JPS5836965A - Improved lightweight aggregate and manufacture - 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 an improved lightweight aggregate and a method for producing the same.

This article relates to a lightweight aggregate that is significantly improved in terms of weight reduction, heat insulation, and economy using lime cake and a method for obtaining it.

The porous granules 1 conventionally used as this type of aggregate, such as volcanic gravel, are extremely porous substances. As a result, when concrete is kneaded using these materials, cement and water infiltrate into the pores of the axillary porous object, so the axillary porous material is used as is for rounding to reduce the weight of concrete. was difficult.

On the other hand, the specification of Igan@Da 3-/3431a describes volcanic lapilli obtained by filling the concave grooves on the surface of volcanic lapilli with clay, iron oxide powder, or mold containing nine iron that is generated during grading. An improved aggregate obtained by coating particles with cement and curing is disclosed. Although this improved aggregate has excellent water absorption and compressive strength, the air-dry specific gravity of concrete F obtained by using it is 1,1, which is lower than lightweight concrete F.
It is still unsatisfactory as a material for use. 1 ft. This high air-dry specific gravity is thought to be mainly due to the fact that the porous particles were directly coated with cement, which allowed water and cement to penetrate up to 1 sK into the pores of the particles. Therefore, the amount of cement required increases, which is also bad from an economic point of view.

In the summer, Tokuko 18 Hiro 7-. No. 3!04/Hatsuha discloses an artificial lightweight aggregate obtained by coating both surfaces of a porous granular material with a hot metal material of a refractory material and an adhesive, and then firing the material. However, as mentioned above, this method includes a firing step, and is considered to lack energy efficiency from the viewpoint of energy saving.

In order to solve these various drawbacks of the prior art, in the present invention, the t&plane of the granular material of the porous material as the main raw material is
One-layer binding [cover with lime cake and a mixture containing cement or cement and gypsum, and then carefully cover with a mixture containing cement and 72 lacquer.

Thus, according to the present invention, it is possible to obtain a lightweight aggregate that is sufficiently satisfactory as a material for lightweight concrete and is also advantageous from an economic point of view.

The porous material that can be used in the lightweight aggregate of the present invention may be any material that is lightweight and available from harmful sources, such as volcanic lapilli such as anti-flinder rock, coal slag, industrial waste, and hollow materials. Examples include selantsk and glass aggregate.

These are divided into nm grains by suitable means, and the maximum *g product meets the JIS standard for natural or by-product lightweight aggregate, that is, the average grain gIkλ
Make it 0~j.

The lime cake used in Honsha@ni- can be of any origin. Usually, we refer to the dehydrated cake of nine sludge mainly containing calcium such as slaked lime, lime carbonate, and lime sulfate. The cakes obtained by smoke desulfurization, the cakes obtained at various sugar factories, etc. are too numerous to mention.

Of course, it goes without saying that slaked lime, carbonated lime, sulfated lime, etc., or a mixture thereof can be used in place of the lime cake. It is preferable to use lime cake whose main component is calcium carbonate, which is produced as a by-product in the sugar manufacturing process at plants, beet sugar factories, raw material factories, etc.

In sugar factories, slaked lime is added to the sugar solution to make it alkaline, and by blowing vertical air gas into it, impurities in the sugar solution are adsorbed and removed. The carbonate lime produced at this time is 2
Im cake and [a large amount is ejected.

It is unlikely that such a lime cake would be used in the current way, and in fact, it would be a big problem from a corporate standpoint as a SW Qin item.

Lime cake contains 1k) of water (e.g. 4I41).
Although it is in the form of clay, when it dries, its particle size is smaller than that of cement, and it is lightweight.

Furthermore, it has excellent bonding properties with cement as the first layer and with porous materials as the lateral layer.

When using KII, it is possible to use a moistened clay-like material, and to omit extra operations such as crushing.

In the present *tC, the first coating layer covers the surface of the porous material to limit the water absorption rate of the porous material and prevent water from entering the pores as much as possible. This ensures that the final product becomes a scene.

