JPS6030244B2 - Manufacturing method of concrete products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention aims to provide a new method for three-dimensionally producing precast concrete products and other concrete products.

Precast concrete products are the mainstream of today's concrete products, and are widely used for various types of construction, civil engineering, and other construction materials and equipment. However, these precast products are generally formed by filling them into molds, and in the case of hollow bodies or molded bodies with similar recesses, it is necessary to fill them into the inner and outer molds, and many molds are used. It also requires a lot of man-hours such as press-fitting, tamping, vibration, etc. to form a densely packed state. In recent years, spraying construction has been increasingly adopted for this type of mold filling method, and when using this spray construction, essentially no formwork is required, and the man-hours required for preparing and demolding the formwork are reduced. It has the advantage of significantly reducing time, but
In this spraying construction, there is also scattering, sagging, and peeling from the three-dimensional vertical or similar spraying surface, and there is a disadvantage that there is a large loss from such points. In general, it is necessary to solidify as is and surface finishing is not possible, so even if it can be used for the construction of the lower layer, it is rarely used for general precast products that require a smooth surface finish. It is not available. This applies not only to precast products but also to general concrete products. The present invention has been devised after repeated studies in view of the above-mentioned circumstances, and is a method of forming a shell of cement or the like with respect to the pongee aggregate used in concrete as described above, and further adding fluid mortar with water. By using aggregates in a dry state, we ensure favorable transportability for spraying, and by combining them, even when spraying on vertical surfaces or ceiling surfaces, there will be no scattering, rebounding, or splashing as described above. We succeeded in completing the application to a very small extent, and it was confirmed that the surface finish could be completed immediately after spraying since the spraying was done without any drips.

That is, the present invention provides a method for manufacturing concrete products such as precast products by the spraying method based on this new confirmation, and if precast products are obtained by the spraying method, the number of formworks will be significantly reduced. For example, when obtaining a cylindrical object such as a pipe or a U-shaped gutter, even if a forming form is required, the inner or outer mold is not required, making the formwork structure simpler and easier. There is no longer a need to prepare inner and outer molds, find predetermined dimensions, and assemble them accurately as in the past, and there is no difficulty in filling the narrow gap with concrete or the like.
It is very easy to set reinforcements and other settings because they are done under sufficiently open conditions, and in the case of products that require an outer skin such as iron skin, it also serves as the formwork, and generally For these types of products that require striations and core materials, these products can be manufactured without a formwork by using mesh with a relatively small mesh in the core layer, or by incorporating perforated plates or simple plate materials and spraying them from the inside and outside. can be obtained. This also applies to simple pillar materials and beam materials, and it can be made into a product simply by spraying it from the outside onto a core material such as an H-shaped steel or beam, or a mesh material wrapped around the core material, as in the past. The manufacturing complexity can be effectively eliminated. To explain the present invention more specifically, the present inventors have developed suitable surface water adhesion conditions for pongee aggregate such as sand, which is an essential material in the production of concrete products as described above. It was confirmed that an extremely stable shell could be formed by layering a hydraulic material such as cement powder, and a method as disclosed in Showa Jukunen Patent No. 12164 was proposed.

In other words, when using this technology, it is possible to sufficiently modify the pongee aggregate, which is clearly distributed throughout the structure, and to obtain a product with excellent strength, with little variation, and as described above. The shell is extremely stable, and the shell that has been formed for a day does not peel off during normal washing, and what is preferable is that the shell layer is in the kneaded material and has a bearing effect. In particular, when prepared as a fluid mortar, it has good fluidity and is excellent in so-called workability and pumping. A further advantage is that it enables construction without separation breathing even in general pouring or injection molding, and when utilizing these characteristics in spraying construction, it is necessary to use aggregate in a dry state separately from the fluid mortar. By preparing and pressure-feeding each separately, the transportability for spraying is improved, and by combining them during spraying, it is possible to apply with very little peeling or sagging, and at the same time, it can be applied immediately after spraying. If this advantage is adopted in the production of precast products, it will be possible to spray mortar or concrete with almost no loss even on a sufficiently open spray surface, and it will also be possible to finish the spray continuously. Then, the widely open spraying surface can be finished, and the desired product can be obtained simply and efficiently. It goes without saying that there is no need to worry about preparing, storing, roughing, and removing formwork. Specific embodiments of the present invention will be described with reference to the accompanying drawings. Sand used for preparing mortar or ready-mixed concrete as described above is generally prepared by dehydrating it.

