JPH10226556A - Concrete - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the concrete, etc., without the fluidity and its strength after curing being significantly decreased by using the molten slag produced by melting such waste as sewage sludge incineration ash as the fine aggregate and to furnish a waste utilizing concrete more effective than before by stably using a large amt. of waste also in a coarse aggregate and in the material other than the aggregate. SOLUTION: The molten slag produced by melting at least one kind among city refuse, city refuse incineration ash and sewage activated sludge incineration ash, and the cinder ash generated by the combustion of pulverized coal are used as a fine aggregate, and both are mixed in 30:70 to 70:30 weight ratio of the former to the latter to produce mortar or concrete. In this case, clinker ash as the waste generated when coal, etc., are burned is used as the coarse aggregate, and the waste can also be used in the material(cement, cement admixture and water) other than the aggregate. The total amt. of the waste to be used is preferably controlled to >=1000kg/m<3> and limited to the extent that the fluidity and strength of the ordinary concrete are attained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mortar or concrete using a material derived from waste for a part or all of constituent materials, and a technique for manufacturing the same.

[0002]

2. Description of the Related Art From the viewpoint of effective utilization of resources, many attempts have been made to use various wastes as cement / concrete materials. Garbage incineration plants, thermal power plants,
Concrete that uses slag obtained by melting incineration ash discharged from sewage treatment plants etc. for fine aggregate or coarse aggregate,
This is one example. But these concretes are sand,
There is a drawback that the fluidity is extremely poor as compared with concrete using ordinary aggregate such as gravel.

In these methods, concrete 1
m ³ waste origin of usage at most 50 material per
It is only about 0kg, and from the viewpoint of effective use of waste,
It was not enough technology.

[0004]

As described above, concrete using conventional incinerated ash slag as an aggregate has a remarkably poor fluidity as compared with concrete using ordinary aggregates such as sand and gravel. There were drawbacks. The present invention has been made in the course of research for solving this drawback.

[0005] The slag produced by melting the incinerated ash of municipal garbage and sewage sludge is divided into granulated slag, which is formed by being poured into water and then rapidly cooled, and granulated slag, which is gradually cooled in air. There is an air-cooled slag that is used. The particle size distribution of these slags fluctuates greatly depending on conditions such as the material, the melting method, and the cooling method, but there are many portions of 1 mm or more. May contain oversized particles. In particular, the air-cooled slag is pebble-like and has many grains exceeding 10 mm, and cannot be used as it is as fine aggregate.

[0006] The particle size of the molten slag can be adjusted to an appropriate range as a fine aggregate by grinding and sieving. However, even with concrete using molten slag of an appropriate range of particle size as fine aggregate, the unit water volume increases compared to concrete using ordinary sand as fine aggregate, and equivalent fluidity cannot be obtained. Yes, that is already known (Public Works Technical Data Vol. 29, No. 4, 199)
Page).

[0007]

According to the present invention, in order to utilize the above-mentioned problematic molten slag, a part thereof is replaced with cinder ash, which is also waste and is desired to be effectively used. Surprisingly, the present inventors have found that a decrease in liquidity can be avoided, and have solved the above-mentioned problems.

That is, the present invention uses slag and cinder ash produced by melting waste such as municipal garbage, municipal garbage incineration ash, and sewage sludge incineration ash for part or all of the fine aggregate, or in addition to this. Mortar or concrete is manufactured using clinker ash for part or all of the coarse aggregate, and the obtained mortar or concrete is
It is an object of the present invention to provide a material which has less decrease in fluidity and strength after hardening as compared with that using ordinary aggregates such as sand and gravel, and is of a practically acceptable degree. That is, it is an object of the present invention to provide a mortar or concrete having the same fluidity and strength as the case where ordinary aggregate is used, even though aggregates derived from waste are used. Furthermore, in the present invention, various kinds of wastes are used in a large amount and stably for materials (cement, cement mixture, water) other than aggregates, and more effective waste recycling than conventional waste-based concrete. It provides a method.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, there are two types of molten slag, granulated slag and air-cooled slag, and both can be used in the present invention. In the case of granulated slag, the particle size is close to the particle size range of the fine aggregate, so that it can be used as it is. However, the incorporation of particles exceeding the particle size range, especially fine powder, is inevitable.
It is desirable that the particle size of 90% by weight or more is in the range of 0.15 to 10 mm. In the case of air-cooled slag, as described above, since the particle size is larger than the fine particle size range, the slag cannot be used as it is, and is crushed and used in the range of fine aggregate. Also in this case, as in the case of the granulated slag, the particle size of 90% by weight or more is 0.15 to 10%.
mm.