The thickness of the first coating layer is 0. ! If it is thicker than this, the specified strength of the lightweight aggregate will not be achieved, and if it is too thin, the purpose of weight reduction will not be achieved, and water and cement will not penetrate into the porous core. This is not desirable because it cannot be effectively prevented.

The amount of lime cake used in the formation of the first covering layer should be 4/-0 weight or less based on the porous material as the core, and the amount of cement or cement and gypsum that acts as a binder is based on lime cake. as 0. /~10(
weight ratio).

However, this drop/cover layer as well as the core of the porous material have poor mechanical strength.

Therefore, by further providing the No. 1 coating layer, the necessary mechanical strength is imparted to the aggregate, and workability in producing the aggregate is improved.

In the present invention, it is preferable that the thickness of the coating layer is from 1 to 2. If the thickness of this layer is made thicker than the above range, it will not be possible to reduce the weight of the resulting final product.
Further, if the thickness is made thinner than in the above range, the desired strength cannot be obtained.

#The fly ash used in the λth coating layer is used to improve the workability of the aggregate production. That is, by using this, it becomes possible to proceed to the step of forming the second coated layer without going through a long drying step after applying the first coating layer. This is because fly ash is a substance with extremely high water absorption.

On the other hand, the amount of fly ash used in the formation of the coating layer is the same based on the porous material, 4 I0 weight or less, To6, and the amount of cement used is about 1 l-1 to the fly ash. be done. 7 used in ζζ
Tsuiatsushie, of course, contributes to the weight reduction of aggregates in single-shot cases.

According to another aspect of the present invention, during the formation of the coating layer, the step of kneading the coating mixture with the coating layer is performed, for example, from one end of a rotary drum type construction mixer or by electroplating after the formation of the seventh layer. It can also be carried out by feeding an intermediate product and spraying the coating mixture upwards on the input side of the carpet drum.

Additionally, the thickness of the first and a-th coating layers can be determined to be optimal depending on the am of the porous material, the weight, and the average particle size and strength of the final product; Moreover, Yong JIK understands that it is possible to change.

Thus, according to the present invention 11, it is possible to obtain a new aggregate that is lightweight and has excellent economic efficiency. Porous materials, which have traditionally been difficult to use as lightweight aggregates, can be used advantageously. Furthermore, a new use for lime cake as industrial waste can be provided.

Hereinafter, the present invention will be explained in more detail with reference to Examples. However, it should be understood that the present invention is not limited in any way to these Examples.

The main raw material components used in the following examples and specific soft N are as shown in No. 1*.

Table 1 Ingredients Lime Cake Anti-Fire Stone Torand 1-ment Silica (510,)
/, 7 7! , 911=Jco,O alumina (At, 0.) 0. j //,
4I2! f, 3-acid self-propagation (Fe, O,)
0. /
/, 43 3. 2 Calcium carbonate (Goco) Dayo da quicklime (Cab)
/, 0II4! f, comagnesia (40) 0-ko 0.3 ri 1.6 organic matter yo-3 moisture i, 0 to zo + Na, 110 K, 4
0So, /・I Others /, 0
/, Co*lime cake is obtained from refined sugar factories.

Example / Average grain @1 of anti-flinder rock, which is considered to be a relatively common sight, in volcanic lapilli
The 7th coating layer (/■ ) was formed, and after about 70 minutes at round 0 order i, a mixture of portland cement 1# and fly ashco 4 was added and kneaded for about -0 minutes to form a 1st coating layer (c 2). After that, the resulting product was cured for 3 days at room temperature, and the product was used to obtain a water-cement ratio [(water/cemen) Table 1 shows the physical properties of the nine aggregates and concrete obtained in the Qin test during the second curing period.

A cross-sectional view of the nine-light aggregate thus obtained is shown in Figure 1.Example In order to increase the compressive strength as co-concrete.

