CN112174590A - Preparation method of recycled concrete and recycled concrete - Google Patents
Preparation method of recycled concrete and recycled concrete Download PDFInfo
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- CN112174590A CN112174590A CN202011121123.2A CN202011121123A CN112174590A CN 112174590 A CN112174590 A CN 112174590A CN 202011121123 A CN202011121123 A CN 202011121123A CN 112174590 A CN112174590 A CN 112174590A
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28C5/00—Apparatus or methods for producing mixtures of cement with other substances, e.g. slurries, mortars, porous or fibrous compositions
- B28C5/003—Methods for mixing
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28C7/00—Controlling the operation of apparatus for producing mixtures of clay or cement with other substances; Supplying or proportioning the ingredients for mixing clay or cement with other substances; Discharging the mixture
- B28C7/0007—Pretreatment of the ingredients, e.g. by heating, sorting, grading, drying, disintegrating; Preventing generation of dust
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B28—WORKING CEMENT, CLAY, OR STONE
- B28C—PREPARING CLAY; PRODUCING MIXTURES CONTAINING CLAY OR CEMENTITIOUS MATERIAL, e.g. PLASTER
- B28C7/00—Controlling the operation of apparatus for producing mixtures of clay or cement with other substances; Supplying or proportioning the ingredients for mixing clay or cement with other substances; Discharging the mixture
- B28C7/0007—Pretreatment of the ingredients, e.g. by heating, sorting, grading, drying, disintegrating; Preventing generation of dust
- B28C7/0023—Pretreatment of the ingredients, e.g. by heating, sorting, grading, drying, disintegrating; Preventing generation of dust by heating or cooling
- B28C7/0038—Cooling, e.g. using ice
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B18/04—Waste materials; Refuse
- C04B18/16—Waste materials; Refuse from building or ceramic industry
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/02—Treatment
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/02—Treatment
- C04B20/023—Chemical treatment
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/02—Treatment
- C04B20/026—Comminuting, e.g. by grinding or breaking; Defibrillating fibres other than asbestos
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
- C04B20/02—Treatment
- C04B20/04—Heat treatment
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Abstract
The application discloses recycled concrete's preparation method and recycled concrete belongs to the technical field of concrete preparation, realizes having solved to a certain extent that concrete waste is extravagant, influence environment scheduling problem, and its technical essential is: the preparation method of the recycled concrete is characterized by comprising the following steps of: s1, humidifying and freezing; adding water into the waste concrete blocks for humidifying, and placing the waste concrete blocks in a refrigeration house for freezing and refrigerating; s2, mechanically crushing; mechanically crushing the frozen waste concrete blocks by using a crushing device; s3, acidizing; placing the crushed waste concrete material into acid liquor for reaction and activation; s4, drying and grinding; washing and drying the waste concrete material after the acidification treatment, grinding the waste concrete material after drying, and performing air draft dust removal during grinding; s5, screening and mixing the materials; s6, preparing concrete. By the scheme, the waste concrete is effectively processed into the recycled aggregate, and the recycled concrete is further prepared.
Description
Technical Field
The application relates to the technical field of concrete preparation, in particular to a preparation method of recycled concrete and the recycled concrete.
Background
In recent years, the world building industry has entered a high-speed development stage. The occupation of natural resources and the negative impact on the environment caused by concrete as the largest man-made material also lead to the discussion of sustainable development problems. The amount of waste concrete removed annually in the world, waste concrete from new buildings, and waste concrete discharged from concrete plants, prefabrication plants, etc. is enormous. Meanwhile, the discharge amount of the waste concrete is expected to increase along with the acceleration of the urbanization process worldwide, and the removal and the modification of the original building are increased day by day.
However, the conventional treatment method of the waste concrete mainly transports the waste concrete to the suburb for stacking or landfill, which not only costs a large amount of transportation cost and causes secondary pollution to the environment, but also occupies a large amount of valuable land resources, and simply abandons the waste of natural resources.
