JPH044921B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for cutting semi-solidified concrete slabs in a flat casting production method for large lightweight foam concrete slabs, pre-cast concrete slabs, etc.

In general, the width of the plate in lightweight foam concrete
Large plates of 600m/m or more and regular pre-cast plates are made using a flat casting method in which reinforcing bars such as reinforcing bars and wire mesh are placed horizontally to the bottom of the formwork, and raw material slurry such as mortar is injected into the formwork. After reaching a semi-cured state, it is manufactured by steam curing, etc.

Conventionally, when manufacturing plates whose length and width are smaller than the bottom plate, when manufacturing two or more plates with one formwork, when manufacturing plates with a planar shape other than rectangular, partitions are used in the formwork. It is formed by placing plates in the width direction, length direction, etc., and between the plates. In addition, since lightweight cellular concrete can be easily cut even after hardening, it is also manufactured by cutting after hardening.

In addition, when manufacturing plates with rectangular or other shaped openings, injection is performed after placing a partition in the shape of the opening (usually called an opening jig) in the mold, and the raw material slurry is poured into the mold. Manufactured by blocking. However, both cases had the following drawbacks.

(1) Placement and fixing work is extremely time-consuming.

(2) Each formwork must be equipped with various partition plates and opening jigs.

Therefore, the present invention seeks to solve the above problems,
In ceramics and many other industries that process plastic materials,
Although it is common, in the field of concrete slab manufacturing, due to the brittle and easy-to-adhere characteristics of unsolidified concrete, (1) it is easy to cause defects on the cut surface; (2)
We worked on developing a cutting method using a plate-shaped blade, which had not been put to practical use due to the problem that the cut surface was not smooth, and changed the direction of blade movement, hardness of unsolidified concrete, blade thickness, blade movement speed, etc. As a result of extensive research, we have found that under certain specific conditions, the above-mentioned problem does not occur and it can be put to practical use.

To explain in detail based on the drawings, when cutting, as shown in FIG. The plate is cut by lowering and raising the horizontal blade straight at a speed of .
Also, when cutting out the opening, as shown in Figure 2,
Cutting is performed in the same manner as the cutting described above using a cutting blade 8 bent in the same shape as the opening.

Next, cutting conditions such as the blade movement method, blade thickness, and cutting speed will be explained.

(1) How to move the blade The direction of the blade movement is to make the cutting edge of the plate-shaped blade parallel to the plate surface, and lower and raise it straight to the cutting direction. If the cutting edge is not parallel, adhesion is likely to occur, and if the cutting edge is not straight down and up, chips will occur at the top and side of the cut surface when it is raised.

(2) Hardness of unsolidified concrete Hardness is measured by the resistance when a cylinder with a diameter of 20 m/m is pressed against the object to be cut and buried to a depth of 35 m/m. It is essential to perform the cutting within the range of ² . 5 [lb/
If the blade is below 30 [lb/in ^{2 ]} , the adhesion will be high and the blade will break when raised after cutting, regardless of the blade thickness or cutting speed. If the blade is thick, the blade will deform, and if the blade is thick, it will cause defects on the cut surface when cutting.

(3) Blade thickness Blade thickness has a close relationship with cutting hardness; the upper limit of blade thickness is controlled by the plasticity of unsolidified concrete, and the lower limit is controlled by the bending strength of the blade. Therefore, the relationship between the lower limit and the case where a steel cutter is used is shown in FIG. The shaded area in the figure is the valid range, with the upper limit shown by a solid line and the lower limit shown by a broken line. Therefore, the blade thickness should be 5 within the specified cutting hardness range.
Cutting should be done using a blade within the effective range of m/m or less. However, within the scope, as much as possible,
Cutting with a thin blade is preferable in terms of the smoothness of the cut surface.

(4) Blade shape Regarding the cross-sectional shape of the blade, if the smoothness of the cutting surface is important, it is better to have a shape in which the parts other than the cutting edge are parallel, and if cutting accuracy is more important than smoothness. It is best to have a tapered shape in areas other than the cutting edge, and it is desirable to use different types of blades as necessary.

Note that in order to reduce the resistance during cutting, it is preferable to provide notches of various shapes. However, the shape, size, and number of notches must be determined with due consideration to the strength and flatness of the blade.

(5) Cutting speed (a) Blade descending speed For the next cutting, the speed at which the blade descends is 200% in the cutting hardness range and blade thickness range as described above.
It should be less than mm/S. If the cutting speed is higher than this, the cutting resistance becomes large, resulting in peeling and chipping of the cut surface. For example, cutting hardness 20lb/in ² blade thickness 4
When cut at a descending speed of 210 mm/s at m/m,
Peeling with a thickness of 1 to 2 m/m occurred on the cut surface.

