CN111423174A - Recycled concrete and preparation method thereof - Google Patents

Recycled concrete and preparation method thereof Download PDF

Info

Publication number
CN111423174A
CN111423174A CN202010215135.5A CN202010215135A CN111423174A CN 111423174 A CN111423174 A CN 111423174A CN 202010215135 A CN202010215135 A CN 202010215135A CN 111423174 A CN111423174 A CN 111423174A
Authority
CN
China
Prior art keywords
glaze
recycled
coarse aggregate
concrete
modified
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN202010215135.5A
Other languages
Chinese (zh)
Other versions
CN111423174B (en
Inventor
刘俊涛
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Xi'an Shuntong Building Materials Co ltd
Original Assignee
Xi'an Shuntong Building Materials Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Xi'an Shuntong Building Materials Co ltd filed Critical Xi'an Shuntong Building Materials Co ltd
Priority to CN202010215135.5A priority Critical patent/CN111423174B/en
Publication of CN111423174A publication Critical patent/CN111423174A/en
Application granted granted Critical
Publication of CN111423174B publication Critical patent/CN111423174B/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B28/00Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
    • C04B28/02Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
    • C04B28/04Portland cements
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C8/00Enamels; Glazes; Fusion seal compositions being frit compositions having non-frit additions
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B20/00Use 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
    • C04B20/10Coating or impregnating
    • C04B20/1055Coating or impregnating with inorganic materials
    • C04B20/1074Silicates, e.g. glass
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2201/00Mortars, concrete or artificial stone characterised by specific physical values
    • C04B2201/50Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)

Abstract

The invention discloses recycled concrete and a preparation method thereof, and relates to the technical field of concrete. The technical key points are as follows: the raw materials comprise the following components in parts by weight: cement 280-300kg/m3(ii) a 70-90kg/m of fly ash3(ii) a Sand 800-3(ii) a 790 kg/m glaze modified recycled coarse aggregate3(ii) a 190-kg/m natural gravel3(ii) a Additive 8-10kg/m3(ii) a 155-K kg/m water3. The recycled concrete has the advantages of improving the slump and the mechanical strength of the recycled concrete.

