JP2008036532A - The effective use method for construction sludge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve an inexpensive solidifying treatment and a utilization technique by excluding dewatering treatment using a dewatering treatment apparatus, reducing the amount of cement for use in cement solidification and using low-cost cement when high-water content construction sludge is effectively used. <P>SOLUTION: To adjust the water content of the high-water content construction sludge, a roof tile-crushed rubble which is one of construction waste materials having a high water absorption performance and is not established with a treatment method is mixed. The grain size of the roof tile-crushed is adjusted at 40 mm or smaller. The mixture of the construction sludge and the roof tile-crushed is loaded with cement as a solidifying agent. Normally, Portland cement can also be used. However, an inexpensive treatment can be performed by applying Portland blast furnace cement. Further, a blend ratio of cement can be reduced down to not more than 20%. After loading and mixing treatment, it is aged in heaps. Thereafter, it is crushed into a size enough for utilization as a material for civil engineering/construction. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for effectively using construction sludge.

  The conventional method of effectively using construction sludge is a method of mixing only concrete shell and cement with construction sludge, drying the kneaded mixture, crushing the dried kneaded mixture and using it as roadbed material (for example, , Patent Document 1), obtained by dehydrating cake obtained by dehydrating construction sludge, granulating by adding a solidifying agent made of cement, water and additives and kneading, curing, drying and classification A method of using a granulated product in a predetermined particle size range as a recycled crusher or recycled particle size-adjusted crushed stone by mixing with a crushed concrete shell (for example, see Patent Document 2), including bentonite sludge or sewage The construction sludge, the solidifying agent, and the crushed stone are mixed and agitated to solidify the construction sludge, and after curing for a predetermined period, use it as civil engineering / construction materials or recycled soil ( In example, see Patent Document 3), and the like.

  Hereinafter, a conventional technique will be described. In the method of Patent Document 1, only concrete shell and cement are mixed with construction sludge, the mixed material is dried, and the dried mixed material is crushed to obtain a roadbed material. The concrete shell obtained by crushing concrete waste is preferable because it has a large surface area and good water absorption. When ordinary cement is used, the blending ratio is construction sludge 100: concrete shell 90-110: cement 40-60. When the particle size after crushing is 0 to 30 mm or 0 to 40 mm, the compressive strength necessary as a roadbed material is obtained, and the workability is also improved.

  In the method of Patent Document 2, granulation is performed by adding a solidifying agent made of cement, water and additives to a dehydrated cake obtained by dehydrating construction sludge and kneading, and the resulting granulated product is submerged in water. After drying for a certain period of time, drying, and classifying the granulated product after drying, the granulated product of a predetermined particle size range obtained by classifying the granulated product after crushing the concrete shell It is the method of utilizing as a reproduction crusher run and / or reproduction particle size adjustment crushed stone by mixing with.

In the method of Patent Document 3, the construction sludge (X) containing bentonite sludge or sewage, the solidifying agent (Y), and the crushed stone (Z) are converted into X: Y: Z = 10: 1 to 2: By mixing and stirring at a weight ratio of 1 to 2, the construction sludge is solidified, cured for a predetermined period, and then used as a civil engineering / construction material or reclaimed soil. A solidifying agent containing 13 to 16% by weight of silicon dioxide, 7 to 9% by weight of sulfur trioxide and 4 to 6% by weight of aluminum oxide is used. The obtained sludge solidified product is a method of crushing to a required size so that it can be used as civil engineering / construction material or recycled soil after curing for a predetermined period.

JP 2003-342902 A JP 2003-33798 A Japanese Patent Laid-Open No. 10-244297

  In the conventional method described in the above-mentioned Patent Document 1, in the case of high water content construction sludge, it is impossible to adjust the moisture only by charging the concrete shell, and the blending ratio is construction sludge 100: concrete shell 90-110. : Cement is 40 to 60, and the amount of cement is large, resulting in a high-priced roadbed material. In the method described in Patent Document 2, it is indispensable to dewater the construction sludge using a dewatering device. In the method described in Patent Document 3, construction sludge, a special solidifying agent, and crushed stone are mixed. In the case of high water content construction sludge, it is impossible to adjust the moisture only by adding crushed stone.

  The present invention seeks to solve the problems of such a conventional configuration, omits the dehydration process using the dehydration apparatus, uses a small amount of cement, and an inexpensive cement. The purpose is to realize low-cost processing and utilization technology.

  The present invention has been variously studied to achieve the above object. It was decided to mix materials with high water absorption capacity to adjust the water content of high water content construction sludge. In the case of the concrete shell described in Patent Document 1, some effects were recognized in the low water content construction sludge, but some dehydration treatment was indispensable in the high water content construction sludge. As a result of various investigations, it has been found that the object of the present invention can be achieved by mixing a kind of construction waste material, and a tile crushing shell whose processing method has not been determined.

  The first problem solving means has found that one of the objects of the present invention can be achieved by adjusting the particle size of the above-mentioned tile crushing shell to 40 mm or less. In addition, the second problem solving means has found that one of the objects of the present invention can be achieved by applying blast furnace cement as cement. Furthermore, the third problem solving means has found that one of the objects of the present invention can be achieved by setting the cement blending ratio to 20% or less.

