JP2018094493A - Production method of recycled aggregate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a recycled aggregate, which is a method for producing the recycled aggregate from a concrete waste, the method enabling aggregate to be surely recovered from the concrete waste and enabling high-quality recycled aggregate to be produced.SOLUTION: The production method of a recycled aggregate comprises: a crushing-selection step 1 of performing crushing processing on a concrete waste into a concrete mass of 40 mm or less using a crusher, and removing an iron scrap using a magnetic separator; a kneading step 2 of further performing crushing processing on the concrete mass using a jaw-crusher type concrete mass processing device and kneading the obtained crushed concrete mass, thereby obtaining a crushed material; and a screening step 3 of performing screening processing on the crushed material, thereby obtaining a coarse aggregate of 40-5 mm; and a washing-classifying step 4 of performing water-washing processing and classifying processing on the coarse aggregate.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing recycled aggregate, and more particularly, to a method for recycling concrete waste as a resource, and a method for producing recycled aggregate from concrete waste.

  Conventionally, concrete waste materials generated in the demolition work of structures and the like have been variously recycled as recycled concrete (hereinafter referred to as “RC”). However, in recent years, heavy metal hexavalent chromium contained in cement has been regarded as a problem, and most of the concrete waste has become industrial waste, and only a part of it is used for road backfill. .

  In addition, when RC is used as an aggregate, in addition to the problem of heavy metal hexavalent chromium caused by old structures, there is a problem that cement lump is mixed and the strength is weaker than virgin aggregate. It has been pointed out. This is because the cement lump and deposits absorb water and become brittle. Against this background, an increasing number of local governments are banning the use of RC as aggregates, and in newly constructed structures, cement that does not contain heavy metal hexavalent chromium and virgin aggregates are used. doing. This also contributes to environmental destruction caused by aggregate mining.

  On the other hand, as a technique for recovering aggregate from concrete waste and producing recycled aggregate, a method of pulverizing and sorting concrete waste has been mainly used. For example, in the production of recycled aggregate, concrete waste is crushed with a jaw crusher, and then sorted into sand cement less than 5 mm in diameter and gravel crushed stone greater than 5 mm in diameter using a vibrating sieve. Each of these is subjected to grinding treatment by a grinding machine to separate the mortar from the sand cement and collect the sand, and peel the mortar from the gravel and collect the gravel crushed stone (Patent Documents 1 and 2). In addition, a method for producing a recycled aggregate has also been proposed in which abrasive grains are continuously emitted to a crushed concrete and subjected to grinding treatment to remove the attached mortar (Patent Document 3).

JP 2005-34761 A JP-A-8-245248 JP 2011-111342 A

  By the way, the above-mentioned jaw crusher used for crushing concrete waste is an apparatus originally applied to crushing rocks and ores whose individual hardness is relatively approximate, and has a binding force with a high-hardness aggregate. When concrete waste consisting of cement is crushed with a jaw crusher, the resulting coarse aggregate has a large amount of mortar components attached, and the fine aggregate is agglomerated into mortar granules. Like the technology, it is necessary to further remove the mortar component by performing a grinding process or the like, and in fact, the aggregate cannot be sufficiently recovered from the concrete block. In addition, the so-called sand blasting method of emitting abrasive grains is inefficient and it is difficult to industrially produce a large amount of recycled aggregate.

  The present invention has been made in view of the above circumstances, and an object of the present invention is a method for producing recycled aggregate from concrete waste, which can reliably recover the aggregate from the concrete waste, and has high quality recycled bone. It is providing the manufacturing method of the reproduction | regeneration aggregate which can manufacture a material.

  In order to solve the above problems, in the present invention, after the concrete waste material is crushed to obtain a concrete block, the concrete block is further crushed by using a jaw crusher-type concrete block processing apparatus, The crushed material in which the coarse aggregate, fine aggregate and cement components are separated, in other words, the coarse aggregate, fine aggregate and cement powder with only cement powder adhering to the surface. A mixture was obtained. Then, the crushed material is subjected to a sieving process and a water washing process to regenerate the aggregate.

