Recovery method of residual concrete

Abstract

The invention provides a method for recovering residual concrete. In the method, a water-absorbent resin and a residual concrete material are mixed to form a premixture, the water content of the residual concrete material is 8.33%-25%, and the weight ratio of the water-absorbent resin to water in the residual concrete material is 1: 1-1: 20. And then, stirring the premixture to obtain a recycled concrete material. Therefore, the flowability of the concrete recycled material can be improved, and the concrete recycled material is easy to recycle.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for recycling concrete surplus materials, and more particularly to a method for recycling concrete surplus materials using water-absorbing resin. BACKGROUND

[0002] In recent years, due to the rapid development of social and economic activities, general construction projects and major public projects such as transportation construction have increased, and the amount of soil and stone left over from the construction output is quite large. The remaining soil and stone includes concrete surplus materials generated based on calculation errors, weather influences, or construction stages.

[0003] Concrete surplus materials left in ready-mixed concrete trucks or construction site concrete mixing plants are known to be washed with a large amount of water to produce concrete recycling materials. Concrete recycling materials have been classified by the Environmental Protection Agency as general business waste, and their disposal requires additional costs. Furthermore, the concrete recycling materials produced thereby contain hydrated calcium salts, gravel and sand, and a large amount of water, so they are not easy to solidify, and their appearance is like sludge, making subsequent treatment and application quite difficult.

[0004] Existing concrete surplus material treatment devices can, for example, put concrete sewage into a sedimentation tank for sedimentation, and then use a water pump to extract the sewage with less mud content on the upper layer of the sedimentation tank for filtration (such as the ready-mixed concrete plant waste sludge treatment and recycling equipment of new patent publication No. TW M636970), but this sewage treatment method takes a long time to settle, requires several sedimentation tanks, has low treatment efficiency, and a layer of mud and sand can easily solidify at the bottom of the sedimentation tank after long-term use, making it difficult to recycle sand and soil, and easily causing waste of construction resources. In addition, other concrete sewage purification devices (such as Chinese patent publication No. CN117504407A) use a centrifugal barrel with a filter core to filter sewage. Or like the concrete recycling treatment device provided by Chinese patent publication No. CN116328895A, which is equipped with different screening equipment. However, the above-mentioned methods all require the purchase of additional equipment, increasing operating costs, and if traditional sedimentation tanks are used, there is the disadvantage of water resource consumption.

[0005] Therefore, there is an urgent need to provide a method for recycling concrete surplus materials using a relatively simple method to reduce water resource waste and recycle concrete surplus materials. SUMMARY

[0006] One aspect of the present invention provides a method for recycling concrete surplus materials by mixing water-absorbing resin with concrete surplus materials to make the concrete surplus materials easier to recycle.

[0007] According to one aspect of the present invention, a method for recycling concrete residue is provided. In this method, a water-absorbing resin and concrete residue are first mixed to form a premix, wherein the water content of the concrete residue is 8.33% to 25%, and the weight ratio of the water-absorbing resin to the water in the concrete residue is 1:1 to 1:20. The premix is ​​then stirred to obtain recycled concrete.

[0008] According to one embodiment of the present invention, the above-mentioned concrete residue includes cement, and the cement includes tricalcium silicate (3CaO·SiO2), dicalcium silicate (β-2CaO·SiO2), tricalcium aluminate (3CaO·Al2O3), tetracalcium aluminoferrite (4CaO·Al2O3·Fe2O3), or any combination thereof.

[0009] According to one embodiment of the present invention, the above-mentioned water-absorbing resin comprises polyacrylate.

[0010] According to one embodiment of the present invention, the above-mentioned absorbent resin has a free absorption capacity of more than 10 g / g for 3.5 wt% saline solution.

[0011] According to one embodiment of the present invention, the average particle size of the above-mentioned water-absorbing resin is 0.05 mm to 3.00 mm.

[0012] According to one embodiment of the present invention, based on a concrete residue weight of 100 wt%, the content of the above-mentioned water-absorbing resin is 3.5 wt% to 8.5 wt%.

[0013] According to one embodiment of the present invention, the mixing time of the above-mentioned mixed water-absorbing resin and concrete residue is 1 minute to 5 minutes.

[0014] According to one embodiment of the present invention, the moisture content of the above-mentioned recycled concrete is less than 5%.

