JP2003192409A - Method for producing granular construction material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a material which has a strength suitable for application conditions by regenerating powder after removing sand and gravel from sediment as granule having a particle size larger than the sediment. <P>SOLUTION: Cement type solidifying material, reinforcing material and water are mixed to mud of rocky powder. The mixture is deaerated by vacuum suction, is cured and is hardened. The hardened material is pulverized to granule and is classified by every size of particles. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of utilizing fine rocky powder generated when procuring aggregates as a construction material, not as a waste but as a recycled resource. The present invention relates to a method for producing a granular construction material in which rocky powder is regenerated into particles having a large particle size that can be used for aggregate, roadbed crushed stone, and the like.

[0002]

2. Description of the Related Art In the fields of construction and civil engineering, it has become increasingly difficult to procure fine aggregates and coarse aggregates used for concrete in recent years. Currently, the use of sea sand is greatly restricted due to the problem of corrosion of reinforcing bars, and sand and gravel larger than that are procured by cutting down the earth and sand from a mountain etc. This is the current situation.

[0003]

When sand, gravel, or the like is taken out from the earth and sand, components such as fine particles having a smaller particle size than that remain. In reality, sand and sand are washed with water to separate the sand and gravel, and finer particles smaller than that are flocculated and deposited in water to form a mud. Actually, this is further mechanically solidified with a filter press to dehydrate the water into a form called a dehydrated cake, and this dehydrated cake was not used as a material but was discarded as waste at present. is there. At present, a large amount of this so-called dehydrated cake is produced, and the actual situation is that disposal of the cake requires a large amount of money. In addition, as the demand for effective use of resources is exclaimed, the desire to regenerate the fine rocky powder contained in the dehydrated cake is increasing day by day.

Natural sand and crushed stone have high compressive strength, and if only natural sand and crushed stone were used, they were not always suitable as materials. For example, crushed stone is laid as the upper layer of roadbed and octopused, compacted with tamper, roller, etc. to considerably increase the strength and support the vertical load, but only natural crushed stone with high compressive strength is sufficient. There was a case that it could not be compacted. If the strength of each crushed stone is high, the stone will not deform even when compacted, and the pointed parts of the stone will hit each other, forming a compacted layer with many voids. It is understood that a large amount of voids makes it impossible to obtain a large load bearing performance, and the high strength of individual particles does not necessarily improve the overall performance. For this reason, not only natural crushed stones but also particles with lower strength than this are mixed to crush or deform the low-strength particles that have fallen between natural crushed stones. It is reduced and the solidification progresses, and it becomes possible to perform better compaction. For this reason, it has been desired to develop a granular construction material which is lower in strength than natural crushed stone, and whose strength can be appropriately adjusted depending on the construction site or the situation at the site and which replaces crushed stone.

If the stone is a natural stone, the strength will not be further increased after the construction. This is because natural stone is not a substance that is being hardened, and it cannot be expected that the performance of roadbeds will be improved after construction. However, if a hardening granular material is used instead of natural stone, the strength performance is improved even after the construction. For example, if a material whose hardening is in progress is used even after being applied to the above-mentioned subbase layer, the strength is low during compaction and the compaction of the layer can be achieved by compaction, and after that, individual particles are hardened. As it progresses, the load-bearing performance of the roadbed is improved, and much greater strength can be expected. in this way,
It has been desired to develop a granular construction material having a completely different hardening progress performance from natural stone.

[0006]

The present invention has been made to solve the above problems, in which fine rocky powder after removing sand and gravel from earth and sand is treated with a hardening material such as cement. An object of the present invention is to provide a method for producing a granular construction material in which kneading and curing are performed, and the strength after curing can be freely adjusted by crushing this, and the curing progresses thereafter, and the strength of roadbed etc. is increased. And

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION A method for manufacturing a granular construction material according to the present invention is a method in which after removing sand, gravel or gravel from earth and sand,
This is a method in which a rocky powder, which is a finer particle substance having a particle size smaller than that, is made into a particle having a particle size larger than that and used as a construction material. Before the powder is taken out, all kinds of general sediment such as mountains, rivers, and hills can be used, and calcareous sediment, volcanic ash sediment, sediment of sediment such as sandstone, and bedrock are on the surface. Earth and sand generated after being weathered nearby for many years,
It doesn't matter what kind. These soils are crushed, rinsed with water, and then screened to separate sand, gravel, gravel, etc. according to size. The rocky powder with smaller particles than the separated sand etc. is washed away with water and becomes mud. This mud is regenerated into particles with a larger particle size. In fact, water is often dehydrated to some extent to form a cake cake.