  That is, the gist of the present invention is a method for producing recycled aggregate from concrete waste material, wherein the concrete waste material is crushed into a concrete block of 40 mm or less by a crusher and the iron scrap is removed by a magnetic separator and the concrete block. Crushing / sorting process to sort, concrete crushing and crushing process with concrete crusher-type concrete lump processing equipment, and crushing process to obtain crushed material by sieving A method for producing recycled aggregate, comprising: a sieving step to obtain a coarse aggregate of 40 to 5 mm by treatment; and a washing / classification step of subjecting the coarse aggregate to water washing treatment and classification treatment Exist.

  According to the method for producing a reclaimed aggregate according to the present invention, the crushing process uses a jaw crusher-type concrete lump processing device to crush the concrete lump and at the same time perform the lump decontamination process, Since the aggregate, the fine aggregate and the cement component are separated, the aggregate can be reliably recovered from the concrete waste material, and a high-quality recycled aggregate can be produced. Moreover, the soil improvement material can be made from the sediment of the waste water generated in the cleaning / classification process and the powder removed in the sorting process, and all the waste concrete can be reused. Therefore, the present invention is useful for environmental conservation, such as reducing industrial waste and preventing environmental destruction due to the mining of aggregates from mountains and rivers.

It is a flowchart which shows the outline | summary of the manufacturing method of the reproduction | regeneration aggregate which concerns on this invention. It is the longitudinal cross-sectional view seen from the side surface which shows the whole structure of the processing apparatus of the concrete lump used in the scouring process. It is the longitudinal cross-sectional view seen from the side surface which shows the structure of the principal part of the processing apparatus of a concrete lump.

  An embodiment of a method for producing a recycled aggregate according to the present invention (hereinafter abbreviated as “manufacturing method” as appropriate) will be described with reference to the drawings. The production method of the present invention is a method of producing recycled aggregate from concrete waste, and as concrete waste, for example, all of general concrete waste, such as concrete waste generated during building demolition work, house demolition, etc. Concrete waste such as generated foundation parts can be mentioned.

  In the present invention, aggregate is a concept including coarse aggregate and fine aggregate. In addition, a concrete lump of 40 mm or less refers to a concrete lump that passes through a 40 mm mesh screen, and a coarse aggregate of 40 to 5 mm refers to an aggregate that passes through a 40 mm mesh screen and does not pass through a 5 mm mesh screen. The 5 mm to 75 μm fine aggregate refers to an aggregate that passes through a 5 mm mesh screen and does not pass through a 75 μm mesh screen (filter). Furthermore, a powder of 5 mm or less refers to a mixture of powder and granular material that passes through a 5 mm mesh screen, and a powder of 75 μm or less refers to a powder that passes through a 75 μm mesh screen (filter). .

  As shown in FIG. 1, the manufacturing method of the present invention crushes concrete waste into a concrete lump of 40 mm or less using a crusher, and also crushes and sorts the concrete lump by removing iron scraps using a magnetic separator. 1 and a crushing process 2 for further crushing and crushing the concrete lump by a jaw crusher type concrete lump processing device to obtain a crushed material, and sieving the crushed material to obtain an aggregate. It comprises a sieving step 3 to be obtained and a washing / classifying step 4 in which the aggregate is subjected to water washing treatment and classification treatment.

  In the crushing / sorting step 1, for crushing concrete waste, a jaw crusher is usually used as a crusher. The jaw crusher is a device that is generally used for crushing rocks and ores. It is fixed to the main body frame, and has a fixed jaw with a substantially flat fixed tooth inside. And a swing jaw having a substantially flat moving tooth attached to the inside thereof. In the jaw crusher, a substantially V-shaped crushing chamber (processing chamber) is configured when viewed from the side by fixed teeth and moving teeth, and the upper and lower ends of the crushing chamber are respectively a supply port and a discharge port for an object to be processed. It is an exit. The lower end portion of the swing jaw is supported on the main body frame side so as to be swingable via a toggle plate, and the upper end portion of the swing jaw is installed in a horizontal direction and rotated by a drive source via a bearing. It is pivotally attached. Therefore, the rotation of the eccentric shaft causes the upper end side of the moving tooth to perform a circular motion when viewed from the side, and the lower end side of the moving tooth swings up and down in an arc shape, while the moving tooth repeatedly approaches and separates from the fixed tooth. Thus, the object to be processed in the crushing chamber can be crushed.

