JPH02103242A - Hydraulic light-weight composition and production thereof - Google Patents

Abstract

PURPOSE:To obtain the subject light-weight composition having stable strength, water-resistance, etc., and suitable for various construction and building works by uniformly distributing foamed polystyrene beads in a hydraulic composition. CONSTITUTION:A hydraulic light-weight composition having a specific gravity of 0.3-1.8 is produced by adding and mixing (A) 10-47vol.% of bubbles composed of a frothing agent (e.g., an alkyl sulfate) and a film-forming water-base resin (e.g., acrylic resin) to a kneaded material of (B) a hydraulic substance such as cement, adding and kneading (C) 5-55vol.% of foamed styrene and (D) aggregate and/or additive (e.g., sand or gravel) to the kneaded mixture of the components A and B and hardened the mixture after forming.

Description

Detailed Description of the Invention "Object of the Invention" The present invention relates to a hydraulic lightweight composition and a method for producing the same, and provides a hydraulic lightweight composition that has expanded polystyrene particles evenly distributed and is stable in strength and other properties. The present invention also aims to provide a manufacturing method that can produce relatively simple and accurate products.

(Industrial Application Field) A hydraulic lightweight composition with a specific gravity of about 0.3 to 1.8, stably and uniformly containing expanded polystyrene and air bubbles for various civil engineering and construction applications, and its manufacturing technology.

(Prior art) Lightweight structural members made of inorganic hydraulic substances such as cement have been widely used in the field of civil engineering and construction. Their demand is increasing due to the structural advantages afforded to them.

In other words, bubbles are formed by using a foaming agent or by vaporized gas caused by a chemical reaction. often use lightweight analogues of
A typical example of the latter is silicate lime autoclave culture (referred to as ALC).

There are two ways to form and incorporate air bubbles: one is to mix a foaming agent into kneading water and cause the air bubbles to be drawn in during stirring, and the other is to create air bubbles in a liquid containing a foaming agent through a foaming machine and then knead the mixture.

(Problems to be Solved by the Invention) In any of the above-mentioned conventional bubble forming and mixing techniques, the bubble film is unstable, tends to lose weight even when cast in a mold, and has poor strength even after curing. is not sufficient.

Furthermore, the quality of lightweight aggregates varies widely, and stable strength and
It is difficult to obtain a heavy composition, and since the water absorption is high, the amount of mixed pure water used increases, and the strength of the cured product decreases.

On the other hand, those whose weight is reduced by forming air bubbles through a chemical reaction are -
Chemical reaction still occurs even after molding for boat fishing! 14! This makes it difficult to obtain a composition in a predetermined form, and the quality varies widely. In particular, ALC has open cells, increases water absorption, has poor freeze-thaw resistance, and loses alkalinity, so it is necessary to apply anti-rust treatment to reinforcing bars and the like. Of course, the equipment for autoclave curing must be large and complicated.

Expanded polystyrene is widely used today as packaging materials and heat insulating materials, and unlike the porous aggregates mentioned above, it is an excellent lightweight material with almost no water absorption and little variation in quality. If the above-described lightweight hydraulic composition is mixed into a kneaded material, aggregate separation will occur due to the difference in specific gravity, making it impossible to obtain a product with stable and uniform distribution. It is also conceivable that this hydraulic material kneaded material containing expanded polystyrene is cured in an autoclave and the expanded polystyrene is melted to create a structural material with voids covered with a polystyrene film, but in this case as well, aggregate separation is necessary. Therefore, it is difficult to use it stably.

"Structure of the Invention" (Means for Solving the Problems) The present invention has been devised after repeated studies to solve the problems of the conventional products as described above, and is as follows.

1. The essential components are (A): expanded polystyrene, (B): bubbles made of a foaming agent and aqueous resin with film-forming ability, (C): hydraulic substance such as cement, and the volume ratio is (A). 5 to 55% of the ingredients (
8) A hydraulic lightweight composition containing 10 to 47% of component (C), the remainder being component (C), and having a specific gravity of 0.3 to 1.8.

2. (A): Expanded polystyrene, (B): Cells made of a foaming agent and aqueous resin with film-forming ability, (C): Hydraulic substances such as cement, (D): Sand, gravel, and other aggregates and one or both of the additives are essential components, and the volume ratio of component (A) is 5 to 55%, (
A hydraulic lightweight composition containing 10 to 47% of component B), the remainder being component (C) and component (D), and having a specific gravity of 0.3 to 1.8.