Disclosure of Invention
In order to realize effective recycling of waste concrete, the application provides a preparation method of recycled concrete and the recycled concrete.
In a first aspect, the present application provides a method for preparing recycled concrete, which adopts the following technical scheme:
a preparation method of recycled concrete comprises the following steps:
s1, humidifying and freezing; adding water into the waste concrete blocks for humidifying, and placing the waste concrete blocks in a refrigeration house for freezing and refrigerating;
s2, mechanically crushing; mechanically crushing the frozen waste concrete blocks by using a crushing device, and controlling the particle size not to be larger than 30 mm;
s3, acidizing; placing the crushed waste concrete material into acid liquor for reaction and activation;
s4, drying and grinding; washing and drying the waste concrete material after the acidification treatment, grinding the waste concrete material after drying, and performing air draft dust removal during grinding;
s5, screening and mixing the materials; screening the dried waste concrete material, wherein the waste concrete material with the particle size of more than 4mm is used as a recycled coarse aggregate, and the waste concrete material with the particle size of less than 4mm is used as a recycled fine aggregate;
s6, preparing concrete; and putting the recycled coarse aggregate, the recycled fine aggregate, the cement, the mineral admixture, the water reducing agent, the regulator and the like into a concrete mixer for stirring to prepare the recycled concrete.
By adopting the technical scheme, the waste concrete is recycled and is made into the concrete which can be utilized, and when the recycled concrete is prepared, the waste concrete block is crushed after being subjected to humidity conditioning and freezing, the activity state of molecules in the material can be reduced in the freezing process, so that the whole waste concrete block is relatively easier to crush, the crack range and the number of gaps on single particles of the crushed waste concrete material are smaller, the surface area of the waste concrete aggregate is reduced, the water absorption rate of the finally obtained aggregate is reduced, the strength after the aggregate supports the concrete in the later period is improved, the effect can be seen by combining the result analysis in the specific embodiment, and meanwhile, when the waste concrete material is subjected to acidizing, the hydrochloric acid solution can react with cement hydrate such as Ca (OH)2 and the like on the waste concrete material, and further, the surface structure of the recycled aggregate particles is improved, so that the particle surfaces are smoother, fine powder is not easy to generate in the subsequent process, the water absorption is avoided to be larger, the compressive strength of the finally prepared recycled concrete is further improved, and the effect can be seen by combining the result analysis in the specific implementation mode.
Further setting the following steps: s6 specifically includes the following steps:
s6.1: the cement, the mineral admixture and the recycled fine aggregate are dry-mixed in a concrete mixer and uniformly mixed to obtain a mixed material;
s6.2: adding 80% of water required by the mixture obtained in the step S6.1, uniformly stirring, adding a water reducing agent and the rest 20% of water without stopping the concrete mixer after stirring, and continuing stirring after adding is finished until the mixture is formed into slurry;
s6.3: and (4) putting the recycled coarse aggregate into the mortar obtained in the S6.2, and stirring to obtain recycled concrete.
By adopting the technical scheme, the recycled coarse aggregate is added into the rest of the components for stirring after delay, so that the cementing material and the recycled fine aggregate are fully contacted and bonded firstly, and then the recycled coarse aggregate is added and stirred subsequently, so that the recycled fine aggregate is distributed in gaps of the recycled coarse aggregate to realize more full connection between recycled fine aggregate particles and the surrounding recycled coarse aggregate particles, the connection relation between the aggregates is improved, namely the stability of the prepared concrete is improved, and the result analysis in a specific implementation mode can also obviously show that.
Further setting the following steps: the acid solution used in step S3 is hydrochloric acid.
By adopting the technical scheme, hydrochloric acid is utilized to react with cement hydrate such as Ca (OH)2 on the waste concrete material, so that the surface structure of the recycled aggregate particles is improved, the particle surfaces are smoother, fine powder is not easy to generate in the subsequent process, the excessive water absorption is avoided, and the compressive strength of the finally prepared recycled concrete is improved.
Further setting the following steps: in step S4, the drying temperature is 100 ℃, and the drying time is 1 h.
