JPH0480806B2 - - 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.

<Prior art> 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.

The conventional cutting of 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.Afterwards, 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 normally closed. 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 cutting start point when forming a panel by cutting a concrete aggregate block horizontally using a horizontally stretched wire. The purpose is to provide a method that prevents this from happening.

<Structure of the Invention> The above object is to press and hold both sides of the block near the cutting start end in the width direction and cut while maintaining the cutting gap at the cut start end to prevent the block from sagging. 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 predetermined intervals 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 stretched in tension between the wire fasteners 4 on both opposing vertical sides 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 gate-shaped frame 3 is mounted on a known moving device such as a trolley, and is horizontally moved over a distance approximately equal to the entire length of the block 2 to cut the block 2 horizontally.

A holding device 7 is provided on the bottom frame 1 on the cutting start end side. The holding device 7 includes a U-shaped channel-shaped base frame 9 that is slidable along the guide groove 8 of the bottom frame 1, and a base frame 9.
a fluid pressure cylinder 10 provided on both flanges of the
A holding plate 1 attached to the piston side of the cylinder 10
1. The holding device 7 is formed so as to surround the cutting start end of the block 2, and friction plates 12 made of an elastic material such as rubber or sponge are attached to the surface of a holding plate 11 facing both sides of the block 2.
The friction plate 12 is formed by forming the surface of the presser plate 11 into an uneven surface.
can also be omitted. In this case, it is necessary to set the biasing force of the fluid pressure cylinder 10 to be smaller than the compressive strength of the block 2.

When the wire 6 starts cutting and cuts about 10 cm horizontally into the block 2, the holding device 7 is moved along the guide groove 8 and the holding plates 11 are positioned outside on both sides near the cutting start end. Next, the fluid pressure cylinder 10 is operated to gently hold both sides of the block 2 with the friction plates 12.

The above-mentioned occurrence of cracks in the vicinity of the cutting start point seen at the beginning of cutting can be prevented by pressing and holding both sides of the cutting start end of the block 2 in the width direction.

In the above embodiment, the wire 6 is stretched parallel to the end face of the block 2, but it may be stretched diagonally to the end face. Further, the moving speed of the wire 6 is reduced near the cutting end portion, thereby making the cutting even smoother.

<Effects of the Invention> As described above, since the wire cutting is performed by pressing and holding both sides of the cutting start end of the concrete aggregate block in the width direction, the block does not sag, and therefore it No cracks occur during cutting.

[Brief explanation of the drawing]

Figures 1A to 1C are perspective views showing a conventional wire cutting method for unreinforced cellular concrete, Figures 2A and 2B are perspective views showing a state in which cracks occur, and Figure 3 shows an apparatus for carrying out the method of the present invention. The perspective view shown in FIG. 4 is a plan 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 moving a horizontally stretched wire horizontally relative to the bottom frame, pressing and holding both sides of the block near the cutting start end in the width 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 both sides of the block near the cutting start end are pressed with a pressure smaller than the compressive strength of the concrete aggregate.