  The operation of the first problem solving means is as follows. That is, the high water content construction sludge contains 50 to 99% of water. The water absorption capacity of the tile crushing shell whose particle size is adjusted to 40 mm or less is 2 to 3 times the water absorption capacity of the concrete shell described in Patent Document 1. This value can be used as a moisture adjusting material.

  The operation of the second problem solving means is as follows. That is, in the present invention, it is possible to use a solidifying agent such as ordinary Portland cement, but by using a cheaper blast furnace cement, it is possible to perform low-cost processing.

  Further, the operation of the third problem solving means is as follows. That is, in the present invention, by using a blast furnace cement which is less expensive than a solidifying agent such as ordinary Portland cement and the blending ratio thereof is 20% or less, it is possible to further reduce the cost.

  As described above, the construction sludge effective utilization method of the present invention eliminates the dehydration process using the dehydration apparatus, uses an inexpensive cement, and provides a low-cost treatment and utilization technique with a small amount of cement. it can.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples. In addition, the ratio of the mixing | blending component in each case is represented by the mass%.

  A highly crushed construction sludge stored in a concrete storage tank having a length of 3 m, a width of 5 m, and a depth of 2 m was charged with a tile crushing material adjusted to 40 mm or less, and mixed and stirred using a construction machine. In addition, 99% of water was contained in said high water content construction sludge, and the mixing ratio was 200 weight part of tile crushing shells with respect to 100 weight part of high water content construction sludge. Next, it was put into a hopper using a construction machine, conveyed from below to a mixer by a belt conveyor, and kneaded while adding ordinary Portland cement. Then, it discharged using the belt conveyor under a mixer. The amount of cement added was 20% of the total amount of construction sludge and tile crushing shell.

  The above effluent was cured for 1 week in a pile. After curing, it was crushed to 40 mm or less. The particle size test result according to JIS A1102 “Aggregate screening test method” is shown in FIG. FIG. 1 shows that it conforms to the particle size range of Crusharan 40 mm (C40) defined in JIS A5001 “Crumble for road”. Moreover, the CBR test result by JIS A1211 is shown in FIG. The revised CBR value of 63.3% at 90% compaction in Fig. 2 is the "Pavement Construction Handbook (2006 edition)" published by Japan Road Association, Table 78, Table 5.2.1 "Lower layer roadbed material" The value is 20% or more of the standard value described in “Quality Standards”, and 89.9% of the corrected CBR value at a compaction degree of 95% is shown in Table-5.3.1 The value is 80% or more of the reference value described in “Quality standard of roadbed material”, and Example 1 shows that both upper layer roadbed material and lower layer roadbed material can be used, depending on the degree of compaction.

  Exactly the same as the method described in Example 1, except that the particle size of the tile crushing shell is 25 mm or less, ordinary portland cement is replaced with blast furnace cement, and the amount of cement added is 10% of the total amount of construction sludge and tile crushing shell. Processed. The particle size test results are shown in FIG. FIG. 3 shows that the particle size range of 40 mm (C40) specified by JIS A5001 “road crushed stone” is met. Further, the CBR test results are shown in FIG. 43.0% of the corrected CBR value at a compaction degree of 90% in FIG. 4 is a value that is 20% or more of the standard value described in the above-mentioned “Quality standard for lower layer roadbed material”, and the compaction degree. The corrected CBR value at 95% is 112.8%, which is 80% or more of the reference value described in the above-mentioned “Quality standard for upper-layer roadbed material”, and Example 2 also depends on the degree of compaction. However, it can be used for both upper layer roadbed material and lower layer roadbed material.

As in Example 2, the particle size of the tile crushing shell was 25 mm or less, ordinary portland cement was replaced with blast furnace cement, and the amount of cement added was 5% of the total amount of construction sludge and tile crushing shell. The same treatment as that described in Example 1 was performed. The crushed particle size after curing was set to 10 mm or less to obtain recycled sand. The particle size test results are shown in FIG. The cone index of this reclaimed sand was 2250 kN / m ² . This value is shown in Table 5.3.1, “Soil Classification Criteria for Construction Soil”, in “Soil Test Methods and Explanations (First Revised Edition)” published by the Geotechnical Society of Japan. It is classified into two types of construction generated soil, and application standard such as backfilling of work, road (roadbed) embankment, backfilling of civil engineering structures, embankment for road road bodies, etc. (table on page 270-5.3. According to 2 (a)), the values are classified into those that can be used as they are for all purposes.

  The construction sludge and construction waste tiles that are expected to be used effectively can be used in all quantities and can be used as high-strength roadbed materials. It can also be used as landfill material, which is useful for environmental conservation.

3 is a particle size test result according to JIS A1102 of Example 1. 2 is a CBR test result according to JIS A1211 of Example 1. FIG. 4 is a particle size test result according to JIS A1102 of Example 2. It is a CBR test result by JIS A1211 of Example 2. 4 is a particle size test result according to JIS A1102 of Example 3.

Claims (4)

  Efficient use of construction sludge, characterized by adding and crushing tile crushing shell into high water content construction sludge to adjust moisture, kneading and solidifying cement, crushing and using as roadbed material and landfill material Method.   The method for effectively using construction sludge, wherein the tile crushing shell according to claim 1 is 40 mm or less.   The method according to claim 1, wherein the cement according to claim 1 is a blast furnace cement. An effective utilization method of construction sludge, wherein the blending ratio of the cement according to claim 1 is 20% or less.

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