(b) Blade rising speed After cutting, the speed at which the blade is raised is 200.
It is necessary to raise the temperature within mm/S. This is because, if the cutting speed is higher than this, mortar will adhere to or be adsorbed on the surface of the blade, causing defects on the cut surface. As an example, when a cutting hardness of 30 [lb/in ² ] and a blade thickness of 3 mm were raised at 210 mm/S after cutting, a defect with a depth of 40 m/m and a thickness of 20 m/m was generated in the upper part of the cut surface.

Above, we have described the essential conditions when cutting unsolidified concrete slab with a plate-shaped blade, but in addition to that, in order to prevent the occurrence of chips and improve the smoothness of the cut surface,
Explain the points that should be considered.

(1) Accuracy of the rising angle of the blade It was found that when the blade is lowered, cut, and then raised, if the angle difference with respect to the cutting surface is 2 degrees or more, chips are likely to occur in the upper part of the cutting surface. Therefore, sufficient consideration should be given to this point.

(2) Application of mortar release agent By applying an oil that does not impair the physical properties and appearance of concrete, generally called concrete release agent, to the surface of the plate-shaped blade, it not only improves the smoothness of the cut surface, but also improves the smoothness of the cut surface. We found that it is also effective in preventing defects. Therefore, it is preferable to apply as much concrete mold release agent as possible when cutting.

In addition, the cutting device applied to implement the method of the present invention will be explained in detail based on the drawings. In the case of cutting, the cutting jig shown in FIG. 4 is used as a cutting jig for easy manual cutting and an opening cutting jig. In this jig, a plate-shaped blade 3 having a blade thickness of 5 m/m or less is fixed to a rib 4 for reinforcement and flatness by tightening bolts 5, as shown in FIG. The protruding portion of the reinforcing rib 4 serves as a grip for the operator to cut. As mentioned above, if the cutting resistance is desired to be lowered, the plate-shaped blade may be provided with a rectangular or other cutout as shown by the broken line in the figure. In addition, when the smoothness of the cut surface is important, the cross section of the blade 3 should be parallel as shown in Fig. 6 1, and when cutting accuracy is important, the cross section should be parallel as shown in Fig. 6 2. As shown in the figure, the parts other than the cutting edge are tapered. Therefore, the plate-like blade 3 can be replaced by removing the mounting bolt 5 if necessary.

Next, a positioning and angle holding jig for cutting with this cutting jig will be explained. This jig is used for positioning during cutting, and as mentioned above, if there is an angle difference of 2 degrees or more when the blade is raised compared to when it is lowered, it will cause chipping, so this is a jig to prevent this.

As shown in Figure 8, this jig consists of a base plate 7 fixed to the bottom plate of the formwork and a side plate 6 forming a slit, and the width of the slit is equal to the blade thickness plus plate thickness x tan2°. It's summery. To use it, as shown in Figure 8, set it on the bottom plate of the formwork at the cutting position, fix it to the bottom plate of the formwork with a screwdriver, and then lower and raise the plate-shaped blade 3 while passing between the slits. The cutting is performed by Further, when cutting out the opening, an opening cutting jig shown in FIG. 9 is used. This jig is a plate-shaped blade similar to the cutting jig described above, bent into the same shape as the opening 8, attached to reinforcing ribs 9 with bolts 10, and is supported when the operator makes a notch. It is fixed to a support beam 11 by tightening bolts 12. Therefore, when cutting out openings of different shapes and dimensions, use bolt 1.
2 can be removed and replaced with one of a different shape. In addition, as in the case of cutting, the positioning and angle holding jig 12 as shown in FIG. 10 is used to perform cutting.

Next, I will explain what is done using semi-automatic equipment rather than manual labor. Figure 11 shows a semi-automatic device for cutting, in which the formwork with unsolidified concrete 2 placed on the formwork bottom plate 1 is moved on rails and set so that the predetermined cutting position is directly below the blade 3. The cutting is then performed by an automatic lifting device 15 such as an air cylinder attached to the device frame 13. Furthermore, since the slide mechanism 14 is fixed to the main body frame 13 of the apparatus, it has the advantage that it can be cut with high accuracy and without causing damage.

Further, the application of the concrete mold release agent can be performed by an automatic application mechanism 16, and this mechanism impregnates both sides of the plate-shaped blade 3 with the mold release agent, as shown in the cross section of FIG. 12. Sponge or felt18
etc. are pressed by support ribs 17, and when the plate-shaped blade 3 is lowered, a mold release agent is applied to the surface of the blade, and when it is raised, it serves to remove concrete attached to the surface of the blade 3. be.