A cement-based solidifying material, a reinforcing material mainly composed of inorganic particles and water are added to the mud and kneaded. In fact, mud is often in a state called dehydrated cake that is dehydrated into a lump. As the cement-based solidifying material, ordinary Portland cement, early-strength cement, blast furnace cement, etc. are used, but at the same time, industrial waste such as fly ash and foundry ash is also adopted as the cement-based solidifying material for Portland cement, etc. In addition, it is included in the weight of the solidifying material. In order to increase the compressive strength of the granules to be produced, basically, the mixing ratio of the cement-based solidifying material may be increased, and it is preferable to select it in the range of 10 to 40% of the total weight. As the reinforcing material, it is possible to employ mineral particles such as mineral waste such as slag and foundry sand, ceramic waste, and debris that are also industrial waste. Other natural waste such as crushed stone, natural sand, and artificial sand can also be used.
This can also contribute to the recycling of these industrial wastes. The reinforcing material enhances the strength of the powder and stabilizes the strength like concrete aggregate. The reinforcing material is preferably larger than the strength obtained by the granules produced by the present invention, and is 200% of the strength of the granules.
Having the above strength makes the quality of the product reliable.

The mixture prepared by adding the cement-based solidifying material, the reinforcing material and water and kneading the mixture is deaerated by vacuum suction, cured and hardened. Table 1 shown below shows the results of experiments conducted by changing the mixing ratio of the materials, and the mixing ratio of the cement-based fixing material was selected from 10 to 40%. I also selected the type of reinforcing material and measured the strength of each. In Table 1, FA is fly ash,
SS is slag (5 mm or less), SG is slag (13 mm)
Below), IS indicates foundry sand, IA indicates foundry ash, and W of compressive strength indicates which week (week). The result of this experiment shows that the mixing ratio of cement-based solidifying material is 1
When increasing in the range of 0 to 40%, the compressive strength gradually increases, and that is, the strength increases almost in proportion to the mixing ratio. However,
It is also true that increasing the mixing ratio of the cementitious solidifying material will increase the cost, and as one of the objects of the present invention, depending on the construction site or construction situation, freely adjust the compressive strength of the required granules. , The construction cost may be kept to the minimum necessary without using extra solidifying material. For example, granules used for sidewalk subgrades that do not require too much strength do not have any problem even if the strength is a little low, and are manufactured by suppressing the mixing ratio of the cement-based solidifying material to have the necessary minimum strength. is there. This makes it possible to carry out construction at low cost. This is possible by not using natural stone, but by hardening the rocky powder with a cement-based solidifying material.

[0010]

[Table 1]

The mixture is degassed by vacuum suction, which also dramatically increases the compressive strength of the granules. In Table 1 above, what is indicated in parentheses in the item of compressive strength is one that is cured and cured without vacuum suction, and the strength is approximately 2.5 when vacuumed and degassed. Understand that it will almost double. A graph showing the relationship between the presence or absence of this deaeration process and the level of compressive strength depending on the mixing ratio of the cementitious solidifying material is shown in FIG.
It can be understood from this graph that when degassing by vacuum suction is performed, the compressive strength is between 2 times and 2.5 times that of the experiment without vacuum.
Also, it can be understood that the compressive strength increases proportionally by increasing the mixing ratio of the cementitious solidifying material. Thus, it can be understood that the strength of the product having the required compressive strength can be predicted almost accurately by increasing or decreasing the mixing ratio of the cement-based solidifying material.
In other words, instead of examining and selecting the compressive strength of the finished product, by adopting the manufacturing method of the present invention, the compressive strength of the granules to be manufactured can be predicted at the design stage, and the minimum required It can be understood that it can be manufactured by procuring materials and costs.

The hardened mixed material is crushed by a crusher to obtain a granular construction material. The crusher type, performance, and crushing time are appropriately selected according to the size of the granules, and the particle size is adjusted to a certain size. The particles are screened and screened according to the size of the particles to sort. If a powder with a small particle size appears, it can be added to rocky powder again and mixed, and then solidified and pulverized again to form a granule.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the embodiments shown in the drawings. FIG. 2 shows the flow of the manufacturing process according to the present invention, in which rocky powder, cementitious solidifying material, reinforcing material and water are put in the mixer 1 and mixed, stirred and kneaded. Make a mixed material. This is put into the extruder 2 and vacuum-sucked to degas. In this state, it is aged for several days to several weeks and crushed by the crusher 3. The crushed particles having different particle diameters are screened and screened, and the particles are divided into plural particle diameters such as powder, sand, gravel, and gravel.

