JPS60264375A - Cement composition - 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 Field of the Invention The present invention relates to cement compositions, and in particular to cement compositions suitable for the preparation of mortars used in extrusion molding.

[Background of the invention] Water-based kneaded materials (made by adding water to cement, lightweight aggregate, etc.) are used as exterior wall materials, roofing materials, flooring materials, pillar materials, etc. of buildings.
Molded bodies made by extruding mortar are widely used.

In general, such molded bodies are easy to construct because they can be sawed, nailed, etc. Also, since they are precast products and are lightweight, they can shorten the construction period and reduce construction costs. It has many advantages.

Furthermore, since such molded bodies have heat insulating and soundproofing properties, their use is preferable from the perspective of energy conservation, and is also desirable from the perspective of protecting privacy due to densely populated housing. Use is recommended.

The mortar used for extrusion of such lightweight moldings is typically made of lightweight aggregates such as perlite, shirasu/herune, and pulp, and inorganic fibers such as asbestos, glass fiber, and carbon fiber, or organic fibers such as vinylon fiber. It is prepared by mixing a fibrous substance such as cement with cement, adding a predetermined amount of water to the mixture, and kneading the mixture.

In recent years, in order to further reduce the weight of such molded bodies or to further improve their heat insulation and soundproofing properties, hollow structures (for example, those having one or more through holes) have been developed. An extrusion molded body of structure) is manufactured.

[Problems with the Prior Art] However, molded bodies obtained by extrusion molding using the above mortar generally have poor shape retention +lJ. That is, there is a problem in that the dimensional accuracy decreases significantly during the time between molding and solidification.

A molded body having such a hollow structure tends to deform due to its own weight during solidification after extrusion molding. This modification will be explained in detail with reference to the attached drawings.

FIG. 1 is a perspective view schematically showing a hollow prism, which is the simplest example of a hollow structure, and FIG. 2 is a front view thereof.

A molded body manufactured by extrusion molding is usually left standing horizontally as shown in FIG. 1 and solidified.

At this time, due to the weight of the molded body, the first side part 1 of the molded body is deformed by curving down along the center in the length direction (a deformation generally referred to as "sag"), and the side part 2. 2
° especially tends to deform so that its lower part bulges outward. Such a modification is shown in dashed lines in FIG. That is, as shown in FIG. 2, a molded body having a hollow portion at its center tends to have a tendency for the length of each side to fluctuate with the passage of time from molding to solidification. A molded body that is deformed so that the lengths of each side are significantly different is inconvenient for actual use.

Therefore, in practice, methods have been adopted to improve shape retention by reducing the amount of water used during kneading. However, when the amount of water is reduced in this way, the fluidity of the mortar tends to decrease.

When extrusion molding is performed using such mortar with low fluidity, it is necessary to extrude the mortar while applying a considerably high pressure.

There is a problem in that the lightweight aggregate in the mortar is destroyed or cement components infiltrate into the fine pores of the mortar, increasing the specific gravity of the molded product.There is also a problem in that the fibrous material is destroyed and its strength is reduced.

Furthermore, in addition to the shape retention described in ``2,'' such a molded body also has the ability to be sawed, drive a nail, and hold a nail (nailing performance) as described above. Various performances related to workability during construction, such as good performance, are required.

Such performance is mainly achieved by adding lightweight aggregates and fibrous materials, and as described in -1-, lightweight aggregates and fibers are added during the extrusion process under high pressure. If the structure of the shaped material is destroyed, it may not be possible to nail or saw the resulting molded product during construction, making it difficult to perform the construction work. A problem also arises when the performance is significantly reduced.

Furthermore, applying high pressure when forming such mortar not only causes problems in workability as mentioned above, but also
It also causes deterioration of the heat insulation and soundproof properties of the molded article.

[Object of the invention] The object of the present invention is to provide a cement composition which is particularly suitable for preparing mortar for extrusion molding.

More specifically, the present invention provides a molded product obtained by extrusion molding a mortar prepared using the cement composition, which has good shape retention, that is, a molded product with good dimensional accuracy, and when the molded product is constructed. An object of the present invention is to provide a cement composition for mortar preparation that is suitable for forming a molded article that allows operations such as sawing, nailing, and nailing to be performed easily and reliably.

[Summary of the Invention] The present invention comprises (A) cement, (B) crushed synthetic resin foam particles in an amount of 0.5 to 2 times the volume of the cement, and (C) inorganic particles in an amount of t to 3 times the volume of the cement. and a cement composition characterized in that it contains (D) 0.5-6% by weight of a fibrous material and (E) 0.4-2% by weight of a plasticizing agent, respectively, based on the cement. provide something.