Figure 13 shows a semi-automatic device for cutting out openings. By using two lines of equipment similar to the cutting device, it is possible to cut out with high precision and without causing damage, depending on the shape of the opening. It can be replaced using an automatic coating mechanism similar to that used for cutting equipment. or,
This device can also perform cutting. In addition, instead of moving and positioning the formwork on the rails,
These devices themselves may be of a mobile type.

[Example 1] As an example of manually cutting out the opening, the particle size
A concrete raw material slurry was prepared by adding 70% water to solid components such as crushed silica stone of 300 μm or less and quicklime cement, and further adding a small amount of a foaming agent. The raw material slurry is spread over the width of the reinforcing bars for the opening plate placed horizontally.
It was poured into a formwork of 1800 m/m, length 4200 m/m, and depth 200 m/m. The raw material slurry foams and has a hardness of 15
When it reached [lb/in ² ], the cutting positioning/lowering/rising angle holding jig was fixed to the bottom plate of the formwork with bolts. And the same shape as the opening, length 1200m/m x width 600m/
Bent into a rectangle of m, blade width 250m/m, blade thickness 3
A mineral oil-based concrete mold release agent with a viscosity of 300 cp was applied to the surface of the blade of a cutting jig for openings with a flatness of 2 m/m. The opening cutting jig is then pushed downward in about 2 seconds by one worker on each side of the formwork, adjusting the position and angle using the positioning jig, and cutting is performed in about 2 seconds. Then the cutting jig was raised.

After curing this product, we measured the condition of the cut surface of the plate and found that there were no defects at all, and the flatness was good at 2 mm.
Good results were obtained with a depth of 1 m/m and no problems in terms of appearance or accuracy.

[Example 2] As an example of cutting between plates using a power-driven device, a raw material slurry for lightweight foamed concrete having the same composition as in Example 1 was prepared. and width 1800
m/m, length 4200m/m, depth 200m/m in a wheeled mobile formwork with plate length 1600m/m and 2600m/m
After placing each reinforcing bar, the injection was carried out. Thereafter, when the foaming was completed and a semi-cured state was obtained, the side plates of the form were removed from the mold. When the hardness reached 15 [lb/in ² ], the formwork on the rail was moved under the gate-type fixed cutting device, and the formwork was positioned so that the blade would come within 2 hours. And blade length 1800m/m, blade width 250m/
A cutting blade with a blade thickness of 2 m/m and a flatness of 2 m/m was cut using an air cylinder drive mechanism equipped with a vertical lifting guide while applying a mineral oil-based concrete mold release agent with a viscosity of 300 cp to an impregnated fett on the surface of the blade. Descend at a descending speed of 200 mm/s to perform cutting, then
It was raised at a rising speed of 200mm/s. When the condition of the cut surface of this product after curing was measured in the same manner as in Example 1, there was no occurrence of defects and the flatness was extremely good at 1 m/m. In addition, very good results were obtained regarding the smoothness, with no lamellar undulations occurring at all.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a cutting blade cutting unsolidified concrete in the direction of the arrow, and FIG. 2 is a similar perspective view showing a cutout. Figure 3 is a diagram showing the relationship between cutting hardness and blade thickness, and the diagonal lines indicate the applicable range. FIG. 4 is a perspective view of the cutting jig, FIG. 5 is a sectional view thereof, and FIGS. 6 1 and 2 show examples of the cross-sectional shape of the cutting blade. Figure 7 is a perspective view of the cutting blade positioning jig;
The figure is a perspective view showing the application of the jig, Fig. 9 is a perspective view of the cutting jig, Fig. 10 is a perspective view showing the application of the jig, Fig. 11 is a perspective view of the semi-automatic cutting device, and Fig. 12 is a perspective view of the cutting jig. FIG. 13 is a side view of the release agent application device and a perspective view of the semi-automatic opening cutting device. 1 is a formwork bottom plate, 2 is unsolidified concrete, 3 is a cutting blade, 4 is a reinforcing rib, 5 is a tightening bolt,
6 is a cutting position determining board, 7 is a cutting position determining board, 8
is a cutout blade, 9 is a reinforcing rib, 10 is a tightening bolt, 11 is a support beam, 12 is a cutout positioning jig,
13 is a device frame, 14 is a slide mechanism, 15
16 is an automatic lifting device, 16 is an automatic coating mechanism, 17 is an impregnated material supporting rib, 18 is a release agent impregnated material, and 19 is an automatic coating mechanism.

Claims (1)

[Claims] 1. An unsolidified concrete slab with a hardness of 5 to 30 lb/in ² is processed using a plate-shaped blade with a blade thickness of 0.5 to 5 m/m from the top surface to the bottom surface at a speed of 200 mm/s or less.
A method for cutting a semi-solid concrete slab, characterized by cutting the slab by lowering and raising a horizontal blade straight, and/or cutting out by bending a plate-shaped blade into the same shape as the opening of the slab.