FIGS. 3 and 4 show an example in which the granular construction material manufactured by the present invention is used for the upper roadbed of the road. The upper roadbed of a roadway receives a large load and requires relatively high strength. In the examples, the granules 5 manufactured with the mixing ratio of the cement solidifying material being 29% are used. The particle size was in the range of 0 to 40 mm, and the compressive strength of only the granules 5 was 12.2 N / mm ² . It has a particle size of 0-40 mm and a compressive strength of 15
It was mixed with crushed stone 6 composed of 0 N / mm ² of natural stone. The weight ratio of the granules to the natural stone was 1: 1. The granules composed of such manufactured granules and natural stones are used as the upper layer roadbed and have a thickness of 150.
laid in mm. When such a roadbed is compacted with a tamper, the roadbed support coefficient immediately after its construction is 23k.
It was possible to obtain g / cm ³ . When only granules made of natural stone were laid and compacted to a thickness of 150 mm, the mass was 18 kg / cm ³ . In other words, it can be understood that the case where the granules manufactured according to the present invention and the granules made of natural stone are mixed and applied, a larger load bearing performance can be obtained as compared with the case where only the granules of natural stone are used.
This is because the granules produced by the present invention are deformed or crushed between the granules made of natural stone, and the granules are solidified. The state before compaction is shown in FIG. 3, but there are many voids between the granules 5 and 6, and FIG. 4 showing the state after compaction shows that the granules 5 produced by the present invention are the same. It can be understood that voids disappeared due to crushing of the sharp parts around the, or cracking or deformation of the particles themselves, resulting in solidification.

In the above-mentioned construction example, the roadbed bearing coefficient immediately after construction was 23 kg / cm ³ , but the result was measured after 4 weeks of construction, and the roadbed bearing coefficient was 2 kg.
It was 8 kg / cm ³ . In other words, the roadbed bearing capacity coefficient was higher after a lapse of time than immediately after construction. This means that the strength of each particle 6 cannot be improved after construction if it is a natural stone, but the particle 5 produced according to the present invention is one in which hardening is in progress due to the cement-based solidifying material, and with the passage of time. It is considered that the strength of the granules 5 themselves increased and the performance of the roadbed itself improved.

Experiments were carried out using the granules according to the present invention in a sidewalk subgrade. The roadbed for sidewalks has a lower load than the roadway and does not require much strength. Therefore, granules produced by mixing 10 parts by weight of the cement-based solidifying material were used. The compressive strength during the production of the granules was 4.5 N / mm ² , and particles having a particle size of 0 to 30 mm were laid in a thickness of 100 mm. No granules made of natural stone are used. When this was compacted, the roadbed supporting force coefficient was dramatically improved from 5 kg / cm ³ of natural stone to 8 kg / cm ³ . It is considered that this is because the granules were deformed or crushed by compaction and became more solid, and when measured 4 weeks later, the roadbed bearing coefficient was 15 kg / cm ^{3 and} the load bearing performance was improved. Was showing.

[0017]

The present invention has the above-mentioned structure and can obtain the following effects. Since rocky powder that cannot be used as sand or gravel can be used as granules by using a cementitious solidifying material like sand and gravel, it is possible to effectively use resources without leaving what was previously discarded. Can be realized, and the problems of the disposal site and costs associated with the disposal can be greatly improved. By changing the mixing ratio of the cement-based solidifying material,
It is possible to manufacture granules with almost the expected strength, and it is possible to freely adjust the granules with the expected strength with the minimum materials and costs, and calculate to keep the manufacturing cost low according to the construction conditions at the design stage. it can. It is possible to manufacture granules with a relatively lower strength than granules made of natural stone by cement-based solidifying material, and by using this granule and mixing it with natural stone for use in roadbeds, etc. It is possible to construct roadbeds with a higher load-bearing performance than the actual ones. It is solidified with a cement-based solidifying material, and the hardening of the granules continues even after the construction, and it can be expected to improve the performance after construction, which cannot be obtained with natural stone.

[Brief description of drawings]

FIG. 1 is a graph showing a relationship between a mixing ratio of a cement-based solidifying material and strength development by deaeration.

FIG. 2 is an explanatory diagram showing a manufacturing process.

FIG. 3 is a cross-sectional view of a roadbed before compaction using the granules and natural stone manufactured according to the present invention.

FIG. 4 is a cross-sectional view of the roadbed after being compacted by rollers.

[Explanation of symbols]

1 mixer 2 extruder 3 crusher 4 screen 5 Granules produced by the present invention 6 Natural stone granules

Claims (4)

[Claims] 1. A mud consisting mainly of fine rocky powder after removing sand and gravel from the earth and sand is kneaded together with a cement-based solidifying material and a reinforcing material mainly consisting of inorganic particles and water. A method for producing a granular construction material in which a mixture is deaerated by vacuum suction to be cured and cured, and then pulverized to be granular. 2. The compression ratio after curing is adjusted by appropriately selecting the mixing ratio of the cementitious solidifying material from 10 parts by weight to 40 parts by weight in the total weight. Manufacturing method of granular construction materials. 3. The method for producing a granular construction material according to claim 1, wherein the reinforcing material is selected from an inorganic waste granular material having a strength of 200% or more of the cured construction material. 4. The production of granular construction material according to claim 3, wherein one or more materials are selected from the industrial waste particles such as fly ash, slag, and foundry sand as the reinforcing material. Method.