JPS5814289B2 - Omnia board prestressed Pca board manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a prestressed Pca board, a so-called Omnia board, which is known as the waste frame floor construction method.

Slabs in construction work have high development value as a building part because of their production and performance, and many floor construction methods have been created.

Recently, a formwork floor construction method that features unsupported construction has been proposed, but from the viewpoint of industrialization and labor saving, there are still some problems, and the current situation is that it is costly. .

On the other hand, there is a waste frame floor construction method that uses what is called an omnia board, in which the lower half of the slab is a Pca board, but since this is a thin Pea board, it is difficult to transport, erect, and place concrete. It is easy for cracks to form during construction, and it is necessary to take adequate measures such as shoring during erection.

If an unsupported floor construction method becomes possible using Omnia boards, a remarkable effect can be expected as unsupported discarded formwork.

In order to realize unsupported construction with Omnia board, its thin wall P
Prestress may be introduced into the ca portion to obtain a prestressed Pca plate having a prestressed structure.

Prestressed structures are established as a construction method that prevents cracks from occurring in concrete by placing prestressed steel on RC members in advance and introducing eccentric moments and axial forces in response to moments expected in members (columns, beams, floors). are doing.

To do this on the Omnia board, put the PC on the Pca board.
Prestressing is introduced using special equipment by wiring steel wires or stranded steel wires, but there is a cost burden for the construction method in the factory equipment at the time of manufacturing, so it is not possible to use common construction methods such as building slabs. The reality is that it has not been used except in special cases.

The present invention has been made in view of the above points, and does not require special production equipment, can introduce prestressing with simple equipment, greatly reduces the cost burden, and is capable of producing waste form frames for omniar boards. This expands the scope of application of the floor construction method, and its gist is that if the purpose is only to prevent cracks due to its own weight during construction, then the estimated moment applied to the floor members should be The idea is to utilize the bending rigidity of reinforcing bars to introduce a reverse moment into the Pca member to counter the assumed moment.

This will be explained in detail below based on the drawings.

That is, first, as shown in FIG. 1, an arch-shaped Omnia plate assembly reinforcing bar 1 is manufactured.

As shown in Fig. 2, this is placed in a formwork 3 on a bed 2, and a reverse moment P that opposes the assumed moment is applied from above to the assembly reinforcing bar 1, and the arch-shaped assembly reinforcing bar 1 is placed in a lying position. Make it.

In this state, concrete 4 is poured into the formwork 3 as shown in FIG.

FIG. 4 shows an aspect in which the reverse moment P that was applied in advance is released when demolding is performed when the concrete 4 has developed a predetermined strength. I can bounce back.

In the study of the bending stiffness of the assembled reinforcing bars, it was confirmed that the bending stiffness was set within the allowable stress-elasticity range of the reinforcing bars.

As mentioned above, the prestress Pca of the omniar plate of the present invention
Plate 5 does not introduce an eccentric moment and axial force into the prestressed steel material as in conventional prestressed structures, but utilizes the bending rigidity of the assembled reinforcing bars of the Omnia plate, which can be done with simple equipment. No special tension applying device is required, and the cost of the product can be greatly reduced.

[Brief explanation of the drawing]

1 to 4 are process flowcharts of the present invention, and FIG. 1' is a longitudinal cross-sectional view of assembled reinforcing bars. Brief explanation of symbols, 1...Assembly reinforcing bar, 2...Bed, 3
...Formwork, 4...Concrete, 5...Prestressed Pca board of Omnia board.

Claims (1)

[Claims] 1 The assembled reinforcing bars of the Omnia plate are configured in an arch shape, and when concrete is poured into the formwork, a reverse moment is applied to the arch-shaped assembled reinforcing bars in advance to counter the expected moment that will be applied during erection, and the reinforcing bars are pushed into a lying position. Concrete is placed under pressure, and after the poured concrete IJ-t develops its strength,
A method for manufacturing a prestressed Pca plate of an Omnia plate, characterized in that the pushing force is released and a reverse moment utilizing the bending rigidity of assembled reinforcing bars is incorporated as prestress.