JP2006320814A - Manufacturing method of recycled fine aggregate, and recycled fine aggregate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of recycled fine aggregate which produces small amount of adhered materials except the aggregate ingredient such as mortar and the like and is capable of manufacturing recycled fine aggregate with high quality. <P>SOLUTION: Concrete masses B generated at a construction site and the like are formed into the crushed concrete V which is produced by a jaw crusher 3. The crushed concrete V is polished by an ore polishing machine 10 at a first ore polishing step and classified by a vibration sieve 8. The crushed material S2 substantially corresponding to sand and crushed material S3 corresponding to fine aggregate, which have been crushed by the vibration sieve 8, are polished in the presence of a polish treatment stone 61 by the ore polishing machine 11 at a second ore polishing step after mixing at a predetermined ratio. Thus, the mortar moiety M which has been adhered to the surface of the fine aggregate ingredient is removed and the recycled fine aggregate N in which the amount of the adhered mortar moiety M is small is obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aggregate manufacturing method for recovering a high-quality fine aggregate component from concrete waste generated at a construction site or the like.

  In recent years, the disposal of a large amount of concrete waste generated with the dismantling of concrete structures such as buildings and factories has become a problem. Concrete waste contains a large amount of aggregate components such as coarse aggregate and fine aggregate. Therefore, from the viewpoint of environmental problems, it is desirable to collect and reuse these aggregate components.

By simply crushing the above-mentioned concrete waste, the mortar component is attached to the surface of the coarse and fine aggregates contained in the concrete, and the water absorption rate is high and reused as aggregate. The quality is extremely bad. Therefore, the present inventors put the crushed concrete waste into the water in which the water flow is generated in the vertical direction as disclosed in Patent Document 1 below, and the mortar component adheres based on the difference in specific gravity. We have found a way to selectively extract the coarse aggregate components that have not been used.
Japanese Patent Laid-Open No. 10-17341

  The coarse aggregate (recycled coarse aggregate) recovered by the method disclosed in Patent Document 1 has a mortar component sufficiently removed from the surface, and is re-produced as a coarse aggregate in the same manner as the virgin coarse aggregate. Available. However, the fine aggregate-like substance generated when the coarse aggregate component is recovered by the method disclosed in the above-mentioned Patent Document 1 is referred to in the former Ministry of Construction's “Temporary Quality Standards for Each Use (Draft)”. It corresponds to a kind of recycled fine aggregate, and the amount of residual mortar on the surface of the fine aggregate component is relatively large. Thus, when the thing with much residual amount of mortar is used as a raw material of concrete, there existed a problem that the water absorption rate was high and durability after hardening became very low.

  Then, the present inventors tried the manufacturing method which performs a grinding process twice, in order to improve the quality of a reproduction | regeneration fine aggregate. In the case of producing recycled fine aggregates in this way, what has undergone the first grinding process (hereinafter referred to as the first grinding process if necessary) is used as it is for the second grinding process (hereinafter referred to as necessary). If it is crushed by the second grinding process), the amount of mortar attached to the surface of the aggregate component will decrease, but the aggregate component will be excessively crushed and most of it will be used as fine aggregate It turned out to be a waste called the so-called “zero thing” impossible.

  In addition, when most of the aggregate components are excessively pulverized as described above, for example, those that are processed by the second grinding process have a small amount of mortar and can be used as recycled fine aggregates. Even if it is included, there is a problem that it takes a lot of time to collect it.

  Furthermore, as mentioned above, recycled fine aggregate is made from concrete crushed material obtained by crushing concrete waste collected from various construction sites, etc., so the amount of mortar contained in the raw material and aggregate There is a high possibility that the particle size distribution of the components is scattered. Therefore, as the inventors have tried, simply performing the grinding process a plurality of times, the amount of mortar attached to the surface of the recovered recycled fine aggregate N, the particle size distribution of the recycled fine aggregate N, etc. There is a high possibility that the quality of the material will vary, and a high-quality recycled fine aggregate that can replace virgin fine aggregate cannot be provided.

  Therefore, an object of the present invention is to provide a production method capable of producing a high-quality recycled aggregate with a small amount of substances other than aggregate components such as mortar.

  The invention according to claim 1, which is provided to solve the above-described problem, is a method in which a crushed concrete containing a fine aggregate component and a grinding treatment member having higher strength than the crushed concrete are rubbed together in a liquid. The first grinding process to be crushed, the fine aggregate equivalent crushed material having a particle size equivalent to the fine aggregate from the crushed concrete ground in the first grinding process, and the fine aggregate equivalent crushed material In the liquid, a sorting process for selecting a crushed material equivalent to sand with a larger diameter, and a crushed crushed material in which a fine aggregate crushed material and a sand crushed material are mixed at a predetermined ratio, It is the manufacturing method of the reproduction | regeneration fine aggregate which collect | recovers a fine aggregate component through the 2nd grinding process rubbed and crushed in.

  In the production method of the present invention, the fine grinding ingredient is not simply subjected to the grinding treatment multiple times, but is crushed and peeled to some extent through the first grinding process, and the particle size is smaller than this. The intermediate crushed material obtained by mixing large crushed sand equivalent crushed material at a predetermined ratio is subjected to grinding treatment in the second grinding process. Therefore, even if the crushed material in the second grinding step is crushed, it is not crushed to a fine powder state like the above-mentioned “zero thing”. Therefore, according to the present invention, the amount of mortar attached to the surface of the aggregate component from the crushed concrete is small, and a recycled fine aggregate suitable for use as a substitute for virgin fine aggregate can be obtained in high yield. Can be recovered.

  Further, in the production method of the present invention, the intermediate crushed material in which the mixing ratio of the fine aggregate-corresponding crushed material and the sandstone-corresponding crushed material that has been selected in the sorting step is arbitrarily adjusted is ground in the second grinding step. be able to. Therefore, according to the production method of the present invention, it is possible to provide a reclaimed fine aggregate adjusted to a desired particle size distribution regardless of the quality of the crushed concrete (waste material) supplied as a raw material in the first grinding step.