[0015] According to one embodiment of the present invention, the above method further includes screening the recycled concrete and calculating the fineness modulus, wherein the fineness modulus is 2.3 to 3.1.

[0016] According to one embodiment of the present invention, the above-mentioned concrete residue includes gravel and sand, and the above method further includes coarsely screening the concrete recycling material to separate the gravel and sand.

[0017] By applying the water-absorbing resin and its manufacturing method of the present invention, when concrete residue with a specific water content is mixed with a specific proportion of water-absorbing resin, the fluidity of the recycled concrete material can be improved, making it easier to separate the coarse and fine particles. Detailed Implementation

[0018] As used herein, "around," "about," "approximately," or "substantially" generally means within 20 percent, or within 10 percent, or within 5 percent of a given value or range.

[0019] Embodiments of the application are discussed more fully below with reference to the figures. However, it can be appreciated that embodiments provide many applicable concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative and not limiting of the scope of the application.

[0020] As mentioned above, the present application provides a method for recycling concrete surplus materials. The method mixes a specific amount of water-absorbing resin with concrete surplus materials based on the water content of the concrete surplus materials to improve the flowability of the concrete surplus materials and to easily separate coarse aggregates and fine aggregates from the concrete surplus materials.

[0021] The method for recycling concrete surplus materials provided by the present application includes mixing concrete surplus materials with water-absorbing resin to obtain a premix. In some embodiments, the concrete surplus materials are unset concrete surplus materials remaining in a concrete mixing device, such as a ready-mix concrete truck or a self-built concrete mixing plant at a construction site, but the present application is not limited thereto. The concrete surplus materials can be any unset concrete surplus materials remaining in a construction project.

[0022] In some embodiments, the unset concrete surplus materials include cement, aggregates, and mixing water, in which the cement can be Portland cement, blast furnace slag (fine powder obtained by grinding blast furnace stones quenched in water in a steel mill), or fly ash (coal ash from a coal-fired power plant), and the aggregates include coarse aggregates (gravel or crushed stone) and fine aggregates (sand). In some embodiments, the concrete surplus materials include cement, gravel, and sand, and the like. In the foregoing embodiments, the cement includes tricalcium silicate (3CaO-SiO2), dicalcium silicate (β-2CaO-SiO2), tricalcium aluminate (3CaO-Al2O3), tetracalcium aluminoferrite (4CaO-Al2O3-Fe2O3), or any combination thereof.

[0023] In some embodiments, the water-absorbing resin has a free absorption amount of 3.5 wt% saline solution of greater than about 10 g / g, preferably greater than 20 g / g. The water-absorbing resin having the foregoing free absorption amount has a good water absorption effect on the water content in the concrete surplus materials.

[0024] In some embodiments, the water-absorbent resin comprises a polyacrylate salt. For example, the method for preparing the polyacrylate salt comprises a radical polymerization reaction of an aqueous solution of unsaturated monomers. In some embodiments, the neutralization rate of the aqueous solution of unsaturated monomers is about 55 mol% to about 80 mol%. The aqueous solution of unsaturated monomers comprises acid group monomers having unsaturated double bonds, such as acrylic acid, methacrylic acid, 2-acrylamido-2-methylpropane sulfonic acid, maleic acid (cis-butenedioic acid), cis-butenedioic anhydride, fumaric acid (trans-butenedioic acid), and trans-butenedioic anhydride. The aqueous solution of unsaturated monomers can comprise one monomer, or two or more of the above-mentioned monomers.

[0025] In other embodiments, other hydrophilic monomers having unsaturated double bonds, such as acrylamide, methacrylamide, 2-carboxyethyl acrylate, 2-carboxyethyl methacrylate, methyl acrylate, ethyl acrylate, dimethylamino propyl acrylamide, and chloroacrylamido trimethylamine, can be selectively added. The amount of the above-mentioned hydrophilic monomers added is determined based on the principle of not damaging the properties of the water-absorbent resin, such as retention and absorption rate.