By adopting the technical scheme, the waste concrete material and the waste ceramic material which are added with water for humidifying are dried, so that the influence of the moisture still existing in the waste concrete material on the performance of the subsequently prepared concrete is avoided.
Further setting the following steps: in step S1, the freezing temperature is-20 deg.C, and the freezing time is 75 min.
By adopting the technical scheme, the waste concrete material and the waste ceramic material are well frozen, so that subsequent crushing and grinding are facilitated.
Further setting the following steps: the solid content of the adopted water reducing agent is 20 percent, and the water reducing rate is 25 percent.
By adopting the technical scheme, the high-efficiency water reducing agent is selected to further improve the fluidity of the prepared concrete, so that the pumping performance of the concrete in the subsequent working process is ensured.
In a second aspect, the present application provides a recycled concrete prepared by the above preparation method, which adopts the following technical scheme:
the recycled concrete prepared by the preparation method of the recycled concrete is characterized in that: the paint comprises the following components in parts by weight:
and (3) regenerating coarse aggregate: 900 portions of 1160 materials
Regenerating fine aggregate: 650-750 parts
Mineral admixture: 230 portions 285 portions
Cement: 315 one 360 portions
Water reducing agent: 8.8 to 10.2 portions of
A regulator: 9.5 to 12 portions of
Water: 138 and 165 portions.
Through adopting above-mentioned technical scheme, the preparation that utilizes the recycled aggregate that the discarded concrete was made to carry out the concrete realizes utilizing of discarded concrete, combines the performance detection data in the embodiment to see out simultaneously, and sufficient compressive strength can be reached to the recycled concrete that makes, realizes effectively utilizing the discarded concrete, avoids wasting the resource, reduces environmental pressure.
Further setting the following steps: the mineral admixture comprises the following components in parts by weight:
80-100 parts of fly ash;
110 portions and 130 portions of mineral powder;
40-55 parts of silica fume.
By adopting the technical scheme, the addition of the fly ash can achieve the effect of reducing the cement dosage, the spherical glass body contained in the fly ash can effectively reduce the yield shear stress of the mixture, and further the mixture has larger fluidity, the mineral powder can achieve the effects of reducing the cement dosage and reducing the adiabatic temperature rise, meanwhile, the construction performance of the concrete can be effectively improved, and the later strength of the concrete and the durability of resisting sulfate corrosion, chloride dialysis and the like are improved.
To sum up, the beneficial technical effect of this application does:
(1) the waste concrete is effectively utilized for preparing recycled concrete, so that waste and influence on the environment are avoided, and certain economic benefit is brought;
(2) the waste concrete is treated by adopting modes of freezing, crushing, acidizing and the like, so that the property of the waste concrete is optimized, and the compressive strength of the finally prepared recycled concrete is guaranteed.
Drawings
FIG. 1 is a schematic flow diagram of a preparation method of the present application.
Detailed Description
The present application is described in further detail below with reference to the attached drawings.
Example 1
Referring to fig. 1, a method for preparing recycled concrete disclosed in the present application includes the following steps:
s1, humidifying and freezing; c40 waste concrete blocks are selected, added with water for humidifying and placed in a refrigeration house for freezing and refrigerating; wherein the water content is controlled to 10% of the total weight when adding water for humidifying, the freezing temperature is set to-20 deg.C, and the freezing time is 75 min;
s2, mechanically crushing; mechanically crushing the frozen waste concrete blocks by using a compression roller type crusher, and controlling the particle size to be not more than 30 mm;
s3, acidizing; placing the crushed waste concrete material into an acidification pool filled with hydrochloric acid solution for reaction and activation, wherein the acidification time is 30 min;
s4, drying and grinding; washing and drying the waste concrete material after the acidification treatment, controlling the drying temperature to be 100 ℃ and the drying time to be 1h, grinding the waste concrete material after drying, and performing air draft dust removal during grinding;
s5, screening and mixing the materials; screening the dried waste concrete material, wherein the waste concrete material with the particle size of more than 4mm is used as a recycled coarse aggregate, and the waste concrete material with the particle size of less than 4mm is used as a recycled fine aggregate;
s6, preparing concrete; putting the recycled coarse aggregate, the recycled fine aggregate, the cement, the mineral admixture, the water reducer, the regulator and the like into a concrete mixer for stirring to prepare recycled concrete, and specifically comprising the following steps:
s6.1: the cement, the mineral admixture and the recycled fine aggregate are dry-mixed in a concrete mixer and uniformly mixed to obtain a mixed material;
s6.2: adding 80% of water required by the mixture obtained in the step S6.1, uniformly stirring, adding a water reducing agent, a regulator and the rest 20% of water without stopping the concrete mixer after stirring, and continuously stirring after adding is finished until the mixture is formed into slurry;
s6.3: and (4) putting the recycled coarse aggregate into the mortar obtained in the S6.2, and stirring to obtain recycled concrete.