  Moreover, in the manufacturing method of the recycled fine aggregate of this invention, the crushed material equivalent to the above-mentioned "sand berries" can be employ | adopted as a crushed material corresponding to sand. Therefore, according to the method for producing recycled fine aggregate of the present invention, it is possible to make maximum use of the concrete crushed material generated at the construction site and the like and to provide a high-quality recycled fine aggregate.

  Moreover, the invention according to claim 2 provided to solve the above-described problem is that a crushed concrete containing a fine aggregate component and a grinding treatment member having a higher strength than the crushed concrete in liquid. The first grinding process that is crushed and crushed, the fine aggregate equivalent crushed material having a particle size equivalent to the fine aggregate from the crushed concrete ground in the first grinding process, and the fine aggregate equivalent Sorting step for selecting midway crushed material composed of one or both of sand crushed material having a larger diameter than the crushed material, and polishing member having lower crushing strength than the crushed material and the above-mentioned grinding treatment member Is a method for producing a reclaimed fine aggregate, in which a fine aggregate component is recovered through a second grinding step in which the fine aggregate components are rubbed and polished in a liquid.

  In the method for producing recycled aggregate according to the present invention, the partially crushed material is taken out by grinding to some extent in the first grinding step, and the crushed material is removed by a polishing member having a lower crushing strength than the grinding member. There is a second grinding process in which they are rubbed and polished. According to such a production process, it is possible to sufficiently remove the mortar remaining on the surface of the crushed material, and the amount of mortar attached is extremely small. In addition to being able to be manufactured, it is possible to prevent the occurrence of problems such as deterioration in quality due to excessive pulverization and the fine aggregate component being crushed into a fine powder state referred to as “zero thing” described above. Therefore, according to the production method of the present invention, high-quality recycled fine aggregate can be recovered from the waste concrete material with high yield, and resources can be used effectively.

  Here, since most of the crushed material has a mortar portion adhering to the surface, the particle size is reduced by the amount of the mortar portion that has been scraped off in the second grinding step. Therefore, the product obtained through the second grinding process is generally adopted as having a particle size distribution equivalent to that of the fine aggregate generally adopted as the particle size of the crushed material. The particle size is smaller than the fine aggregate, and it is difficult to use it as it is.

  Invention of Claim 3 provided based on this knowledge is a process in which the 2nd grinding process grinds the halfway crushed material which mixed the fine aggregate equivalent crushed material and the sandstone equivalent crushed material in a predetermined ratio It is a manufacturing method of the reproduction | regeneration fine aggregate of Claim 2 characterized by the above-mentioned.

  According to such a manufacturing method, it is possible to manufacture a regenerated fine aggregate that is inferior to that of a fine aggregate generally employed in terms of particle size distribution in addition to quality.

  Invention of Claim 4 is a manufacturing method of the reproduction | regeneration fine aggregate of Claim 2 or 3, wherein a grinding | polishing processing member contains either one or both of gravel and crushed stone.

  The polishing member employed in the method for producing a recycled fine aggregate of the present invention includes gravel and crushed stone, and the crushing strength is close to that of a fine aggregate component. Therefore, in the method for producing recycled fine aggregate according to the present invention, only the mortar content can be scraped off without applying excessive impact to the fine aggregate component contained in the crushed material in the second grinding step. The yield of reclaimed fine aggregate due to chipping or cracking of aggregate components does not occur. Therefore, according to the present invention, a high-quality recycled fine aggregate can be provided.

  Invention of Claim 5 is characterized by the crushing strength of the gravel and the crushed stone which comprise the grinding | polishing processing member used in a 2nd grinding process being higher than the crushing strength of the mortar part contained in concrete waste material, A method for producing a recycled fine aggregate according to any one of claims 2 to 4.

  According to this manufacturing method, it is possible to sufficiently grind off the mortar component adhering to the surface of the fine aggregate component in the second grinding step, and to provide a high-quality recycled fine aggregate.

  The invention according to claim 6 is characterized in that the gravel and crushed stone constituting the polishing member are classified into a plurality of groups according to the particle diameter, and the mixing ratio of the groups is adjusted to a predetermined ratio. Item 6. A method for producing a recycled fine aggregate according to any one of Items 2 to 5.

  According to the present invention, polishing conditions in the second grinding process can be optimized, and the yield and quality of recycled fine aggregate can be improved.

  Here, in consideration of the particle size configuration of the recycled fine aggregate produced by the production method according to any one of claims 1 to 6, the sandy equivalent crushed material is a concrete crushed material that has undergone the first grinding process. Of these, it is desirable that the particle diameter is 15 mm or less.

  Further, in consideration of the particle size configuration of the recycled fine aggregate produced by the production method according to any one of claims 1 to 6, the sandy equivalent crushed material is the concrete crushed material that has undergone the first grinding process. It is even more preferable that the particle diameter is 8 mm or less (claim 8).

  According to this manufacturing method, it is possible to manufacture a high-quality recycled fine aggregate whose particle size distribution is within the optimum range for the fine aggregate.

  The invention according to claim 9 is characterized in that the fine aggregate equivalent crushed material is contained in an amount of 30% to 70% by weight with respect to the total amount of the intermediate crushed material. It is a manufacturing method of the reproduction | regeneration fine aggregate of description.

  In the method for producing a recycled fine aggregate according to the present invention, the composition ratio of the fine aggregate equivalent crushed material and the sandy equivalent crushed material constituting the intermediate crushed material is adjusted to be within the above-described range. Therefore, according to the production method of the present invention, it is possible to produce a regenerated fine aggregate having a particle size distribution optimal for use as a substitute for a virgin fine aggregate.

  Here, according to the manufacturing method of the reclaimed fine aggregate shown in each claim described above, it is possible to reduce the amount of mortar attached to the surface of the fine aggregate component without over-pulverizing the concrete crushed material. it can.

