JP2018199273A - Method of manufacturing mixture using leftover ready-mixed concrete - Google Patents

Abstract

To provide a method of manufacturing a mixture using leftover ready-mixed concrete capable of easily, by using an agitator car, modifying the ready-mixed concrete left over at a construction site or the like into a new mixture and cleaning an interior of a drum of the agitator car.SOLUTION: A granular flowability lowering agent 2 having a structure in which fibers are intertwined is charged into a drum 11 of an agitator car 10 in a state where leftover ready-mixed concrete 1 is stored in the drum 11 so that the ready-mixed concrete 1 and the flowability lowering agent 2 are stored in the drum 11. Then, the ready-mixed concrete 1 and the flowability lowering agent 2 are agitated and mixed to form a mass 4 by rotating the drum 11 of the agitator car 10 storing the ready-mixed concrete 1 and the flowability lowering agent 2, and the formed mass 4 is discharged from an opening portion 12 of the drum 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a mixture using residual ready-mixed concrete, and more specifically, ready-mixed concrete remaining at a construction site or the like can be easily modified into a new mixture using an agitator car, and The present invention relates to a method for producing a mixture using residual green concrete capable of cleaning the inside of a drum.

  As a means for transporting ready-mixed concrete (hereinafter referred to as ready-mixed concrete) made in a manufacturing plant to a construction site, an agitator vehicle (truck mixer, ready-mixed vehicle) having a drum that can rotate in a loading platform portion is used. In construction sites and the like, if there is a shortage of ready-mixed food in the middle of construction, the work will be delayed, so it is common to carry in slightly more ready-made food than the amount actually used. Therefore, some raw concrete remains at construction sites.

  The remaining ready-mixed concrete is returned to the ready-mixed factory and separated into sludge water, fine aggregate, and coarse aggregate by a cleaning process. This cleaning process requires a lot of labor and cost. There is a method in which the remaining raw concrete is discharged outside the agitator car and solidified, then crushed, and then crushed into a crushed stone. However, the crushing operation requires a lot of time and labor.

  On the other hand, with respect to the agitator wheel, water is poured into the drum using a hose, and the drum in which water has entered is rotated to clean the inside of the drum to which the raw concrete is attached. Also, a worker regularly enters the drum and manually removes the lump of concrete that has adhered to the inner wall of the drum and the mixing blade and solidified using a spatula or the like. As a method for effectively cleaning the inside of the drum, a method of cleaning the inside of the drum by jetting water at a high pressure has been proposed. In this case, however, a large-scale apparatus is required (for example, see Patent Document 1). ). In addition, in this method, since a large amount of sewage is generated after cleaning the inside of the drum, the treatment of sewage is also a problem.

  By the way, the fluidity reducing agent used in order to improve the excavation soil etc. which were obtained at the construction site is proposed (refer patent documents 2 and 3). This fluidity reducing agent contains particulates having a structure in which fibers are entangled, and when mixed with excavated soil, moisture and soil particles in the soil are physically constrained by voids formed by the entanglement of fibers. Due to this characteristic, the excavated soil can be improved to a reinforcing improved soil having a practically sufficient strength. The inventors of the present application paid attention to the characteristics of the fluidity reducing agent, and as a result of various studies, have come up with the present invention.

JP 2004-195446 A Japanese Patent No. 59331267 Japanese Patent No. 5959709

  The purpose of the present invention is to use the remaining ready-mixed concrete that can be easily modified into a new mixture using an agitator car and the inside of the drum of the agitator car can be cleaned. It is in providing the manufacturing method of the mixture which was.

  In order to achieve the above object, a method for producing a mixture using residual ready-mixed concrete according to the present invention includes a drum for an agitator vehicle containing a residual ready-mixed concrete and a granular fluidity reducing agent having a structure in which fibers are intertwined. By rotating, the ready-mixed concrete and the fluidity reducing agent are agitated and mixed to form a lump, and the lump is discharged from the opening of the drum.

  According to the present invention, it is possible to produce a massive body in which both of them are united by simply rotating and rotating the drum of an agitator wheel containing the remaining ready-mixed concrete and the fluidity reducing agent. In this way, the lump obtained by modifying ready-mixed concrete can be effectively used as a landfill material. In addition, there is a merit that it can also be used for processing the ready-mixed concrete remaining at the construction site. Furthermore, in the process of manufacturing the lump, the fluidity reducing agent and the ready-mixed concrete adhering to the inner wall of the drum and the mixing blade are mixed inside the rotating drum and gradually grow as a lump. Since the ready-mixed concrete is taken in as a constituent member of the massive body, it is removed from the inner wall of the drum and the mixing blade to clean the inside of the drum. Accordingly, the time and labor required for cleaning the agitator vehicle can be significantly reduced. Since the agglomerates are produced using the moisture contained in the ready-mixed concrete, it is not necessary to use additional water, or even when water is added, the amount of water used is extremely small, and sewage Hardly occurs.