The inorganic lightweight aggregate used in the present invention includes Barley I.
is preferable, the crushed synthetic resin foam particles are preferably expanded polystyrene crushed particles, and the plasticity improving agent is
It is preferable to use at least one compound selected from the group consisting of methylcellulose, ethylcetate, lulose, carboxymethylcellulose, polyethylene oxide, and polyvinyl alcohol.

[Effects of the Invention] The molded product obtained by extrusion molding the mortar prepared using the cement composition of the present invention has good accuracy in the Xj method, and
Further, workability during saw cutting, nail driving, and nail processing is extremely good. In particular, a molded article having a hollow structure produced using the cement composition of the present invention has extremely good dimensional accuracy and becomes an excellent structural material.

[Detailed description of the invention] The cement used in the present invention is not particularly limited as long as it is commonly used, and for example, portland cement, fly ash cement, blast furnace slag cement, silica cement, etc. can be used. .

The crushed synthetic resin foam particles used in the present invention are not particularly limited as long as they have almost no water absorption and do not absorb almost any water even when pressure is applied during extrusion molding. can be used.

Examples of such crushed synthetic resin foam particles include crushed polystyrene foam, crushed polyurethane foam, and the like. In the present invention, it is particularly preferable to use crushed granules of expanded polymethylene.

The particle size of crushed synthetic resin foam particles is generally 2 m.
It is preferable to use one with a diameter of 1.2 mm or less, usually 1.2 mm or less. When the particle size is larger than 2 mm, the surface of the molded article tends to become rough due to the elastic recovery force of the crushed particles, and the fluidity of the prepared mortar tends to decrease.

The blending ratio of crushed synthetic resin foam particles to cement needs to be 0.5 to 2 times the volume of the cement used. If the blending ratio is less than 0.5 times, the discharge pressure of the mortar must be increased during the production of the molded body, and the structure of the inorganic lightweight aggregate and fibrous material in the molded body is destroyed, and on the other hand, If the amount is more than twice the amount, the shape retention will deteriorate and the surface of the molded article will become rough, which is not preferable.

In the cement composition of the present invention, it is necessary to further mix an inorganic lightweight aggregate with the above-mentioned crushed synthetic resin foam particles.

There are no particular restrictions on the inorganic lightweight aggregate as long as it is commonly used, such as perlite, vermiculite,
Shirasu balloons, microballoons, etc. can be used, but pearlite is preferably used in view of its affinity with crushed synthetic resin foam particles.

There are no particular restrictions on the type of pearlite, and for example, pearlite, obsidian, or other igneous rocks that are fired and expanded can be used.

Inorganic lightweight aggregates are generally 2 mm or less, usually 1.
It is preferable to use particles with a particle size of 2 mm or less. If the particle size is larger than 2 mm, the surface of the molded product may become rough, and the fluidity of the mortar tends to decrease.

The mixing ratio of inorganic lightweight aggregate is 1 of the volume of cement used.
It is necessary to use ~3 times the amount. Is the blending ratio i4? i
If the amount is less than 3 times the amount, the prepared mortar will have low fluidity and poor moldability, while if it is more than 3 times the amount, the medium amount of water must be increased to obtain the plasticity required for molding, or the plastic material -j- agent must be used more often, and such mortar is not preferred because it may cause poor solidification, reduce the strength of the molded product, and increase the drying shrinkage rate.

The cement composition of the present invention needs to contain 0.5 to 6% by weight of fibrous material based on the cement used. There are no particular restrictions on the fibrous material that can be used, as long as it is a fibrous material that is commonly used for reinforcing lightweight cement, for example, asbestos, inorganic fibers such as glass fiber, carbon fiber, or vinylon. Examples include organic mats such as fibers, and these can be used alone or in combination.

If the amount of the fibrous substance is less than 0.5% by weight, the shape retention and strength of the molded object will be reduced, and if it is more than 6% by weight, the prepared mortar will become hard, making it difficult to extrude and mold smoothly. This makes it extremely difficult and undesirable.

It is necessary that the cement composition of the present invention contains a plasticity improving agent in an amount of 0.4 to 2% by weight based on the cement used. The plasticizer that can be used is not particularly limited and can be appropriately selected from plasticizers that can impart appropriate plasticity to mortar.

