JP2803406B2 - Aggregate for mortar and concrete - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aggregate used for kneading mortar and concrete.

[0002]

2. Description of the Related Art In general, mortar / concrete is composed of a hardening agent such as cement, a fine aggregate such as sand, a coarse aggregate such as gravel, a water reducing agent and the like. When these mortar / concrete compositions are kneaded with water, the components of cement, such as calcium oxide, silicon dioxide, and magnesium oxide, react with water and gradually harden and solidify including the aggregate. . The water reducing agent has the function of improving the dispersibility of cement and reducing the amount of water for kneading mortar / concrete.

Incidentally, it is desirable that such mortar concrete has high compressive strength. Currently, high-strength mortar concrete having compressive strength of about 800 to 1000 kgf / cm ² is desired.
Concrete is actually used, but in recent years,
Ultra high strength mortar concrete having a compressive strength of 000 kgf / cm ² or more has been demanded.

[0004]

SUMMARY OF THE INVENTION However, 100
In ultra-high strength mortar concrete exceeding 0 kgf / cm ² , it is necessary to increase the strength of the cement paste and to select an aggregate having a strength equal to or higher than this. However, generally used fine aggregates such as river sand, mountain sand, crushed sand and the like often include those having low strength (hardness). For this reason, even if the strength of the cement paste is increased, there is a problem that the strength of the aggregate itself is low, so that it becomes impossible to stably produce ultra-high strength mortar / concrete.

[0005] In view of the foregoing, an object of the present invention is to provide a mortar / concrete aggregate having high strength, which is suitable for producing ultra-high strength mortar / concrete.

[0006]

In order to achieve the above object, the present invention relates to a method for producing a mineral composition comprising corundum (α-Al 2 O).
3) and bauxite containing mullite (Al6Si2O13) as a main component and not containing rutile (TiO2).
2. Increase the content of squid or rutile (TiO2)
5% or less .

Further, the chemical composition of bauxite is expressed as Al ₂
O ₃ 86% or more, Fe ₂ O ₃ 2.5% or less, SiO 2
₂ is desirably 7.5% or less, and TiO ₂ is desirably 3.5% or less.

[0008]

The aggregate for mortar and concrete according to the present invention uses bauxite containing corundum (α-Al2O3) and mullite (Al6Si2O13) as main components and does not contain rutile (TiO2).
By setting the content of rutile (TiO2) to 3.5% or less , a high-strength aggregate can be supplied. Therefore, the use of this aggregate makes it possible to stably produce ultra-high strength mortar concrete.

Further, the chemical composition of bauxite is expressed as Al ₂
O ₃ 86% or more, Fe ₂ O ₃ 2.5% or less, SiO 2
₂ is 7.5% or less, what TiO ₂ is less than 3.5% by bone material, it is possible to obtain a particularly good strength.

[0010]

Embodiments of the present invention will be described below in detail. In this embodiment, among the compositions used for mortar and concrete, the mineral composition of the fine aggregate is corundum (α-Al 2 O 3).
And calcined bauxite containing mullite (Al6Si2O13) as a main component is used. At this time, the bauxite does not contain rutile (TiO2), or
It is preferable that the content of rutile (TiO2) is 3.5% or less .

The chemical composition of the bauxite is, for example, 86% or more of Al ₂ O _{3 and} 2.5% of Fe ₂ O _3.
Hereinafter, the content of SiO ₂ is set to 7.5% or less, and the content of TiO ₂ is set to 3.5% or less.

The following Table 1 shows the measurement results of the compressive strength of the concrete using the fine aggregate of the present embodiment and the conventional fine aggregate.

[0013]

[Table 1]

That is, in Table 1 above, the measurement example of No. 1 is for the case where the fine aggregate of the present embodiment is used, and the measurement example of No. 2 is for the conventional case where hill sand is used as the fine aggregate. In each of these measurement examples, as shown in the table, the composition (water / cement, admixture, fine aggregate, coarse aggregate, etc.) shown in the table (Kg / m
³ ) shall be prepared separately. The test piece used for this measurement had a diameter of 10 cm and a length of 2 cm.
A 0 cm cylinder was used.

According to the results of the above measurement examples, in the case of No. 1, that is, when the fine aggregate of this example was used, the 4-week strength of concrete showed a remarkably high value of 1360 kgf / cm ^2, and the ultra-high strength It is understood that it is formed as mortar concrete. On the other hand, in the case of the conventional No. 2, the 4-week strength is similarly low at 879 kgf / cm ² .

As described above, in the fine aggregate of this embodiment, corundum (α-Al 2 O 3) and mullite (Al 6 Si
The calcined bauxite mainly composed of 2O13) is used, and the content of rutile (TiO2) is
By setting the content to 3.5% or less, the strength of the fine aggregate becomes extremely high, and in addition, the adhesive force with the cement paste is improved. Ultra-high strength of mortar / concrete can be achieved.

[0017]

Claim 1 of the present invention as described above, according to the present invention or
In the mortar / concrete aggregate shown in FIG. 2 or 3, the mineral composition is bauxite mainly composed of corundum (α-Al 2 O 3) and mullite (Al 6 Si 2 O 13), and does not contain rutile (TiO 2).
Since the content of rutile (TiO2) is set to 3.5% or less, fine aggregate having extremely high strength can be obtained. Therefore, by preparing mortar concrete using this fine aggregate, it is possible to provide ultra-high-strength mortar concrete having extremely high compressive strength.

According to a third aspect of the present invention, the chemical composition of bauxite is as follows: the content of Al2O3 is 86% or more;
2O3 2.5% or less, SiO2 7.5% or less, Ti
Since O2 is set to 3.5% or less, a fine aggregate having particularly excellent strength can be obtained, and various excellent effects such as further increasing the strength of mortar concrete can be obtained.

────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kenichi Ichinose 4-640 Shimoseito, Kiyose-shi, Tokyo Obayashi Corporation Technical Research Institute (58) Field surveyed (Int.Cl. ⁶ , DB name) C04B 14/02 C04B 14/30 C04B 28/00-28/36

Claims (3)

(57) [Claims] The mineral composition is corundum (α-Al2O).
3) and bauxite containing mullite (Al6Si2O13) as a main component and not containing rutile (TiO2).
Mortar and concrete for aggregate, characterized that no. 2. The mineral composition is corundum (α-Al2O).
3) and mullite (Al6Si2O13) as main components
Bauxite, the content of rutile (TiO2)
Is not more than 3.5% . 3. The chemical composition of bauxite is Al2O3.
86% or more, Fe2O3 2.5% or less, SiO2
It is noted that 7.5% or less and TiO2 is 3.5% or less.
The bone for mortar and concrete according to claim 2, wherein
Wood.