JP2008050189A - Ready mixed concrete sludge regenerating method and regenerated material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that ready-mixed concrete sludge shows strong alkalinity (pH12.5) and is discharged in a large quantity of about 3,000,000 m<SP>3</SP>/year all over the country and almost carried in a controlled type disposal site to become one of causes of bringing pressure on the remaining capacity of the disposal site, for example in Kagoshima prefecture who does not have sufficient disposal facility, the sludge is difficult to be disposed and regenerated. <P>SOLUTION: In the regeneration of the ready-mixed concrete, the ready-mixed concrete sludge is recovered and cement, water and crushed stone are added thereinto to be kneaded to produce regenerated ready-mixed concrete. The regenerated ready-mixed concrete is cured and hardened in a molding flask and the solidified concrete is crushed and/or pulverized to form a regenerated mixing material having a particle diameter equal to or below a prescribed particle diameter. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to the treatment and recycling of raw consludge discharged during the production and distribution of ready-mixed concrete.

Raw consludge is an industrial waste exhibiting strong alkalinity (pH 12.5), and is sludge composed of raw concrete and washing water from mixer trucks and return concrete remaining during delivery on site. The ready-mixed concrete sludge are those very large amount discharged annually 3,000,000 m ³ about the country.

  Since raw consludge is required to be disposed of in a managed-type disposal site as it is, there is a problem of pressing the remaining capacity of the disposal site. In Kagoshima Prefecture, there is currently no managed disposal site in the prefecture, so industrial waste is being discharged outside the prefecture.

  Even in areas with managed disposal sites, there are many areas with a residual volume of 2-3 years. Even when constructing a new disposal site, it is difficult to secure a future disposal site due to the opposition of local residents and due to environmental considerations.

  Therefore, a processing method for separating and reusing the aggregate from the remaining ready-mixed concrete has been developed (for example, Patent Document 1).

  Furthermore, using a high alkalinity exceeding pH 12 of concentrated sludge water, it is mixed with a blast furnace slag material that can be expected to be hydraulic due to alkali stimulation in a batch pulverization mixer, and has the same hydraulic property as cement and high viscosity. An active slurry was obtained and kneaded into ready-mixed concrete to increase its separation resistance, and the ready-mixed concrete was recycled (for example, Patent Document 2).

  Also, in the recycling method of ready-mixed concrete residue generated when washed with a transport vehicle or a plant mixer in a ready-mixed plant, gravel, sand, cement hydrate and cement hydrate can be reused. It was not possible to use it. However, a method for reclaiming fresh concrete washing residue has been developed that can easily wash the concentrator, continuously concentrate sludge water, and install equipment relatively inexpensively. (FIG. 4) (for example, patent document 3).

JP-A-6-134748 JP-A-7-328695 JP-A-9-57737

  The present invention is a sludge exhibiting strong alkalinity (pH 12.5), which is obtained by solidifying and stabilizing raw consludge which was mostly brought into a managed disposal site, and further known crushers and batch mixers (For example, JP-A-2004-130276) and a classifier (sieving machine) or the like is used to change the properties into a reusable crusher run that can be used as a roadbed material, a base material, and a pipe protection material.

  This makes it possible to recycle the raw consludge that has been disposed of in the past as a resource, and to extend the remaining years of the disposal site.

That is, the present invention changes the property that can be effectively used as a reclaimed crusher run that can be used as a roadbed material etc. in a simple process (Fig. 1), with a large amount of landfilled raw consludge discharged annually (3 million m ³ ). The purpose of this project is to recycle raw consludge that was previously disposed of in landfills as resources, and to extend the remaining years of the disposal site.

