JPS61225006A - Manufacture of light-weight aerated concrete - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing lightweight cellular concrete. More specifically, the present invention relates to a method for producing lightweight cellular concrete using a resin-lined formwork that is easy to release from the mold and can withstand high temperatures.

The following three types of methods are used to produce lightweight aerated concrete.

(1) Gas beton type A method in which foaming agents and auxiliary agents such as aluminum metal powder are mixed as uniformly as possible into mortar, poured into a mold, and foamed by generating hydrogen gas within the mold.

(2) A method in which a mixed foam type blowing agent is mixed into mortar, poured into a mold after preliminary stirring, and foamed by foaming the mortar within the mold.

(3) Preform type A method in which a foaming agent is foamed in advance to adjust the foam, the foam is mixed into a thoroughly kneaded slurry, and then the foam is poured into a mold.

In recent years, high-rise buildings have become popular not only for commercial use but also for residential and condominium use in the architectural world, and in addition to reducing the weight of building exterior wall materials (curtain walls, spandrels, etc.) and floor panels, non-combustible insulation materials are being developed. There is a need to prevent waste of thermal energy by using

However, to date, efforts have been made to meet this demand by improving the insulation of exterior walls by using lightweight aerated concrete panels for walls, floors, etc., but efforts are also being made to streamline construction work and streamline transportation and construction. is now in demand.

In order to satisfy these two conditions at the same time, it is planned to increase the size of concrete panels. The currently used aerated concrete panels generally have a width of 600 mm.
, length 1,800~3,500mm, thickness 100~
150mm panels are being made, and in order to manufacture them, a slurry made by mixing cement, lime, silica sand, etc. with water and a foaming agent is poured into a reinforced formwork, and the process is continued for several to 10 hours. After the above period, the concrete reaches a gel state that can be removed from the mold, so at this stage the concrete is removed from the mold and cut to the required thickness using piano wire, etc., and the individual panels obtained by cutting are Next, it is sent to an autoclave steam curing process, and after being sufficiently hardened by high-temperature steam curing, it is taken out from the autoclave and the surface is subjected to the necessary surface drawing processing by a mason, that is, drawings, patterns, letters, and various other drawings on the surface. The product is made into a product. The term "drawing" includes both the case of carving the surface to draw a pattern, and the case of drawing a pattern etc. by oozing out the surface.

However, at present, the above-mentioned current dimensions have been changed to create large lightweight aerated concrete plates with high demands, such as widths of 5 to 15 liters.
In manufacturing large concrete panels such as those with a length of 10 to 15 seconds and a thickness of 0.2 to 0.511 mm, the following problems arise and must be solved.

That is, in any of the above methods (1) to (3), due to the exothermic reaction during normal pressure foaming, the surface of the molded product reaches a temperature of nearly 100°C, and the inner surface of the mold in contact with it also reaches approximately the same temperature.
Due to the temperature difference between the outside surface of the formwork and the outside surface of the formwork, which is at a temperature approximately equal to the atmospheric temperature, the formwork may undergo expansion deformation and be damaged. For this reason, it is necessary to make the formwork have a special weight structure or to provide the formwork with an escape slide structure.

For example, Japanese Patent Publication No. 40-24903 discloses a special structure for preventing such problems. Furthermore, at present, panels that have been foamed at room temperature are generally self-supporting even when cut, so in high-temperature curing in an autoclave, curing is performed in the form of panels that have been removed from the formwork and cut.゛On the other hand, when high-temperature steam curing is performed with an intermediate molded product placed in the mold, if the curing reaction does not proceed sufficiently, the mold will shrink even when rapidly cooled by opening the autoclave after high-temperature curing. This may cause deformation and damage to the panel.
be.

When curing the molded product together with the formwork in high-temperature steam, the formwork and molded product must be cured after first applying a mold release agent such as heavy hydrocarbon, water glass, or oil-glycerin asphalt to the inner surface of the formwork. It is inevitable that the molded product will stick and become difficult to release from the mold, or that the molded product will be partially damaged.

These mold release agents remain on the surface layer of the molded product regardless of the amount, and they penetrate into the surface cellulose as foreign matter, so it is difficult to form a waterproof coating film on the surface after molding. In this case, the adhesion of the waterproof coating film to the molded product is significantly inhibited, and buildings using such concrete panels are
The waterproofing process becomes incomplete, which in turn leads to frost damage during cold weather, which becomes a serious impediment to construction.

The curing reaction of slurry begins when the slurry is generated, and the chemical reaction continues even while it is being poured into the formwork. In particular, applying movement, deformation, load, vibration, etc. while it is in a gel state will cause the crystal structure to form. The stabilization of the growth of the reinforcing bars is hindered, and the solidification reaction of the anti-corrosion slurry around the reinforcing bars has not yet completed. .

