JPH0250846B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of cutting lightweight cellular concrete mortar blocks with steel wire to produce large-sized lightweight cellular concrete blocks.

Conventionally, lightweight aerated concrete plates, which use the method of cutting mortar blocks with steel wires, have a product width of
Most of them were 600mm, and large, integrally molded versions with wider widths were rarely commercialized.

As the market demands, the product plate width is 1200-2450mm.
There was a strong desire for something with a wide width, as it would enhance the design of the product and make construction more efficient. For this purpose, two existing products with a product width of 600 mm were
A method of assembling ~4 pieces to make a product with a width of 1200 to 2400 mm was also implemented, but it was expensive, and since it was not integrally molded, the appearance and quality of the molded joint was inferior to that of an integrally molded product. It was hoped that a large version of lightweight aerated concrete would emerge. Some product widths
A one-piece molded plate of 1500 mm or less was being sold on a trial basis, but it had poor dimensional accuracy (thickness accuracy), flatness, and appearance as described below, as well as other problems with productivity, so it was decided not to commercialize it in earnest. I had not reached that point yet.

By the way, conventionally, when cutting lightweight aerated concrete blocks (hereinafter referred to as blocks) that have been semi-hardened with steel wire, the width of the block at the time of cutting is generally 600 mm, and some products have a width of 1500 mm. was also attempted.

However, when cutting, the mortar hardness at the time of cutting is set to 15-23 (in accordance with the invention Mortar hardness is measured using a penetrating Yamanaka soil hardness meter, and is the resistance to penetration into a mortar block of a steel cylinder with a diameter of 20 mm and a length of 35 mm expressed in pounds. For example, 12 pounds. The mortar hardness was 12 (the measured point was the center of the block surface near the point where the block was cut), which was a relatively high hardness.

For this reason, when cutting a mortar block with a mortar hardness of 15 to 23 using steel wire, if the cutting width is 600 mm, the dimensional accuracy (length, wall thickness) of the cut block must be within ±2 mm. had become a sufficient product. However, when the product width of the block to be cut increases to 1200 mm or more, the thickness accuracy after cutting is ±3.0 to ±3.5 mm, which deteriorates the dimensional accuracy, and the unevenness of the product surface can be discerned by visual inspection. This resulted in a defective surface and poor flatness. In addition, unevenness on the surface of the plate due to poor cutting may cause problems such as cracks occurring in the block when the cut block is divided one by one and moved onto a support stand for final curing in an autoclave. I was getting used to it.

As mentioned above, it is difficult to cut a large plate with a wide cutting width using cutting lines such as piano wire to obtain a product with a good appearance and good dimensional accuracy (i.e., a product with dimensional accuracy equivalent to a product width of 600 mm). It was. Therefore, in the past, it was thought that in order to manufacture a large, integrally molded plate, inefficient methods such as curing in an autoclave and then scraping the surface again were required.

The inventor of the present invention conducted extensive research to obtain a large, integrally molded version with a product width of 1200 mm or more with good dimensional accuracy by cutting along cutting lines with high production efficiency.
The present invention has been discovered. In addition, a product with good dimensional accuracy, which is the object of the present invention, is a product block with wall thickness accuracy within ±2 mm and flatness within ±1 mm (hereinafter, wall thickness accuracy and flatness are collectively referred to as (Also referred to as dimensional accuracy.)

That is, in the present invention, a mortar block with a product width of 1200 mm or more and a mortar hardness of 1 to 12 is cut horizontally with a steel wire while placed on the bottom plate of the form, and then the mortar block is cut horizontally with a steel wire until the mortar hardness reaches at least 15. This is a method for manufacturing a large version of lightweight aerated concrete, which is characterized by leaving it on the bottom plate of the formwork.

In the present invention, it is essential that the hardness of the mortar block at the time of cutting is 1 to 12. If the mortar hardness is 13 or more, the dimensional accuracy of the cutting block (in the large version referred to in the present invention) may exceed ±2 mm, or the product may have noticeable traces of the cutting steel wire on its appearance. Also, the mortar hardness at the time of cutting is 1
When it is less than 1, the block cannot maintain its original shape.

Furthermore, in order to prevent deformation or cracking when moving the mortar block to the cutting process or during cutting, it is essential to cut horizontally with a steel wire while the mortar block having the hardness of the present invention is placed on the bottom of the formwork. be. Note that the steel wire used in the present invention is preferably one with high tensile strength, such as piano wire specified by JIS.