[0026] In some embodiments, the method for preparing the polyacrylate salt comprises adding a radical polymerization reaction crosslinking agent to allow the water-absorbent resin composition to have a proper crosslinking degree, thereby improving the processability of the water-absorbent resin composition after the polymerization reaction. In some embodiments, the radical polymerization reaction crosslinking agent can be selected from compounds comprising two or more unsaturated double bonds, such as N,N-bis(2-propenyl)amine, N,N-methylenebisacrylamide, N,N-methylenebismethacrylamide, propylene glycol diacrylate, ethylene glycol dimethacrylate, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, glycerol trimethacrylate, glycerol plus ethylene oxide triacrylate or trimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, N,N,N-tris(2-propenyl)amine, ethylene glycol diacrylate, polyoxyethylene glycerol triacrylate, diethyl polyoxyethylene glycerol triacrylate, triethylene glycol diacrylate, and the like, or compounds comprising two or more epoxy groups, such as sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, and the like. Two or more radical polymerization reaction crosslinking agents can be used alone or in combination. In some embodiments, the amount of the radical polymerization reaction crosslinking agent is 0.001 wt% to 5 wt%, preferably 0.01 wt% to 3 wt%, based on 100 wt% of the solid content of the aqueous solution of unsaturated monomers. If the amount of the radical polymerization reaction crosslinking agent is within the above-mentioned range, the crosslinked core structure formed after the reaction has better mechanical properties, thereby facilitating mechanical processing, and the water-absorbent resin prepared subsequently has better water-absorbing properties.

[0027] In some embodiments, the radical polymerization reaction described above can be performed in a batch reaction vessel or a conveyor belt reactor.

[0028] In some embodiments, the gel obtained after the radical polymerization reaction is first cut into small gel bodies with a diameter of less than 2.0 mm, preferably less than 1.0 mm, using a mincer. Then, the small gel bodies are dried by baking and further sieved. In some embodiments, the drying temperature can be from 100°C to 180°C. The drying process using the aforementioned temperature range can effectively control the drying time and the cross-linking degree, so as to avoid a large amount of residual unreacted monomers.

[0029] In some embodiments, the particle size of the water-absorbing resin is from about 0.05 mm to about 3.00 mm, preferably from about 0.10 mm to about 2.00 mm. Controlling the particle size to the aforementioned range can reduce the amount of fine powder in the finished product, and can make the water-absorbing resin have better absorption performance and avoid the separation efficiency of coarse and fine materials being poor due to particle expansion after mixing with the concrete surplus material.

[0030] In some embodiments, based on 100 wt% of the concrete surplus material, the water-absorbing resin is used in an amount of from about 3.5 wt% to about 8.5 wt%, preferably from about 4.0 wt% to about 6.0 wt%. Using the water-absorbing resin in the aforementioned amount can effectively mix the water-absorbing resin with the concrete surplus material to absorb the water in the concrete surplus material.

[0031] Since the concrete surplus material contains water, in some embodiments, the water content of the concrete surplus material is from about 8.33% to about 25%. The main purpose of adding the water-absorbing resin is to absorb the water in the concrete surplus material. Therefore, in some embodiments, the weight ratio of the amount of the water-absorbing resin added to the water in the concrete surplus material is from about 1:1 to about 1:20, preferably from about 1:1 to about 1:10. If the water in the concrete surplus material is more than 20 times the amount of the water-absorbing resin, the absorption amount is insufficient, and therefore the subsequent concrete recycled material has poor slurry dispersibility; if the water in the concrete surplus material is less than the amount of the water-absorbing resin used, the water-absorbing resin does not fully absorb the water, resulting in unnecessary waste.

[0032] Then, the concrete surplus material recycling method comprises a stirring operation on the premixture to obtain a concrete recycled material. In some embodiments, the stirring operation is performed for a time of from about 1 minute to about 5 minutes, preferably from about 1 minute to about 3 minutes. The aforementioned mixing time is sufficient for the water-absorbing resin to absorb water to saturation, so by effectively controlling the mixing time, the process efficiency is improved and energy waste is avoided.

[0033] In some embodiments, the moisture content of the concrete recyclate is less than 5%. Because the concrete recyclate has the aforementioned moisture content, the concrete recyclate can be easily unloaded from the concrete mixing device, and the flowability of the concrete recyclate is good. In some embodiments, the method of recycling the concrete remainder further includes coarse screening the concrete recyclate to separate coarse particles (gravel or crushed stone) and fine particles (sand).