  In the crushing / sorting step 1, the crusher as described above is used to crush the concrete waste material to produce a concrete lump of 40 mm or less. In the crushing process, a concrete block exceeding 40 mm is again charged into a crusher and crushed to the above size. Next, using a magnetic separator, iron scraps such as reinforcing bars are removed. As the magnetic separator, an electromagnetic pulley, a plate magnet, or various magnetic separators that combine a magnetic drum and a conveyor can be used. The crushing / sorting step 1 is not a series of steps in the present invention, and may be carried out as a separate step. In that case, for example, RC40-0 is commercially available that has been crushed to 40 mm or less and from which iron scraps have been removed. A concrete lump may be used, and this may be applied to the scouring step 2, which is the next step.

  In the kneading and unraveling step 2, the concrete crush is processed by using a jaw crusher type specific concrete lump processing device 2A (hereinafter abbreviated as “processing device”) as shown in FIGS. Further, crushing treatment and crushing treatment are performed to obtain a crushed material (a mixture of coarse aggregate, fine aggregate and cement powder). The configuration of the processing apparatus 2A is as follows.

  As shown in FIG. 2, the processing apparatus 2A basically has a jaw crusher structure, is fixed to the main body frame 21, and has a substantially flat plate-like fixing tooth 222 on the inside thereof. The swing jaw 23 is disposed so as to face the fixed jaw, and has a substantially flat moving tooth 232 on the inside. The main body frame 21 constitutes a front frame 212 assembled to the front side with respect to a base frame 211 installed horizontally, side blocks 213 assembled to the left and right sides, and left and right side portions of the processing chamber 24 described later. It is mainly comprised from the side guard 214 and said fixed jaw 22 as a rear frame assembled | attached to the back side.

  The fixed tooth 222 is a plate-like member in which a number of groove-shaped crushing teeth are arranged on the surface, and the fixed jaw 22 is interposed via a fixed tooth mounting seat 221 provided with an engaging portion (not shown) on the surface. By attaching to the inner side (processing chamber 24 side), the plate surface is arranged in a vertical state. Usually, the width (length in the horizontal direction) of the fixed teeth 222 is designed to be about 600 to 1300 mm, and the length (length in the height direction) is designed to be about 600 to 2000 mm.

  On the other hand, the moving tooth 232 is a plate-like member in which a number of groove-shaped crushing teeth are arranged on the surface, like the fixed tooth 222, and the moving tooth provided with an engaging portion (not shown) on the surface. By being attached to the inner side (the processing chamber 24 side) of the swing jaw 23 via the attachment seat 231, the plate surface is disposed so as to be inclined. The moving teeth 232 have a gently curved shape so as to bulge inward (to the processing chamber 24 side) in order to feed the concrete block downward. Usually, the width (length in the lateral direction) of the moving tooth 232 is designed to be about 600 to 1300 mm, and the length (length in the height direction) is about 600 to 2000 mm, like the fixed tooth 222.

  Further, the angle between the fixed tooth 222 and the moving tooth 232 (the opening angle on the opposite sides) is set to 20 to 35 degrees by the inclination of the swing jaw 23. Thereby, in the processing apparatus, when viewed from the side by the fixed teeth 222 and the moving teeth 232, a substantially V-shaped processing chamber 24 is configured, and the upper and lower ends of the processing chamber 24 are respectively connected to the supply port 241 and the processing port 24. A discharge port 242 is provided.

The size of the processing chamber 24 is designed to be approximately the same size as in the crushing processing of rocks and the like. The width of the supply port 241 at the upper end of the processing chamber 24 (frontage in the left-right direction) and the width of the discharge port 242 at the lower end of the processing chamber 24 (frontage in the left-right direction) are the same as the widths of the fixed teeth 222 and the moving teeth 232. It is. Usually, the opening amount L ₁ of the supply port 241 (the distance in the horizontal direction between the upper end portion of the fixed tooth 222 and the upper end portion of the moving tooth 232) is set to 200 to 250 mm. Further, the opening amount _{L 2} of the discharge port 242 (the horizontal distance between the lower end of the lower portion and Doha 232 fixed teeth 222) is set to 35～40Mm.