Furthermore, it is essential to harden the mortar blocks cut in this manner while remaining on the bottom plate of the form until the mortar hardness reaches at least 15 (for example, 15 to 23). If the mortar hardness is increased in this manner, the dimensional accuracy will not deteriorate and cracks will not occur in the block even if the block is moved to another stand such as a support stand for curing autoclave books.

In order to obtain an even better lightweight cellular concrete large-sized product, it is more preferable to carry out the test under the following conditions.

(1) Diameter of steel wire In order to reduce the problem of how to hold the steel wire at the end and the possibility of breakage of the steel wire at the supporting part, the use of too thin a steel wire should be avoided. If it is too thick, especially in the case of multi-layer cutting as shown in Figure 1 (c), there will be an allowance for cutting, which may bend the cut block at the top and cause cracks, so the diameter of the steel wire used is 0.8. ~2.0mm
It is more preferable that

(2) Tension of the steel wire The tension of the steel wire is determined to reduce the deflection (X/W) of the steel wire in the mortar block during cutting, as shown in Figure 1 E. It is preferable to use the wire under high tension close to the breaking strength of the steel wire.

(3) Angle of steel wire when cutting mortar blocks When cutting, the steel wire is run parallel to the width (W) direction of the product block (or the product block is run parallel to it). By inserting the steel wire into the product block at a slight angle with respect to parallelism, it is possible to further improve dimensional accuracy by reducing misalignment and shock when the steel wire first enters the block.

(4) In order to further improve the dimensional accuracy of the product, it is preferable that the flatness and level accuracy of the formwork supporting the block and the steel wire holding portion of the cutting machine be within ±0.5 mm.

If the conditions shown in each item above are followed, a large plate with even better flatness and wall thickness accuracy can be obtained.

In addition, in the present invention, the aim of achieving flatness accuracy within ±1 mm and wall thickness accuracy within ±2 mm is not only from the viewpoint of simply increasing dimensional accuracy, but also from the viewpoint of achieving autoclave curing. When moving a block from the formwork to another support stand, if the levelness of the block surface is poor, a gap of 2 mm or more will occur between the support stand and the block, which may cause cracks in the block. This is because problems arise. The reason why cracks occur if the dimensional accuracy of the cut mortar is poor is because the bending strength of the block at this time is only about 0.3 to 0.4 KG/cm ² at most when the block has an absolute dry specific gravity of 0.500. .

Below, examples will be shown to demonstrate that even a large version of lightweight cellular concrete can be made into a product with excellent wall thickness accuracy and flatness accuracy by the method of the present invention.

Example 1 Reinforcement bars with a diameter of 6 mm and 8 mm were used as the main reinforcement of the rebar cage, and rebars with a diameter of 5 mm and 6 mm were used as the horizontal reinforcement, and the rebar cage was arranged in accordance with the ALC JIS standard, and the mortar composition was Based on ALC JIS standards: 58 parts by weight of silica, 10 parts by weight of quicklime, 32 parts by weight of cement
Parts by weight of raw materials and 70 parts by weight of water were used. Here, the quicklime and silica stone used were ones that had been pulverized in advance to a specific surface area of 3500. This mortar composition was mixed, and immediately before pouring into the mold, aluminum powder was added so that the absolute dry specific gravity of the product was 0.500. Product dimensions include width 1800mm (hereinafter referred to as 1800W), length 4200mm (hereinafter referred to as 4200L), and height.
For the purpose of obtaining a 125mm (hereinafter referred to as 125T) product,
A formwork with a width of 1800 mm (hereinafter referred to as 1800W), a length of 4200 mm (hereinafter referred to as 4200L), and a height of 180 mm (hereinafter referred to as 180H) was used, and the above mortar was poured into it. The mortar block that foams after pouring the mortar is hardened to a mortar hardness of 3 pounds, and then only the side parts of the formwork are removed, and while placed on the formwork bottom plate 3, the steel wire (steel wire with a diameter of 1.0 mm) and the formwork are removed. Move the mortar block onto a mortar cutting machine whose bottom stand is maintained within ±0.3 mm, and cut the mortar block into one piece (one layer) with product dimensions of 1800W x 4200L x 125T, as shown in Figure 1A. ). The mortar hardness at the time of cutting was 4. The steel wire with a diameter of 1 mm (the supporting part of the steel wire is shown as 2 in the drawing) itself was not run in the product width W direction, but was cut while being fixed. The block that has been cut is
The mortar was allowed to harden to a hardness of 20, at which point the mortar debris at the top of the cut shown in FIG. The flatness was measured in both the width and length directions of the block by stretching a water string and lightly applying a steel stretcher, and the flatness was within ±1 mm in both directions. In addition, after curing in the autoclave, the thickness accuracy of the product was measured at 15 locations as shown in Figure 2. The thickness is 125±2mm in all parts.
The radius was within the range of 125.0 mm and R = 3.6 mm. Furthermore, after cutting and curing, no gaps were observed between the product block and the support stand when it was moved to the support stand 4 as shown in Figure 1B, and no cracks were observed in the plate body during molding or after curing. It was not recognized.