[0034] The following examples are presented to illustrate the application of the present application, but are not intended to limit the present application, and those skilled in the art can make various modifications and improvements without departing from the spirit and scope of the present application.

[0035] Preparation of water-absorbent resin

[0036] Preparation Example 1

[0037] Step 1-1: 437.5 g of a 48 wt% aqueous sodium hydroxide solution and 583.2 g of water were placed in a 2000 c.c. conical flask, and 540 g of acrylic acid was slowly added. The dropwise addition ratio of the sodium hydroxide / acrylic acid was in the range of 0.85 to 0.95, and the temperature of the neutralization reaction system in the flask was maintained at 15°C to 40°C. After completion, the temperature of the system was controlled at 4°C to 10°C to obtain a monomer 42 parts by weight of an unsaturated monomer aqueous solution in which 70 mole% of the acrylic acid was partially neutralized as sodium acrylate.

[0038] Step 1-2: 1.1 g of N,N'-methylenebisacrylamide (a radical polymerization crosslinking agent) was added to the above unsaturated monomer aqueous solution, and the temperature was maintained at about 20°C. Then, 0.3 g of hydrogen peroxide, 3.6 g of sodium bisulfite, and 3.6 g of ammonium persulfate were added as polymerization initiators to perform a radical polymerization reaction. Then, the resulting gel was shredded using a cutting mill, and gel particles having a particle size of 2 mm or less in diameter were sieved out.

[0039] Step 1-3: After drying the gel particles at a temperature of 130°C for 2 hours, sieving was performed using a screen having a fixed particle size of 0.1 mm to 0.85 mm to obtain water-absorbent resin particles having an average particle size of 425 μm.

[0040] Step 1-4: A mixed solution of ethylene glycol, 1,4-butanediol (produced by Formosa Plastic Corporation), and methanol was prepared as a surface crosslinking agent, and the volume ratio of ethylene glycol, 1,4-butanediol, and methanol was 1:1:0.5. 200 g of the above water-absorbent resin particles were mixed with the surface crosslinking agent, and heat treatment was performed at a temperature of 150°C for 1 hour, and after cooling, a water-absorbent resin, designated as RC100, was obtained. The free absorption amount of the water-absorbent resin RC100 with respect to 3.5 wt% saline water was 20 g / g.

[0041] Preparation Example 2

[0042] Step 2-1: 437.5 g of a 48 wt% aqueous sodium hydroxide solution and 583.2 g of water were placed in a 2000 c.c. conical flask, and 180 g of acrylic acid was slowly added. The dropwise addition ratio of sodium hydroxide / acrylic acid was in the range of 0.85 to 0.95, and the temperature of the neutralization reaction system in the flask was maintained at 15°C to 40°C. Next, 360 g of acrylic acid was slowly added (the dropwise addition ratio of sodium hydroxide / acrylic acid was in the range of 0.85 to 0.95), and after the dropwise addition was completed, the temperature of the system was controlled at 4°C to 10°C to obtain a monomer 42 parts by weight of an unsaturated monomer aqueous solution in which 70 mole% of the acrylic acid portion was partially neutralized as sodium acrylate.

[0043] Step 2-2: 1.5 g of N,N'-methylenebisacrylamide (a radical polymerization crosslinking agent) was added to the above unsaturated monomer aqueous solution, and the temperature was maintained at about 20°C. Then, 0.3 g of hydrogen peroxide, 3.6 g of sodium bisulfite, and 3.6 g of ammonium persulfate were added as polymerization initiators to perform radical polymerization. Then, the resulting gel was shredded using a cutting mill, and gel particles having a particle size of 2 mm or less in diameter were sieved out.

[0044] Step 2-3: After the gel particles were dried at a temperature of 130°C for 2 hours, sieving was performed using a screen having a fixed particle size of 0.1 mm to 0.85 mm to obtain water-absorbing resin particles having an average particle size of 230 μm.

[0045] Step 2-4: A mixed solution of ethylene glycol, 1,4-butanediol (produced by Formosa Plastic Corporation), and methanol was prepared as a surface crosslinking agent, and the volume ratio of ethylene glycol, 1,4-butanediol, and methanol was 1:1:0.5. 200 g of the above water-absorbing resin particles were mixed with the surface crosslinking agent, and heat treatment was performed at a temperature of 150°C for 1 hour, and after cooling, a water-absorbing resin, designated as RC200, was obtained. The free absorption amount of the water-absorbing resin RC200 with respect to 3.5 wt% saline was 15 g / g.

