JP2824131B2 - Granulated blast furnace fine aggregate - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to fine aggregate for concrete and mortar.

Prior art In recent years, the use of sea sand and mountain sand has tended to increase due to the depletion of river sand and the regulation of extraction as fine aggregate for concrete and mortar. In addition, there is a problem that the transportation cost increases to transport to the inland area. Regarding mountain sand, for example, when masago, which is weathered residual soil of granite widely distributed in Japan, is used, there is an advantage that it is possible to collect a large amount and reduce the transportation cost when using it inland, but weathering Concrete using sand sand requires a large amount of water in order to obtain a certain consistency due to its weakness due to the large amount of fine powder and high water absorption, etc. Problems such as durability and watertightness and an increase in the amount of unit cement are caused.

Problems to be Solved by the Invention As described above, the sand absorption is high in water absorption, stability loss weight, and washing loss weight, and the fine powder of 0.15 mm or less and the coarse particles of 2.5 to 5 mm are very large and the particle size distribution is also large. It has the quality of being biased.

An object of the present invention is to improve the quality of such sand, to reduce the unit water volume and to improve the strength.

Means for Solving the Problems The present invention provides an inexpensive granulated crush (hereinafter simply referred to as granulated) as a by-product when producing pig iron, a low water absorption rate, a low stability loss weight and a low washing loss weight, and a particle size distribution. The present invention is intended to achieve the above object by obtaining a fine aggregate obtained by mixing fine particles with a quality of 0.3 to 2.5 mm having a large intermediate particle size.

That is, the granulated blast furnace fine aggregate of the present invention
40 to 60%, preferably 50%.

The present inventors, in the granulated earth sand substitute AE concrete using AE agent, by changing the replacement rate of granulation used for fine aggregates with constant unit water volume etc. (this is hereinafter referred to as the same blend), As a result of the slump test, as shown in FIG. 1, it was found that the slump significantly increased when the water cement ratio was 45%, 55% or 65%, and the water granulation replacement ratio was up to 50%. As shown in Table 1, when the slump increases and the water granulation replacement rate is 50%, the workability is improved and the slump is increased because the particle size distribution from 0.3 to 5 mm is almost uniform. it is conceivable that.

The present inventors then increased or decreased the unit water amount so as to obtain a target slump of 8 ± 1 cm and a target air amount of 6 ± 1% at each of the water granulation substitution rates (this is hereinafter referred to as “adjustment blending”). Fig. 2 shows the relationship between the water granulation alternative rate and the unit water volume of the granulated sand-mass earth AE concrete. As can be seen from the figure, the unit water volume decreased the most when the water granulation replacement ratio was 50%, and decreased by about 20 kg / m ³ when the water cement ratio was 45% and the water granulation replacement ratio was 50%. This is considered to be due to the remarkable improvement of particle size by substituting granulation and the extremely low water absorption of granulation, which improved the consistency of granulated sand-sand substitute AE concrete.

The compressive strength of concrete is determined by increasing the cement space ratio determined by the following formula within the range where the amount of air contained in the concrete is constant and the aggregate strength does not affect the concrete strength (within 410 kg f / cm ² strength). Can be enhanced.

C: Absolute volume of cement V: Void formed in concrete Table 2 shows the relationship between the cement space ratio and compressive strength with the same and adjusted blending.

The present inventors also used a Los Angeles test machine as a granulator to substitute for sand sand, used a granulator processed by turning 10 rpm into 10 steel balls and rotating at 250 rpm. However, the grain shape was improved, the fluidity was improved, and the compressive strength of the concrete using the raw water granulation was increased. This is presumably because the water granulation was crushed and the specific surface area was increased, and the adhesive strength of the cement paste was increased.

FIG. 3 shows the relationship between the cement water ratio and the compressive strength of the granulated sand substitute AE concrete using unprocessed water granulation and the above-mentioned processed water granulation.

In addition, since granulated granules replaced with sand sand originally do not require the use of a delayed-type high-performance water reducing agent, the delayed-type high-performance water reducing agent is added excessively with the increase in the rate of water granulation replacement, and the first flocculation occurs. Time and closing time tend to be delayed. Therefore, it is necessary to reduce the amount of the delayed-type high-performance water reducing agent or to use a standard-type high-performance water reducing agent with an increase in the water granulation replacement ratio.

Although the embodiment has been described as a fine aggregate for concrete, it goes without saying that the same effect can be obtained by using the fine aggregate for mortar.

Effect of the Invention As described above, the fine aggregate for concrete and mortar of the present invention replaces water granulation on masago by 40 to 60% and improves the particle size. By using this, the workability of concrete is improved. It can improve the unit water amount as well as the strength.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the water granulation substitution rate and slump.
Figure 2 is a graph showing the relationship between the water granulation replacement rate and the unit water volume,
FIG. 3 is a graph showing the relationship between the cement water ratio and the compressive strength of processed and unprocessed water granulation.

Claims (3)

(57) [Claims] 1. Granulated blast furnace fine aggregate obtained by substituting 40-60% of granulated slag as a by-product generated when pig iron is produced in masago. 2. The granulated blast furnace fine aggregate according to claim 1, wherein the granulated slag replaced with the masago is 50%. 3. The granulated blast furnace fine aggregate according to claim 1, wherein the granulated slag is processed to increase the specific surface area.