JPH0298406A - Manufacture of precast concrete slab - Google Patents

Abstract

PURPOSE:To finish precisely the rear of a precast concrete slab and make insertion hardware buryable easily and precisely in a fixed position and posture, by a method wherein a press concrete foam to which the insertion hardware is fitted detachably is pressed against the top of concrete. CONSTITUTION:A bed concrete form 1 provided with a bottom concrete frame 1a and circumferential concrete form 1b is mounted horizontally. After tiles for placement are arranged within the bed concrete form 1 backwardly, a reinforcing rod 3 is arranged through a spacer 4. A thick concrete 5 whose slump is about 0-5cm is placed within the bed concrete form 1. While the concrete is not solidified, a press concrete form 7 to which an insert hardware 6 having a female screw on the undersurface is fitted detachably through a bolt 8 is pressed against the top of the concrete 5 while imparting an oscillation with a facelike vibrator 9 and the insert hardware 6 is pressed into the concrete 5. When the concrete 5 is solidified, connection between the insert hardware 6 and press concrete form 7 is released by pulling out the bolt 8, the press concrete form 7 is removed and demolded from the bed concrete form 1 at need.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention can be combined with a precast slab or cast-in-place concrete that constitutes a wall or floor by itself, and be structurally integrated to constitute a composite wall or a composite floor. The present invention relates to a method of manufacturing a precast plate for permanent formwork.

[Prior Art] For example, taking a precast plate for permanent formwork constituting a composite wall as an example, conventionally, as shown in FIG. After laying tiles d for driving to form a surface finishing layer face down inside the 2-doped crusher C, reinforcing bars e are placed, and an inverted ■-shaped three-dimensional truss-shaped assembly reinforcing bar ( So-called Omnia muscle or Kaiser muscle) F, the lower half of which is the bed form C
The insert metal g for attaching the inner form for cast-in-place concrete is placed inside the bed form C with its upper half protruding above the bed form C, and is screwed into the reinforcing bar e with the insert metal g. They are fixed by welding through mating bolts h, and in this state, concrete i is cast inside the bed formwork C, and after the concrete l has hardened, it is removed from the mold to produce a precast version for permanent formwork. are doing.

In addition, in the method for manufacturing a precast version for permanent formwork that constitutes a composite floor using the inverted V-shaped three-dimensional truss-like assembly reinforcing bars r described above, the above-mentioned driving tiles d are not used, and the bed formwork C is The difference from the case of synthetic walls is that the inner surface of the bottom formwork a is a molding surface with a smooth surface finish, and insert metal fittings g for installing the inner formwork are not installed. The manufacturing method is almost the same as the manufacturing method of precast plates for permanent formwork that constitute walls. In addition, as shown in Fig. 7, instead of using the above-mentioned inverted V-shaped three-dimensional truss-like assembly reinforcing bars f, shear bolts j are screwed to a large number of insert metal fittings g buried on the back side, and cast-in-place concrete is constructed. A precast version for permanent formwork, which is structurally integrated with the concrete floor to form a composite floor, was also developed, for example, in
It is known from Publication No. 3-78614. Also when manufacturing this precast version, the metal insert g is fixed to the reinforcing bar e by welding.

[Problem to be solved by the invention]

The above conventional example has the following problems.

+11 Although the surface and surrounding side surfaces of the manufactured precast version were finished with good precision by the bed form C, the product accuracy of the back surface of the precast version (the top of the concrete at the time of manufacture) was poor.

(2) Not only does it take a lot of effort to weld the insert hardware g, but it is also difficult to mount the insert hardware g accurately in a predetermined position and perpendicular to the precast plate, and the positional accuracy and verticality of the insert hardware g Accuracy was often poor.

The present invention has been made in view of the above-mentioned conventional drawbacks, and the main object of the present invention is to enable the back side of a precast plate to be finished with high precision.

Another object of the present invention is to enable the metal insert to be easily and accurately buried in a vertical position at a predetermined position on the back side of a precast plate.

[Means to solve the problem]

The technical means taken by the present invention to achieve the above object are as follows.

That is, in the method for manufacturing a precast plate according to the present invention, concrete is placed inside a bed formwork that includes a bottom formwork and a peripheral formwork, with reinforcing bars placed therein, and while the concrete has not yet hardened. Then, a holding formwork with insert hardware removably attached to the bottom is pressed against the top of the concrete, and after the concrete has hardened, the insert fittings and holding formwork are uncoupled and removed from the mold, allowing the inserts to be placed on the back side. It is characterized by producing a precast version with hardware.

In addition, the precast plate may be a precast plate for permanent formwork that constitutes a composite wall or a composite floor as described in the conventional example, or a precast plate that itself constitutes a wall or floor. In the former case, the insert hardware is used for attaching inner formwork, shear bolts, etc., but in the latter case, the insert hardware is used for attaching hanging handles during transportation, and for attaching ceiling hanging bolts. will be used for etc.