[0046] Evaluation method

[0047] Concrete recycled material

[0048] According to the specifications of CNS 1240 concrete granules, and according to the provisions of the concrete fine granule sieve analysis described by the Ministry of Economic Affairs Geology Survey and Mining Management Center, the fineness modulus (F.M) needs to be between 2.3 and 3.1, and the fineness modulus (F.M) cannot deviate from the reference fineness modulus (F.M) by more than 0.2. The fineness modulus (F.M) can be calculated using the following formula (1).

[0049] Fineness modulus (F.M) =∑(Cumulative percentage of each sieve number) / 100 (1)

[0050] The various sieve numbers, corresponding standard sieve widths and sieving percentages of the fineness modulus (F.M) are shown in Table 1 below.

[0051] Table 1

[0052] Mesh (inches) CNS 386-1 Standard Mesh Opening (mm) CNS 1240 Percent Passing (percent) 3 / 8 9.5 100 4 4.75 95-100 8 2.36 80-100 16 1.18 50-85 30 0.6 25-60 50 0.3 5-30 100 0.15 0-10

[0053] Water-absorbent resin

[0054] To evaluate the properties of the water-absorbent resin of the present application, the physical properties thereof were analyzed by the following test methods, and unless otherwise specified, the measurement conditions described below were performed at room temperature of 23±2°C and relative air humidity of 45±10%. The water-absorbent resin should be sufficiently mixed before analysis.

[0055] Absorption ratio

[0056] 1 g (S1) of the water-absorbent resin was added to a Japanese-style nonwoven cloth tea bag (size 160 x 120 mm 2 ) having a blank weight W1, and after being compacted using a hot air machine, the tea bag was immersed in 1 L of 3.5 wt% saline solution for 30 minutes, and then taken out and hung for 5 minutes before being weighed (W2). The absorption ratio of the water-absorbent resin was calculated using the following formula (2).

[0057] Absorption ratio = (W2-W1-S1) / S1 (2)

[0058] Particle size analysis

[0059] The particle size analysis test of the water-absorbent resin was performed in accordance with the measurement method specified by ERT 220.2 (12) of the European Disposables and Nonwovens Association (EDANA).

[0060] Example 1

[0061] The concrete surplus material formulation of Example 1 was Portland cement 3.5 kg, gravel 8.5 kg, sand 10 kg, and water 2 kg. The concrete surplus material was approximately 0.1 cubic meters (m 3) with a water content of 8.33%. First, the concrete surplus material was poured into a horizontal double shaft mixer (Model: Jinlei Machinery KNER2012) and stirred for 1 minute at a speed of 50 rpm to make the concrete surplus material into a slurry. Then, 1.5 kg of water-absorbent resin RC-100 was poured into the double shaft mixer, wherein the amount of water-absorbent resin RC-100 was 6.25 wt% of the concrete surplus material. After stirring for 1.5 minutes at a speed of 50 rpm, the concrete recycled material was obtained. The concrete recycled material was heated in an oven at 110°C for 30 minutes, and then sieved to calculate the fineness modulus, the results of which are shown in Table 2.

[0062] Examples 2 to 7

[0063] Examples 2 to 7 used a similar recycling process as Example 1, with the difference that Example 2 used 1 kg of water-absorbent resin RC-200, which was 4.17 wt% of the concrete surplus material; Example 3 used 1 kg of water-absorbent resin RC-100, which was 4.17 wt% of the concrete surplus material, and the stirring speed of the concrete surplus material and water-absorbent resin was 100 rpm; Example 4 used 1 kg of water-absorbent resin RC-200, which was 4.17 wt% of the concrete surplus material, and the stirring speed of the concrete surplus material and water-absorbent resin was 100 rpm; and Example 5 used 1 kg of water-absorbent resin RC-100, which was 4.17 wt% of the concrete surplus material, and the stirring speed of the concrete surplus material and water-absorbent resin was 100 rpm.