  Accordingly, the invention according to claim 10 provided on the basis of such knowledge is a mortar component adhering to the fine aggregate component by the method for producing a recycled fine aggregate according to any one of claims 1 to 9. Is a regenerated fine aggregate produced by performing the second grinding step until the weight becomes 25% or less of the regenerated fine aggregate by weight.

  According to the present invention, it is possible to provide an extremely high quality recycled fine aggregate having an adhesion amount of mortar of 25% or less by weight without excessively pulverizing the fine aggregate component.

  Invention of Claim 11 is manufactured by implementing the 2nd grinding process by the manufacturing method of the reproduction | regeneration fine aggregate in any one of Claims 1 thru | or 9, until water absorption becomes 5% or less. It is the reproduction | regeneration fine aggregate characterized by the above-mentioned.

  According to the present invention, it is defined in the “Provisional Quality Standards by Use (Draft) for Reuse of Concrete By-products (draft)” issued by the former Ministry of Construction on April 11, 1994. It is possible to provide a high-quality recycled fine aggregate that satisfies the quality of the recycled fine aggregate (one type).

  ADVANTAGE OF THE INVENTION According to this invention, the amount of other components, such as mortar, attached is few, and the reproduction | regeneration fine aggregate optimal to mix | blend as a fine aggregate with a concrete composition can be provided.

  Then, the manufacturing method of the reproduction | regeneration fine aggregate which is one Embodiment of this invention is demonstrated in detail, referring drawings. FIG. 1 is a conceptual diagram schematically showing a method for producing a recycled fine aggregate according to the present embodiment. FIG. 2 is a conceptual diagram showing the flow of the manufacturing process of the recycled fine aggregate according to the present embodiment. Moreover, FIG. 3 is sectional drawing which shows the grinding machine used in this embodiment. FIG. 4 is a conceptual diagram showing a specific gravity sorting device used in the present embodiment.

  As shown in FIGS. 1 and 2, the aggregate manufacturing method of the present embodiment is roughly configured by three flows: a pretreatment flow, a coarse aggregate recovery flow, and a fine aggregate recovery flow. Each of the pretreatment flow, the coarse aggregate recovery flow, and the fine aggregate recovery flow includes a plurality of steps. Hereinafter, a method for manufacturing a recycled aggregate will be described step by step with reference to the drawings.

  In the method for producing a recycled fine aggregate according to the present embodiment, a lump of waste concrete material (hereinafter referred to as a concrete lump B if necessary) generated at a building demolition site or the like in a crushing step that is the first stage of the pretreatment flow. Is conveyed by a truck or the like and put into the hopper 1.

  The concrete block B put into the hopper 1 is transferred by the reciprocating feeder 2 which is reciprocating and is put into the jaw crusher 3 (crusher). When the concrete block B is thrown in, the jaw crusher 3 has a fixed plate 5 and a movable plate 6 that reciprocates in a direction approaching and separating from the fixed plate 5 as the rotating body 7 rotates. The jaw crusher 3 crushes the concrete block B introduced between the fixed plate 5 and the movable plate 6 to obtain a concrete crushed material V. When the crushing process for crushing the concrete block B is completed, the concrete crushed material V is charged into the grinding machine 10, and the manufacturing process shifts to the first grinding process.

  In the first grinding process, the concrete crushed material V is ground by the grinding machine 10. The grinding machine 10 used here is a rod mill type in which a plurality of rod rods 18 (a grinding treatment member) are arranged in a hollow body 15 (stirring chamber) as shown in FIG. The main body 15 is configured to rotate. The grinding machine 10 has a configuration in which a loading port 16 for loading the concrete crushed material V is provided on one end side of a cylindrical main body 15 and a discharge port 17 is provided on the other side. The discharge port 17 is provided with a universal adjustment plate 20 that is movable so as to change the opening diameter. The discharge port 17 makes it possible to select the diameter of gravel crushed stone to be discharged by adjusting the fixing position of the universal adjustment plate 20. A trommel classifier 22 made of a wire mesh screen 21 is provided outside the discharge port 17. In addition, in this embodiment, although the rod rod 18 is used as a grinding process member, you may replace this with spherical states, such as iron.

  When the concrete crushed material V is thrown into the charging port 16 of the grinding machine 10 together with water and the main body 15 starts rotating at a predetermined rotational speed, the first grinding process is started. In the first grinding step, the crushed concrete V and the rod rod 18 collide with each other in the main body 15 and are pulverized, and the mortar component adhering to the surface of the crushed concrete V is peeled off and polished. When the rotation time of the main body 15 reaches a predetermined time, the rotation of the main body 15 stops, and the mixture of the crushed concrete V and the mortar adhering thereto is discharged from the discharge port 17 to complete the first grinding process. .

  The crushed concrete V discharged from the discharge port 17 of the grinding machine 10 in the first grinding process is supplied to the vibrating sieve 8, and the processing process shifts to the sorting process. In the sorting step, the crushed concrete V is divided into a gravel crushed stone portion having a diameter of 20 mm or more (hereinafter referred to as an oversized crushed stone portion U) and a large-diameter gravel crushed stone portion having a diameter of 20 to 8 mm (hereinafter referred to as the crushed concrete 8 , Coarse aggregate equivalent crushed material S1), gravel crushed stone portion having a diameter of 8 to 5 mm (hereinafter referred to as gravel equivalent crushed material S2), and fine aggregate equivalent crushed material S3 having a diameter of 5 mm or less. being classified. That is, the sand equivalent equivalent crushed material S2 is a coarse aggregate equivalent crushed material S1 crushed to a size corresponding to the coarse aggregate of the concrete crushed material V and a fine size crushed to a size equivalent to the fine aggregate. It has an intermediate size of the aggregate equivalent crushed material S3. The sandy equivalent crushed material S2 only needs to have a particle size within the above-mentioned range, but is preferably 15 mm or less, and more preferably 8 mm or less.