3. (A): expanded polystyrene, (B): bubbles made of a foaming agent and aqueous resin having film-forming ability, (C): hydraulic substance such as cement, in a kneaded product of component (C). A method for producing a hydraulic lightweight composition, which comprises adding and kneading component (B) to a mixture, and then adding and kneading component (A), followed by molding and curing.

4. (8): Expanded polystyrene, (B): Cells made of a foaming agent and aqueous resin with film-forming ability, (C): Hydraulic substances such as cement, (D): Sand, gravel, and other aggregates. Add and knead component (B) into a kneaded product of component (C) using either or both of the following: A method for producing a hydraulic lightweight composition.

(Function) Components (A) and (B) reduce weight and provide water absorption and water resistance. In addition, the component (B) prevents separation of the component (A) in the kneaded product, resulting in a stable product. Furthermore, the component (C) imparts properties as a hydraulic composition.

By setting the content of component (A) to 5% or more and the content of component (B) to 10% or more, the aforementioned weight reduction can be appropriately achieved, and (A)
Effective strength can be obtained by controlling the component to 55% or less and the component (B) to 47% or less.

By setting the specific gravity of the molded product to 0.3 or more, strength can be maintained, and by setting the specific gravity to 1.8 or less, lightness can be achieved.

Component (A) is added and kneaded to a mixture of component (C) and component (B) to prevent separation of component (A) in the kneaded product and to obtain a composition of stable quality without variation. .

(Example) To explain in more detail the above-mentioned product according to the present invention, as the foamed polystyrene (A) used in the present invention, almost all commercially available foamed polystyrenes can be used. It is.

Its form may be one that has been foamed in advance depending on the conditions of use, or it may be one that has been heated and foamed and cured in the form of beads containing a foaming component at the molding site. Further, although it is usually spherical, recycled foamed polystyrene scraps or amorphous shapes can also be used. The foaming ratio is preferably 5 to 60 times (approximately 0.02 to 0.2 in terms of true specific gravity); if it is less than 5 times, the weight reduction effect will be poor;
Moreover, it is not preferable from an economic point of view, and if it exceeds 60 times, it tends to be crushed and deformed during kneading, which is not preferable.

The size should be selected depending on the scale of the molded object, etc., and is not particularly stipulated, but industrially it is 0.5 to 20 mm in diameter.
Spherical shapes of about m+s are easily obtained, and diameters of 1n to 5
n is easy to knead. In addition, regarding the amount used, it is preferable to use it in a volume ratio of 5 to 55% in the molded body, and 5%
When it is less than 55%, the weight reduction effect is small, and when it exceeds 55%, the strength of the molded product tends to decrease significantly. More preferably, it is used in an amount of 10 to 30% in view of the trade-off between weight reduction and strength.

The bubbles made of the foaming agent and the aqueous resin having film-forming ability ([1)] have the following component composition. That is, (a) a foaming agent, (aqueous resin having BL film forming ability), and (C) water.
The foaming agent (B) is an essential component for lowering the surface tension of the foaming liquid and foaming it, but it is not generally commercially available. Almost any foaming agent that can be used can be used. Specific examples include alkyl sulfuric acid, alkylaryl sulfonic acid,
Examples include sodium, potassium, and ammonium salts such as alkylaryl polyether sulfate, so-called anionic emulsifiers, nonionic emulsifiers such as resin acid soaps, polyoxyethylene alkyl ethers, and polyoxyethylene alkyl phenol ethers, and one or two of them. It is used as a mixture of the above. The amount used is preferably 3 to 15% by weight as a solid content ratio in the foaming liquid. That is, if the amount used is less than 3% by weight, the foaming effect of the composition will not be sufficient, and if the amount exceeds 15% by weight, the water resistance and water absorption of the resulting cement molded product will deteriorate, which is not preferable. Preferably 3
~10% by weight.