  The swing jaw 23 provided with the moving teeth 232 is supported so that the upper and lower ends thereof can swing. That is, the lower end portion of the swing jaw 23 is urged in a direction away from the fixed jaw 22 by the urging means 25 and is supported on the main body frame 21 side through the toggle plate 26 so as to be swingable. As the biasing means 25, for example, a hook bolt attached to the lower end portion of the swing jaw 23 is locked and a hook bolt inserted into the front frame 212, and the front frame 212 projects to the opposite side of the swing jaw 23. It is configured by a combination of a coil spring, a washer, and a nut that are attached to the base end side of the hook bolt and constantly pull the hook bolt toward the front frame 212 side.

  The toggle plate 26 is a support plate arranged along the width direction of the swing jaw at the lower end portion of the swing jaw 23, and both side edges thereof are formed in an arc shape. One side edge (right side edge in the figure) of the toggle plate 26 is fitted into the groove of the toggle block 261, and the other side edge (left side edge in the figure) of the toggle block 261 is swinging. The jaw 23 is fitted in a groove as an engaging portion formed on the lower end back surface portion. The toggle block 261 is mounted on a pedestal 262 and attached to a height-adjustable toggle plate mounting plate 263 inside the front frame 212, and is stored under a horizontal member 215 that is a part of the main body frame 21. In addition, the height is finely adjusted by inserting a spacer between the base 262 and the horizontal member 215.

  An upper end portion of the swing jaw 23 is rotatably attached to an eccentric shaft 27 that is installed in the horizontal direction and is rotated by a drive mechanism via a bearing 28. The eccentric shaft 27 is rotatably supported above the main body frame 21 by bearings (not shown) mounted on the left and right side blocks 213. As shown in FIG. 3, the eccentric shaft 27 is a shaft in which the rotation center M is deviated from the center O of the shaft cross section, and the rotation shaft 270 of the flywheel 29 on the drive mechanism side is at the rotation center M of the eccentric shaft 27. Are combined. Usually, the diameter of the eccentric shaft 27 is designed to be 200 to 250 mm. In addition, as a drive mechanism, the mechanism which rotates the flywheel 29 with a motor via a V belt is generally used, and the rotation speed of the eccentric shaft 27 is normally set to 280 to 390 rotations / minute.

In the processing apparatus 2A, the rotation of the eccentric shaft 27 by the drive mechanism as described above causes the upper end side of the moving tooth 232 to perform a circular motion when viewed from the side, and the lower end side of the moving tooth 232 swings up and down in an arc shape. However, the moving tooth 232 repeatedly approaches and separates from the fixed tooth 222, and the concrete mass in the processing chamber 24 can be processed. In that case, in the processing apparatus 2A, as shown in FIG. 3, the eccentric amount Lg of the eccentric shaft 27 is set to 10-15% of the average opening ratio _{L 1} of the supply port 241. Specifically, when the average opening ratio _{L 1} of the supply port 241 is designed to 200～250Mm, eccentricity Lg of the eccentric shaft 27 is 15 to 40 mm, preferably is set to 20 to 30 mm.

In the processing apparatus 2A, the eccentric amount Lg of the eccentric shaft 27 is from the rotation center M of the eccentric shaft 27 (the center of the rotation shaft 270 on the drive mechanism side) to the center O of the cross section orthogonal to the length of the eccentric shaft 27. The distance. Further, as described above, the opening amount L ₁ of the supply port 241, refers to the horizontal distance between the upper ends of the Doha 232 fixed teeth 222, the average opening ratio L _1, the maximum It refers to an intermediate value between the opening amount L ₁ and minimum opening amount L _1.

  In the processing apparatus 2A, by setting the eccentric amount Lg of the eccentric shaft 27 to the above specific range, it is possible to recover the coarse aggregate and the fine aggregate from the concrete lump with a high yield. That is, in the processing apparatus 2A used in the present invention, the moving tooth 232 repeatedly approaches and separates from the fixed tooth 222 due to the rotation of the eccentric shaft 27, thereby processing the concrete lump introduced from the supply port 241. While crushing in the chamber 24, the produced concrete granule is brought into contact with stirring in the processing chamber 24.