  The excessively large crushed stone U is equivalent to or slightly smaller than the concrete crushed material V supplied to the jaw crusher 3, and the concrete crushed material V is discharged without being sufficiently crushed by the grinding machine 10. is there. Therefore, the excess crushed stone U is returned to the inlet 16 of the grinding machine 10 as shown by the arrow in FIG. 1 and crushed again.

  The coarse aggregate-corresponding crushed material S1 contains a coarse aggregate component that can be used as a coarse aggregate as a main component, and includes mortar and impurities that adhere to these surfaces. Further, the sandy equivalent crushed material S2 and the fine aggregate crushed material S3 are mainly composed of fine aggregate components that can be used as fine aggregates. Contains impurities. When the concrete crushed material V is classified into three types according to the particle size in the separation step, the processing flow shifts from the pretreatment flow to the fine aggregate recovery flow and the coarse aggregate recovery flow.

  When the processing flow proceeds to the fine aggregate recovery flow, first, mixing is performed so that the sand equivalent equivalent crushed material S2 and the fine aggregate equivalent crushed material S3 selected by the vibration sieve 8 in the above-described separation step have a predetermined ratio by weight. Then, the intermediate crushed material P is prepared (mixing step). Here, the content of the fine aggregate equivalent crushed material S3 with respect to the total amount of the intermediate crushed material P is desirably 70% or less by weight, and more preferably 50% or less.

  When the preparation of the intermediate crushed material P is completed in the mixing step, the processing step shifts to the second grinding step. In the second grinding process, the grinding machine 10 is used as in the first grinding process. In the second grinding process, the crushed material P is put into the grinding machine 10, and when the main body 15 is rotated and polished, the crushed material P is crushed and softer than the aggregate component adhering to the surface. As the part peels off, the aggregate component is exposed. When a predetermined time elapses after the crushed material P is put into the grinding machine 10 and grinding is started, the rotation of the main body 15 is stopped. After the main body 15 stops rotating, when the mixture of the recycled fine aggregate N and the mortar portion M adhering thereto is discharged from the discharge port 17, the second grinding process is completed.

  The recycled fine aggregate N discharged from the grinding machine 10 through the second grinding process is discharged in a state in which impurities such as mortar M and wood chips that are atomized at the time of peeling are mixed. Therefore, the mixture of the regenerated fine aggregate N and the mortar content M is put into the spiral classifier 25 and separated into the regenerated fine aggregate (sand) N and the waste containing the mortar content M and impurities. Waste such as mortar M is separated from water by the thickener 26 and discarded.

  On the other hand, the coarse aggregate equivalent crushed material S1 selected by the vibration sieve 8 in the separation process described above is input to the specific gravity sorting device 30 as shown in FIG. 1, and the treatment process proceeds to the coarse gravel separation process.

  Here, the coarse aggregate equivalent crushed material S1 is mainly composed of the regenerated coarse aggregate R from which the mortar M adhering to the surface has been removed by crushing and grinding by the grinding machine 10, and the vibrating sieve 8 Some pulverized mortar M, impurities, etc., which could not be removed in FIG. The coarse aggregate equivalent crushed material S <b> 1 also contains a coarse aggregate-like mortar M which has been hardened to the same particle size as the recycled coarse aggregate R and could not be crushed by the grinding machine 10. Therefore, the coarse aggregate equivalent crushed material S <b> 1 is input to the specific gravity sorting device 30 in order to sort these and collect the recycled coarse aggregate R.

  When coarse aggregate equivalent crushed material S1 is thrown into specific gravity sorter 30, processing process will shift to a rough gravel separation process. As shown in FIG. 4, a water tank 31 in which separation water is stored is provided. In the water tank 31, a mesh-like screen plate 33 having a large number of through holes 32 is installed substantially horizontally so as to be immersed in the separation water. The upper portion of the screen plate 33 functions as a separation chamber 34 for separating the coarse aggregate equivalent crushed material S1. The lower part of the screen plate 33 is divided into three sections, and a first tank 36a, a second tank 36b, and a third tank 36c are formed. The lower end portion of each tank is opened, and the heavy aggregate that falls from the through hole 32 of the screen plate 33 can be discharged.

  Air chambers 37a, 37b, and 37c that open downward are provided in the first, second, and third tanks 36a, 36b, and 36c, respectively. Each of the air chambers 37a, 37b, and 37c is configured to be able to forcibly introduce air from the outside independently and to suck and discharge the air inside the air chambers 37a, 37b, and 37c. The specific gravity sorting device 30 is configured such that air supply / exhaust to the air chambers 37a, 37b, and 37c is repeated at a predetermined cycle. In addition, the timing of air supply / exhaust in each air chamber 37a, 37b, 37c is gradually shifted from the upstream side (first tank 36a side) to the downstream side (third tank 36c side). Therefore, when the specific gravity sorter 30 operates, the water level in the water tank 31 moves up and down with the supply and exhaust of air in the air chambers 37a, 37b, and 37c, and the separation water in the water tank 31 flows from the upstream side toward the downstream side. Ripples.

  A shooter 41 is provided at the downstream end of the water tank 31, that is, downstream of the third tank 36 c, and an inlet 43 (intake portion) that opens toward the separation chamber 34 is provided at the upper end of the shooter 41. ing. A rotary gate 45 that is rotated by a motor is provided inside the inlet 43. The inlet 43 of the shooter 41 is opened over a predetermined height from the upper surface of the screen plate 33, and the upper end of the opening is at a position lower than the water level for separation in the water tank 31. A cut gate 46 for moving in the vertical direction and adjusting the opening degree of the inlet 43 is disposed at the inlet 43 of the shooter 41.

  Above the inlet 43 of the shooter 41, a take-out part 47 for discharging the coarse aggregate equivalent crushed material S1 accumulated in the separation chamber 34 and having a light specific gravity accumulated on the upper side is provided. Yes. The take-out portion 47 and the inlet 43 are partitioned by a partition wall 48 (boundary portion). The partition wall 48 is inclined outward and downward in order to smoothly and naturally flow the aggregate material having a small specific gravity overflowing from the water tank 31 to the outside of the water tank 31.