The aqueous resin having film-forming ability described in (b) above stabilizes the bubbles foamed by the foaming agent, and furthermore, the bubbles are mixed into an inorganic compound such as cement paste and hardened to form a molded body. When this occurs, the water in the bubble film is absorbed and diffused into the cured cement, and at the same time, the water-based resin is concentrated on the cell walls and forms a film, contributing to improvements in the physical strength, water absorption resistance, etc. of the cured molded product. The form can be either water-soluble or water-dispersible.

Specifically, synthetic resins include acrylic resin, acrylic styrene resin, vinyl acetate resin, styrene butadiene rubber (SBR), urethane resin, alkyd resin, oil-free alkyd resin, polyamide, melamine resin,
There are water-soluble resins and water-dispersible resins such as polyvinyl alcohol, maleic rosin, and modified types of these resins.

In addition, natural products and resins obtained by modifying or chemically treating natural products include casein, modified starch,
Examples include modified cellulose such as methylcellulose and hydroxyethylcellulose, and gum arabic, and it is possible to use one or more of these resins, but resins are broadly classified into anionic, cationic, and nonionic types depending on their charge state. In this case, the combined use of the anionic type and cationic type may cause the resin to aggregate, so sufficient care must be taken when using the resin. Any aqueous resin having film-forming ability can be used, but a combination of a water-soluble resin and a water-dispersible resin is particularly preferred in order to obtain a stable composition. This is because the water-soluble resin mainly prevents the diffusion of water in the bubbles through its water-retaining properties and viscosity, contributing to the stabilization of the bubbles. When dried and cured, they form a resin film with good water resistance, contributing to improved water absorbency and strength, and it is presumed that this is because they function complementary to each other.

The selection of water-based resin, the amount used, and the ratio of water-soluble resin to water-dispersible resin can be selected in various ways, but should be adjusted within a range that does not adversely affect economic efficiency, ease of handling, and hardening of cement. It is. The amount used is preferably 97 to 85% by weight of the solid content in the foaming liquid. Further, the ratio of the water-soluble resin to the water-dispersible resin is particularly preferably 90/10 to 60/40 (solid content ratio).

The solid content concentration of the foaming liquid is preferably 1 to 10% from the viewpoint of ease of handling and economical efficiency.If it is less than 1%, the foam stabilizing effect will be small, while if it exceeds 10%, it will be unfavorable because it will be less economical.

The foaming ratio (bubble volume/liquid volume) of the above-mentioned foaming liquid is preferably in the range of 10 to 35 times from the viewpoint of ease of foaming with a foaming machine, and furthermore, considering foam stabilization, strength, etc., the foaming ratio is about 10 to 25 times. It is appropriate to The amount of air bubbles used is preferably 10 to 47% by volume in the molded body, and 1
If it is less than 0%, the effect of weight reduction and the effect of reducing aggregate separation of expanded polystyrene, which will be described later, will be small, and if it exceeds 47%, the strength of the molded product will tend to decrease significantly. Furthermore, 10-30%
It is desirable to use . In any case, the bubbles of the present invention exist stably even when the bubbles themselves are kneaded or dispersed in mortar or the like.

Next, as for the hydraulic cement (C), one or a mixture of two or more of alumina cement, white Portland cement, ordinary Portland cement, early-strength Portland cement, various mixed cements, etc. can be used, and ordinary Portland cement is preferably used. It is

In addition, in addition to ordinary aggregates such as sand and gravel, the aggregates that can be used as required in (C) include pumice, vermiculite, anti-flame stone, and ALC.
Lightweight aggregates such as perlite and asbestos, carbon fiber,
Examples include polyvinyl alcohol fibers, polypropylene fibers, nylon fibers, glass fibers, steel fibers, etc., and one or a mixture of two or more of these may be used.

In addition to the above-mentioned components (A), (B), and (C), other organic or inorganic admixtures (materials) can be used as long as they do not depart from the characteristics of the present invention. For example, known and commonly used water reducing agents such as melamine sulfonic acid, naphthalene sulfonic acid, and polycarboxylic acids, polyoxyalkylene glycol and polycarboxylic acid thickeners, water retention agents, gluconic acid, and oxycarboxylic acid curing agents. retardant, shrinkage adjusting material such as fly ash or Denka C5A (manufactured by Denki Kagaku Co., Ltd.),
Examples include foaming agents such as aluminum powder, hardening agents such as alkali metal carbonates, and slaked lime, and these admixtures (materials)
can be added as appropriate depending on the use.