At that time, while the eccentric amount of the eccentric shaft in the conventional jaw crusher is 10mm or less, 10 to 15 of the average opening ratio _{L 1} of eccentricity Lg of the processing apparatus 2A in the eccentric shaft 27 is supply port 241 %, Specifically, the eccentric amount Lg is set to 15 to 40 mm, and the operating range of the moving tooth 232 is large, and the above concrete particles, in other words, the coarse aggregate and cement component to which the mortar component is adhered The agglomerated fine aggregate can be brought into contact with each other so as to disentangle, and the coarse aggregate, the fine aggregate and the cement component can be separated. As a result, it is possible to obtain a coarse aggregate and a fine aggregate, that is, a polished aggregate, in which cement powder is adhered to the surface. And since the upper limit of the operating range of the swing jaw 23 is prescribed | regulated, a coarse aggregate is not crushed so much.

  In the disentangling process 2, in order to increase the aggregate recovery rate and to produce a higher quality recycled aggregate, the processing time by the processing apparatus 2A is preferably 2 to 5 minutes, and the processing time is not secured. In some cases, two processing devices 2A arranged in series can be used. That is, the concrete processing unit 2A performs concrete lump crushing and squeezing processing, and then the second processing unit 2A performs further scouring processing. Thus, by using the two processing devices 2A, the processing time of the concrete block in the squeezing step 2, in other words, the residence time in the processing device 2A can be set to 2 to 5 minutes. .

  The reason for setting the residence time is as follows. That is, when the residence time in the processing apparatus 2A is less than 2 minutes, the dissociation of the coarse aggregate, the fine aggregate, and the cement component is insufficient, and the aggregate recovery rate decreases. On the other hand, even if the processing apparatus 2A performs processing for more than 5 minutes, the aggregate recovery rate cannot be further increased, leading to a decrease in manufacturing efficiency. In addition, when using two processing apparatuses 2A, you may convey a to-be-processed object with a conveyor from the 1st processing apparatus 2A to the 2nd processing apparatus 2A, and it is below the 1st processing apparatus 2A. The 2nd processing apparatus 2A may be arrange | positioned and a to-be-processed object may be dropped.

  Next, as shown in FIG. 1, in the sieving step 3, the crushed material obtained in the scouring step 2, that is, a mixture of coarse aggregate, fine aggregate and cement powder is subjected to sieving treatment. In the sieving process, for example, a trommel is used, and a coarse aggregate of 40 to 5 mm and a granular material of 5 mm or less are selected. The trommel is equipped with a sieve body formed by attaching a net or punching metal to a cylindrical frame, and the sieve body is inserted into the sieve body by rotating the sieve body with the axis of the sieve body horizontally or slightly inclined. This is a known rotary sieving device for sieving the workpiece.

  In the washing / classifying step 4, the coarse aggregate of 40 to 5 mm sieved in the sieving step 3 is subjected to water washing treatment and classification treatment to an arbitrary particle size. That is, in the washing / classifying step 4, as in the sieving step 3 described above, a sieving apparatus such as a trommel is used, and the aggregate is adhered to the surface of the aggregate by washing with water while being immersed in washing water. Remove the cement powder. Then, the obtained aggregate can be further classified into aggregates having an arbitrary particle size by performing a classification process using a sieve device of a mesh sieve having different mesh sizes.

  On the other hand, for the granular material having a size of 5 mm or less that has been screened in the screening process 3, the powder is removed in the screening process 5. In the selection step 5, the powder obtained in the sieving step is subjected to an air selection process, and a powder of 75 μm or less is removed from the powder to obtain a fine aggregate of 5 mm to 75 μm. Then, the obtained fine aggregate is subjected to water washing treatment and classification treatment in a washing / classification step 6 using an appropriate mesh screen device. Thereby, the fine aggregate of arbitrary particle diameters can be obtained. In addition, as said sieve apparatus which wash | cleans and classifies 5 mm-75 micrometers fine aggregate, the classifier which classify | selects the granular material of a predetermined particle diameter from the water with which the granular material was mixed can be utilized.