  The coarse aggregate equivalent crushed material S1 thrown into the water tank 31 floats and settles in the water tank 31 on the pulsation of water for separation generated in the water tank 31 in accordance with the operation of the specific gravity sorting device 30, and gradually downstream. Flowing into. The mortar and impurities in the coarse aggregate equivalent crushed material S1 have a larger floating force when the water flow is generated than the recycled coarse aggregate R, and the amount of sedimentation when the water flow is stopped is small. Therefore, after the coarse aggregate equivalent crushed material S1 is charged, when the specific gravity sorting device 30 continues to operate, the regenerated coarse aggregate R settles down in layers based on the difference in floating force and sedimentation amount in water, Above that, a mortar portion M solidified into a coarse aggregate is accumulated. In addition, the light aggregates such as the fine aggregate-corresponding crushed material S3 and the fine mortar portion M are partly piled upward, and the remainder floats above the separation water. In practice, the amount of mortar M attached to the surface of the recycled coarse aggregate R is not uniform depending on the degree of crushing and grinding in the grinding machine 10. Therefore, also about the layer of the reproduction | regeneration coarse aggregate R, the thing with much adhesion amount of the mortar part M moves upwards, and the thing with little adhesion of the mortar part M will dive below.

  Of the coarse aggregate equivalent crushed material S1 accumulated in layers on the downstream side of the water tank 31, the recycled coarse aggregate R having a large specific gravity passes through the cut gate 46 and is forcibly taken into the shooter 41 by the rotary gate 45. It is done. The recycled coarse aggregate R taken into the shooter 41 is discharged from the opening 50 below the shooter 41 and collected. Moreover, since the thing except the reproduction | regeneration coarse aggregate R is wastes with low utility value, such as the mortar part M and a wood chip, it is discarded after removing a water | moisture content in the thickener 26. FIG.

  As described above, in the method for producing a recycled fine aggregate according to the present embodiment, the concrete aggregate V crushed S3 from the concrete crushed V ground in the first grinding step and sand having a larger particle size than this. The actual equivalent crushed material S2 is selected, and the intermediate crushed material P obtained by mixing them in a predetermined ratio is subjected to a grinding process in the second grinding process. Therefore, in the second grinding step, the intermediate crushed material P is crushed to expose the fine aggregate component, and the amount of mortar M attached to the surface of the fine aggregate component is reduced. In addition, since the intermediate crushed material P includes the sandy equivalent crushed material S2 having a particle size larger than that of the fine aggregate crushed material S3, the crushed material P is said to be so-called “zero” even if it is ground in the second grinding process. It is not crushed to a fine powder state like what is called. Therefore, according to the method for producing a recycled fine aggregate of the present embodiment, the amount of mortar M attached from the crushed concrete V is small, the water absorption rate and the like are stable, and the virgin fine aggregate is substituted. Recycled fine aggregate N suitable as a product can be recovered with high yield.

  Moreover, in the manufacturing method of the reproduction | regeneration fine aggregate N of this embodiment, the sand substance equivalent crushed material S2 and the fine aggregate equivalent crushed material S3 which were selected by the selection process are mixed to a predetermined ratio by the mixing process, and the intermediate crushed material It is set as P and it is set as the structure which grinds this by a 2nd grinding process. Therefore, according to the manufacturing method of this embodiment, regardless of the quality and composition of the concrete waste lump (concrete lump B) used as the raw material of the recycled fine aggregate N, the sand equivalent equivalent crushed material S2 and the fine aggregate equivalent crush The grinding process can be performed in the second grinding process in a state where the product S3 is mixed in a desired ratio. Therefore, according to the manufacturing method of the present embodiment, it is possible to provide the reclaimed fine aggregate N adjusted to a desired particle size distribution regardless of which concrete block B is used as a raw material.

  In the above embodiment, an example is shown in which the sandstone equivalent crushed material S2 and the fine aggregate equivalent crushed material S3 are polished in the first grinding process and selected in the sorting process. However, the present invention is not limited to this, and sandstone-equivalent crushed material S2 or fine aggregate-equivalent crushed material S3 may be generated in another production flow or the like.

  According to the method for producing a recycled fine aggregate of the above embodiment, what has conventionally been discarded as what is called “sandy” can be effectively used as the sandy equivalent crushed material S2. Therefore, according to the manufacturing method of this embodiment, the concrete crushed material V can be effectively used to the maximum, and a high-quality recycled fine aggregate N can be provided.

  According to the method for producing a recycled fine aggregate of the above embodiment, the amount of mortar M attached to the surface of the recycled fine aggregate N can be reduced without excessively crushing the crushed concrete V. Therefore, according to the above-described method for producing recycled fine aggregate, the second grinding process is continued until the mortar component M adhering to the fine aggregate component N becomes 25% or less of the recycled fine aggregate N by weight. Therefore, it is possible to provide an extremely high quality recycled fine aggregate N. Moreover, according to the manufacturing method described above, the grinding treatment can be performed until the water absorption rate of the regenerated fine aggregate N becomes 5% or less. Therefore, according to the above-mentioned method for producing recycled fine aggregate, the recycled fine bone defined in “Provisional quality standard (draft) by use related to reuse of concrete by-products” (former Ministry of Construction Technical Development No. 88) A high-quality recycled fine aggregate N that satisfies the quality of the material (one type) can be provided.

  In the present embodiment, since the recycled fine aggregate N is recovered through the first grinding process and the second grinding process, most of the mortar portion M peeled off by grinding or polishing is crushed and pulverized. Therefore, there is a possibility that it cannot be sufficiently separated by the dry classification method. However, in the present embodiment, in the second grinding process, a mixture mainly composed of the regenerated fine aggregate N and the mortar content M is charged into the spiral classifier 25 and wet-classified. Therefore, according to the manufacturing method of the present embodiment, it is possible to provide a high-purity recycled fine aggregate N with less mortar M mixing.

