JPH0721221B2 - Construction method of reinforced concrete slab - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing a reinforced concrete slab for constructing a composite structured slab from a precast half slab and cast-in-place concrete.

(Problems to be solved by the invention) By constructing a composite structure of a slab from a precast concrete floor slab and cast-in-place concrete, labor saving in construction and shortening of the construction period are achieved, and further, the center of the slab in the thickness direction. A slab structure has been implemented so far, in which the hollow part is hollow and the beam is omitted, and at the same time the rigidity is increased by increasing the composition to improve work efficiency and sound insulation performance of the floor.

This composite slab precast floor slab has conventionally been made thinner than the workability of transportation and suspension, and has a structure in which a truss streak is projected on the upper surface side for integration with cast concrete and the precast plate main body. There is a structure in which ribs are projected in two directions to improve rigidity, but in the former case, since rigidity is low, support work is required from concrete pouring to strength development.
On the other hand, in the latter case, since the weight becomes large, the workability becomes poor.
There is a problem.

The present invention has been made by paying attention to the problems of the conventional precast plate, and proposes a method of constructing a slab structure that overcomes the weak points of the both.

(Means for Solving the Problem) In the present invention, the width of the half slab that is the precast floor slab is set to one or a plurality of the half slabs are connected to one span length, and ribs are arranged in parallel in one direction on the upper surface thereof. Then, half slabs are manufactured in a projecting form, and the ribs are spaced in the length direction, and the embedding material that forms the hollow part is installed in the concrete. By installing ribs in two directions around the embedding material, the weight of each half slab is reduced while increasing the rigidity of the slab, while at the same time improving workability and economic efficiency by reducing the number of supporting work.

Since the embedding materials are installed at intervals in the length direction of the ribs, by placing concrete on the entire surface of the half slab, the concrete is placed on both sides of the embedding material in the direction orthogonal to the rib length direction. Ribs are formed by hammered concrete,
The slab was constructed in such a way that this rib and the upward rib of the half slab fit together, ensuring the integrity of the half slab and the post-cast concrete, as well as the composite of the half slab and the post-cast concrete. The slab has ribs in two directions, so that the force can be transmitted in two directions.

(Example) The present invention will be described below with reference to the drawings illustrating an example.

The present invention comprises a half slab 1 made of precast concrete in which a lower end bar 2 is embedded and a rib 1a is projected in one direction and a cast-in-place concrete 3, and a slab S made of reinforced concrete or steel reinforced concrete is used.
Is how to build.

The width of the half slab 1 is one or a size such that a plurality of half slabs are connected to each other to form one span length as in the embodiment shown in FIG. 1. In this embodiment, the half slabs 1 have ribs 1a at their end portions, The bolts 5 are inserted into the through holes 1b, 1b projecting from the la 1 and are connected to each other.

In the slab S, embedding materials 8 are installed between the ribs 1a, 1a of the half slab 1 at intervals in the length direction of the ribs 1a as shown in the drawing, and as shown in FIG. Is reinforced and concrete 3 is placed. The embedding material 8 is a hollow or lightweight box body formed of rock wool or the like in a box shape, and is embedded in the concrete 3 to form a hollow portion in the concrete 3.

As shown in FIG. 3, the rib 1a has a loop bar 7 through which the upper end bar 4 is inserted, the upper part of which is exposed from the upper end of the rib 1a and is embedded in the vertical direction, and the anchor bar is provided in a direction orthogonal to the rib 1a. 9 are juxtaposed in parallel so that the half slab 1 and the cast-in-place concrete 3 can be integrated.

When one span is relatively large, as shown in FIG. 2, by inserting the PC steel material 6 into the insertion hole 1b penetrating through all the ribs 1a and introducing prestress to the half slab 1, The unity between the slabs 1 and 1 is complemented. In this case, the connecting bolt 5 is unnecessary.

As shown in FIG. 5, the PC steel material 6 is optionally arranged in the longitudinal direction of the rib 1a which is the long side direction of the slab S.

The upper end streak 4 is laid on the half slabs 1, 1 connected by the bolts 5 or the PC steel material 6, and the concrete 3 is cast to sandwich the embedding material 8 and the ribs 1a of the half slab 1 are cast. A hollow slab S having ribs formed in two directions is formed from the concrete 3.

Since the embedding material 8 is installed at intervals in the length direction of the rib 1a, ribs are formed by the concrete 3 on both sides of the embedding material 8 in the direction orthogonal to the length direction of the rib 1a. Since the slab S is constructed so that the ribs 1a of the half slab 1 are fitted to each other, the integrity of the half slab 1 and the concrete 3 is ensured, and at the same time, the slab S has ribs in two directions. The structure allows transmission of forces in two directions.

The half slab 1 constituting the hollow slab S can be manufactured at the site as a single plate having a width of 1 span as shown in FIG. The bolt 5 is not required, which is more economical and saves labor.

(Effects of the Invention) The present invention is as described above, in which a half slab of a precast floor slab is provided with ribs protruding in one direction, and ribs are formed in the direction orthogonal to the ribs by casting concrete, and a total of two ribs are formed. Since the slab has a structure in which ribs are arranged in one direction, the rigidity is higher than that of a slab having a conventional structure, and since the ribs of the half slab are only in one direction, the weight per sheet is reduced. Due to the rigidity of the half slab itself, the number of supporting works is reduced, and workability and economy are improved at the same time.

In particular, since the embedding material is installed at intervals in the length direction of the rib, ribs are formed by post-cast concrete on both sides of the embedding material in the direction orthogonal to the length direction of the rib of the half slab. The slab is constructed in such a way that the upward ribs of the half slab fit together, ensuring the integrity of the half slab and the post-cast concrete. It becomes the structure that can transmit.

[Brief description of drawings]

FIG. 1 is a plan view showing a connected state of half slabs, second
The figure is a perspective view showing a part of it, Fig. 3 is a cross-sectional view showing the concrete pouring situation, Fig. 4 is a perspective view showing a half slab of one sheet, and Figs. 5 and 6 are FIG. 4 is a cross-sectional view taken along line XX and YY of FIG. 4 showing a concrete pouring state. S ... slab, 1 ... half slab, 1a ... rib, 1b ...
… Insertion hole, 2 …… bottom end streak, 3 …… concrete, 4 ……
Top bar, 5 ... Bolt, 6 ... PC steel, 7 ... loop bar, 8 ... Embedded material, 9 ... Anchor bar.

Claims (1)

[Claims] 1. A precast concrete made of a single plate or a plate having a width which is a span length formed by connecting a plurality of plates, in which ribs are jutted in parallel in one direction on the upper surface and lower end bars are embedded. Between the ribs of the half slab made of, with an interval in the length direction, install an embedding material that forms a hollow part in the concrete, place the concrete by placing the upper end bar on this half slab, A method for constructing a reinforced concrete slab for constructing a slab having a structure in which ribs are formed in two directions around an embedding material.