In addition, since the steel wire itself is not running on the cut surface of the plate, there is a uniform rough surface due to cut mortar debris, but there are almost no tree-ring-like steel wire traces, and the appearance is uniform. It was hot.

Also, when the steel wire itself was run perpendicularly to the product block and the other conditions were the same as above (however, the steel wire was set at a position 0.3 mm thicker), the results were obtained. The printed plate has the same dimensional accuracy (flatness and wall thickness accuracy) as above,
The surface of the plate cut with the steel wire not only showed no trace of the steel wire, but also had a smooth surface.

The above procedure was repeated 10 times, and in each case, a product with the same dimensional accuracy as above was obtained.

Example 2 Using the same rebar cage and mortar as in Example 1, in order to simultaneously obtain three pieces of product dimensions 1500W x 4200L x 125T in the same formwork, 1500W x 4200L x 455H
was poured into the formwork. With a mortar hardness of 4 pounds, the sides of the formwork were removed, and as shown in Figure 1 C, the steel wire support interval was set to 1600 mm, and four steel wires with a diameter of 1.0 mm were supported at a tension of 40 kg/wire at the same time. I used it to cut it. Note that the set interval between the steel wires was 125.0 mm. The mortar hardness at the time of cutting was 6 at the center of the side surface of the block, and the cutting was carried out without running the steel wire in the width direction of the block. Therefore, on the cut surface, uniform roughness due to mortar chips during cutting remained, but no steel wire traces were observed. After cutting the blocks, let the mortar harden to 20, remove the mortar waste from the top row in Figure 1, and cut each block sequentially from the top product block to the bottom product block in Figure 1. As shown in Figure 2, the product is moved onto the support stand 4, and the flatness of the cut surface of the steel wire is adjusted using a water thread and a steel stretcher at each location in the width direction and length direction (the thickness shown in Figure 2). When we checked all the locations (same location as measurement location 5), all locations were within ±1 mm or more. After curing in an autoclave, the thickness of the product was measured at 15 locations shown in Figure 2. All locations are within ±2mm,
= 124.6mm and R = 3.9mm. Furthermore, since the cutting was performed at a low hardness, there was a concern that mortar blocks would adhere during curing after cutting, but no adhesion of blocks between layers was observed. Furthermore, there were no harmful cracks in the product block before or after autoclave curing.

According to the method of manufacturing a large lightweight cellular concrete version of the present invention, the following effects can be obtained.

According to the present invention, a large one-piece molded lightweight cellular concrete version with a wide product width of 1200 mm or more (for example, 1200 to 2450 mm) with excellent flatness and wall thickness accuracy can be obtained by an economical method that requires only a cutting process. be able to.

Excellent flatness and wall thickness accuracy are not just a matter of good dimensional accuracy; they also allow large semi-hardened blocks to be kept horizontally while being placed in the autoclave from the mold during pouring. It is possible to establish an economical manufacturing method for large-sized lightweight cellular concrete with almost no cracking during the process of transferring it to the support stand during the process up to the can.

Furthermore, when cutting by running the steel wire itself parallel to the width of the product block, in addition to the above effects, not only no trace of the steel wire is observed, but also a smooth product with a smooth cut surface can be obtained. .

[Brief explanation of drawings]

Figure 1 A, B, C, D, and Ho are diagrams for explaining the method of the present invention. Figure 1 A shows a perspective view in the case of single-layer molding, and Figure 1 C shows a perspective view in the case of three-layer molding. Figures 1(b) and 1(d) are perspective views when the hardened block is moved to a support stand after cutting, and Figure 1(e) is a diagram showing the state of the steel wire at the time of cutting. FIG. 2 is a perspective view illustrating the locations where the wall thickness and flatness of the block are measured. 1...Block, 2...Steel wire support part, 3...Formwork bottom plate, 4...Support stand, 5...Measurement point.

Claims (1)

[Claims] 1 Product width is 1200mm or more and mortar hardness is 1 to 12
A lightweight aerated concrete characterized in that a mortar block of 1 is cut horizontally with a steel wire while placed on the bottom plate of a form, and then left on the bottom plate of the form until the mortar hardness reaches at least 15 or more. How to make a large version.