In contrast, in the present invention, a lining that can withstand high temperatures is applied to the inner surface of the form, and foaming and gelation is performed at room temperature for a necessary period of time.
This method is then left in the formwork and subjected to horizontal high-temperature curing in an autoclave, making it possible to manufacture odd-shaped products such as floor slabs and thin products such as partition boards, and in some cases, the formwork can be cured at high temperatures. Since the lining is molded with artistic depictions on both the upper and lower linings, a panel with beautiful depictions on both the upper and lower surfaces can be manufactured in a single process at the same time as solidification.

In order to achieve stable consolidation of the slurry, it is important to keep the panel stationary, and shaking the uncured panel should be avoided as much as possible, otherwise it will not be possible to cure the slurry at high temperatures. There is a good chance that the final product will suffer from cracks and a decrease in strength.

The present invention uses a formwork lined as described above,
It can be used in any of the methods (1), (2), and (3) above, but for example, in method (1), ordinary cement, lime, silica sand, water, and foamed metal powder can be used. The resulting slurry was poured into a reinforced formwork whose inner surface was lined as described above, and foaming and gelation were completed in about 2 to 5 hours. Then, the formwork was placed in an autoclave and cured at high temperature for about 6 hours.
If it is carried out for ~10 hours, the mold release layer is formed on the inner surface of the mold, so it is easy to release the mold, and since the curing reaction takes place in the mold from beginning to end in a static state, it is possible to prevent the formation of internal stress. This prevents stress damage to the product and significantly improves yield.

Furthermore, the formwork can be assembled as shown in FIG. 1.2. In this case, there is no need to specifically fix the lower plate to the formwork; either a steel plate is used as the bottom plate and the formwork is placed on top of it, or a locking device that locks the periphery of the formwork is attached to the bottom steel plate. After assembling the formwork, it is possible to line the inner surface of the formwork and the inner surface of the top cover, and also to draw markings on the lining layer on the inner surface of the bottom plate.Depending on the size of the formwork, several molds can be placed on one bottom plate. It is also possible to leave the frame still and use it by moving it in and out of the autoflave.

However, it will be readily understood that according to the present invention, the lining can be applied to conventional molds.

As mentioned above, in the present invention, the high temperature curing is performed at a temperature of about
It was carried out under the conditions of 180℃ and pressure 10.2kg/Cm'',
A lining layer that can withstand high temperatures is provided on the formwork, and the resin used for the lining is preferably a non-adhesive high temperature resistant resin such as silicone resin or polyfluororesin.

Examples of the silicone resin include silicone rubber for alkali-resistant high-temperature release, and examples of the polyfluororesin include 4-fluoroethylene-6-fluoroethylene copolymer, 4-fluoroethylene-perfluoroalkoxine ethylene copolymer, and polyfluoroethylene. -3-・Ethylene fluoride chloride is used.

Preferred mold release agents for use in the present invention are listed above as examples, but the invention is limited only to these.

Any resin can be used as long as it shows equivalent properties.

The present invention will be explained below using examples.

Example 1 (Gas beton type and silicone resin lining) Lightweight cellular concrete was produced by the following method.

Aluminum metal powder is added to a kneaded slurry of a mixture of quicklime, slaked lime, finely divided quartz crystalline silica sand, Portland cement, various auxiliary agents such as a foam retaining agent, and water, and the mixture is stirred to obtain a concrete slurry.