[0010] Cinder ash is a type of coal ash generated in a coal-fired power plant, and is recovered from a coal saver and an air preheater. Other types of combustion ash from coal-fired power plants include powder fly ash collected by an electrostatic precipitator and lump clinker ash collected from the bottom of the combustion furnace. Fly ash has a particle size of usually 20 μm or less, which is too small to be used for fine aggregate, but the particle size of cinder ash is several tens μm to several mm, and a part of the particle size is fine aggregate. Within the appropriate range. In addition, although there is an attempt to use Cinder Ash alone as fine aggregate, since water absorption is higher than sand,
The fluidity is worse than concrete using sand (see the 3rd Annual Conference of Concrete Engineering, 69-72).

In the present invention, when used alone or mixed with sand for fine aggregate, molten slag and cinder ash, which have not been able to obtain appropriate fluidity, are mixed at an appropriate ratio. The purpose of this invention is to produce mortar or concrete having almost the same fluidity as concrete using sand as fine aggregate. The molten slag and the cinder ash are desirably mixed in a range of molten slag: cinder ash = 30: 70 to 70:30. The replacement ratio of sand by these is not particularly limited, but from the viewpoint of effective use of waste, if it is less than 20% by weight, it is too low. Therefore, 20% by weight or more is desirable in practical use.

Another feature of the concrete of the present invention is that clinker ash generated from a coal-fired power plant is used as the coarse aggregate. As described above, clinker ash is a lump obtained from the bottom of the combustion furnace of a thermal power plant. When combined with cinder ash, clinker ash accounts for about 70% of the total ash of the power plant. Instead, it was used for landfills. This is pulverized to a particle size in the range of coarse aggregate for use. Fine particles are also generated with the pulverization.
The particle size of 0% by weight or more is desirably 2.5 to 30 mm. In order to adjust the particle size more strictly, it is preferable to use a classification operation such as sieving. The substitution rate of gravel by clinker ash is not particularly limited, as in the case of the above-mentioned sand. However, from the viewpoint of effective utilization of waste, if it is less than 20% by weight, it is too low.
% By weight or more is desirable.

In view of the purpose of using as an aggregate, the particle size is ideally in the range specified in JIS A 5004, etc., 0.15 to 10 mm for molten slag and cinder ash, and 2.15 for clinker ash.
Most preferably, it is 5 to 30 mm.

Further, it is possible to increase the usage ratio of other materials constituting the concrete by utilizing the waste. In other words, to the extent that fluidity and strength after hardening are almost equivalent to mortar or concrete using ordinary aggregates such as sand and gravel, wastes other than molten slag and cinder ash are used. , It is possible to further increase the use ratio. For example, fly ash, concrete sludge, glass cullet, slag fine powder, municipal garbage slag, sewage sludge slag, ceramic waste, clinker ash, concrete waste, waste brick, etc. Wastes that have been reduced in volume by operations such as compression or compression, or that have been treated as such by landfilling, can be used as cement raw materials, cement mixing materials, kneading water, aggregates, etc., to achieve more efficient use of resources. realizable.

From the viewpoint of effective utilization, the total amount of waste is desirably higher, and is preferably 8 per m ^{3 of} concrete.
It is preferably at least 00 kg, more preferably at least 1000 kg / m ³ (50% by volume when the density of concrete is 2.0 g / cm ³ ). However, the total amount used is not unlimited for the purpose of the present invention, and the flowability and strength are almost in the same range as in the case of concrete using sand or gravel as an aggregate. That means to some extent. The permissible range for the above-mentioned equivalent fluidity and strength is, in the case of concrete, a fall of a slump value within about 30 mm of a concrete obtained from the practical use of ordinary aggregate. In the case of mortar as well, the flow value obtained when ordinary aggregate is used is reduced within 20 mm. For the same reason, in the case of concrete, the 28-day strength obtained when ordinary aggregate is used is reduced within about 5 MPa (megapascal) for the same reason, and the same is true for mortar.

[0016]

EXAMPLES Table 1 shows the measurement results of the flow of mortar using molten slag and cinder ash as aggregates. Molten slag is granulated slag obtained by melting city garbage incineration ash in a burner type melting furnace and quenching with water. Cinder ash is JIS A6201 by a classifier from coal combustion ash from a thermal power plant.
The residue excluding fly ash conforming to (concrete fly ash) was used. JIS standard sand was used for comparison. The test was based on JIS R 5201 (physical test of cement), with a water cement ratio of 0.65 and an aggregate cement ratio of 2.0, and ordinary cement was used as the cement.

[0017]

[Table 1]

The flow value is 209 mm when using only molten slag (No. 2), 213 mm when using only cinder ash (No. 3), and 213 mm when using standard sand (No. 1 and 2). 248 mm) are smaller by 39 mm and 35 mm, respectively. However, when a mixture of the molten slag and the cinder ash is used, the flow is increased as compared with a case where the molten slag is used alone. When the mixing ratio is 25:75 (No.
4, no. In 6), the flow improvement effect is small,
% (240%) when mixed (No. 5)
The difference from the standard sand is reduced to 8 mm.