As such a dehydration treatment method, it is advantageous to use pressure difference conditions and impact force, and the specific method is described in patent application No. 14718 (1978) by the present inventors.
(Japanese Unexamined Patent Publication No. 53-71859) and Showa 5 Kyooh Patent Application No. 12
Proposals such as No. 6517 (Tokukan Sho 56-51317) have been made. A portion of the water necessary for kneading is sprayed in advance on the sand that has been dehydrated in this way and mixed with it.
Within the range of ~35%, a specific value according to the shell-building conditions in each case.The exact amount of water deposited is within 2% of the soil, especially around 1% of the soil, and this is mixed with cement powder to form the above-mentioned. Forms a shell. When making concrete, coarse aggregate is mixed, and when reinforcing by mixing steel fiber vertical, etc., the coarse aggregate and steel fiber vertical are also mixed with cement powder at the same time or separately. form a shell. As the setting component, resin-based or asphalt-based components may be used as appropriate. To the above-mentioned shelled pongee aggregate, the remaining water required for mixing is added and kneaded to form mortar or ready-mixed concrete, which is then pumped using a pump or the like and generally sprayed using a nozzle. In the case of this nozzle spraying, in the present invention, as a preferred method, the amount of water of the kneaded material to be pumped is suitably increased to facilitate the pumping, and high pressure using the same shelling sand is applied in the vicinity of the spraying nozzle. The method is to add and mix the air-forced material and spray it, thereby reducing the amount of water in the entire spraying process and reducing its fluidity at the spraying part to achieve the desired water-cement ratio.

Of course, the above-mentioned kneaded material can be directly applied by spraying force using a rotating plate or the like. The composition and fluidity of the mortar mixture to be pumped are shown in Table 1 below, and the cement-sand ratio (C/S) can be varied over a wide range from 1/1 to 1/2. However, by appropriately changing the W/C (water-cement ratio), appropriate fluidity can be obtained for each.

Table 1 also shows the W/C of shells and the combination of pongee aggregate and coarse aggregate sand in the aggregate fed by high-pressure air, which is added and mixed to this and has almost no fluidity on the spraying surface. Examples of ratios are shown in Table 2 below.

Note to Table 2: S/G is the ratio of sand to square bone. For W/C of such aggregate shell layer, it is 10 to 3.
Although it can be carried out by appropriately changing the W/C within the range of about 0%, a W/C of about 16 to 20% as described above is most suitable for high-pressure pneumatic feeding, and there is little scattering of cement during spraying.

In addition, this high-pressure air pumping system can be reinforced by adding metal, glass, asbestos, synthetic, carbon, Hinaho, etc. As long as the material is long, it can be sprayed with virtually no problems. Further, these shells may also be formed with a shell similar to the above. The mixing ratio of the pump-fed kneaded material in Table 1 and the shell aggregate in Table 2 is appropriately selected so that the W/C in the spraying process is approximately 30 to 40%. When "Aggregate 1" in Table 2 is added to "Kneaded material 1" in The composition of the spray paint obtained is as shown in Table 3 below.

3. The amount of dust when spraying as shown in Table 3 is applied to a vertical wall surface, the downfall stress and average compressive strength immediately after construction, and their coefficient of variation are shown in Table 4 below. That's right.

Table 4 shows that the amount of dust generated during spraying is significantly smaller than that of the conventional spraying method, and the amount of rebound is also significantly smaller than the conventional spraying method, which reaches around 30%. Therefore, this level of loss is close to the amount lost in pouring and other cases, and considering the merits of the spraying method, it can be applied to the production of various precast products to achieve efficient production.