Examples of such plasticizers include methylcellulose, ethylcellulose, carboxymethylcellulose, polyethylene oxide, and polyvinyl alcohol, and these may be used alone or in combination. It is particularly preferred to use a plasticizer containing methylcellulose.

If the amount of the plasticizer added is less than 0.4% by weight, the prepared mortar will lack plasticity and smooth extrusion will be difficult, and if it is more than 2% by weight, the prepared molded product may swell, This is undesirable because it reduces shape retention, such as causing "sag".

In addition to the above-mentioned components, the cement composition of the present invention may optionally contain additives such as fine aggregate, a dispersant for lightweight aggregate, a surfactant, and other commonly used admixtures. It is also possible to mix them.

There are no particular restrictions on the method for producing the cement composition of the present invention,
It can be prepared by a conventional mixing method. For example, a regular mixer can contain seven particles], synthetic resin foam crushed granules, inorganic lightweight aggregate, fibrous materials, and ifr plasticity! j. Methods such as adding and mixing agents can be used.

There are no particular limitations on the preparation of mortar using the cement composition of the present invention, such as a method in which the cement I composition of the present invention is put into a normal cement mixer, mortar mixer, etc. and kneaded with a predetermined amount of water. can be used. In addition, cement, crushed synthetic resin foam particles, inorganic lightweight aggregate, fibrous material γ'I, and li) plastic material and agent were added to a ment mixer, mortar mixer, etc., and a predetermined amount of η was added.

Add some water? It is also +1 power to prepare it by M kneading method.

The mortar thus prepared is molded by a conventional method using a commonly used molding machine.

Next, Examples and Comparative Examples of the present invention will be shown.

The physical properties of the cement composition of the present invention were evaluated by the following method.

(A) Shape retention evaluation method Using the mortar prepared in the Examples and Comparative Examples, a molding machine of 36 mm x 36 m in the center was
60mm x 60m with a hollow part of m (b in Figure 2)
m (a in Figure 2) and length 100100O C in Figure 1
) was molded into a hollow prism.

As shown in FIG. 1, this hollow prism was left standing horizontally and solidified. After solidification, the distance # (d in Figure 2) from the lowest part of the downwardly curved part in the force direction to the horizontal plane formed by both widthwise ends of the upper surface part is calculated. It was measured. In other words, as shown in Fig. 2, the depression distance #(d) at the largest deformation part of the dihedral
, and its d (if +Fj is 1 mm or less,
"Good shape retention", "slightly poor shape retention" in the range of 1 to 2.5 mm, and "poor shape retention" in the case of 2.5 mm or more.

(B) Method for evaluating workability (workability) The hollow square column shown in Figure 1 was tested for saw cutting, nailing, and nailing performance in accordance with the method used during actual construction. Workability was judged comprehensively.

[Example 1] 1 volume part of crushed polystyrene particles (particles 1 yen:
1, 2mm or less), 1.5 Barley I (of the United States)
Manufactured by Ube Industries ■, product name: Barley I/1 type) and cement, 5% by weight of asbestos (made in Canada, grade name: S-6D), 0.8% by weight of methyl cellulose (
Manufactured by Shin-Etsu Chemical, product name: Metrose 90SH-1 5
000) in a mixer and mixed to prepare a cement composition.

j, Cement I/Cement used in the obtained seven-mention composition
38% by weight of water was added and kneaded to prepare a mortar.

5 Using this mortar, the above hollow prism was manufactured by extrusion molding.

The obtained hollow prism had a d value of 1.0 mm or less and exhibited good shape retention.

Furthermore, the performance of saw cutting, nailing, and nailing were all good, indicating excellent workability.

[Example 2] Example 1 except that the amount of crushed polystyrene granules used in the cement was 1.5 parts by volume, the amount of pearlite used was 2 parts by volume, and the amount of methylcellulose used was 1.0% by weight. A cement composition was prepared in the same manner, and mortar was prepared in the same manner except that the amount of water used was 40% by weight.

Using this mortar, a hollow prismatic column described in -1- was manufactured by extrusion molding.

The obtained hollow prism had a d(itt) of 1.0 mm or less and exhibited good shape retention.

Furthermore, the performance of saw cutting, nailing, and nailing were all good, indicating excellent workability.

6 [Example 3] In Example 1, the amount of perlite used was 2.5 parts by volume relative to the cement, and the amount of asbestos was changed to vinylon fiber (manufactured by Kuraray ■,
Grade name: RM182X6, 1, 8 denier X6mm
), and the amount used in cement is 0.6% by weight.
A cement composition was prepared in the same manner except that the amount of methylcellulose used was 1.5% by weight, and a mortar was prepared in the same manner except that the amount of water used was 45% by weight.

