JPH0480804B2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a method for cutting aerated concrete;
In particular, it relates to a method of cutting blocks of aerated concrete to form panels.

<Conventional technology> Aerated concrete is heat-insulating, non-combustible, fire-resistant, sound-absorbing,
It is widely used as a building material because it is lightweight and has excellent functions. Generally, water bubbles are mixed into hydraulic cement materials using surfactants,
Aluminum powder is added and foamed, and after molding, it is hydrothermally cured in an autoclave and manufactured into a product.
Furthermore, concrete sets relatively slowly, which is the so-called slow setting type, and before it progresses to hardening, it can be easily cut with a wire such as a piano wire. Therefore, in order to obtain panels as building materials, it is common to form blocks into blocks and then cut them with wire.

A conventional method of cutting a cellular concrete block using a wire will be explained with reference to FIGS. 1A to 1C. Aerated concrete block 1'
is placed on a stand 2', and the horizontally stretched wire 3' is moved vertically relative to the stand 2'. In the case of FIG. 1A, only a small area panel can be obtained. Moreover, in the case of FIGS. 1B and 1C, the concrete does not have shape retention, so buckling occurs and is unstable.
Furthermore, a common drawback of the above three examples is that a beautiful cut of the product cannot be obtained unless the wire 3' is bitten into the stand 2' at the cutting end. This complicates the structure of the platform 2' (usually the bottom molding frame).

In order to improve the above problem, a method has been used in which a horizontally stretched wire is moved horizontally relative to the table to cut the block on the table. When using this method, the upper panel cut with wire will rest flat on the lower panel during cutting, so the buckling problem mentioned above does not occur and the table does not have a complicated structure. Smooth cutting can be achieved even when cutting.

However, it is known that cracks occur on the panel surface near the cutting start end of the block. The cause of cracks is related to the diameter of the wire used for cutting and the number of cutting stages. That is, 2nd A
As shown in the figure, when a cutting gap 4' is created by cutting the wire 3', the panel becomes cantilevered and flexes, producing a crack 5' on the surface in the width direction. Further, when cutting is performed in multiple stages as shown in FIG. 2B, the bending allowance of the upper panel becomes considerably larger based on the addition of the cutting gap below, so that cracks 5' are more likely to occur in the upper panel.

The above phenomenon is observed at the beginning of cutting, and after that, as the wire 3' progresses, concrete chips generated by the wire cutting clog the cutting gap 4' and prevent the panel from sagging, so the crack 5' is Usually does not occur.

<Objective of the Invention> The object of the present invention is to prevent cracks from occurring on the surface of the panel near the starting edge of the cut when a block of concrete aggregate is cut horizontally with a horizontally stretched wire to form a panel. The purpose is to provide a method that prevents this from happening.

<Structure of the Invention> The above object is to press and hold almost the entire end surface of the cutting start end of the block in the horizontal direction, and to prevent the block from sagging by cutting while maintaining the cutting gap at the cutting start end. This is achieved by a method for cutting unreinforced cellular concrete characterized by the following.

<Example> Hereinafter, an example of the present invention will be described with reference to FIGS. 3 and 4.

An aqueous slurry of aerated concrete is poured into a formwork consisting of four side frames (not shown) and a bottom frame 1. When the aqueous slurry is solidified to obtain a long block 2 with a rectangular cross section, the block is placed on the bottom frame 1 and transferred to a cutting process in order to cut out a panel from the block with its four circumferential side frames removed.

The block cutting device includes a frame 3, for example in the form of a portal. The portal frame 3 includes a horizontal side 3A and a vertical side 3B hanging from both ends of the horizontal side, and both vertical sides 3B have a plurality of wire fasteners 4 spaced apart from each other at a predetermined interval in the vertical direction and vertical sides 3B. A wire guide rod 5 is provided respectively. A wire 6 such as a piano wire is tensioned between the wire fasteners 4 on both vertical sides facing each other via the respective wire guide rods 5. Therefore, the wires 6 are stretched horizontally at intervals above and below. In this case, the portal frame 3 needs to be constructed firmly so as not to be deformed by the tension of the wire 6. The portal frame 3 is mounted on a known moving device such as a trolley, and is moved horizontally over a distance approximately equal to the entire length of the block 2 to cut the block 2 horizontally.

A pressing device 7 is provided on the bottom frame 1 on the cutting start end side. The pressing device 7 includes a substrate 8 attached in advance to the end surface of the bottom frame 1, and a presser plate 9 to be pressed against the end surface of the block 2.
and a biasing member 10 that presses the presser plate 9 against the block 2 based on the substrate 8. The biasing member 10 is fixed to the presser plate 9 and has a stud 11 that passes through a through hole in the substrate 8 and protrudes outward, and both plates 8,
Compression spring 1 located between 9 and surrounding stud 11
2. A friction plate 1 made of an elastic material such as rubber or sponge is placed on the surface of the presser plate 9 facing the block 2.
Install 3. It is also possible to form the surface of the presser plate 9 into an uneven surface and omit the friction plate 13. It is also necessary to set the biasing force of the compression spring 12 to be smaller than the compressive strength of the block 2.

Prior to cutting the block 2, the stud 11 is pulled to the right through the hole in the substrate 8, and the portal frame 3 is disposed between the friction plate 13 and the end face of the block 2. Cutting with the wire 6 is started, and when about 10 cm is cut horizontally into the block 2, the tensile force of the stud 11 is relaxed and the friction plate 13 is brought into gentle contact with the end face of the block 2.

The above-mentioned cracking phenomenon near the cutting start point seen at the initial stage of cutting is due to
This is prevented by the friction between them. Further, since the biasing force of the compression spring 12 is smaller than the compressive strength of the block 2, the end face of the block 2 is not deformed.

In a second embodiment, the biasing member 10 can be replaced by a hydraulic cylinder fixed to the base plate 8.

In these embodiments, the presser plate 9 is pressed against the block 2 after cutting is started, but cutting may be started after the presser plate 9 is pressed.
Further, the wire 6 may be stretched obliquely rather than parallel to the end surface of the block 2, and the moving speed of the wire 6 can be reduced near the cutting end to make the cutting even smoother.

<Effects of the Invention> As described above, since the wire cutting is performed by pressing the end face of the cutting start end of the concrete aggregate block in the horizontal direction, the block does not sag, and therefore the cracks caused by conventional wire cutting are eliminated. It never occurs.

[Brief explanation of the drawing]

Figures 1A to 1C are perspective views showing a conventional method for cutting unreinforced cellular concrete using a wire, Figures 2A and 2B are perspective views showing how cracks occur, and Figure 3 shows the main parts of the present invention. The perspective view, FIG. 4, is a side view of FIG. 3. 1...Bottom frame, 2...Block, 6...Wire.

Claims (1)

[Claims] 1. A concrete aqueous slurry containing a foaming agent is poured into a mold, and after the slurry has solidified, the four side frames are released, leaving the bottom frame, and the concrete aggregate block is removed. , in a method of cutting a block on a bottom frame by horizontally moving a horizontally stretched wire relative to the bottom frame, substantially the entire end face of the cutting start end of the block is pressed and held in the horizontal direction; A method for cutting unreinforced cellular concrete, characterized in that the block is prevented from sagging by cutting while maintaining a cutting gap at the cutting start end. 2. The cutting method according to claim 1, wherein the end face of the cutting start end of the block is pressed with a pressure smaller than the compressive strength of the concrete aggregate.