JP2000264690A - Pulverized volcanic glass-incorporated lightweight high- strength concrete and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject concrete with its lightweightness and high mechanical strength compatible with each other by packing voids among cement particles with pulverized volcanic glass having an average particle size of a specific value or lower. SOLUTION: This concrete is obtained by incorporating cement with pulverized volcanic glass <=15 μm in average particle size in the weight ratio of the latter to the former of 1.0-3.0 followed by adding water and a water reducing agent to the mixture and then kneading the resultant mixture followed by curing the mixture thus kneaded; wherein the pulverized volcanic glass is afforded with an appropriate particle size distribution through pulverization process, being excellent in fluidity, packing the voids among the cement particles, thereby forming the aimed dense concrete and obtaining the objective highly waterproof lightweight concrete with high compressive strength and flexural strength; the pulverized volcanic glass is made from not only silas, but also one of various kinds of volcanic rocks including obsidian, pitchstone and perlite. This concrete is suitably used as PC concrete, segment concrete, precast concrete or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a finely ground volcanic glass lightweight high-strength concrete and a method for producing the same.

[0002]

2. Description of the Related Art The finely ground volcanic glass compounded is made of aluminosilicate glass, is very fine, has a large specific surface area, and has an appropriate particle size distribution. Reacts with the cement to form a strong bond, thereby exhibiting high strength. Finely ground volcanic glass has a true specific gravity of about 2.4 and is smaller than the specific gravity of cement and silica sand, which is commonly used. Therefore, by adding an appropriate amount of finely ground volcanic glass, it exhibits lightness and excellent fire resistance. Combined functionality.

The point of the present invention is to utilize the excellent reactivity of finely ground volcanic glass having an average particle size of 15 μm or less with cement. Here, when synthetic resin beads are used in place of the finely ground volcanic glass, since there is no reactivity with such cement, strong bonding between these particles and cement particles does not occur, and high strength do not become. The finely ground volcanic glass used in the present invention, the smaller the particle size,
Since the specific surface area is increased and the reactivity with the cement is also increased, especially when the average particle diameter is 10 μm or less, as shown in Example 1 described later, about 20% compared to concrete using standard sand. Despite being lightweight,
Compressive strength and bending strength are significantly improved. As a matter of course, in the “specific strength” obtained by dividing the strength value by the bulk specific gravity of the concrete, both the specific bending strength and the specific compression strength showed a remarkable improvement in strength.

In the case of using finely ground volcanic glass, since the average particle size is 15 μm or less and the specific surface area is large, a large amount of water tends to be required at the time of kneading. About 4% or less)
It became possible to suppress the moisture more than necessary. This is an important point in using finely ground volcanic glass, and is a point at which high strength is exhibited.

Therefore, in the present invention, the inventors of the present invention focused on the fact that they are contained in concrete compositions as applications in which the high fluidity and other properties of the finely ground volcanic glass can be utilized, and have conducted extensive studies, and have studied the light weight of the finely ground volcanic glass. This led to the invention of high-strength concrete. And the present invention
The aim is to develop concrete that has both lightness and high strength, which were difficult with conventional technology.

[0006]

The object of the present invention is to provide a finely ground volcanic glass lightweight high-strength concrete containing finely ground volcanic glass in its composition. As described above, the method is characterized in that volcanic glass fine powder pulverized to an average particle size of 15 μm or less flows into and fills voids between cement particles.

[0007] According to the finely ground volcanic glass lightweight high-strength concrete having the above structure, the finely ground volcanic glass has an appropriate particle size distribution due to the pulverizing process, has excellent fluidity, and is introduced into the voids between cement particles. By filling voids, it becomes dense concrete, and it becomes lightweight concrete with high compressive strength, bending strength and waterproofness, and can be widely used for products such as PC sheet pile, segment, precast board, fume pipe and the like.