  For example, the classifier is provided with a storage tank to which a mixture of earth and sand and water is supplied as an object to be processed, a precipitation tank for precipitating sand and overflowing water containing powdery material, and a punching hole. A large number of scoop parts are connected in the shape of a water wheel, and a bucket car scoops out the material to be treated in the storage tank, and an outlet for the sand scooped out at the scoop part is arranged from the center of rotation of the bucket car toward the outside of the device. It is mainly composed of the vibrating sieve and the screw conveyor that returns the sand precipitated in the settling tank to the storage tank. Therefore, in the cleaning / classifying step 6, the fine aggregate can be cleaned and classified simultaneously by using the classifier as described above. The technology of such a classifier is disclosed in Japanese Patent Application Laid-Open No. 8-66641, and is put into practical use as a product name “Ultra Classifier” manufactured by Komaki Kogyo Co., Ltd.

  In addition, the waste water (muddy water) generated in the washing / classification step 4 for producing a coarse aggregate of 40 to 5 mm and the washing / classification step 6 for producing a fine aggregate of 5 mm to 75 μm is once set in a sedimentation tank (illustrated). (Omitted) and then separated into water and sediment in the settling tank. And a soil improvement material can be manufactured by performing a dehydration process (process shown with the code | symbol 7 in FIG. 1), a drying process, and a grinding | pulverization process to a deposit. In addition, the precipitate obtained in the above precipitation tank can be reused as a backfilling material by improving it into a granular material in a dehydrated state without drying and grinding. The water recovered in the precipitation tank can be reused for water washing.

  As described above, according to the production method of the present invention, in the scouring step 2, the specific processing device 2A is used to crush the concrete lump, and at the same time, the scouring process is performed to obtain coarse aggregate, fine Since the aggregate and the cement component are separated from each other, the aggregate can be reliably recovered from the concrete waste material, and a high-quality recycled aggregate can be manufactured. In addition, the soil improvement material can be produced from the sediment of the wastewater generated in the washing / classifying steps 4 and 6 and the powder removed by the air sorting process in the sorting step 5. Therefore, according to the present invention, it is possible to reuse all concrete waste that is currently industrial waste, reduce industrial waste, and prevent environmental destruction by mining aggregates. Prevention can also be expected.

Example:
Recycled aggregate was produced from concrete waste by the production method of the present invention shown in FIG. 1, and a concrete colloid was produced using the obtained aggregate, and its compressive strength was confirmed. At that time, in the disentangling step 2, as the processing apparatus 2A, the eccentric amount Lg of the eccentric shaft 27 is set to 10 mm, 15 mm, 20 mm, 30 mm, and 40 mm, respectively, and the concrete lump by the processing apparatus 2A is prepared. The state of the crushed material (mixture of coarse aggregate, fine aggregate and cement powder) obtained by the crushing and demulsification treatment was observed.

  In the preparation of the co-sample, concrete was kneaded using sieving 40-20 mm coarse aggregate 6.7 kg, fine aggregate 5.5 kg, Portland cement 2.4 kg, and water 1.2 kg. The ratio of fine aggregate to total aggregate was 45% by weight, and the water cement ratio was 50% by weight. In accordance with JIS A1132, five specimens of 125 mmφ × 250 mm were prepared and subjected to air curing at 20 ° C. for 48 hours, released from mold, and then subjected to water curing at 20 ° C. for 7 days. The compressive strength was measured according to JIS A1108 “Concrete compressive strength test method”, and the average value was obtained.

  As a result, as shown in Examples 1 to 4 in Table 1, from the compressive strength of the specimen, the processing apparatus 2A is good in the aggregate obtained by the apparatus having the eccentric amount Lg of the eccentric shaft 27 of 15 to 40 mm. In particular, it was confirmed that the aggregate obtained with the eccentricity Lg set to 20 mm was excellent. Moreover, as a result of observing the crushed material obtained in the processing apparatus 2A, when the residence time in the processing apparatus 2A is 2 minutes or less, the disaggregation of the coarse aggregate, the fine aggregate, and the cement powder is insufficient, and the residence time is 3 to 3. It was confirmed that 4 minutes was preferable.

