JPS63251554A - Precast concrete panel having shear reinforcing bar and its production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to precast concrete (hereinafter referred to as PC
In particular, it relates to PC boards in which the shear reinforcing bars protrude from the top of the PC board and the joint surface is improved when concrete is poured on top of the boards to form a composite board, and the manufacturing method of the PC boards. It is.

[Conventional technology]

Walls and floor slabs of buildings are prefabricated with precast reinforced concrete boards, and when the thickness is thick, PC board is used as formwork on one or both sides of the wall,
For floorboards, it is used as the formwork for the bottom surface, and is used to form a composite board with cast-in-place concrete. At this time, reinforcing reinforcing bars are added to such an integrated plate body to incorporate columns and beams, and at the same time, these reinforcing bars function as shear reinforcing bars. In particular, when it comes to floorboards, which are known as "half slabs" and have reinforcing bars as beams, the bottom chord of the beam is buried in the slab, the top chord is protruded from the top surface, and the upper and lower reinforcing bars are are connected by lattice muscles and serve as shear muscles. Among them, a board material known as ``Omnia version'' is also used in a form other than a composite board.

Such a PC board is integrated with post-cast concrete to exhibit the required performance as a slab structure, and shear reinforcing bars and shear casters are used individually.

On the other hand, PC boards are usually manufactured by building a formwork with a height equal to the thickness of the board on top of the surface plate and pouring concrete horizontally to produce a simple PC board with flat surfaces on both sides. can be,
For this purpose, we manufacture one PC at a time at a PC factory, and
The so-called ``layered construction method'' is used, which utilizes the smooth top surface of the board, uses it as the bottom formwork, and raises the side formwork in sequence.

[Problem that the invention seeks to solve]

In the conventional manufacturing method of PC board, even if the hardening and curing of the concrete board is promoted, in order to continue the manufacturing process, a large number of surface plates and formwork centers and a vast PC pouring yard are required. and requires a storage yard for the products due to the rotational use of formwork.

If the laminated construction method is adopted here, the manufacturing area will be reduced, but if the PC board has a protrusion on one side as mentioned above, the board surface cannot be used, and the advantages of this construction method cannot be utilized. .

Furthermore, in the "laminated construction method" 1 of PC boards combined with post-cast concrete, a concave cotter is formed to join both concretes, and inserts are used for the same purpose, shear hardware, Although it is used to attach PC board lifting hooks, it is not suitable for combining with post-cast concrete of PC boards in which a part is buried in concrete and the rest continuously protrudes outside the board, like shear reinforcing bars. Therefore, the above-mentioned individual manufacturing method has to be used, and a large amount of heating energy and equipment for this purpose are required to promote curing. Moreover, shear reinforcing bars only become effective when the PC board and post-cast concrete begin to shift slightly, and shear co-reinforcement bars have the problem of "peeling" at the bonding surface between the two concretes, and these problems are caused by Alone, it cannot be said to be a perfect solution for composite concrete.

[Means for solving problems]

The present invention was developed to provide a PC board and a method for manufacturing the same that can eliminate the above-mentioned problems. is buried in cosiclete, and shear reinforcing bars are disposed in the longitudinal direction with the remainder protruding from one side.
It is a C plate, and the gist is that the integrity of composite concrete is achieved by combining shear reinforcing bars and shear bolts, so that the shear reinforcing bars can be used to deal with misalignment of both layers, and the shear reinforcing bars can be used to deal with peeling. Moreover, the gist of the second invention is to interpose a spacer with a height exceeding the height of the protrusion between the upper and lower plates of concrete that is poured in layers. The PC board of the present invention is characterized in that it has longitudinal shear reinforcing bars, and a large number of concave cotters are formed in a row by spacers installed in parallel between the shear reinforcing bars.
In the invention, a rod-shaped spacer with a row of protrusions on the lower surface is installed on the upper surface of the concrete in which a part of the protruding object is to be buried, which is cast on a surface plate, and the protruding part is buried in the concrete. Manufacture of a PC board characterized by having a process of placing the next stage of flat plate formwork on the top surface, pouring the next stage of concrete on this surface, and repeating the layered construction method in this way. It's a method. The present invention enables the design of slabs that ensure long-term structural quality and are suitable for buildings with composite slabs where single slab floors are unsuitable, such as warehouses for heavy goods and factory floors with strong vibrations. This made it possible.

[Example] A PC board having a concave cotter and shear reinforcing bars of the present invention will be described in detail based on drawings of examples.

FIG. 1 is a perspective view of a PC board 1 having shear reinforcing bars according to the present invention, and FIG. 2 is a vertical sectional view of a floor slab 2 including this PC board 1. In FIG. 1, 11 is a reinforced concrete plate of the PC board 1, 12 is a concave shearcotter (hereinafter simply referred to as cotter) provided on the upper surface thereof, and 13 is a shear reinforcing bar. As shown in FIGS. 3(a) and 3(b), the shear reinforcing bars 13 consist of an upper chord bar 14 and two lower chord bars I5 arranged in parallel in a triangular shape, and a large number of chevron-shaped shear bars as shown in FIG. muscle 16
Assemble it in a dye mold, or weld the two wave-shaped lattice bars 17 as shown in (b) to form a triangular beam, and in both cases, insert the lower chord member 15 into the concrete plate ll of the PC board 1. They are buried and three or more are arranged parallel to one direction of the PC board 1 at least on the sides and the center. These shear reinforcing bars 13 are not limited to triangular cross sections, and may have upper and lower parallel chord shapes. Third
Figure (C) shows yet another example, in which concrete 1
A shear reinforcing bar 13 is formed by connecting the lower necks of a large number of shear bolts 18 implanted in the shear reinforcing bar 1 with a top chord bar 14. In the middle of the shear reinforcing bars 13 as described above, cotters 12 are arranged parallel to the shear reinforcing bars 13 in, for example, two rows and recessed from the upper surface.