[0008] As a method for producing the above-mentioned finely ground volcanic glass lightweight high-strength concrete, as described in claim 2, the weight ratio of cement to weight 1 is 1.
It is characterized by adding a finely ground volcanic glass having an average particle size of 15 μm or less at a ratio of 0 to 3.0, adding water and a water reducing agent thereto, kneading the mixture, and curing the mixture to produce concrete. It is a suitable production method for filling the finely ground volcanic glass with a cement ratio of 1.0 or less,
Although the strength is high, the weight cannot be reduced because the specific gravity of the finely ground volcanic glass is about 2.4. With a cement ratio of 3.0 or more,
Not high strength. The finely ground volcanic glass used in the present invention has a specific gravity lower than that of standard sand.
Even with a value of ~ 3.0, the weight can be reduced sufficiently.

The above-mentioned finely ground volcanic glass includes, in addition to shirasu, finely ground bodies of various volcanic glass rocks such as obsidian, pinestone, and perlite.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, as an embodiment of the present invention, examples of blending of cement, finely ground volcanic glass, water and a water reducing agent are shown in Table 1 below. In any case based on these formulation examples, after kneading, it is to be cured,
The strength of the cured finely ground volcanic glass lightweight high-strength concrete after curing is as shown in Table 2 below.

<Examples and Comparative Examples> Comparative examples are based on JIS.
Reference is made to the basic formulation of R5201-1997.
Curing used the accelerated test technique to see the long-term strength. Specifically, one day after molding, 70% after demolding
Cured in warm water at 9.5 days for 9.5 days.

[0012]

[Table 1]

[0013]

[Table 2]

As the "finely ground volcanic glass", finely ground shirasu obtained by crushing shirasu existing in Minamikyushu was used. Curing method (all under the same conditions): One day after molding, the specimen was cured in a moisture box, and after demolding, in hot water at 70 ° C. for 9.5 hours. * The above bending strength and compression strength are average values (3 samples).

Lightening rate = (1- (Kasa specific gravity of finely ground volcanic glass concrete / Kasa specific gravity of standard sand concrete))
× 100 Specific bending strength = Bending strength of each example / Kasa specific gravity of each example Specific compressive strength = Compression strength of each example / Kasa specific gravity of each example Characteristics of concrete including finely ground volcanic glass: Light weight,
High strength Flexural strength and compressive strength showed remarkably high strength despite being about 20% lighter (compared with the concrete specific gravity of concrete) than a JIS standard specimen using standard sand.
It is considered that the cement had good reactivity, was strongly bonded, and had a very high compressive strength because of its solid state. The specific strength (the value obtained by dividing the bending strength and the compressive strength by the bulk specific gravity) is, of course, extremely excellent.

[0016]

As described above, according to the lightweight high-strength concrete containing the finely ground volcanic glass according to the present invention, the finely ground volcanic glass flows into the voids between the particles of cement to fill the voids and to be densely packed. Concrete having high compressive strength and bending strength, waterproofness and light weight can be provided, and can be used in various applications, for example, PC sheet pile, segment, precast,
It becomes a concrete suitable as a product such as a fume tube.

According to the method for producing a lightweight and high-strength concrete containing finely ground volcanic glass according to the present invention,
This is a very simple and cost-effective manufacturing method.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yoshitaka Jinno 1445-1 Oda, Hayato-cho, Aira-gun, Kagoshima Prefecture Inside the Kagoshima Industrial Technology Center (72) Harumi Morita 14445-1, Oda, Hayato-cho, Aira-gun, Kagoshima Kagoshima Prefectural Industrial Technology Center

Claims (2)

[Claims] An average particle size of 15 μm is formed in a void between cement particles.
m. High-strength concrete of finely ground volcanic glass, characterized by being filled with volcanic glass fine powder pulverized to m or less. 2. A weight ratio of 1.0 to 1 weight of cement.
A finely ground volcanic glass lightweight characterized by adding a finely ground volcanic glass having an average particle size of 15 μm or less at a ratio of ~ 3.0, adding water and a water reducing agent, kneading the mixture, and curing to produce concrete. Manufacturing method of high-strength concrete.