The application also provides recycled concrete prepared by the method, wherein the weight parts of the components are shown in the table 1.
Examples 2 to 6
The difference from the example 1 is that the prepared recycled concrete has different weight parts of each component, and the specific numerical values are shown in the table 1. Table 1: numerical table of weight parts of each component in the recycled concrete.
Example 7
The difference from the embodiment 3 is that the preparation method of the recycled concrete in the embodiment comprises the following steps:
s1, humidifying and freezing; c40 waste concrete blocks are selected, added with water for humidifying and placed in a refrigeration house for freezing and refrigerating; wherein the water content is controlled to 10% of the total weight when adding water for humidifying, the freezing temperature is set to-20 deg.C, and the freezing time is 75 min;
s2, mechanically crushing; mechanically crushing the waste concrete blocks by using a compression roller type crusher, and controlling the particle size to be not more than 30 mm;
s3, acidizing; placing the crushed waste concrete material into an acidification pool filled with hydrochloric acid solution for reaction and activation, wherein the acidification time is 30 min;
s4, drying and grinding; washing and drying the waste concrete material after the acidification treatment, controlling the drying temperature to be 100 ℃ and the drying time to be 1h, grinding the waste concrete material after drying, and performing air draft dust removal during grinding;
s5, screening and mixing the materials; screening the dried waste concrete material, wherein the waste concrete material with the particle size of more than 4mm is used as a recycled coarse aggregate, and the waste concrete material with the particle size of less than 4mm is used as a recycled fine aggregate;
s6, preparing concrete; and putting the recycled coarse aggregate, the recycled fine aggregate, the cement, the mineral admixture, the water reducing agent, the regulator and the like into a concrete mixer together for stirring to prepare the recycled concrete.
Comparative example 1
The difference from the embodiment 3 is that the preparation method of the recycled concrete in the embodiment comprises the following steps:
s1, mechanically crushing; c40 waste concrete blocks are selected and mechanically crushed by a crushing device, and the particle size is controlled to be not more than 30 mm;
s2, acidizing; placing the crushed waste concrete material into an acidification pool filled with hydrochloric acid solution for reaction and activation, wherein the acidification time is 30 min;
s3, drying and grinding; washing and drying the waste concrete material after the acidification treatment, controlling the drying temperature to be 100 ℃ and the drying time to be 1h, grinding the waste concrete material after drying, and performing air draft dust removal during grinding;
s4, screening and mixing the materials; screening the dried waste concrete material, wherein the waste concrete material with the particle size of more than 4mm is used as a recycled coarse aggregate, and the waste concrete material with the particle size of less than 4mm is used as a recycled fine aggregate;
s5, preparing concrete; putting the recycled coarse aggregate, the recycled fine aggregate, the cement, the mineral admixture, the water reducer, the regulator and the like into a concrete mixer for stirring to prepare recycled concrete, and specifically comprising the following steps:
s5.1: the cement, the mineral admixture and the recycled fine aggregate are dry-mixed in a concrete mixer and uniformly mixed to obtain a mixed material;
s5.2: adding 80% of water required by the mixture obtained in the step S5.1, uniformly stirring, adding a water reducing agent and the rest 20% of water without stopping the concrete mixer after stirring, and continuing stirring after adding is finished until the mixture is formed into slurry;
s5.3: and (4) putting the recycled coarse aggregate into the mortar obtained in the S5.2, and stirring to obtain recycled concrete.