In addition, by using a presser mold having an uneven portion for molding a shark-cotter on its lower surface as a pressing mold, a precast plate for a permanent mold having a shark-cotter on the back side can be manufactured.

In this case, a formwork including a bottom formwork and a peripheral formwork is used as the holding formwork, and the holding formwork is stacked in multiple stages and used as a bed formwork, thereby forming a plurality of permanent formworks. Precast versions can be manufactured for.

In addition, inside the bed formwork including the bottom formwork and the peripheral formwork,
In addition to arranging reinforcing bars, a planar truss body consisting of an upper chord member and a lower chord member parallel to each other and a lattice member located between them is positioned with its lower half side inside the bed form;
The upper half side is placed in a state that protrudes above the bed formwork, and in this state, concrete is poured inside the bed formwork, and while the concrete is still not hardened, multiple places are placed at the position of the truss body as a boundary. A presser formwork that is divided into pieces and has insert metal fittings removably attached to the bottom surface is pressed against the upper surface of the concrete, and after the concrete has hardened, the insert metal fittings and the presser formwork are uncoupled and removed, and the back side is removed. Precast versions for permanent formwork can be produced with insert hardware and projections for connection to cast-in-place concrete on the sides.

In either case, while applying vibration to the holding formwork,
It is desirable to press the holding formwork against the upper surface of the concrete.

[Effect]

According to the above configuration, by pressing the holding formwork against the upper surface of the concrete, the back surface of the precast plate (the top end of the concrete) can be finished with high precision.

By detachably attaching the insert hardware to the underside of the holding form, there is no need to weld the insert fitting to the reinforcing steel, and bolts can be used to attach the insert fitting to the holding form, and gun The attachment work can be made easier, and the metal insert can be buried in a predetermined position accurately and vertically.

By forming the uneven portion for forming a jerk scoop on the lower surface of the holding mold, it is possible to form a shear contour in a desired shape over the entire back surface of the precast plate.

By pressing the holding form against the upper surface of the concrete while applying vibration to the holding form, the insert hardware and the uneven portion for molding the shark turret on the lower surface of the holding form can be easily pushed into the concrete surface.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIGS. 1A to 1F show a method of manufacturing a precast plate for permanent formwork that is structurally integrated with cast-in-place concrete to form a composite wall. This manufacturing method is as follows.

As shown in FIG. 1(A), the bottom formwork 1a and the bottom formwork 1a
The peripheral formwork 1b is detachably connected to the peripheral formwork 1b with bolts, etc.
A bed form l equipped with the above is installed horizontally on the floor of a working yard at a factory or construction site.

As shown in FIG. 1 (b), tiles 2 for driving to form a surface finishing layer inside the bed form l
After placing the reinforcing bars 3 with spacers 4 in between. The reinforcing bars 3 may be made of reinforcing bars arranged in a vertical and horizontal lattice pattern, welded wire mesh, expanded metal, or the like.

In this state, as shown in Figure 1 (c), the bed form l
Hard-kneaded concrete 5 with a slump of about O to 5011 is placed inside the concrete.

While the concrete 5 has not hardened yet, as shown in FIGS. 1(d) and (e), a retainer form 7 to which a metal insert 6 having a female thread on the lower surface is removably attached is placed on the upper surface of the concrete 5. 8 is a bolt for attaching the insert hardware 6, which is inserted into the through hole provided in the holding formwork 7 from above and screwed into the insert hardware 6. be.

Reference numeral 9 denotes a planar vibrator detachably attached to the upper surface (or side surface) of the holding formwork 7, and while applying vibration to the holding formwork 7 with the planar vibrator 9, the holding formwork 7 is By pressing the metal insert 6 against the upper surface of the concrete 5, the metal insert 6 is easily pushed into the concrete 5. When the weight of the holding form 7 is small, the holding form 7 may be positively pressed against the bed form 1 using bolts 10 or the like.

In this state, the concrete 5 is cured for a predetermined period,
When the concrete 5 has hardened, remove the bolts 8, disconnect the insert hardware 6 and the holding formwork 7, remove the holding formwork 7, and if necessary, dismantle the surrounding formwork 1b of the bed formwork 1. , take out the product (demould it). As shown in Figure 1 (f), the surface is finished with tiles 2 and the back side is equipped with insert metal fittings 6 used for attaching the inner formwork. Precast version A for permanent formwork
is manufactured.