The manufacturing order of the product according to the present invention is: - Components (A) and (B) are sequentially mixed into mortar etc. prepared from the component (C) using a mortar mixer beforehand on a boat, dispersed and homogenized, and then packed into a mold. Take care of yourself. The mold filling can be made at the construction site and poured directly on the site, or it can be poured into a mold for molded products in the factory. Further, there is no particular restriction on the shape of the mold as long as it can be formed by normal mold filling work.

However, excessive use of pipe rakes during mold filling is undesirable because aggregate separation tends to occur.

Curing can be done in the same way as regular concrete without any problems. In other words, various curing methods such as standard curing, steam curing, carbon dioxide gas curing, and autoclave curing can be used. During autoclave curing, expanded polystyrene is melted and the void occupied by expanded polystyrene in the molded state (before melting) is removed. Since the molten polystyrene forms a film and adheres to the wall of the tube, there is no significant deterioration in physical properties such as strength, and even in this case, stable production is possible.

As described above, according to the present invention, cured products with a wide range of specific gravity can be obtained with almost no restrictions on the molding method or curing method,
It can be used in a wide range of applications as a lightweight component for civil engineering and construction structures. The composition according to the present invention stably contains expanded polystyrene and air bubbles, and also exhibits various physical properties. Unlike the bubbles produced by ordinary foaming agents, the bubbles present stably in the cement mixture and are viscous, which significantly increases the resistance of foamed polystyrene to aggregate separation, making it possible to form a cured product with a uniform composition. Even after curing, the cells remain as closed cells, and the cell walls are covered with a film-forming resin film, which, combined with the low water absorption of expanded polystyrene, provides excellent water absorption and freezing resistance. It is recognized that it exhibits physical strength such as meltability, bending, and compression.

Some specific manufacturing examples of products according to the present invention are shown in the following table. Magnet 1 has excessive foaming due to the foaming agent and water-based resin as components (B), and Magnet 6 has excessive foaming due to the foaming agent (B) component and )
There is very little foaming due to the foaming agent and water-based resin that are the ingredients.
Sample No. 2 has an excess amount of expanded polystyrene, which is the component (8), and is a comparative example, and the others are production examples of the present invention that satisfy the requirements of the present invention.

"Effects of the Invention" According to the present invention as explained above, lightweight foamed polystyrene can be effectively and uniformly incorporated into a hydraulic composition to obtain a preferable stable lightweight body, and it can also be used for this purpose. By foaming with a foaming agent and a water-based resin having film-forming ability, it is possible to similarly reduce weight and improve strength and water resistance, thereby providing an effective lightweight composition. This invention is industrially very effective because it is easy to use, has few restrictions such as molding methods and curing methods, and can appropriately produce products that can be applied to a wide range of uses.

Claims (1)

[Scope of Claims] 1. (A): expanded polystyrene; (B): bubbles made of a foaming agent and an aqueous resin having film-forming ability; (C): a hydraulic substance such as cement; 5 to 55% of component (A) by volume (
A hydraulic lightweight composition containing 10 to 47% of component B), the remainder being component (C), and having a specific gravity of 0.3 to 1.8. 2. (A): Expanded polystyrene, (B): Cells made of a foaming agent and aqueous resin with film-forming ability, (C): Hydraulic substances such as cement, (D): Sand, gravel, and other aggregates. and one or both of the additives are essential components, and the volume ratio of component (A) is 5 to 55%, (
A hydraulic lightweight composition containing 10 to 47% of component B), the remainder being component (C) and component (D), and having a specific gravity of 0.3 to 1.8. 3. (A): expanded polystyrene, (B): bubbles made of a foaming agent and aqueous resin having film-forming ability, (C): hydraulic substance such as cement, in a kneaded product of component (C). A method for producing a hydraulic lightweight composition, which comprises adding and kneading component (B) to a mixture, and then adding and kneading component (A), followed by molding and curing. 4. (A): Expanded polystyrene, (B): Cells made of a foaming agent and aqueous resin with film-forming ability, (C): Hydraulic substances such as cement, (D): Sand, gravel, and other aggregates. Add and knead component (B) into a kneaded product of component (C) using either or both of the following: A method for producing a hydraulic lightweight composition.