On the other hand, as shown in Figure 1, on the inner surface of a reinforced steel formwork with a width of 2 m, a height of 25 cm, and a length of 5 m, the inner surfaces (1, 1'), bottom (3), and M (4) of Thickness 5+sm, 25
Made of iron with silicone RTV rubber lining (2.2°, 3.8) made by Shin-Etsu Chemical, +sm (patterned has a drawing) and thickness 5mm (textured pattern has a drawing on the bottom side). The formwork is installed so that it can freely expand and contract as long as the four fixed side surfaces, such as 1, 1'', and the iron bottom surface, which is larger than the rectangular shape surrounded by them, are in the horizontal direction. As an example of the mounting method, a side view is shown in FIG. 2 and an enlarged view is shown in FIG. 3, in which the member 8 is fixed to the side bottom member using stud bolts. There are wheels (5.5°,
, , ) The formwork can be freely transported by means of a trolley 8. The upper lid can be opened and closed by a hinge 7 provided at the base of the upper lid, but it can be fixed with bolts as shown in FIG. When the concrete slurry made of the above mixture is poured into the formwork, a large amount of heat is already generated due to the reaction of some quicklime and aluminum powder with water, and gas is generated within the formwork. The top surface of the mortar is 25
c■, and the temperature reached 80 to 90°C, but the silicon resin, which is a thermally poor conductor lined inside the formwork, acts as a thermally conductive buffer, so that the inner and outer surfaces of the formwork iron plate are The temperature difference was kept within 20°C, although the outside temperature was 15°C.In particular, the bottom iron plate has a 251m thick engraved patterned silicon resin lining on the top, so the temperature difference is rather close to the top of the formwork. The entire rectangular four-sided formwork expanded slightly, but the horizontal expansion remained within a few 8 degrees, and there was no deformation of the steel plates on the six sides of the formwork that would interfere with the production of lightweight aerated concrete. I couldn't see it at all. Furthermore, the slurry adhered to the back side of the patterned lid. Therefore, without changing this horizontal state, only the lid was removed and the formwork was heated to about 180°C (steam pressure about 10°C) for the next process.
．． It was possible to carry it into the autoclave for high temperature curing at 2 kg/cnf). Furthermore, no problems due to thermal expansion of the metal parts were found when the internal temperature of the autoclave decreased after high-temperature curing was completed. Furthermore, the mold release of the final molded product is good due to the silicon-resin lining, and a lightweight aerated concrete panel with no damage is obtained, and all surfaces are beautiful and microscopically smooth, making it even more beautiful. A product having sculptural patterns, texture patterns, etc. on both the upper and lower surfaces was successfully obtained. There was no surface contamination at all, and the next painting finishing process could be started as is.

Example 2 (Gas beton type and polyfluoroethylene lining) Example 1 was repeated using the same reinforcing formwork as used in Example 1. As inner lining materials, tetrafluoroethylene-6-monofluorinated propylene copolymer (FEP), 4-fluorinated ethylene-perfluoroalkoxyethylene copolymer (PFA), and polytrifluorochloroethylene copolymer provided by Mitsui Fluorochemical Co., Ltd. 3 using (C:TFE)
A lightweight cellular concrete panel was manufactured using a slurry having the same composition as that used in Example 1. As a result, lightweight cellular concrete with a more beautiful surface than that of Example 1 could be produced without any difficulty in demolding.

Example 3 (Preform type and silicone resin lining) The foam adjustment mixture was stirred with a stirring blade to adjust the foam in advance. On the other hand, portland cement, silica powder, lime,
Make a cement slurry by thoroughly mixing the quick-hardening cement.
A mixed solution of the above-mentioned foaming agent, etc. was added thereto. The above slurry was poured into a mold with reinforcement similar to that used in Example 1, and allowed to stand to gradually gel and solidify. After being left in this state for 3 hours, the mold was inserted into an autoclave maintained at a temperature of 180° C., maintained at this temperature, and subjected to high-temperature aging for 8 hours, and then taken out from the autoclave.

As a result, lightweight cellular concrete panels with a more beautiful surface texture than those of Examples 1 and 2 were obtained. As with Example 1, the product could be manufactured without any difficulty at all when releasing from the mold.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the formwork according to the present invention. FIG. 2 is a sectional view taken along the line A-A in FIG. 1, and FIG. 3 is an enlarged explanatory view of the lower left corner showing how the formwork is installed. 1.1° formwork side plate 2.2" lining layer (side) 3,
Lining layer (bottom) 4. Top lid 5.5° wheel 6. Top lid lining layer 7. Hinge 8, trolley 9. mounting hardware

Claims (6)

[Claims] (1) A method for manufacturing a lightweight aerated concrete panel, characterized in that the foamed concrete panel is manufactured using a formwork in which the bottom or side surfaces and/or top cover of the formwork used for manufacturing the lightweight aerated concrete panel is lined. . (2) The manufacturing method according to claim 1, wherein the lining is made of silicone resin or polyfluoroethylene resin. (3) The manufacturing method according to claim 1, wherein the lining can withstand high temperature curing at a temperature of about 180°C. (4) The manufacturing method according to claim 2, wherein the inner surface of the upper cover and/or the bottom of the formwork lining is depicted with characters, figures, patterns, etc., or has a smooth surface. (5) When manufacturing lightweight aerated concrete panels using the above formwork, after curing at room temperature for about 2 to 5 hours,
The manufacturing method according to claim 1, which comprises curing at a high temperature for 6 to 10 hours in an autoclave maintained at a temperature of about 180° C. and 10 atm. (6) The manufacturing method according to claim 5, wherein the room-temperature curing and high-temperature curing are performed while the mold is still in the mold without being released from the mold.