The effect of the mixing ratio of the molten slag and the cinder ash to the sand was as follows: molten slag: cinder ash = 5
In the case of 0:50, the mixing ratio with respect to sand is 20% (No.
7), 50% (No. 8), and 80% (No. 9), there is not much difference in the flow, but from the viewpoint of effective utilization of waste, the mixing ratio is desirably 20% or more.

The measurement results (sample Nos. 2, 3, 4, 5, and 6) when the standard sand content is zero are shown in FIG. 1 as shown in the drawing. Using this figure, the mixing ratio of molten slag and cinder ash was 70: 3, respectively.
When the flow values of 0 and 30:70 are obtained, both are 22
8 mm, which is about 20 mm lower than the flow value in the case of 100% standard sand. However, this is within the range of the decrease in the fluidity (flow value) permitted by the present invention, and such a decrease is practically acceptable, and the mixing ratio of molten slag and cinder ash is 7
It can be seen that predetermined properties are shown within the range of 0:30 and 30:70.

Table 2 shows the test results of concretes A and B using various waste-derived materials. The materials used for the test concrete are as follows. A Cement: ordinary cement Fine aggregate: municipal incineration ash molten slag, cinder ash (1: 1 mixture) Coarse aggregate: clinker ash Kneading water: tap water B cement: 50% fly ash in ordinary cement
Mixed fine aggregate: Municipal garbage incinerated ash molten slag, Cinder ash (1: 1 mixture) Coarse aggregate: Clinker ash Kneading water: Fresh concrete sludge recovered water C Cement: Normal cement Fine aggregate: River sand Coarse aggregate: Crushed stone Kneading Water: tap water

[0022]

[Table 2]

In concrete A, molten slag and cinder ash were used for fine aggregate, and clinker ash was used for coarse aggregate. Clinker ash is obtained by crushing the bottom ash of a coal burning furnace of a thermal power plant to adjust the particle size. In the concrete B, a cement mixed with 50% of fly ash and recovered water of ready-mixed concrete sludge were used. Table 2 also shows, as a comparison, test results of concrete C using a normal material.

The following can be seen from this table. In other words, the physical properties of the waste concrete A are slightly higher than those of the concrete C using a normal material in order to obtain the same slump, and the unit water volume is slightly larger, and thus the strength is slightly lower. Having. Concrete B has a greater unit water content and lower strength than concrete A, but is sufficient as practical concrete. Also, from this table, the degree of decrease in compressive strength of concrete utilizing waste is calculated in comparison with ordinary concrete, and it is about 3 MPa even for concrete B, which has a larger decrease. This is within the range of the above-mentioned permissible reduction in strength (5 MPa). At this level of reduction, the concrete has sufficient practicality. That is, it is almost in the same range as ordinary concrete.

[0025]

According to the present invention, by using a combination of a molten slag and a cinder ash in a predetermined ratio for the aggregate, the flowability and the strength decrease are surprisingly small, and are substantially the same as those in the case of using the ordinary aggregate. Was able to express the fluidity and strength. Also, when a large amount of various waste-derived materials such as aggregates are used, the produced concrete etc. has almost the same fluidity and strength as when using ordinary aggregates such as natural sand and gravel. As a result, it is possible to produce concrete using a large amount and stably of various waste-derived materials, which greatly contributes to effective use of resources.

[Brief description of the drawings]

FIG. 1 illustrates a relationship between a mixing ratio of molten slag and cinder ash and a mortar flow value.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Daisuke Sawaki 2-1-1 Tsukimi-cho, Kumagaya-shi, Saitama Chichibu Onoda Co., Ltd. Central Research Laboratory

Claims (5)

[Claims] 1. A molten slag produced by melting at least one kind of waste such as municipal garbage, municipal garbage incineration ash, and sewage sludge incineration ash as fine aggregate, and Cinder Ash generated by combustion of pulverized coal. And the mixing ratio (weight ratio) of molten slag and cinder ash is 30:70 to 70:
A mortar or concrete using an aggregate derived from waste, characterized by being 30. 2. The method according to claim 1, wherein the particle size of 90% by weight or more of the molten slag is 0.15 to 10 mm, and the particle size of 90% by weight or more of the cinder ash is 0.15 to 10 mm. Mortar or concrete. 3. The mortar or concrete according to claim 1, wherein clinker ash generated by burning coal or the like is used as the coarse aggregate. 4. The mortar or concrete according to claim 1, wherein the particle size of 90% by weight or more of the clinker ash is 2.5 to 30 mm. 5. A material derived from waste is also used as a constituent material (cement, cement mixture, water) other than the aggregate, and the total amount of the material derived from waste is 1000 kg or more per 1 m ^{3 of} mortar or concrete. The mortar or concrete according to claim 1, 2, 3, or 4, wherein