  In the said embodiment, although the example which employ | adopted the rod rod 18 as the grinding process member in the 1st and 2nd grinding process was illustrated, this invention is not limited to this, For example, it is generally used as an aggregate. It is also possible to substitute the same kind of rocks or ceramic balls, or use rod rods 18 together with rocks or balls.

  In the above embodiment, the crushed material P is ground using the grinding machine 10 having the same configuration as that used in the first grinding process in the second grinding process. It is also possible to grind using a grinding machine 11 as shown in FIG.

  More specifically, the grinding machine 11 has a cylindrical main body 60 (stirring chamber) having openings at both ends as shown in FIG. The main body 60 has a hollow shape, and the intermediate crushed material P and a large number of polishing stones 61 are accommodated therein. The grinding stone 61 is used for grinding the crushed material P in place of the rod rod 18 employed in the grinding machine 10 described above. The polished stone 61 is a mixture of rocks having a large particle size and small rocks in a predetermined weight ratio. The grinding stone 61 has a hardness comparable to that of the sandstone-equivalent crushed material S2 and the fine aggregate-equivalent crushed material S3, and is sufficiently stronger than the rod 18 used as a grinding member in the first grinding process. Is low.

  More specifically, the polished stone 61 can be of the same type as that generally used as an aggregate, such as andesite, basalt, porphyry, granite and other igneous rocks. It is possible to employ all rocks and ceramics including metamorphic rocks such as slate and schist, sedimentary rocks such as sandstone and limestone. The grinding stone 61 may be cracked or chipped with the grinding of the sandy equivalent crushed material S2 or the fine aggregate crushed material S3. Therefore, in order to prevent the purity of the product from deteriorating due to mixing of the fragments of the polishing stone 61, the polishing stone 61 is of the same quality as the sandstone equivalent crushed material S2 and the fine aggregate equivalent crushed material S3. It is desirable.

  The polishing stone 61 may have various particle sizes, but even if the particle size is uniform, it is adjusted to have a predetermined particle size distribution. May be. More specifically, for the polished stone 61, for example, rocks are classified into a plurality of groups for each particle size, and the one adjusted to have a predetermined particle size distribution by appropriately adjusting the blending ratio is used. Can do. More specifically, the polished stone 61 is classified into, for example, rocks having a particle size of 100 to 80 mm, particles having a particle size of 80 to 60 mm, particles having a particle size of 60 to 40 mm, and particles having a particle size of 40 mm or less. And each compounding ratio can mix | blend with a predetermined ratio by weight ratio, and can adjust the particle size distribution. The polishing stone 61 is input until the grinding machine 11 is about 1/3 to 1/4 of the inner diameter r of the main body 60 when the grinding machine 11 is stopped.

  In the main body 60, a raw material input port 62 for introducing the intermediate crushed material P is formed on one end side in the axial direction, and a processing stone input port 63 for supplying polishing stone 61 and water is formed on the other end side. Has been. The main body 60 has a discharge port 65 formed on a cylindrical surface on the processing stone input port 63 side, that is, on the side opposite to the processing stone input port 63. The discharge port 65 is provided with a net 66 having a size that allows fine aggregates to pass through, that is, an opening of about 5 mm.

  The main body 60 can be rotated about the central axis X by a driving device (not shown). A plurality of stirring blades 67 are provided on the inner peripheral surface of the main body 60 at equal intervals over the entire periphery. All of the stirring blades 67 extend along the central axis X of the main body 60 and protrude in the direction of the central axis X. The stirring blade 67 is for scraping up and stirring the polishing stone 61 and the fine aggregate-corresponding crushed material S3 that are thrown in along with the rotation of the main body 60 along the inner peripheral surface.

  When grinding the crushed material P by the grinding machine 11, the crushed material P and water are put together into the main body 60 of the grinding machine 11. The ratio of the water and the crushed material P introduced from the raw material inlet 62 can be adjusted as appropriate. However, when considering the grinding efficiency, the ratio of the water and the crushed material P is about 2: 3 to 2: It is desirable to adjust to about 5.

  When the main body 60 is rotated in a state where the halfway crushed material P, water, and the grinding stone 61 are put into the main body 60, the halfway crushed material P and the grinding stone 61 are stirred and slid in the water. Further, some of the partially crushed material P and the polishing stone 61 are scraped up by the stirring blade 67 attached to the inner peripheral surface of the main body 60 and fall into the main body 60, and are subjected to the accompanying impact. Further, in the main body 60, the fine aggregate equivalent crushed material S3 and the sandstone equivalent crushed material S2 rub against each other, so that the surface of the fine aggregate equivalent crushed material S3 is polished and adhered to the surface. Is scraped off. That is, since the grinding machine 11 uses the grinding stone 61 having the same degree of hardness as the aggregate component, it is compared with the case where the grinding process is performed by the grinding machine 10 using the iron rod rod 18 or the like. Thus, the impact on the crushed material P is small. Therefore, when the grinding process is performed by the grinding machine 11, the soft mortar portion M adhering to the surface of the fine aggregate component is crushed, and the mortar portion M is peeled off from the surface of the fine aggregate component. Is polished and the fine aggregate component N is exposed.

  When the mortar portion M adhering to the surface of the sandstone-equivalent crushed material S2 and fine aggregate-equivalent crushed material S3 is sufficiently scraped off, the regenerated fine particle having a particle diameter of about 5 mm with almost no mortar content M adhering to the surface. Aggregate N is obtained. The recycled fine aggregate N passes through the mesh body 66 of the discharge port 65 on the downstream side of the main body 60 and is discharged.

  As described above, according to the grinding machine 11, the intermediate crushed material P ground in the first grinding process is polished in the second grinding process and remains slightly on the surface of the fine aggregate component. The mortar content M can be scraped off. Therefore, according to the grinding machine 11, an excessive impact is not applied to the sandy equivalent crushed material S2 and the fine aggregate crushed material S3 constituting the intermediate crushed material P at the time of the second grinding process, and the fine aggregate The quality and yield of the reclaimed fine aggregate N due to cracking or chipping of the components do not decrease.