Comparative example 2
The difference from the embodiment 3 is that the preparation method of the recycled concrete in the embodiment comprises the following steps:
s1, humidifying and freezing; c40 waste concrete blocks are selected, added with water for humidifying and placed in a refrigeration house for freezing and refrigerating; wherein the water content is controlled to 10% of the total weight when adding water for humidifying, the freezing temperature is set to-20 deg.C, and the freezing time is 75 min;
s2, mechanically crushing; mechanically crushing the frozen waste concrete blocks by using a crushing device, and controlling the particle size not to be larger than 30 mm;
s3, drying and grinding; drying the crushed waste concrete material, controlling the drying temperature to be 100 ℃, the drying time to be 1h, grinding the crushed waste concrete material after drying, and performing air draft dust removal during grinding;
s4, screening and mixing the materials; screening the dried waste concrete material, wherein the waste concrete material with the particle size of more than 4mm is used as a recycled coarse aggregate, and the waste concrete material with the particle size of less than 4mm is used as a recycled fine aggregate;
s5, preparing concrete; putting the recycled coarse aggregate, the recycled fine aggregate, the cement, the mineral admixture, the water reducer, the regulator and the like into a concrete mixer for stirring to prepare recycled concrete, and specifically comprising the following steps:
s5.1: the cement, the mineral admixture and the recycled fine aggregate are dry-mixed in a concrete mixer and uniformly mixed to obtain a mixed material;
s5.2: adding 80% of water required by the mixture obtained in the step S5.1, uniformly stirring, adding a water reducing agent and the rest 20% of water without stopping the concrete mixer after stirring, and continuing stirring after adding is finished until the mixture is formed into slurry;
s5.3: and (4) putting the recycled coarse aggregate into the mortar obtained in the S5.2, and stirring to obtain recycled concrete.
Performance detection test:
the concrete samples obtained in the examples and comparative examples were subjected to a compressive strength test, wherein the concrete samples were cubes of 15cm × 15cm × 15cm, three in each set, and cured by a standard method (temperature 20 ℃ ± 2 ℃, relative humidity 95% RH or more) after molding. The resulting performance results are shown in table 2. Table 2: and (5) a compression strength performance detection data table.
And (4) analyzing results:
it can be seen from the combination of example 3 and example 7 that, when the preparation method of example 3 is adopted, the finally prepared recycled concrete has better compressive strength, because the recycled fine aggregate is firstly mixed and stirred with other cementing materials to form slurry, so that the recycled fine aggregate can fully contact the cementing materials, and further, after the subsequent recycled coarse aggregate is put in, when the recycled fine aggregate is uniformly distributed in gaps of the coarse aggregate, the cementing materials form effective and stable bonding between the two aggregates, namely, the compressive strength of the subsequently prepared concrete is better.
It can be seen from the combination of example 3 and comparative example 1 that the recycled coarse aggregate and the recycled fine aggregate obtained by humidifying and freezing the waste concrete block have better compressive strength after the recycled concrete is prepared, because the activity state of molecules in the substance can be reduced in the freezing process, the waste concrete block is relatively easy to break, the crack range and the number of gaps on single particles of the broken waste concrete material are smaller, the water absorption of the obtained aggregate is reduced, and the compressive strength of the prepared recycled concrete is improved finally.
It can be seen from the combination of example 3 and comparative example 2 that the recycled concrete prepared subsequently has better compressive strength after the waste concrete material is acidified, because the hydrochloric acid solution can react with cement hydrate such as ca (oh)2 on the waste concrete material, the surface structure of the recycled aggregate particles is improved, the particle surfaces are smoother, fine powder is not easily generated in the subsequent process, so that excessive water absorption is avoided, and the compressive strength of the finally prepared recycled concrete is improved.