Comparative example:
In the disentangling process 2, a recycled aggregate is produced in the same manner as in the example, except that a processing device 2A in which the eccentric amount Lg of the eccentric shaft 27 is set to 10 mm is used, and a colloid is prepared. The compressive strength was confirmed. The results are shown in Table 1 as Comparative Example 1. Moreover, it produced similarly to Example 1 except the point which used what sieved general RC to 40-20 mm, and the 5 mm-75 micrometer fine aggregate obtained by sieving commercially available river sand. The compressive strength of the joint specimen was confirmed. The results are shown in Table 1 as Comparative Example 2. Furthermore, the compression of the co-product produced in the same manner as in Example 1 except that the aggregate obtained by sieving commercial crushed gravel into 40 to 20 mm and the fine aggregate used in Comparative Example 1 were used. The strength was confirmed. The results are shown in Table 1 as Reference Example 1.

  As shown in Table 1, the concrete using the recycled aggregate produced by the production method of the present invention is very high in strength as compared with the case where the recycled concrete of Comparative Examples 1 and 2 is used. It is almost the same as the strength of concrete when fresh aggregate is used. In other words, according to the present invention, a regenerated aggregate that can be used in the same manner as a fresh aggregate can be obtained.

1: Crushing / sorting process 2: Scouring process 3: Sieving process 4: Washing / classifying process 5: Sorting process 6: Cleaning / classifying process 2A: Concrete lump processing device 21: Main body frame 22: Fixed jaw 222: stationary teeth 23: swing jaw 232: Doha 24: treatment chamber 241: supply port 242: outlet 26: the toggle plate 27: eccentric shaft 270: rotary shaft of the drive mechanism side L _1: open feed ports quantity L _2: discharge Opening amount of outlet O: Center of shaft section M: Center of rotation Lg: Eccentricity

Claims (6)

  A method of producing recycled aggregate from concrete waste, a crushing / sorting process that crushes the concrete waste into a concrete lump of 40 mm or less by a crusher, and sorts the concrete lump by removing iron scraps with a magnetic separator. And a crushing step of further crushing and crushing the concrete lump by a jaw crusher type concrete lump processing device to obtain a crushed material, and sieving the crushed material to obtain a coarseness of 40 to 5 mm. A method for producing recycled aggregate, comprising: a sieving step for obtaining an aggregate; and a washing / classifying step for subjecting the coarse aggregate to a water washing treatment and a classification treatment.   As a concrete lump processing device, a fixed jaw fixed to a main body frame and provided with a substantially flat plate-like fixed tooth on the inside thereof, and a substantially flat plate-like moving tooth provided on the inner side thereof. A swing jaw, and a substantially V-shaped processing chamber is configured when viewed from the side by fixed teeth and moving teeth, and the upper and lower ends of the processing chamber serve as a supply port and a discharge port, respectively. The lower end of the swing jaw is urged in a direction away from the fixed jaw by the urging means and is supported on the main body frame side so as to be swingable via a toggle plate, and the upper end of the swing jaw is installed horizontally and driven. A processing device is used which is rotatably attached to an eccentric shaft rotated by a mechanism via a bearing, and the eccentric amount of the eccentric shaft is set to 10 to 15% of the average opening amount of the supply port. Manufacturing method for regenerating bone material according.   The method for producing a recycled aggregate according to claim 1 or 2, wherein the residence time of the concrete block in the mashing step is 2 to 5 minutes.   Sorting step to obtain fine aggregate of 5mm ~ 75μm by removing powder by air sorting process from 5mm or less granular material obtained in sieving step, and classifying by washing the obtained fine aggregate with water The method for producing a recycled aggregate according to any one of claims 1 to 3, further comprising a washing / classifying step to be processed.   The method for producing a reclaimed aggregate according to claim 4, wherein the soil improvement material is produced from the powder of 75 µm or less removed in the sorting step.   Wastewater generated in each washing and classification process is stored in a sedimentation tank, separated into water and sediment in the sedimentation tank, and then subjected to dehydration treatment, drying treatment and pulverization treatment to produce a soil improvement material. A method for producing a recycled aggregate according to any one of claims 1 to 5.

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