In order to solve the above problems, the present invention
First, recovering ready-mixed sludge, adding cement and water and crushed stone to this to produce recycled ready-mixed concrete, curing it in the mold, and further solidifying it,
A raw consludge regeneration method characterized by forming a regenerated cut material having a grain size equal to or smaller than a treated particle size by crushing and / or pulverizing this,
Secondly, the raw cutting sludge reclaimed material used for the roadbed material, foundation material or pipe support material having a particle size of 30 to 40 mm or less as the reclaimed cutting material according to the first invention,
Consists of.

  Accordingly, cement, water and crushed stone are added and kneaded to this without throwing away the raw consludge, put into the mold, cured and hardened, further solidified, and then crushed and crushed with a crusher to produce roadbed materials, etc. By selecting a cutting material having a particle size equal to or smaller than that, a roadbed material, a base material, or a supporting plate material for an embedded pipe can be obtained.

  Specific civil engineering support board materials that use raw conslag as it is, harden and solidify by adding appropriate amounts of cement, water, and crushed stones, crush them, and compact the undercuts to the required strength by rolling. And industrial waste can be significantly reduced.

  The raw concrete sludge (sludge) discharged and accepted from the raw concrete factory is solidified (coagulated) by the procedure shown in FIG. The raw consludge is weighed together with water, cement and crushed stone according to the formulation shown in Table 1 and kneaded with a mixer.

The blending of each material at this time is appropriate so as to obtain a uniaxial compressive strength of 8 N / mm ² that can be converted from managed disposal to stable disposal after solidification (solidification) while having good workability. To be determined.

  The kneaded material is put into a mold, cured and cured and solidified.

  The kneaded raw consludge mixture is poured into a mold and molded, and solidified (cured and solidified). After a sufficient curing period (about 1 week) to obtain the required strength, the material is crushed and adjusted to a particle size of 30-40 mm or less with a vibrating screen or the like to obtain a regenerated cut material. The cut material refers to a mixture of all undersize (under) particles having a certain particle size (for example, 30 to 40 mm) or less or a mixture of large and small particles selected by a screen.

  In this example, two types of products, “RC-30” and “RC-40”, which are reclaimed crusher runs conforming to “Plant Recycled Pavement Technical Guidelines”, were manufactured.

The uniaxial compressive strength after curing exceeded 8 N / mm ² as shown in FIG. 2 and was sufficiently secured. In addition, as shown in Tables 2 and 3, the particle size distribution is within a predetermined range in any of the products “RC-30” and “RC-40”, and the modified CBR, plasticity index, and wear loss are also reduced. Meets the criteria for a reclaimed crusher run.

  From the above, it was shown that the product manufactured in the present invention can be used as a reclaimed crusher run specified in the “Plant Reclaimed Pavement Technical Guidelines”.

  The apparatus used for kneading in this embodiment can be a mobile solidification apparatus. This device is equipped with a material storage and supply device, weighing device, mixer and discharge device, and can be operated fully automatically by computer control, and the whole is compactly configured and moved on the vehicle. Can do. For this reason, on-site treatment and solidification are possible at the production site of raw consludge.

  In addition, Kagoshima Prefecture has already received permission for the acceptance and recycling of raw consludge.

  As described above, it is not necessary to landfill raw consludge (sludge) generated in large quantities in a managed disposal site, and re-solidified by simple mixing, kneading, molding, and curing to a certain particle size or less to form a recycled crusher run It can be effectively reused as a rolling base material for civil engineering.

It is process drawing of the raw consludge reproduction | regeneration method of this invention. It is a compressive strength test table | surface of a reproduction | regeneration cutting material. It is a conventional raw consludge treatment process diagram. It is process drawing of the conventional processing method.

Claims (2)

Collecting raw consludge, adding cement, water and crushed stone to this to produce recycled ready-mixed concrete, curing and curing it in the mold, and further solidifying it,
A raw consludge regeneration method, characterized by forming a regenerated cut material having a grain size equal to or smaller than a predetermined particle size by crushing and / or crushing the product. A raw consludge reclaimed material used as a roadbed material, foundation material or pipe support material having a particle size of 30 to 40 mm or less.

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