In addition, after pressing the holding formwork 7 onto the top surface of the concrete 5, a spacer made of a square pipe of an appropriate thickness is placed on the top surface of the holding formwork 7, and another bed formwork 1 is stacked on top of it. , it is also possible to manufacture a plurality of precast plates A with the installation area of one bed form. In this case, if a recess into which the bolt head is inserted is formed on the upper surface of the holding formwork 7 so that the head of the bolt 8 does not protrude from the upper surface of the holding formwork 7, the spacer is unnecessary. Although not shown, the bottom surface of the holding form 7 is provided with not only the insert hardware 6 but also an uneven part for molding the shear connector. Then, a shear connector may be formed on the back surface of the precast plate A at the uneven portion by pressing the holding frame 7 against the concrete 5 top plate.

Although the illustrated holding formwork 7 is made of steel, various materials can be selected for the holding formwork 7.For example, if the holding formwork 7 is made of concrete, it will be cheaper and the weight of the formwork will also be large. The weight of the formwork can be used effectively to press against the top of the concrete.

FIG. 2 and FIG. 3 show another embodiment of the present invention. This embodiment is a presser mold that includes a bottom mold 7a and a peripheral mold 7b, and has a concavo-convex portion 11 for molding a shear connector on the lower surface. Frame 7
The feature is that a precast version A for a plurality of permanent formworks for constructing a composite floor is manufactured by stacking the presser formwork 7 in multiple stages and using it as a bed formwork. There is.

That is, concrete 5 is poured inside the bed form l with reinforcing bars 3 placed therein, and while the concrete 5 is still not hardened, the above-mentioned holding form 7 is stacked and pressed against the upper surface of the concrete 5. After that, reinforcing bars 3 are placed inside the holding formwork 7 and concrete 5 is placed, and by repeating the same process, as shown in Fig. 3,
The lower surface is finished smoothly according to the shape of the bottom formwork 7a,
A precast version A for a permanent formwork for constructing a composite floor with a shear connector 12 formed on the back side is manufactured.

In this embodiment, the planar vibrator 9 is removably attached to the upper surface of the bottom formwork 7a, as shown by the solid line in FIG. A planar pie break 9 is removably attached to the concrete 5, etc., and the holding form 7 is pressed against the upper surface of the concrete 5 while applying vibration to the holding form 7. The weight of concrete 5 is calculated from uneven part 1
Since it can be effectively used for pushing 1, the application of vibration may be omitted.

4 and 5 (A) to (E) show another embodiment of the present invention. In this embodiment, instead of the Omnia muscle and the Kaiser muscle, the upper chord member and the lower chord member are parallel to each other, and the space between them is A method of manufacturing a precast version A for a permanent formwork constituting a composite wall using a planar truss body B made of lattice material located at .

The details of this method are as follows.

That is, as shown in FIGS. 4 and 5 (a), the bottom formwork 1a
A bed form 1 comprising a peripheral form tb detachably connected to the bottom form 1a with bolts or the like is installed horizontally on the floor of a working yard at a factory or construction site, and After placing the driving tiles 2 for forming a surface finishing layer inside the formwork 1 face down, reinforcing bars 3 are placed with spacers 4 in between.Next, on top of the reinforcing bars 3, A planar truss body B consisting of upper and lower chord members parallel to each other and a lattice member located between them is placed such that its lower half is located inside the bed form 1 and its upper half is closer to the bed form l. It is also placed in such a way that it protrudes upward.

In this embodiment, the upper chord material and the lower chord material each consist of two reinforcing bars, and the lattice material is composed of one reinforcing bar bent in a zigzag shape. (Alternatively, the entire planar truss body B or the upper chord member and the lower chord member may be made of steel plate.)

In this state, as shown in Figure 5 (b), the bed formwork 1
Hard-mixed concrete 5 with a slump θ˜51 is placed inside the concrete 5.

While this concrete 5 is still not hardened, as shown in FIG. The frame 7 is pressed against the upper surface of the concrete 5, and the insert hardware 6 is pushed under the concrete surface.

In addition, it is desirable to detachably attach a planar vibrator to the upper surface of the holding formwork 7, and press the holding formwork 7 against the upper surface of the concrete 5 while applying vibration to the holding formwork 7 with the planar vibrator. However, it is not always necessary to apply vibration.

After the predetermined curing period has elapsed and the concrete 5 has hardened, remove the bolts 8, disconnect the insert metal fittings 6 and the holding formwork 7, and remove the holding formwork 7, as shown in FIG. 5(d). If necessary, the peripheral formwork tb of the bed formwork 1 is dismantled and the product is taken out (removed from the mold).As a result, the surface is finished with the tile 2 finish, as shown in Fig. 5 (E). The back side is equipped with insert hardware 6 used for installing the inner formwork, and a permanent wall for constructing a composite wall is provided with a protrusion for connection to cast-in-place concrete (the upper half side of the truss body B). A precast version A for formwork is obtained.

In the examples shown in Figures 4 and 5 (A) to (E), the surface is finished with Tile 2 because it is a precast version A for permanent formwork for constructing a composite wall. When producing a precast version A for permanent formwork for constructing a floor, the tiles 2 will be omitted.