  When the main component of the fiber constituting the fluidity reducing agent is a hydrophilic polymer such as cellulose, since it has a large number of hydrophilic groups, it is contained in the ready-mixed concrete that has penetrated into the continuous void formed by the fiber. An electric attractive force acts between the moisture and the fiber. Therefore, since the water that has entered the communicating gap is restrained, the fluidity of the ready-mixed concrete is lowered, and it becomes easy to manufacture a lump.

  Furthermore, when the weight of the fluidity reducing agent mixed with the ready-mixed concrete is set to, for example, 5% or more and 17% or less of the weight of moisture contained in the ready-mixed concrete, it becomes easier to produce a lump.

  The fluidity reducing agent can be put into the drum while still in a bag formed of alkali-dissolved paper. Although the granular fluidity reducing agent is likely to be scattered, the fluidity reducing agent can be prevented from scattering by being put in a bag. Since the bag formed of the alkali-dissolved paper is dissolved by the alkaline ready-mixed concrete, the bag does not remain even when the fluidity reducing agent is put in the bag.

It is explanatory drawing which illustrates in a side view the state which introduce | transduces a fluidity reducing agent into the drum of the agitator vehicle of the state which accommodated the ready-mixed concrete, seeing through the inside of a drum. It is explanatory drawing which illustrates the state which is rotating through the drum which accommodated the ready-mixed concrete and a fluidity reducing agent, and is stirring and mixing, seeing through the inside of a drum, and side view. It is explanatory drawing which illustrates the state which discharged the manufactured lump to the exterior of a drum, seeing through the inside of a drum, and side view.

  Hereinafter, the manufacturing method of the mixture using the ready-mixed concrete of this invention is demonstrated based on embodiment shown in the figure. In addition, in FIGS. 1-3, the inside of the drum of an agitator vehicle is visualized and shown with the broken line.

  As shown in FIG. 1, after the ready-mixed concrete 1 (hereinafter referred to as the ready-mixed concrete 1) is carried into the construction site or the like by the agitator vehicle 10, some of the ready-mixed concrete 1 remains. In the present invention, a clump that can be used as a landfill material, a banking material, or the like is manufactured by skillfully utilizing the remaining raw concrete 1 and the fluidity reducing agent 2 that has been conventionally used for improving excavated soil and the like.

  The agitator wheel 10 includes a rotatable cylindrical drum 11 that accommodates the raw control unit 1 in a cargo bed portion. The drum 11 is arranged with the drum cylinder axis direction facing the longitudinal direction of the vehicle body of the agitator wheel 10, and is installed in the vehicle body in an inclined state with the rear side of the main body higher than the front side. An opening 12 is provided on the upper side of the drum 11 (upper left side of the drum 11 in FIGS. 1 to 3). A spiral mixing blade 13 (hereinafter referred to as a spiral mixing blade 13) along the inner wall surface of the drum 11 is provided inside the drum 11. , Referred to as a blade 13).

  When the drum 11 is rotated in one direction, the raw control unit 1 accommodated in the drum 11 is agitated by the blade 13 while being pushed into the lower side of the drum 11 (lower right side of the drum 11 in the figure). When rotating in the direction, the blades 13 are used to feed the raw control unit 1 to the upper side of the drum 11 so that the raw control unit 1 is discharged from the opening 12. On the upper side of the opening portion 12, there is provided a feeding portion 14 (hopper) communicating with the opening portion 12 for feeding the raw kon 1 and the raw konto 1 material into the drum 11, and below the opening portion 12. A discharge portion 15 (scoop, chute) that communicates with the opening portion 12 for guiding the ready-mixed container 1 discharged from the opening portion 12 to the unloading position is provided.

  As shown in FIG. 1, in the present invention, first, the fluidity reducing agent 2 is introduced into the drum 11 in a state where the raw concrete 1 remaining on the drum 11 of the agitator wheel 10 is accommodated. The fluidity reducing agent 2 is contained.

The fluidity reducing agent 2 used in the present invention is a granular material (powder) having a structure in which fibers are intertwined. This granular material has an average particle diameter of 300 μm or less, and a specific surface area according to the BET method of 0.25 m ² / g to 100 m ² / g, or (1-bulk density / true density) × 100. The porosity is 50% or more, and the specific surface area by the BET method is 0.25 m ² / g or more and 100 m ² / g or less. The average particle diameter here is an average value of particle diameters measured under an optical microscope.

