JPH01165405A - Cutting of lightweight cellular concrete - Google Patents

Abstract

PURPOSE:To avoid occurrence of corner chipping as much as possible at cutting, by casting a raw material slurry for a lightweight cellular concrete kept at a specified temp. in a mold and cutting it while it is uncured. CONSTITUTION:A piano wire is placed on a belt on which a raw material slurry is cast and the raw material slurry kept at 50 deg.C is thereon cast. The cast item can be cut by pulling up the piano wire while being uncured just after the casting. Uncured lightweight cellular concrete means such a condition that when a steel ball of 40mmphi is freely dropped on ALC from the height of 50mm, the trace diameter of the trace of the ball exceeds 28mm. The compounded slurry compsn. is comprised of 20-40wt.% cement, 5-15wt.% lime, 40-60wt.% silica sand and 3-10wt.% plaster and the ratio of water/the solid content is 0.5-0.75. Bubbles are therein introduced and a slurry pref. held at 50-80 deg.C is cast.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a method for cutting lightweight aerated concrete (ALC);
In particular, the present invention relates to a cutting method that prevents corner chipping by cutting the molded uncured ALC with a piano wire.

(Prior art) ALC has been widely used in various housing applications in recent years because it is nonflammable, can be molded into desired shapes, has good workability, is lightweight, has thermal insulation properties, and has sound insulation properties. ing.

ALC is cut into a predetermined size in a semi-cured state immediately after demolding during the molding, curing and curing δ stage, and is cured in an autoclave to form a final product.

(Problem to be solved by the invention) However, when this cutting method is adopted, stress accumulates as the final cut is approached with the help of a means called push cutting, and corner chips occur at the final cut. This is extremely easy to occur, and not only does it take a lot of effort to repair this area later, but it also has the drawbacks of non-uniform quality.

(Means for Solving the Problems) As a result of various studies aimed at eliminating the above-mentioned drawbacks and minimizing corner chipping during ALC cutting, the inventor of the present invention found that the temperature was maintained at 50°C or higher. It has been discovered that the above object can be achieved by casting a lightweight cellular concrete raw material slurry into a mold and cutting it while it is in an uncured state, and this is the gist of the present invention.

In the present invention, the ALC in an unhardened state refers to a state in which the diameter of the trace exceeds 281 cm when a 40-weight φ steel ball is freely dropped onto the ALC from a height of 50 μl.

If the ALC has been hardened to such an extent that the diameter of the trace becomes smaller by 28 mm, corner chipping will occur even if cutting is performed by the method of the present invention.

The cutting method according to the present invention can of course be applied to ALCs having conventionally known compositions and manufacturing methods, but it can also be applied to continuous molding methods, which is preferable. In other words, 1. For example, if a continuous molding method is adopted in which raw material slurry is cast on the surface of a running belt and then cured and hardened until it can be removed from the mold as it travels further on the belt, the belt into which the raw material slurry is cast. Piano wire is first placed on top, ALC raw material slurry maintained at 50°C is poured onto it, and the piano wire is easily pulled upward at any position immediately after that while the uncured state continues as described above. Can be cut.

As a preferable example of manufacturing such ALC, the composition of the slurry is 20 to 40% by weight of cement and 5 to 1% of lime.
5% by weight, silica sand 40-60% by weight.

Water/solids ratio 0.5-0.75 with gypsum 3-10 wt%
bubbles are introduced into this, and the temperature is 50°C or higher, preferably 5°C.
The slurry maintained at 0 to 80°C is poured.

The reason why cutting is possible when the means of the present invention is adopted is not necessarily clear, but if the temperature of the casting slurry is raised to 50°C or higher, the area where the cutting was performed will appear to be the same as before. It seems that it has returned, but when it is semi-cured and demolded, it separates from that part.

Even though they are not hardened, it is presumed that they will not integrate with each other because the water use reaction is progressing.

Claims (1)

[Claims] 1. A method for cutting lightweight cellular concrete, which comprises casting a raw material slurry for lightweight cellular concrete maintained at a temperature of 50° C. or higher into a mold, and cutting the slurry while it is still in an uncured state. 2. The uncured lightweight aerated concrete has a diameter of 40 mm.
The cutting method according to claim 1, wherein when a steel ball is allowed to fall freely onto the concrete from a height of 50 mm, the diameter of the trace exceeds 28 mm. 3. The cutting method according to claim (1), wherein the cutting is performed using piano wire. 4. For cutting, a piano wire is placed on a running belt, a lightweight aerated concrete raw material slurry kept at 50°C or higher is introduced and molded onto this, and the piano wire is pulled up and cut while it is in an uncured state. The cutting method according to claim (1).