Furthermore, in each of the above embodiments, only the case of manufacturing a precast plate for permanent formwork was explained, but the present invention can be applied to a normal precast plate that itself constitutes a wall or floor (both sides are finished). It goes without saying that the present invention can be similarly applied to the method for manufacturing A (precast finished product).

〔Effect of the invention〕

Since the present invention has the above-described configuration, it can achieve the following effects.

(2) According to the configurations of claims (1) to (5), by pressing the holding formwork against the upper surface of the concrete, the back surface of the precast plate (the top end of the concrete) can be finished with high precision.

■As claimed in claim (1), by removably attaching the insert hardware to the lower surface of the holding formwork, there is no need to weld the insert fittings to the reinforcing reinforcing bars, and the attachment of the insert fittings to the holding formwork is easy. Bolts can be used as the means, making the installation process easier and allowing the metal insert to be buried in a predetermined position accurately and vertically.

■As claimed in claim (2), by forming the irregularities for molding shark turrets on the lower surface of the holding mold, it is possible to accurately form the shark turrets of a desired shape with deep irregularities over the entire back surface of the precast plate. .

(2) According to claim (3), the weight of the stacked presser forms and concrete can be effectively used to press the uneven portion for molding the shark turret into the concrete.

■According to claim (4), although the truss body is flat, most of the concrete surface can be pressed and finished with high accuracy using the holding formwork, and it has the same function as the so-called omni version. In addition, a precast plate for permanent formwork with high positional accuracy and vertical accuracy of the insert hardware can be obtained.

(2) According to claim (5), it is possible to easily push the insert hardware and the uneven portion for molding the shark turret on the lower surface of the holding form into the concrete surface.

[Brief explanation of drawings]

FIGS. 1A to 1F are cross-sectional views showing an embodiment of the present invention. 2 and 3 are cross-sectional views showing another embodiment of the present invention. Fig. 4 and Fig. 5 (a) to (e) show another embodiment of the zero launcher, and Fig. 4 is a sectional view parallel to the upper and lower chord members of the truss body, and Fig. 5 (a) to (e). E) is a sectional view taken in a direction perpendicular to FIG. 4. FIGS. 6 and 7 are explanatory diagrams of conventional examples. A... Precast version, B... Truss body, 1...
Bed formwork, la... bottom formwork, 1b... peripheral formwork,
3... Reinforcement bar, 5... Concrete, 6... Insert hardware, 7... Holding formwork, 7a... Bottom formwork,
7b... Peripheral formwork, 11... Concave and convex portion for molding shear connector. Applicant: Takenaka Corporation

Claims (5)

[Claims] (1) Concrete is poured with reinforcing bars placed inside the bed formwork, which has a bottom formwork and peripheral formwork, and insert metal fittings can be attached and removed from the bottom surface while the concrete has not hardened yet. Press the retaining form attached to the top of the concrete, and after the concrete has hardened, disconnect the insert hardware from the retainer form and remove the mold to produce a precast plate with insert hardware on the back side. A method for manufacturing a precast plate, characterized by: (2) Concrete is placed inside the bed formwork, which has a bottom formwork and a peripheral formwork, with reinforcing bars arranged, and while the concrete has not yet hardened, the bottom surface is made uneven for shear cotter forming. A precast plate for permanent formwork with a shear cotter on the back side is manufactured by pressing a holding formwork with a shear cotter formed on the upper surface of the concrete and removing the mold after the concrete has hardened. How to make the plate. (3) As the holding formwork, a formwork including a bottom formwork and a peripheral formwork is used, and by stacking the holding formwork in multiple stages and using it as a bed formwork, a plurality of permanent formworks can be formed. The method for manufacturing a precast plate according to claim (2), characterized in that the method comprises manufacturing a precast plate for. (4) In addition to arranging reinforcing bars inside a bed formwork that includes a bottom formwork and a peripheral formwork, a planar structure consisting of upper and lower chord members parallel to each other and lattice members located between them. A truss body is placed in such a manner that its lower half is located inside the bed form and its upper half protrudes above the bed form, and in this state concrete is poured inside the bed form, While the concrete has not yet hardened, a presser formwork that is divided into a plurality of pieces with the position of the truss body as a boundary and has insert metal fittings removably attached to the bottom surface is pressed against the upper surface of the concrete, and after the concrete has hardened, the insert metal fittings are attached to the upper surface of the concrete. A precast plate for a permanent formwork is manufactured by uncoupling the holding formwork from the holding formwork and removing the mold, thereby producing a precast plate for a permanent formwork, which has insert metal fittings on the back side and a protrusion for connecting to cast-in-place concrete. How to make the plate. (5) The precast according to any one of claims (1) to (4), characterized in that the holding form is pressed against the upper surface of the concrete while applying vibration to the holding form. How to make the plate.