  As the fiber constituting the fluidity reducing agent 2, for example, a fiber containing a hydrophilic polymer is preferable. Examples of the hydrophilic polymer include cellulose, polyvinyl alcohol, polyalkylene glycol (for example, polyethylene glycol and polypropylene glycol), and polyacrylic acid. As this fiber, cellulose is preferable because it has biodegradability and neutral pH (for example, around pH 8) and is excellent in low environmental load. The fluidity reducing agent 2 can be obtained, for example, by pulverizing a piece of paper such as shredder waste or waste paper with a mill.

The fluidity reducing agent 2 is an inorganic filler such as calcium carbonate (CaCO ₃ ), kaolin (Al ₄ Si ₄ O ₁₀ (OH) ₈ ), talc (Mg ₃ Si ₄ O ₁₀ (OH) ₂ ) as an optional component. May be included.

  In this embodiment, the fluidity reducing agent 2 is put in a bag 3 formed of alkali-dissolved paper and sealed. Then, the fluidity reducing agent 2 is charged into the drum 11 from the charging unit 14 while being put in the bag 3. The alkali-dissolved paper is a material that dissolves in an alkaline aqueous solution such as polyvinyl alcohol paper or polyvinyl alcohol-coated paper, and the ready-mixed paper 1 is alkaline. Therefore, the bag 3 made of alkali-dissolved paper enters the drum 11 and dissolves when it comes into contact with the green food 1. That is, the bag 3 does not remain in the drum 11 even if the fluidity reducing agent 2 is put in the bag 3.

  The granular fluidity reducing agent 2 is likely to scatter, but by handling the fluidity reducing agent 2 in the bag 3 as described above, the fluidity reducing agent 2 flows when the fluidity reducing agent 2 is transported or charged into the drum 11. The property lowering agent 2 can be prevented from scattering. Furthermore, by using the bag 3 formed of alkali-dissolved paper, the fluidity reducing agent 2 can be charged from the charging portion 14 while still in the bag 3, so that the fluidity reducing agent 2 is The efficiency of the work put into the drum 11 can be improved.

  The fluidity reducing agent 2 may be prepared in advance by dividing it into bags 3 for each predetermined weight (for example, 5 kg or 10 kg). By subdividing the fluidity reducing agent 2 into the bags 3, it becomes easy to grasp the weight of the fluidity reducing agent 2 to be put into the drum 11, so that the measurement of the fluidity reducing agent 2 on site is unnecessary. Even when the fluidity reducing agent 2 is added, the amount of the fluidity reducing agent 2 can be easily adjusted.

  Next, as shown in FIG. 2, the drum 11 in a state in which the ready-mixed material 1 and the fluidity reducing agent 2 are accommodated is rotated in one direction, whereby the ready-mixed material 1 and the fluidity-lowering agent 2 are stirred inside the drum 11. Mix.

  When the ready-mix 1 and the fluidity reducing agent 2 are stirred and mixed, the water and cement particles constituting the ready-mixed concrete 1 are filled with the minimal air (the air in which the communicating voids in the cotton-like structure of the fluidity reducing agent 2 are filled). Bubbles) and, together with these airs, are physically constrained to the communicating voids. When the fluidity reducing agent 2 contains a hydrophilic polymer such as cellulose, an electrical attractive force acts between the water molecules and the fibers constituting the voids due to the many hydrophilic groups of the hydrophilic polymer. Water entering the communication gap is more strongly restrained. Then, cement particles and aggregates, which are the raw material 1, are gathered together by the fluidity reducing agent 2, thereby forming a mass 4 in which the raw concrete 1 and the fluidity reducing agent 2 are united.

  In the process of manufacturing the lumps 4, the fluidity reducing agent 2 and the green concrete 1 attached to the inner walls of the drum 11 and the blades 13 are mixed inside the rotating drum 11 and gradually grow as the lumps 4. Go. The ready-mixer 1 attached to the inner wall of the drum 11 and the blade 13 is taken in as a constituent member of the lump 4 and thus removed from the inner wall of the drum 11 and the blade 13. In the process of the growth of the lump 4, even when the lump 4 collides with the inner wall of the drum 11 and the blade 13, the raw concrete 1 attached to the inner wall of the drum 11 and the blade 13 is removed.