However, the state of spraying construction using the above-mentioned compound material is as shown in the attached drawings, and FIG. 1 shows the case where a rectangular cylindrical body is obtained. It is formed of a plurality of members 10a to be joined, and has a flange 10b protruding from the upper and lower sides of the member 10a to obtain the thickness of the product to be formed.

FIG. 2 shows a formwork for obtaining a cylindrical body, which is composed of a plurality of parts 10a, each of which has a flange part 10b and is provided with an operating mechanism for assembly and release inside. is the same as in FIG. In other words, these formworks 10' To be more specific, in the case of conventional conventional driving methods, inner and outer formworks are required respectively, and a bottom plate or bed is prepared and the inner and outer formworks are set on it. Furthermore, it is necessary to constantly check the spacing between the inner and outer formwork using a spacing mechanism, but in the case of the present invention, which employs the spraying method, these many formworks are unnecessary, and only one formwork (as shown in the figure) is used. In this case, only the internal mold is required, and even if a process form is required, the number of parts is generally one-third, or at least one-half, and the setting and release operations are significantly simplified. That is clear.

The present invention can be applied not only to the production of three-dimensional products as shown in Figs. 1 and 2, but also to the production of flat plate members.
The advantage of the present invention is that the formwork for a flat plate member can be constructed not in a planar manner, but in a vertical form or in an inclined form with an appropriate oblique angle.

In other words, formwork for flat plate members arranged in a plane requires a vast area, whereas formwork set vertically or inclined allows a large number of products to be manufactured in a significantly smaller area. There is no need to move spraying equipment or the like. In any of these cases, the formwork has a sufficiently open forming surface, and the conventional formwork for obtaining a cylindrical body as shown in Figs. 1 and 2 has an inner and outer formwork. This is essentially different from a method in which concrete is poured into the top through a narrow closed part corresponding to the thickness of the product.

This means that uniform filling and molding can be achieved smoothly without the need for a special vibration mechanism or drying/hardening operation, and not only demolding but also other processing operations are easy. The mold surface is sprayed by a spray nozzle 1, and a pump pressure feed line l is connected to this spray nozzle.
It is preferable that a and the high-pressure pneumatic feed line 2 are connected, and the former is fed mortar with good fluidity as a kneaded material,
For the latter, non-flowable aggregates are pneumatically fed, mixed and sprayed. The simplest example of the product obtained is a flat plate 12 as shown in FIG. 3, the sprayed surface 12d of which is generally obtained with considerable irregularities. Although one surface having irregularities may not necessarily be desirable in terms of appearance, it is often advantageous in actual use. For example, on surfaces that are in direct contact with the soil layer for civil engineering and construction purposes, having such unevenness is the reason for good interaction with the earth and sand and a stable setting, and when applying a decorative layer etc. This is why the uneven rough surface 12d as described above provides more stable adhesion of the decorative layer. However, in cases where such an uneven rough surface 12d is undesirable, the sprayed surface is generally smoothed using a trowel or the like.

What is preferable about this type of surface finishing is that the present invention, which is sprayed using woven shell pongee aggregate, has no separation breathing and there is no need to wait for breathing water to surface, and generally the finishing process can be completed immediately after spraying. Therefore, it can be manufactured as a finished product in a short process time. FIG. 4 shows the case of a product obtained as a part having a semicircular cross section, the inner surface of which is formed into a smooth surface 12c, and the outer surface is formed as a surface 12b which remains sprayed. The outer surface 12b is used as a soil layer embedding surface, and the smooth surface 12c is used as a running water surface.