In Fig. 2, this PC board 1 is stretched across the shoulders of two beams 3.3 in the direction of the shear reinforcing bars 13, and is made of cast-in-place concrete together with the upper concrete 31 of the beams 3 and the upper layer concrete 21 of the floor slab 2. It forms the bottom formwork of the floor slab 2 so that it is integrated.

[Function] The function of the present invention will be explained based on the manufacturing process as well as the second invention related to the manufacturing method. FIG. 4 is a sectional view of a formwork device for explaining the method of manufacturing the PC board 1,
4 is a surface plate installed in a PC board factory. A side formwork 41 is built on this surface plate 4 at a height corresponding to the thickness of the concrete plate 11 of the PC board 1, reinforcing reinforcing bars 19 are arranged inside it, and using this reinforcing bar 19, - In addition to disposing shear reinforcing bars 13 in the force direction, lower chord bars 15 are disposed at a predetermined height. Concrete C is then poured into the formwork 41, and its upper surface is leveled according to the formwork 41.

On the upper surface of this concrete C, spacers 5 shown in FIG. 5 are placed outside and in the middle of the shear reinforcing bars 13. The spacer 5 is made of a suitable piece of wood and is formed into a square piece.Notches 51 are arranged in a row on the lower surface of the spacer 5, and the remaining portion 52 is shaped like a cotter. Normally, the cotter molds 52 are preferably provided at equal intervals, and are formed with a notch depth of about 2 to 7 cm determined based on the thickness of the concrete plate 11, and the height above the notches 51 is set to the height of the shear reinforcing bar 13. The height is set slightly higher than the top height of the upper chord member 14. Such a spacer 5,
The cotter mold 52 is horizontally pressed so as to be buried in the uncured concrete C, and the next stage PCCl2O bottom form 42 is placed horizontally on the parallel spacer 5.

The bottom formwork 42 has a main frame material in a direction orthogonal to the spacer 5, or is made of a thick plate material so as to be similar to the surface plate 4 without bending.

Above this bottom formwork 42, the above steps are repeated,
Using a predetermined number of formwork devices and a well-known layered construction method, a predetermined number of PC boards 1 can be manufactured at only the position of this surface plate 4. After a curing period, if the molds are demolded in order from the upper part, the removal of the spacer 5 becomes the demolding of the molded blocker 12, and a predetermined number of PC boards 1 can be obtained. Of course, hooks for hoisting the PC board 1 can also be attached with a lower protruding height than the shear reinforcing bars 13.

(Effects of the Invention) In forming a deck slab by combining PC boards with post-cast concrete, the present invention simultaneously forms shear reinforcing bars and joint slabs. It is provided as a PC board with both functions. To this end, as a second invention, the problem of protrusions when using the lamination method as a manufacturing method for such PC boards is solved by using spacers provided between each layer, and this spacer also forms a cotter at the same time. As a result, the working area in PC factories can be made more efficient, and the advantages of the laminated construction method can be fully utilized, and the completed PC boards can be effectively used for composite floors that are suitable for heavy goods warehouse floors and factory floors that are subject to strong vibrations. This greatly expands the possibilities of floor design and greatly contributes to the construction industry.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is a perspective view of the PC board of the present invention, FIG. 2 is a vertical sectional view of a floor slab using the same,
FIG. 3 is a detailed view of the shear reinforcing bars, FIG. 4 is a sectional view illustrating the process mainly of the formwork device used in the method for manufacturing PC boards, and FIG. 5 is a detailed view of the spacer. 1...PC board, 2...floor slab, 3...beam, 4...
Surface plate, 5...Spacer, 11...Reinforced concrete, 12...Cotter, 13...Shear reinforcing bar, 14
... Upper chord muscle, 15 ... Lower chord muscle, 16 ... Shear muscle, 17 ... Lattice muscle, 18 ... Shearbolt muscle, 19
... Reinforcement reinforcing bars, 21 ... Upper layer concrete, 31
...Top concrete, 41...Side formwork, 42...
・Bottom formwork, 51...notch, 52...cotter mold. Patent applicant: Shimizu Corporation, representative and patent attorney: Akira Inaba - Toshi Haruta Figure 1 Figure 2

Claims (2)

[Claims] (1) In a precast reinforced concrete plate, the lower part of the shear reinforcing bars set in the longitudinal direction is buried in the precast concrete plate, and the upper part protrudes from the upper surface, and a recessed cotter is installed between these reinforcing bars. A precast concrete plate having shear reinforcing bars, characterized in that rows are formed parallel to the reinforcing bars. (2) In the method of manufacturing a precast concrete plate having shear reinforcing bars with the upper part protruding from the upper surface by the layered construction method, the process of assembling the side formwork on the surface plate, placing the reinforcing bars for the PC board within this formwork. The process of reinforcing, the process of installing shear reinforcing bars using this reinforcing bar, the process of burying the lower part of the shear reinforcing bars in the above-mentioned formwork, and the process of pouring concrete to a predetermined thickness. A process in which rod-shaped spacers are placed in rows to form cotter-shaped protrusions, and the height at the notch is higher than the protruding part of the shear reinforcing bar, with the protrusions buried under the concrete surface. A curing step, a step of installing an upper bottom form on this spacer, a step of repeating the above steps on this bottom form, and a predetermined number of PCs formed into cotters by demolding.
A method for manufacturing a precast concrete plate having shear reinforcing bars, comprising the steps of: obtaining the plate.