  The mixing ratio of the ready-mixed food 1 and the fluidity reducing agent 2 is set to an appropriate ratio by test mixing or the like. When the fluidity reducing agent 2 is cellulose, the weight of the fluidity reducing agent 2 to be stirred and mixed with the ready-mixed material 1 is, for example, 5% to 17%, more preferably 8% of the weight of water contained in the ready-mixed material 1. % To 13%. By making the raw concrete 1 and the fluidity reducing agent 2 into this blending ratio, the lump 4 can be manufactured more easily. When the weight of the fluidity reducing agent 2 to be stirred and mixed is less than 5% of the weight of the water contained in the ready-mixed corn 1, the fluidity reducing agent 2 cannot sufficiently absorb the moisture of the ready-mixed corn 1 and It becomes difficult to collect 1 in a lump. On the other hand, when the weight of the fluidity reducing agent 2 to be stirred and mixed is larger than 17% of the weight of the water contained in the ready-mixed concrete 1, the fluidity reducing agent 2 may be excessive.

  The rotational speed of the drum 11 when the ready-mixed material 1 and the fluidity reducing agent 2 are agitated and mixed can be appropriately determined according to the size of the drum 11, the weight of the ready-mixed product 1, the amount of water contained in the ready-mixed product 1, etc. It may be rotated at a higher speed than the normal rotation speed when conveying 1. Specifically, for example, the rotation speed of the drum 11 is set to about 20 to 30 rpm (per rotation).

The time for stirring and mixing the raw food 1 and the fluidity reducing agent 2 can be appropriately determined according to the size of the drum 11, the weight of the raw food 1, the amount of water contained in the raw food 1, and the like. Specifically, for example, if the volume of the remaining raw cooking 1 is about 1 m ³ , the stirring and mixing time is about 2 to 5 minutes. When the mixing and mixing of the raw concrete 1 and the fluidity reducing agent 2 proceed sufficiently, and almost all of the raw concrete 1 becomes a lump 4, a sound is generated that causes the lump 4 to collide with the inner wall of the drum 11. It is also possible to determine the timing for finishing the stirring and mixing.

  In the case where the remaining raw concrete 1 has low fluidity, a small amount of water can be added to the inside of the drum 11 before the fluidity reducing agent 2 is introduced into the drum 11. By adding water and rotating the drum 11, the fluidity of the raw control unit 1 can be improved, and the raw control unit 1 attached to the inner wall of the drum 11 and the blade 13 can be easily removed. In this case, the weight of the fluidity reducing agent 2 to be added may be determined by taking into consideration the amount of water contained in the remaining raw kon 1 and the weight of the added water.

  Next, as shown in FIG. 3, after all the ready-mixed containers 1 in the drum 11 are formed in the lump 4, the drum 11 is rotated in the other direction to discharge the lump 4 from the opening 12 to the outside of the drum 11. Let The particle size of the mass 4 to be produced is, for example, about several mm to 40 mm. The manufactured lump 4 can be used, for example, as a landfill material or embankment material when forming a landfill site, a temporary work material in the field, a quarry stone under abandoned concrete, a roadbed material under pavement, etc. it can. When discharging the lump 4 from the drum 11, the ready-mixer 1 attached to the inner wall of the drum 11 and the blade 13 is reformed to the lump 4 and is almost removed.

  As described above, according to the present invention, the drum 11 of the agitator wheel 10 containing the remaining raw concrete 1 and the fluidity reducing agent 2 is rotated and the two are stirred and mixed together, so that the two bodies are naturally integrated. 4 can be manufactured. The lump 4 can be effectively used as a landfill material or a fill material. In addition, there is also an advantage that the raw concrete 1 remaining at the construction site or the like can be easily treated in a short time.

  Furthermore, in the process of manufacturing the lump 4, since the fluidity reducing agent 2 and the raw concrete 1 attached to the inner wall of the drum 11 and the blade 13 are taken in as a constituent member of the lump 4 in the rotating drum 11. Then, the attached raw concrete 1 is removed from the inner wall of the drum 11 and the blade 13 to clean the inside of the drum 11. In addition, even when the lump 4 collides with the inner wall of the drum 11 and the blade 13, the raw concrete 1 attached to the inner wall of the drum 11 and the blade 13 is effectively removed. Accordingly, the time and labor required for cleaning the agitator wheel 10 can be greatly reduced. The amount of water used for cleaning the drum 11 can be greatly reduced as compared to the conventional case, and sewage generated after the inside of the drum 11 is washed with water can be greatly reduced.

  Moreover, in this invention, since the lump 4 is manufactured using the water | moisture content contained in the raw kon 1, it is not necessary to use water additionally, or even when adding water, the usage-amount of water is Remarkably small amount. By using the fluidity reducing agent 2 obtained by pulverizing a piece of paper such as shredder waste or waste paper, it contributes to the effective utilization of recycled resources.