FIG. 5 shows a case where the precast material according to the present invention is used as a coating for the H-shaped steel 13, and two U-shaped precast products 12, 12 are used as a formwork, and the H-shaped steel 13 is housed, and in this state, the precast forms 12, 12 are filled with ready-mixed concrete or the like to produce a product. 6 and 7 show the case of a product 12 having reinforcement 14 and an inner hole 12c, in which the reinforcement 14 is applied to a central member 15 such as a pipe material. As will be described later, the central mold member 15 is removed as shown in FIG. As shown in the figures, the material in Figures 6 and 7 has sufficient wall thickness and is suitable for use as pile material or pillar material. It is a great advantage of the present invention that the central member 15 is significantly 4 mm in diameter. It has also been revealed that the pole materials and antibodies for utility poles and the like obtained in this manner can be obtained with a much smaller product diameter to obtain the required strength than those obtained by using conventional inner and outer molds or by centrifugal force forming. This naturally facilitates its handling and construction use. Figures 6 and 7 show the case of spraying from the outside, whereas Figures 8 and 9 show the case of obtaining a socket pipe by spraying from the inside of the formwork, and Figure 10 shows the case of obtaining a socket pipe by spraying from the inside of the formwork. The external appearance of the product is shown with a sloped surface.

That is, a drive roll 5 and a nozzle guide bar 4 are provided in parallel in the formwork 10, and the drive roll 5 rotates in contact with the inner edge of the formwork 10 and the inner surface of the sprayed layer, and the guide rod 4 is rotated by the rotation. The nozzle 1 as described above is sprayed while being moved in the direction of the mold by its engaging member 11, and the outer surface of the formwork 10 rests on the receiving rolls 6, 6. The drive roll 5 has a corrugated roll part 5a formed thereon in correspondence with the socket part 20a of the product 20 as shown in FIG. is also obtained on the inner surface of this socket portion 20a. Although the circumferential rotational speed of the corrugated roll part 5a is relatively high, there is no special resistance because it is not in contact with the sprayed layer until the socket part 20a is sprayed, and the socket part is sprayed in the final process. In this embodiment, the roll 5 is used for a long time including the time of spraying the socket part 20a.
In addition, the inner surface of the socket portion 20a is finished by high-speed rotation of the corrugated roll portion 5a, so the smoothness accuracy on the inner surface of the resulting product is It is clear that this is also preferable. The formwork 5 may be split along the dividing line 10e shown in phantom lines in FIG. 9, but in some cases it may be made of a thin layer of tin plate or the like and the formwork may be attached to the product as a product shell. I can do it. FIGS. 11 and 12 show the case in which the socket tube is obtained by external spraying.

That is, the joint portion 10b formed at the end of the formwork 10 is rotated and driven by the rotating rollers 16, 16, and the formwork 1
The nozzle 1 sprays from the outside (in the case of FIG. 11, from the side in the case of FIG. 12), and each rotating roller 16 is used for rotating the formwork 10 and finishing the surface of the sprayed layer. This is the same as the drive roll 5 in FIGS. 8-9. The formwork may be made of one piece of steel or, depending on the case, a relatively thin layer of steel pipe.
The ones shown in FIGS. 13, 14, and 15 are also for outside spraying, but show a case in which a wire mesh or perforated plate is used as the formwork, and ring parts 18 are provided oppositely at both ends.
A formwork is prepared in which these ring parts 18, 18 are connected by reinforcing bars 14 and spacers 17, and a porous member 19, which is a wire mesh or a perforated plate, is attached to the inner surface.
, 12, it is rotated by rotary rollers 16, 16 and sprayed by nozzle 1.

The baser 17 may be removed during spraying, but may also be buried. As shown in Figures 13 and 14, the spacer 17, which is arranged along the length of the product or provided in the circumferential direction, holds the wire-mesh-like shaped material in the proper position even if the product is long. You can obtain the desired product by doing so. That is, when a perforated plate is used as a formwork in this way, the perforated plate is effectively bonded to the concrete layer, but it is also possible to degas the concrete layer sprayed through such a perforated plate. Yes, it is possible to eliminate air entrained during spraying. In the case of tube manufacturing as shown in Figure 8 and below, even if the forming frame is rotated, the speed is extremely slow, which is completely different from the remarkable high speed in the case of centrifugal force forming. , there is no need to generate centrifugal force, therefore no noise is generated to obtain centrifugal force, there is no need for either an inner mold or an outer mold, and the finished surface can be formed automatically. .