The first coating layer was formed using a mixture of I and gypsum 1007/ and otherwise operated in the same manner as in Example/.
Minutes later f Rutland cement l# and 7I) Iatushi 3-2
# was added and kneaded for about aO minutes to form the first coating layer, and then cured at room temperature for 3 days to produce a lightweight aggregate. Furthermore, using this aggregate, the water-cement ratio of -1 is 4.
Concrete specimens were manufactured under the same conditions as above, including IO, slump: 9 cIL, fine aggregate ratio: 1 Ios, and curing period.

Table 1 shows the physical properties of the aggregate and concrete obtained.

Comparative Example/A concrete specimen was manufactured under the same conditions as in Examples/and A using volcanic lapilli (firestone) as the aggregate. Table 1 shows the physical properties and blending ratio of this ton.

Comparative example.

Under the same conditions, an improved aggregate was manufactured by directly covering the firestone with cement without providing a first layer.Concrete specimens were also manufactured in the same manner as described above, and their physical properties and mixing ratio were determined. Shown in Table 1.

A schematic cross-sectional view is shown in Figure 1.

Considering the above results, all of the new aggregates of the present invention have excellent water absorption, and when used as materials for lightweight concrete, they have excellent strength and weight reduction.
I understand that.

On the other hand, when testing in Comparative Example/ by changing the following conditions, it was found that the water-cement ratio was generally y- os, 1so- is required, and the mixing ratio is also a common value /:! The compressive strength of concrete obtained even if the increase is /:= with respect to (cement: aggregate) is 10011/a
l), this is a lightweight aggregate f) JISfi rating (10
011/cd) tic does not match and is not practical.

Furthermore, although the product of Comparative Example has a water absorption rate comparable to that of the product of the present invention, when it is used as a material for concrete, its absolute dry specific gravity is extremely high. It will be understood that the concrete itself has a large air-dry specific gravity and its compressive strength is not very high, making it unsatisfactory as a bulk aggregate.

The lightweight aggregate of the present invention thus obtained has a rounded, yellowish-gray color and a glossy appearance. By using lime cake as the first coating layer, it is possible to prevent cement and water from penetrating into the aggregate when concrete is mixed, making it possible to meet the requirements for lightweight aggregate.

Reducing the weight of these aggregates is beneficial in terms of transportability, workability, and construction properties in civil engineering, construction, and chain applications.
It is expected that the demand for this type of lightweight aggregate will continue to increase.

In addition, it is an effective way to utilize industrial waste such as lime cake from sugar factories, and as a result, there is no need for the expense required for industrial waste processing, and it is also economical because it does not include a baking process. Extremely large effects can be expected in terms of performance, energy conservation, and resource conservation.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the improved lightweight aggregate of the present invention [L Figure 1 is a cross-sectional view of a conventional improved aggregate shown for comparison. Reference numbers in each figure are as follows. 1: Core of porous material 2: Seventh coating layer 3: Seventh coating layer 3': Cement layer Figure 1 Figure 2

Claims (1)

[Claims] (1) A core of a porous material and a lime cake on the core. The cement is made of lightweight bone, consisting of a first coating layer of a mixture containing cement, gypsum, and water, and a second coating layer of a warm mixture that combines the cement and the cement on the coating layer. Material. ) The porous material may be volcanic lapilli, slag, or coal. The lightweight aggregate according to claim IIS (1), which is selected from the group consisting of hollow cellar aggregate and plastic ivy aggregate. (3) Sort the porous material and then make lime cake,
A second coating layer is formed using cement or a mixture containing cement, gypsum, and water, and a second coating layer is formed using hot metals containing cement and a heat-resistant material, and the mixture is cured and hardened at room temperature. A method of manufacturing lightweight aggregates, including processes. (4) The method for producing a lightweight aggregate according to claim (3), wherein the porous material is selected from the group consisting of volcanic lapilli, slag, coal slag, hollow hollow building blocks, and plastic ivy aggregate. (Excellent) Claim No. (2), wherein the amount of the above-mentioned 2 ^^ used is the amount that can be coated by the weight of the porous material - or less.
9 is the method for producing lightweight aggregate described in paragraph (4). (6) Claim a(
The method for producing lightweight aggregate according to any one of items 3) to (5).