  Furthermore, when transporting the ready-mixed concrete 1 having high fluidity as it is, the transport means is limited to the agitator wheel 10, but in the present invention, the ready-made concrete 1 can be reformed into a solid lump 4, and thus manufactured. The lump 4 can be transported by a normal truck or the like. Since the particle size of the massive body 4 is small, loading and unloading operations during transportation can be easily performed.

  In the above embodiment, the case where the drum 11 is rotated after the fluidity reducing agent 2 is introduced is illustrated. However, the fluidity reducing agent 2 is introduced in a state where the drum 11 in which the raw control unit 1 is stored is rotated. In addition, stirring and mixing can be performed. In addition, for example, when the remaining raw kon 1 once discharged from the drum 11 is returned to the drum 11 again, the fluidity reducing agent 2 is added to the raw kon 1 on the outside of the drum 11, and then flows with the raw kon 1. It can also be put into the drum 11 together with the property lowering agent 2. Further, the fluidity reducing agent 2 can be directly put into the drum 11 without using the bag 3.

  An analysis was made on the amount of flowability reducing agent suitable for producing agglomerates for samples of six ready-mixed concretes (hereinafter referred to as ready-mixed concrete) having different moisture contents and moisture contents. Specifically, the experiment of stirring and mixing raw kon and fluidity reducing agent inside the drum of the agitator car was performed a plurality of times while changing the amount of the fluidity reducing agent for each raw kon sample, and the results of the experiment conducted several times. From this, the amount of the fluidity reducing agent that was not excessive or insufficient to produce the lump was confirmed. Table 1 shows the composition of each raw concrete sample and the added weight of the fluidity reducing agent that was appropriate for each raw concrete sample.

In this experiment, a granular material (powdered cellulose) formed by pulverizing shredder waste (specific surface area 0.23 m ² by BET method) with a mill was used as a fluidity reducing agent. The average particle diameter of the granular material was 200 μm, and the specific surface area of the granular material by the BET method was 1.6 m ² / g. The true density of the granular material was 1.9 g / cm ³ , and the bulk density of the granular material was 0.25 g / cm ³ . The porosity of the granular material was (1-0.25 / 1.9) × 100≈87%.

  As a result of experiments, it has been found that the amount of a fluidity reducing agent suitable for producing a lump depends largely on the moisture content of the green kon. That is, it was found that an appropriate amount of the fluidity reducing agent added can be set based on the weight ratio between the weight of water contained in the raw kon and the weight of the fluidity reducing agent. In other words, the amount of cement, aggregate, admixture, etc. contained in the ready-mixed concrete hardly needs to be taken into consideration when determining the addition amount of the fluidity reducing agent. From the results of the weight ratio (C / A) in Table 1, the weight of the fluidity reducing agent that is stirred and mixed with the green kon is 5% to 17%, more preferably 8% to 13% of the weight of water contained in the green kon. If it is set to about% or less, a lump can be produced without excess or deficiency of the fluidity reducing agent.

  Further, in another experiment, the time required for processing 40 liters of raw concrete is crushed after forming the lump by the manufacturing method of the present invention and after discharging the remaining raw concrete from the outside of the agitator car and solidifying it. Compared with the case of crushed stone. As a result, in the production method of the present invention, it was confirmed that the time required for the processing of green corn could be shortened by about 75% as compared with the conventional method of making crushed stone.

DESCRIPTION OF SYMBOLS 1 Ready-mixed concrete 2 Fluidity reducing agent 3 Bag 4 Lump 10 Agitator wheel 11 Drum 12 Opening part 13 Mixing blade 14 Input part 15 Discharge part

Claims (5)

  By rotating the drum of the agitator wheel containing the remaining ready-mixed concrete and the granular fluidity-reducing agent having a structure in which fibers are intertwined, the ready-mixed concrete and the fluidity-reducing agent are agitated and mixed to form a lump. And a method of producing a mixture using the remaining ready-mixed concrete, wherein the block is discharged from the opening of the drum.   The method for producing a mixture using the remaining ready-mixed concrete according to claim 1, wherein the fibers contain a hydrophilic polymer.   The method for producing a mixture using residual green concrete according to claim 2, wherein the hydrophilic polymer is cellulose.   The weight of the fluidity reducing agent mixed with the ready-mixed concrete is 5% to 17% of the weight of moisture contained in the ready-mixed concrete. Production method.   The production of the mixture using the remaining ready-mixed concrete according to any one of claims 1 to 4, wherein the fluidity reducing agent is put into the drum while being put in a bag formed of alkali-dissolved paper. Method.

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