FIGS. 16 and 17 show the case of forming a tower body such as a tank, in which spraying is performed by the nozzle 1 from the outside of the formwork 25 provided on the base part 24. In the case, a sliding form 7 is used which moves up and down according to the movement of the slider, and the surface is finished after the spraying. Support member 2 suitable for formwork 25
6, as shown in FIG. FIG. 18 and subsequent figures show the case where spraying is performed by a rotating disk. That is, Figures 18 and 19 are for the horizontal type,
Figures 20 and below show the case of a vertical shape, and in those of Figures 18 and 19, a rotating disk 3 provided at the center of the formwork 30 is shown.
A plastic material made of shelled pongee aggregate as described above is fed into the molding material 1, and is blown away by the rotation of the rotating disk 31 at its circumferential speed and deposited on the inner surface of the formwork 30. Continuing with the advancement of the rotating disk 31, the sliding form 7 moves as shown in FIG. 18 or 19 to finish the blown surface. In the case shown in FIGS. 20 and 21, the spraying as shown in FIGS. 18 and 19 is performed in the vertical direction, and the rotating disk 31 is suspended below the hopper 32 by a suitable suspension mechanism. The spraying material stored in the hopper 32 is sequentially pumped and sprayed onto the inner surface of the formwork 35, and the surface of the sprayed layer is finished with the sliding form 7 that follows such a rotating circle. be. In the case of the devices shown in FIGS. 18 to 22, the screw mechanism 36 as shown in FIG.
The material can be supplied to the rotary disk 31 by using only the rotary disk 31.

However, in the same way as when using a spray nozzle, mortar with good fluidity is prepared as non-flowing aggregate, and
As shown in FIG. 22, the mortar is supplied from an introduction pipe 37 provided at the center of the hopper 32, and the above-mentioned non-flowable aggregate is fed by a screw mechanism 36 coaxial with this introduction pipe 37, and the non-flowable aggregate is fed to the lower end of the hopper. The two materials may be mixed in the process from the material to the construction surface via the rotating disk 31. As shown in the figure, the screw mechanism 36 is driven by a motor 38 provided at the top of the hopper 32, and the rotating disk 31 is driven by a motor 39 provided at the bottom side of the hopper 32. The porous plate 19 as shown in FIGS. 13 to 15 described above is not necessarily used as a formwork only in a cylindrical tube, but also in a rectangular or other polygonal shape, or a half-shape thereof as shown in FIGS. 4 and 5. It is clear that a method equivalent to the above would be sufficient, and is a preferred method when obtaining, for example, fish cakes or ship hulls, especially purges.

