixed to the tightening belt 2. Reference numeral 12 denotes a lighting fixture, which can be easily installed as a ceiling-embedded type using the hanging material 13 attached between the units U and by utilizing the lower valley between the units U. Furthermore, as shown in FIG. 3, if a cutout hole 1b is provided in the lower main part of the cylindrical beam 1, the hollow part 1c of the cylindrical beam 1 can be used as an air conditioning equipment duct.

Next, to explain an actual construction example, Fig. 7 is a plan view of a standard floor, where the beam spacing, or span L, is 12 m, and the girder row, or span M, is 6.4 va. A slab can be formed by arranging six units U in parallel without gaps and pouring post-cast concrete 4 to an effective thickness of 100 am. At this time, if each cylindrical beam 1 constituting the unit U has an outer diameter D=300mm and a wall thickness t=80i+m as shown in FIG.
It can exhibit a strength comparable to the design value of type 0 crack bending moment (0φ×60), and can withstand a live load of 300 to 500 kg/m2. Therefore, it is fully applicable to slabs with spans of about 10 to 17 m in buildings such as offices. Further, as mentioned above, the thickness of the post-cast concrete 4 from the upper end of the cylindrical beam to the slab line is T = 10hi+,
Since concrete is inserted into the valley between adjacent cylindrical beams by approximately half of the outside diameter of the cylindrical beams, the rigidity of the slab during an earthquake can be made much stronger than that of a flat slab.

Furthermore, since cylindrical beams can be produced in a factory, they can be manufactured at a cost comparable to that of PC piles, making them extremely economical when considering the cost of formwork and temporary supports. Moreover, since electricity and equipment are integrated into a single structure, there are advantages such as lower floor heights.

[Effects of the Invention] As explained above, the present invention combines a plurality of cylindrical beams into a unit, and connects a plurality of these units in parallel across girders, and pours post-cast concrete on top of these units to integrate them. Since the slab was formed by using the grooves between adjacent cylindrical beams, it was possible to bury electrical wiring piping using the valleys between adjacent cylindrical beams so that their intersections would not rise upwards, and the post-cast concrete cover would not be thin. do not have. In addition, it has significantly higher rigidity than conventional spancrete, making it suitable for large-span buildings.Furthermore, the hollow part of the cylindrical beam can be used as space for equipment ducts, eliminating the need for separate installation. Excellent effects such as these can be obtained.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention, Fig. 2 is a side view of the end thereof, Fig. 3 is a sectional view showing the procedure for implementing the equipment duct, Fig. 4 is a sectional view of the unit, and Fig. 5 is a sectional view showing the implementation procedure of the equipment duct. The figure is a perspective view of the tightening belt, Figure 6 is an exploded perspective view of the tightening tool, Figure 7 is a plan view of the standard floor showing a construction example, and Figure 8 is X-X in Figure 7.
A line sectional view, FIG. 9 is a sectional view of one cylindrical beam, and FIG. 1θ is a sectional view of a main part of a conventional example. 1... Cylindrical beam 1a... Outer peripheral surface 1b...
・Notch hole 1c...hollow part 2...tightening bell) 2a12b...hole 3...tightening tool
3a... Steel sales 3b... Bolt 3c
... Nut 4 ... Post-cast concrete 5 ... Pre-filled concrete 6 ... Gap 7.8 ... Piping 9 ...
Embedded box 10...Ceiling material! l...Ceiling base material! 2...Lighting equipment I3...Hanging material

Claims (2)

[Claims] (1) Concrete cylindrical beam with prestress introduced,
Form a unit by tying multiple pieces side by side,
This hollow slab is characterized by having these units installed side by side across the beams and integrated by pouring post-cast concrete over the entire upper part. (2) The hollow slab according to claim (1), wherein the hollow portion of the cylindrical beam is a space for an equipment duct.