  Further, as described above, when the sand grinding equivalent crushed material S2 and the fine aggregate equivalent crushed material S3 are mixed and subjected to the grinding process in the second grinding process, the sand berries equivalent crushed material S2 and the fine aggregate equivalent are obtained. The crushed material S3 rubs. Since the fine aggregate equivalent crushed material S3 has a smaller particle size than the sandy particle equivalent crushed material S2, the mortar portion M adhering to the surface of the sandstone equivalent crushed material S2 is somewhat polished and scraped off. I can expect. Therefore, according to the manufacturing method described above, the quality of the recycled fine aggregate N can be improved.

  As described above, the grinding stone 61 is made of gravel or crushed stone, has the same hardness as the recycled fine aggregate N, and is sufficiently lower in strength than the grinding member such as the rod 18. On the other hand, the mortar portion M adhering to the surface of the sandstone equivalent crushed material S2 and the fine aggregate equivalent crushed material S3 has a crushing strength lower than that of the polishing stone 61. Therefore, when the intermediate crushed material P and the polishing stone 61 are stirred in water in the second grinding step, the surface of the intermediate crushed material P is polished without crushing the fine aggregate components, and the mortar portion M is scraped off. Can do.

  Tables 1 to 3 show test data on the regenerated fine aggregate collected by the aggregate collection method described in the above embodiment. As shown in Tables 1 to 3, in the present example, the ground mill 10 is used to remove the intermediate crushed material P (P1, P2, P3) having a different mixing ratio between the sand equivalent crushed material S2 and the fine aggregate crushed material S3. The regenerated fine aggregate N obtained by grinding was subjected to grinding (second grinding process), and the particle size distribution, water absorption rate, and coarse particle rate were examined. In addition, the judgment test of the particle size required for examining the particle size distribution of the recycled fine aggregate was carried out by the method prescribed in the “aggregate screening test” defined in JIS A1102. Moreover, the determination test of the surface dry saturation state of the aggregate necessary for obtaining the water absorption rate of the fine aggregate is based on the “fine aggregate density and water absorption test method” defined in JIS A 1109. went. In addition, a washing test was performed on the above-mentioned crushed material P2 based on the method prescribed in “Aggregate washing test method” prescribed in JIS A 1103.

  In this embodiment, the intermediate crushed materials P1, P2, and P3 have different mixing ratios between the sandy equivalent crushed material S2 and the fine aggregate crushed material S3. The intermediate crushed material P1 is obtained by mixing the sandy equivalent crushed material S2 and the fine aggregate crushed material S3 in a weight ratio of 1: 2. That is, the halfway crushed material P1 includes about 66.7% of the fine aggregate equivalent crushed material S3 with respect to the total amount of the halfway crushed material P1. The intermediate crushed material P2 is obtained by mixing the sandy equivalent crushed material S2 and the fine aggregate crushed material S3 at a mixing ratio of 1: 1, and the fine aggregate equivalent crushed material with respect to the total amount of the intermediate crushed material P2. 50% of S3 is included. The intermediate crushed material P3 is obtained by mixing the sand equivalent crushed material S2 and the fine aggregate crushed material S3 at a mixing ratio of 2: 1, and the fine aggregate equivalent crushed material with respect to the total amount of the intermediate crushed material P3. S3 is contained about 33.3%.

(Particle size distribution)
The particle size distribution of the recycled fine aggregate N obtained by grinding with the grinding machine 10 on the above-mentioned crushed materials P1, P2, P3 was examined. As a result, as shown in Tables 1 to 3 and FIG. 6, the regenerated fine aggregate N obtained by processing the midway crushed material P1, P2, P3 has a small content of the fine aggregate equivalent crushed material S3. It was found that the particle size distribution shifted to the larger particle size. In addition, the recycled fine aggregate N obtained by processing the halfway crushed material P1, P2, and P3 are all provisional quality standards (draft) according to use related to the reuse of concrete byproducts (April 11, 1994, Ministry of Construction It was found that it is within the range of the particle size distribution of the regenerated fine aggregate as defined in Idemitsu No. 88) and is well used as a substitute for fine aggregate.

(Water absorption rate)
The water absorption rate of the recycled fine aggregate N obtained by grinding with the grinding machine 10 on the above-mentioned crushed material P1, P2, P3 was examined. As a result, as shown in Tables 1 to 3 and FIG. 7, the regenerated fine aggregate N obtained by processing the midway crushed material P1, P2, P3 has a small content of the fine aggregate equivalent crushed material S3. It was found that the water absorption rate tends to decrease. In addition, the recycled fine aggregate N obtained by processing the halfway crushed material P1, P2, and P3 are all provisional quality standards (draft) according to use related to the reuse of concrete byproducts (April 11, 1994, Ministry of Construction It has been found that the recycled fine aggregate (1 type) specified in the Coordination No. 88) is within the range of water absorption (5% or less) and is well used as a substitute for fine aggregate.

(Coarse grain ratio)
About the above-mentioned crushed material P1, P2, P3, the coarse-grain rate was investigated about the reproduction | regeneration fine aggregate N obtained by grinding with the grinder 10. As a result, as shown in Tables 1 to 3 and FIG. 8, the recycled fine aggregate N obtained by processing the halfway crushed materials P1, P2, and P3 are tentative quality standards for each use related to the reuse of concrete by-products. (Draft) Range of coarse grain ratio derived from the standard grain size of recycled fine aggregate as defined in (April 11, 1994, Ministry of Construction, Technical Development No. 88) (1.95-3. 43) and was found to replace virgin fine aggregate.

(Wash test)
A washing test was performed on the above-mentioned midway crushed material P2. An intermediate dry weight P50 of 500.0 g was prepared and subjected to a washing test. As a result, the absolute dry weight after the washing test was 498.8 g, and the loss rate was 0.24% or less. Under the provisions of the provisional quality standard (draft) for reuse of concrete by-products (draft) (April 11, 1994, Ministry of Construction, Technical Development No. 88), the loss rate of recycled fine aggregates (1, 2) is 5 In view of the fact that it is set as% or less, it was found that the intermediate crushed material P2 of this example greatly exceeds the above-mentioned standard and is sufficient as a substitute for fine aggregate.