Of course, in such a case, spraying can be carried out from the inner and outer surfaces of the formwork. In the case shown in Figures 8 and 9, in which a cylinder is sprayed from the inside to produce a product, either one of the openings at both ends of the cylinder is closed, and there is no air inside the cylinder in such a sealed state. A depressurizing mechanism such as a vacuum pump may be connected through the closing portion to perform the process under depressurized conditions. Furthermore, as the formwork, a backing made of a rubber or synthetic resin membrane material is used,
This is combined with a core material braided in a dragon shape with reinforcing bars, etc., in other words, the backing material is housed in the dragon-shaped core material and air is press-fitted to expand it, and after molding, it is degassed and the backing material is It may be possible to facilitate demolding by removing the body. According to the present invention as described above, fluid mortar made of fine aggregate shelled with a coagulable component and dry aggregate are separately pumped to the mold surface near the spray nozzle. Since various concrete products are obtained by combining and spraying, the formwork structure is greatly simplified compared to conventional methods, and construction and manufacturing can be carried out smoothly under easy-to-handle conditions. In addition, by using the above-mentioned shelled tsumugi bone village and pumping them separately as fluid mortar and dry aggregate, the transportability for pumping is sufficiently good, and these can be By combining and spraying, there is no separation breathing, and it is possible to finish the surface immediately after spraying, and of course, it can be sprayed properly without the need for complicated processes such as press-fitting, vibration, and tamping. This invention is industrially highly effective because it enables the desired product to be obtained, and from both of these, various concrete products can be provided with industrial advantages.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention, and FIGS. 1 and 2 are perspective views showing the structure of the formwork when obtaining a cylindrical body according to the present invention, and FIGS. Some examples of products obtained by the present invention are shown: Fig. 3 is a side view of a plate-shaped body, Fig. 4 is a side view of a circular arc body also obtained by the present invention, and Fig. 5 is a U-shaped body and its use. Fig. 6 is a sectional view of the column, Fig. 7 is a partially cutaway side view, Fig. 8 is a sectional view of the tube obtained by the inside spraying method, and Fig. 9 is a sectional view of the column. A side view, Fig. 10 is a slope view of the product, Fig. 11 is a sectional view when the pipe body is obtained by the outside spraying method, Fig. 12 is a side view thereof, and Fig. 13 is a case where porous material is used as a formwork. Cross-sectional view of, 1st
Figure 4 is a side view before spraying, Figure 15 is a side view showing the finished state of the product, Figure 16 is a sectional view of the tank constructed according to the present invention, and Figure 17 is a partial enlargement during construction. The cross-sectional views from FIG. 18 to FIG. 22 are for the case where a rotating disk is used, and FIG. 18 is a cross-sectional view for a horizontal type system.
Fig. 19 is an explanatory diagram of a modification thereof, Fig. 20 is a partially cutaway slope view in the case of the vertical method, Fig. 21 is a vertical side view thereof, and Fig. 22 is an enlarged sectional view of the hopper and rotating plate portion. It is. However, in these drawings, 1' is the spray nozzle, la
2 is the pump pressure feeding pipe, 4 is the guide rod, 5 is the driving loaf, 6 and 16 are the rotating loaf, 1
12 is a product, 14 is a bar arrangement, and 2 river pipes are respectively shown. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 12 Figure 14 Figure 11 Figure 13 Figure 15 Figure 1 Figure 17 Figure 20 Figure 18 Figure 19 Figure 21 Figure 22

Claims (1)

[Scope of Claims] 1. Using cement as a setting component on a sufficiently open mold surface, a fluid mortar made of fine aggregate as a shell layer with a water-cement ratio of 10 to 30% and a dry state. A method for manufacturing a concrete product, which comprises pumping the aggregates separately, and combining the fluid mortar and the aggregates near a spray nozzle to form a molded product with a reduced W/C. 2. Cement is added and mixed with fine aggregate whose surface water content has been adjusted to 10% or less to form a shell layer with a substantially constant W/C on the circumferential surface of the fine aggregate. A method for producing a concrete product according to claim 1, which uses fine aggregate. 3. The method for producing a concrete product as set forth in claim 1, wherein a finishing treatment for smoothing the surface of the open area of the mold surface is continuously applied to the spraying process. 4. The method for producing a concrete product according to claim 3, wherein the finishing treatment is performed by roller compaction. 5. The method for producing a concrete product according to claim 3, wherein the finishing treatment is performed using a sliding form. 6. The method for producing a concrete product according to claim 3, wherein the finishing treatment is performed with a trowel. 7. The method for producing a concrete product according to claim 1, in which the sprayed surface is left as it is to be used as any surface. 8. The method for producing a concrete product according to claim 7, wherein a decorative layer is deposited on the sprayed surface. 9. A method for manufacturing a concrete product according to claim 7, which is used as a steel material or other porous plate and formwork. 1
0. A method for producing a concrete product according to claim 1, which comprises spraying onto a formwork under deaerated conditions. 11. A method for producing a concrete product according to claim 1, which produces a long object such as a tube, a pipe, or a pile.