The embodiments of the present invention are preferred embodiments of the present application, and the scope of protection of the present application is not limited by the embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.
Claims (8)
1. The preparation method of the recycled concrete is characterized by comprising the following steps of:
s1, humidifying and freezing; adding water into the waste concrete blocks for humidifying, and placing the waste concrete blocks in a refrigeration house for freezing and refrigerating;
s2, mechanically crushing; mechanically crushing the frozen waste concrete blocks by using a crushing device, and controlling the particle size not to be larger than 30 mm;
s3, acidizing; placing the crushed waste concrete material into acid liquor for reaction and activation;
s4, drying and grinding; washing and drying the waste concrete material after the acidification treatment, grinding the waste concrete material after drying, and performing air draft dust removal during grinding;
s5, screening and mixing the materials; screening the dried waste concrete material, wherein the waste concrete material with the particle size of more than 4mm is used as a recycled coarse aggregate, and the waste concrete material with the particle size of less than 4mm is used as a recycled fine aggregate;
s6, preparing concrete; and putting the recycled coarse aggregate, the recycled fine aggregate, the cement, the mineral admixture, the water reducing agent, the regulator and the like into a concrete mixer for stirring to prepare the recycled concrete.
2. The method for producing recycled concrete according to claim 1, wherein: s6 specifically includes the following steps:
s6.1: the cement, the mineral admixture and the recycled fine aggregate are dry-mixed in a concrete mixer and uniformly mixed to obtain a mixed material;
s6.2: adding 80% of water required by the mixture obtained in the step S6.1, uniformly stirring, adding a water reducing agent and the rest 20% of water without stopping the concrete mixer after stirring, and continuing stirring after adding is finished until the mixture is formed into slurry;
s6.3: and (4) putting the recycled coarse aggregate into the mortar obtained in the S6.2, and stirring to obtain recycled concrete.
3. The method for producing recycled concrete according to claim 1, wherein: the acid solution used in step S3 is hydrochloric acid.
4. The method for producing recycled concrete according to claim 1, wherein: in step S4, the drying temperature is 100 ℃, and the drying time is 1 h.
5. The method for producing recycled concrete according to claim 1, wherein: in step S1, the freezing temperature is-20 deg.C, and the freezing time is 75 min.
6. The method for producing recycled concrete according to claim 1, wherein: the solid content of the adopted water reducing agent is 20 percent, and the water reducing rate is 25 percent.
7. The recycled concrete produced by the method for producing recycled concrete according to any one of claims 1 to 6, wherein: the paint comprises the following components in parts by weight:
and (3) regenerating coarse aggregate: 900 portions of 1160 materials
Regenerating fine aggregate: 650-750 parts
Mineral admixture: 230 portions 285 portions
Cement: 315 one 360 portions
Water reducing agent: 8.8 to 10.2 portions of
A regulator: 9.5 to 12 portions of
Water: 138 and 165 portions.
8. Recycled concrete according to claim 7, characterized in that: the mineral admixture comprises the following components in parts by weight:
80-100 parts of fly ash;
110 portions and 130 portions of mineral powder;
40-55 parts of silica fume.
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| CN202011121123.2A CN112174590A (en) | 2020-10-19 | 2020-10-19 | Preparation method of recycled concrete and recycled concrete |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113149564A (en) * | 2021-04-29 | 2021-07-23 | 河南多利克生态环保科技有限公司 | Preparation method of recycled concrete |
| CN114409318A (en) * | 2022-03-03 | 2022-04-29 | 漳州恒宝新建材有限公司 | Preparation method of recycled concrete |
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| CN114409318A (en) * | 2022-03-03 | 2022-04-29 | 漳州恒宝新建材有限公司 | Preparation method of recycled concrete |
| CN114409318B (en) * | 2022-03-03 | 2022-11-18 | 漳州恒宝新建材有限公司 | Preparation method of recycled concrete |
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