  As described above, if the intermediate crushed material P (P1, P2, P3), in which the mixing ratio of the sandy equivalent crushed material S2 and the fine aggregate crushed material S3 is adjusted, is polished in the second grinding process, According to the provisional quality standard (draft) by use related to the reuse of concrete by-products, that is, the quality of replacing concrete by aggregate (April 11, 1994, Ministry of Construction, Technical Development No. 88) It turned out that a fine recycled fine aggregate exceeding the quality defined as an aggregate can be obtained. Further, considering the particle size distribution, the water absorption rate, the coarse particle rate, etc., the intermediate crushed material P is adjusted so that the content of the fine aggregate equivalent crushed material S3 is about 30% to 70% with respect to the total amount. It has been found that refining fine aggregates with quality comparable to virgin fine aggregates can be obtained by grinding in the grinding process.

It is the conceptual diagram which showed typically the manufacturing method of the reproduction | regeneration fine aggregate which is one Embodiment of this invention. It is a conceptual diagram which shows the flow of the manufacturing process of the reproduction | regeneration fine aggregate which is one Embodiment of this invention. It is a conceptual diagram which shows the grinding machine used in the manufacturing method of the reproduction | regeneration fine aggregate which is one Embodiment of this invention. It is a conceptual diagram which shows the specific gravity selection apparatus used in the manufacturing method of the reproduction | regeneration fine aggregate which is one Embodiment of this invention. It is a conceptual diagram which shows the grinding machine used in the manufacturing method of the reproduction | regeneration fine aggregate which is one Embodiment of this invention. It is a graph which shows the particle size distribution of the reproduction | regeneration fine aggregate which is one Example of this invention. In the reproduction | regeneration fine aggregate which is one Example of this invention, it is a graph which shows the relationship between content of the fine aggregate equivalent crushed material contained in the middle crushed material, and the water absorption rate of a reproduction | regeneration fine aggregate. In the reproduction | regeneration fine aggregate which is one Example of this invention, it is a graph which shows the relationship between content of the fine aggregate equivalent crushed material contained in a halfway crushed material, and the coarse grain rate of a reproduction | regeneration fine aggregate.

Explanation of symbols

10,11 Grinding machine 15,60 Main body (stirring chamber)
18 Rod rod (Abrasive processing material)
25 Spiral classifier 61 Polished stone S1 Crushed material equivalent to coarse aggregate S2 Sanded stone equivalent crushed material S3 Fine aggregate equivalent crushed material N Recycled fine aggregate M Mortar content V Concrete crushed material B Concrete lump (concrete waste)
P Midway crushed material

Claims (11)

A first grinding step in which a crushed concrete containing fine aggregate components and a grinding treatment member having a higher strength than the crushed concrete are crushed by sliding in a liquid;
Fine aggregate equivalent crushed material with a particle size equivalent to fine aggregate from the crushed concrete ground in the first grinding process, and sand equivalent equivalent crushed with a larger diameter than the fine aggregate equivalent crushed material A sorting process for sorting objects,
The fine aggregate component is obtained through the second grinding process in which the fine aggregate equivalent crushed material and the sandstone equivalent crushed material are mixed at a predetermined ratio and the grinding treatment member is crushed by sliding in the liquid. A method for producing recycled fine aggregate to be recovered. A first grinding step in which a crushed concrete containing fine aggregate components and a grinding treatment member having a higher strength than the crushed concrete are crushed by sliding in a liquid;
Fine aggregate equivalent crushed material with a particle size equivalent to fine aggregate from the crushed concrete ground in the first grinding process, and sand equivalent equivalent crushed with a larger diameter than the fine aggregate equivalent crushed material A sorting step for sorting the intermediate crushed material constituted by one or both of the objects,
A method for producing a reclaimed fine aggregate that recovers fine aggregate components through a second grinding step in which a ground crushed material and a grinding treatment member having a crushing strength lower than that of the grinding treatment member are rubbed together in a liquid and polished. .   3. The recycled fine aggregate according to claim 2, wherein the second grinding step is a step of polishing an intermediate crushed material in which a fine aggregate equivalent crushed material and a sandstone equivalent crushed material are mixed at a predetermined ratio. Manufacturing method.   The method for producing a recycled fine aggregate according to claim 2 or 3, wherein the polishing member contains one or both of gravel and crushed stone.   5. The crushing strength of gravel and crushed stone constituting the polishing member used in the second grinding process is higher than the crushing strength of mortar contained in the concrete waste material. A method for producing a recycled fine aggregate as described in 1. above.   6. The gravel and crushed stone constituting the polishing member are classified into a plurality of groups according to the particle diameter, and the mixing ratio of the groups is adjusted to a predetermined ratio. Manufacturing method of recycled fine aggregate.   The crushed sand equivalent crushed material has a particle size of 15 mm or less among the crushed concrete obtained through the first grinding step, The recycled fine aggregate production according to any one of claims 1 to 6, Method.   The crushed sand-equivalent crushed material is a concrete crushed material that has undergone the first grinding step, and has a particle size of 8 mm or less, The production of recycled fine aggregate according to any one of claims 1 to 6 Method.   The method for producing a regenerated fine aggregate according to any one of claims 1 to 8, wherein the fine aggregate-corresponding crushed material is contained in an amount of 30% to 70% by weight with respect to the total amount of the intermediate crushed material. .   The second grinding step until the mortar component adhering to the fine aggregate component becomes 25% or less of the recycled fine aggregate by weight by the method for producing the recycled fine aggregate according to any one of claims 1 to 9. Recycled fine aggregate produced by performing   A recycled fine aggregate produced by performing the second grinding step until the water absorption becomes 5% or less by the method for producing a recycled fine aggregate according to any one of claims 1 to 9. .

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