Using this mortar, the above hollow prism was manufactured by extrusion molding.

The obtained hollow prism has a d value of 1.0 mm or less,
It showed good shape retention.

Furthermore, the performance of saw cutting, nailing, and nailing were all good, indicating excellent workability.

[Example 4] Example 1 except that the amount of crushed polystyrene granules used in the cement was 1.5 parts by volume, the amount of pearlite used was 2.5 parts by volume, and the amount of methylcellulose used was 1.5% by weight. A cement composition was prepared in the same manner, and a mortar was prepared in the same manner except that the amount of water used was 40% by weight.

Using this mortar, a hollow prismatic column as described in "-" was manufactured by extrusion molding.

The obtained hollow prism had a d 4fh of 1.0 mm or less and exhibited good shape retention.

Furthermore, the performance of saw cutting, nailing, and nailing were all good, indicating excellent workability.

[Comparative Example 1] A cement composition was prepared in the same manner as in Example 1, except that the expanded polystyrene crushed granules were not used and the amount of Barley I was changed to 2 parts by volume for cement]. Further, a mortar was prepared in the same manner except that the amount of water used was reduced to 42 overlapping parts.

Using this mortar, a hollow prismatic column as described in "-" was manufactured by extrusion molding.

The obtained hollow prism had a d value in the range of 1.0 to 2.5 mm, and its shape retention was somewhat poor.

Furthermore, among the saw cutting, nailing, and nailing performance, the sawing J-cutting and nailing performance were poor.

[Comparative Example 21 In Example 1, use of expanded polystyrene crushed granules for cement without using perlite! j! A cement I composition was prepared in the same manner, except that : was changed to 2 parts by volume, and a mortar was prepared in the same manner, except that the amount of water used was 38% by weight.

Using this mortar, the above hollow prism was manufactured by extrusion molding.

The hollow prismatic pillars had a d value in the range of 1.0 to 2.5 mm, and had somewhat poor shape retention.

In addition, among the performance of saw cutting, nailing, and nailing, the performance of sawing and nailing was poor.

[Comparative Example 3] , ill Example, , you, ya, ya, 7□. In contrast, a cement composition was prepared in the same manner except that the amount of crushed styrene granules used in 6 and 1J was changed to 3 parts by volume. Mortar was prepared.

Using this mortar, the hollow prism shown in [-] was manufactured by extrusion molding.

The obtained hollow prism has a d value of 2.5 mm or more and 4-,
Shape retention was poor.

Furthermore, among the performance of saw cutting, nailing, and nailing, the performance of nailing was particularly poor.

[Comparative Example 4] A cement composition was prepared in the same manner as in Example 1, except that the amount of pearlite used was 4 parts by volume and the amount of methylcellulose was 2% by weight based on the cement, and further the use of water was changed. A mortar was prepared in the same manner except that the amount was changed to 65% by weight.

Using this mortar, a hollow prismatic column as described in "-" was manufactured by extrusion molding.

The obtained hollow prism had a d value of 2.5 mm or more -1, and had poor shape retention.

Also, the performance of saw cutting, nailing and nailing is 0. In particular, the performance of nailing was poor.

[Brief explanation of drawings]

FIG. 1 is a perspective view schematically showing a hollow prism, which is the simplest example of a hollow structure obtained by extrusion molding, and FIG. 2 is a front view thereof. l: [-face part, 2,2°: side part, 3: hollow part, 4; bottom part Patent applicant Ube Industries Co., Ltd. Representative Patent attorney Yasuo Yanagawa 6

Claims (1)

[Claims] 1° cement and a volume ratio of 0.5 to 2
double the amount of crushed synthetic resin foam granules and 1-3 times the amount of inorganic lightweight aggregate, and 0.5-6% by weight of fibrous material and 0.4-2% by weight of plasticizer, respectively, based on the cement. A cement composition comprising: 2. The cement composition according to claim 1, wherein the inorganic lightweight aggregate is pearlite. 3.1 The cement composition according to claim 1, wherein the crushed synthetic resin foam particles are crushed polystyrene foam particles. 4. Claim 1, wherein the plasticizing agent described in item 1 is at least one compound selected from the group consisting of methylcellulose, ethylcellulose, carboxymethylcellulose, polyethylene oxide, and polyvinyl alcohol. cement composition.