[0064] The concrete surplus material of Example 6 was the recycled cement formulation of Patent Publication No. TW I692461: 1 kg of Portland cement, 1 kg of furnace slag powder, 0.7 kg of fly ash, 3 kg of glass sand, and 1.9 kg of water, with a water content of 25% and a volume of about 0.03 m 3 Example 7 used the same concrete surplus material as Example 6, 0.3 kg of water-absorbent resin RC-200, which was 3.95 wt% of the concrete surplus material, and the stirring speed of the concrete surplus material and water-absorbent resin was 100 rpm. The process conditions and fineness modulus of Examples 2 to 7 are shown in Table 2.

[0065] Comparative Examples 1 to 4

[0066] Comparative Examples 1 to 4 utilized a recycling process similar to that of Example 1, with the difference being that Comparative Example 1 used 0.03 kg of superabsorbent resin (brand: Taisubao SK273, average particle size 100 μm, absorption rate 10 g / g), which was 0.125 wt% of the concrete residue, and the mixing time for the concrete residue and superabsorbent resin was 5 minutes; Comparative Example 2 used 2.5 kg of superabsorbent resin (brand: Taisubao SK273, average particle size 100 μm, absorption rate 10 g / g), which was 10.42 wt% of the concrete residue, and the mixing time for the concrete residue and superabsorbent resin was... The mixing time was 5 minutes. Comparative Example 3 used 3 kg of superabsorbent resin (brand: Taisubao SK273, average particle size 100 μm, absorption rate 10 g / g), which was 12.5 wt% of the concrete residue, and the mixing speed of the concrete residue and superabsorbent resin was 100 rpm. Comparative Example 4 used the same concrete residue as Example 6, and 0.03 kg of superabsorbent resin (brand: Taisubao SK273, average particle size 100 μm, absorption rate 10 g / g), which was 3.95 wt% of the concrete residue, and the mixing speed of the concrete residue and superabsorbent resin was 100 rpm. The process conditions and fineness modulus of Comparative Examples 1 to 4 are shown in Table 3.

[0067] Table 2

[0068]

[0069] Table 3

[0070]

[0071] The results of the above embodiments confirm that when concrete residue with a specific water content is mixed with a specific proportion of water-absorbing resin, the flowability of the recycled concrete can be improved, and the resulting recycled concrete has a preset fineness modulus.

[0072] Therefore, the concrete residue recycling method of the present invention, based on the moisture content of the concrete residue, mixes a specific amount of water-absorbing resin with the concrete residue to improve the fluidity of the recycled concrete, making it easier to separate the coarse and fine particles.

[0073] Although the present invention has been disclosed above with reference to several embodiments, it is not intended to limit the present invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for recycling leftover concrete, characterized in that, Include: The water-absorbing resin is mixed with the concrete residue to form a premix, wherein the water content of the concrete residue is 8.33% to 25%, and the weight ratio of the water-absorbing resin to the water in the concrete residue is 1:1 to 1:20; and The premix is ​​then stirred to obtain recycled concrete.

2. The method for recycling residual concrete material according to claim 1, characterized in that, The concrete residue contains cement, and the cement contains tricalcium silicate, dicalcium silicate, tricalcium aluminate, tetracalcium aluminoferrite, or any combination thereof.

3. The method for recycling residual concrete material according to claim 1, characterized in that, This absorbent resin contains polyacrylate.

4. The method for recycling residual concrete material according to claim 1, characterized in that, The water-absorbing resin has a free absorption capacity of more than 10 g / g for 3.5 wt% saline solution.

5. The method for recycling residual concrete material according to claim 1, characterized in that, The average particle size of the water-absorbing resin is 0.05 mm to 3.00 mm.

6. The method for recycling residual concrete material according to claim 1, characterized in that, Based on the fact that the weight of the concrete residue is 100 wt%, the content of the water-absorbing resin is 3.5 wt% to 8.5 wt%.

7. The method for recycling residual concrete material according to claim 1, characterized in that, The stirring operation should last for 1 to 5 minutes.

8. The method for recycling residual concrete material according to claim 1, characterized in that, The moisture content of the recycled concrete is less than 5%.

9. The method for recycling residual concrete material according to claim 1, characterized in that, Also includes: The recycled concrete was screened and its fineness modulus was calculated to be between 2.3 and 3.

1.

10. The method for recycling residual concrete material according to claim 1, characterized in that, The concrete residue contains gravel and sand, and the method further includes: The recycled concrete is coarsely screened to separate the gravel and sand.

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