JPH05194000A - Aggregate for concrete - Google Patents

Abstract

PURPOSE:To provide the aggregate for concrete which has good workability at the time of placing the concrete, excellent application property and can improve the strength and durability of the concrete after curing. CONSTITUTION:This aggregate (processed sea sand 2) for concrete is prepd. by frictionally crushing sea sand 1 having <=4% pass rate of <=0.15mm sieve mesh size to 5 to 15% pass rate of <=0.15mm sieve mesh size. The concrete used for the processed sea sand 2 has the data on slump, etc., better than the data on slump, etc., of the concrete formed by using the sea sand 1. Then, the workability, etc., at the time of placing the concrete formed by using the processed sea sand 2 are much higher than the workability, etc., of the concrete formed by using the sea sand 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aggregate for concrete which is used by mixing with cement.

[0002]

2. Description of the Related Art Regarding sand used as aggregate for concrete, sea sand has been washed with water and used as it is.
However, since such sand has a poor grain size, so-called workability such as fluidity and softness is not good when actually used by mixing with cement, water and the like. Further, in some cases, the strength of the concrete after curing may be insufficient.

[0003]

The problem to be solved by the present invention is that the workability at the time of placing concrete is good, the workability is excellent, and the concrete strength and durability after hardening can be improved. , To provide aggregate for concrete.

[0004]

Means for Solving the Problems The gist of the present invention, which has solved the above problems, is to grind sea sand having a sieve size of 0.15 mm or less and a passing rate of 4% or less to obtain a sieve size of 0.15 m.
The aggregate for concrete is characterized in that the passage rate of m or less is 5 to 15%.

[0005]

The aggregate for concrete of the present invention is prepared by grinding sea sand having a sieve size of 0.15 mm or less and a passage rate of 4% or less to make the passage rate of the sieve size of 0.15 mm or less to 5 to 15%. It is a thing. In other words, it is sand with a higher content of fine grains when viewed as a whole. Since fine-grained sand has a large surface area and easily absorbs water, it has been considered impractical because it requires a large amount of cement and water. However, fine-grained sand
The actual rate of sea sand is increased, and as a result, the amounts of water and cement used can be reduced, and concrete with good workability can be obtained. Further, the concrete strength after hardening becomes high, and the durability also increases.

[0006]

EXAMPLES Examples of the present invention will be described below with reference to tables. Table 1 is the aggregate sieving test table, Table 2 is the particle size curve,
Table 3 is a mix design table of concrete using processed sea sand, Table 4 is a mix design table of concrete using sea sand, and Table 5 is a table showing test results.

In this example, sea sand 1 having a mesh size of 0.15 mm or less and a passage rate of 3% was ground to obtain a concrete aggregate having a mesh size of 0.15 mm or less and a passage rate of 7%. (Hereinafter, the same aggregate for concrete is processed as sea sand 2
Express). Table 1 is a sieving test table for sea sand 1 and processed sea sand 2, and Table 2 shows particle size curves of sea sand 1 and processed sea sand 2. As you can see from Tables 1 and 2, sea sand 1
Compared with, the processed sea sand 2 has a higher content rate of fine particles.

[0008] Sea sand 1 and processed sea sand 2 were each designed as shown in Tables 3 and 4 and tested for surface water, slump, air content, concrete temperature and workability. Good results were obtained. 14.5% concrete slump using sea sand 1
Whereas the concrete slump using the processed sea sand 2 is 19.0 cm, there is a difference of about 5 cm. That is, compared to concrete using sea sand 1 which is a conventional aggregate for concrete, processed sea sand 2
The workability of concrete using is significantly improved. In addition, the unit water volume decreased, and at the same time, the properties of concrete became good.

[0009]

EFFECTS OF THE INVENTION According to the present invention, it is possible to provide an aggregate for concrete which has good workability at the time of placing concrete, is excellent in workability, and can improve the concrete strength and durability after hardening. it can.

[Table 1] It is a sieving test table of aggregate.

[Table 2] It is a table which shows a particle size curve.

[Table 3] It is a mix design table of concrete using processed sea sand.

[Table 4] It is a mix design table of concrete using sea sand.

[Table 5] It is a table which shows a test result.

[Brief description of drawings]

[Explanation of symbols] 1 sea sand 2 processed sea sand

[Procedure amendment]

[Submission date] December 24, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief explanation of the drawing

[Correction method] Delete

Claims (1)

[Claims] 1. A sieving size of 0.15 m is obtained by grinding sea sand having a sieving size of 0.15 mm or less and a passage rate of 4% or less.
Aggregate for concrete, characterized in that the passage rate of m or less is 5 to 15%.