Description

Recycled concrete and preparation method thereof
Technical Field
The invention relates to the technical field of concrete, in particular to recycled concrete and a preparation method thereof.
Background
China is in the high-speed development period of economy, along with the development of the economy and the increase of population of China, the urbanization of villages and towns enables the basic construction to be in the developing climax, the centralized planning of second-line and following cities leads to the dismantling of a large number of existing buildings, the treatment of the generated construction waste and the like also cause huge pressure on the environment, wherein the waste concrete in the construction waste accounts for 30-40 percent; on the other hand, the demand of the great-interest buildings on the sandstone aggregate is increasing, and due to the large amount of mining, the natural environment is greatly damaged, and the natural resources tend to be exhausted gradually. The national goals of energy conservation and emission reduction are more difficult to realize due to the demolition or construction of buildings, building waste generated in the operation and maintenance period of the buildings, excessive exploitation of natural resources and the like. Therefore, a great deal of achievements are made by a plurality of research institutions in the aspects of building energy conservation and emission reduction, and the application and popularization of novel inorganic wall heat-insulating materials and the like, the recycling of building garbage and the like are mainly realized. At present, the preparation of recycled concrete aggregate has a mature technology in China, the technical level is continuously improved, and the recycled aggregate serving as the aggregate of a building main body material has a certain trend.
In application document with publication number CN106927756B, a recycled concrete is disclosed, which is composed of a gelled material, coarse aggregate, fine aggregate, an admixture, natural river sand, recycled modified PET plastic particles, an air entraining agent and water, wherein the recycled concrete comprises the following materials in parts by weight: 300-470 parts of a cementing material, 900-1200 parts of coarse aggregate, 60-250 parts of fine aggregate, 5-8 parts of an additive, 400-700 parts of natural river sand, 125-375 parts of regenerated modified PET plastic particles, 0.3-0.45 of water-to-glue ratio and 0.01-0.03% of air entraining agent in mass of the cementing material.
The concrete mixture slump prepared by the technical scheme is low, because the waste concrete is under the action of large external force in the crushing process, a large number of micro cracks easily appear in the aggregate, and the recycled aggregate has high water absorption rate, more pores, high surface roughness and super-high degree and large slurry consumption compared with natural aggregate, so that the slump is small, the fluidity is poor, the construction is not facilitated, the vibration is not easy to compact, and the phenomena of cavities and honeycombs easily appear in the formed concrete.
Disclosure of Invention
In view of the disadvantages of the prior art, a first object of the present invention is to provide a recycled concrete having an advantage of improving slump of recycled concrete.
The second purpose of the invention is to provide a preparation method of recycled concrete, which has the advantage of improving the slump of the recycled concrete.
In order to achieve the first object, the invention provides the following technical scheme:
the recycled concrete comprises the following raw materials in parts by weight:
cement 280-300kg/m3
70-90kg/m of fly ash3
Sand 800-3
790 kg/m glaze modified recycled coarse aggregate3
190-kg/m natural gravel3
Additive 8-10kg/m3
155-155 kg/m water3
By adopting the technical scheme, after the regenerated coarse aggregate is soaked by the glaze, the glaze enters cracks of the regenerated coarse aggregate, the glaze can be remained on the surface of the regenerated coarse aggregate, and after sintering, the glaze enters the glaze inside the cracks of the regenerated coarse aggregate to form a glaze layer, fills the cracks, reduces the porosity of the regenerated coarse aggregate, and reduces the water absorption of the regenerated coarse aggregate when concrete is stirred; glaze layer is formed after the glaze attached to the regenerated coarse aggregate is sintered, the surface of the regenerated coarse aggregate is wrapped, the roughness of the surface of the glaze layer is reduced, and the slurry consumption can be reduced; the slump and the fluidity of the recycled concrete are improved, so that the concrete is easier to construct and more easy to vibrate compactly, the phenomena of cavities and honeycombs are reduced, and the structural strength of the recycled concrete is improved. Meanwhile, cracks of the regenerated coarse aggregate are filled, so that the glaze modified regenerated coarse aggregate has better deformation resistance; the surface is wrapped, so that the regenerated coarse aggregate is more difficult to crush, the structural strength of the regenerated coarse aggregate can be improved, and the mechanical strength of the regenerated concrete is improved.
More preferably, the preparation method of the glaze modified recycled coarse aggregate comprises the following steps:
crushing waste concrete into coarse aggregates with the thickness of 5-25mm, then washing the crushed coarse aggregates with water, and naturally drying the crushed coarse aggregates to obtain regenerated coarse aggregates;
step two, preparing glaze, namely putting 5 +/-1 part of feldspar, 5 +/-1 part of quartz, 5 +/-1 part of calcite, 17 +/-1 part of kaolin and 4 +/-1 part of alumina in parts by weight into a ball mill, grinding for 20 +/-0.5 hours, and uniformly mixing the ground raw materials to obtain the glaze;
putting the regenerated coarse aggregate into a stirring tank, adding water into glaze, uniformly stirring to obtain glaze slurry, wherein the glaze slurry and the water are 30-40 parts and 50-60 parts by weight respectively, adding the glaze slurry into the stirring tank until the regenerated coarse aggregate is submerged, soaking and stirring for 30 +/-5 minutes;
and step four, fishing out the soaked dry aggregate from the glaze slurry, airing, and then putting into a sintering furnace for sintering for 20-40 minutes at the sintering temperature of 1100 +/-5 ℃ to obtain the glaze modified recycled coarse aggregate. .
By adopting the technical scheme, the aggregate can be cleaned to remove dust on the surface of the aggregate, so that the blockage of the crack of the aggregate by the dust is reduced, and the glaze slip can better enter the crack of the recycled aggregate; the content of glaze slip entering the inside of the regenerated coarse aggregate can be improved by matching with soaking and stirring, and the porosity of the regenerated coarse aggregate is reduced. The glaze slip on the surface and cracks of the regenerated coarse aggregate is denatured after sintering to form a glaze layer with higher hardness, so that the porosity of the regenerated coarse aggregate is reduced, and the slump of the regenerated concrete is improved; after the cracks are filled, the glaze modified recycled coarse aggregate has better deformation resistance, the structural strength of the recycled coarse aggregate is improved, and the mechanical strength of recycled concrete is improved; the glaze layer wraps the surface of the regenerated coarse aggregate, so that the roughness of the surface of the regenerated coarse aggregate is reduced, the slurry consumption is reduced, and the slump of the regenerated concrete is improved; meanwhile, the glaze layer has good hardness, forms a binding effect on the regenerated coarse aggregate, so that the regenerated coarse aggregate is more difficult to crush, has good deformation resistance, and improves the mechanical strength of the regenerated concrete. During the sintering process, if the time is too short, the glaze slip is not completely denatured, and if the time is too long, the self structural strength of the regenerated coarse aggregate is weakened.
More preferably, in the third step, water and a surfactant are added into the glaze material, and the mixture is uniformly stirred to obtain glaze slip, wherein the weight part of the surfactant is 15-20 parts. .
By adopting the technical scheme, the addition of the surfactant can reduce the surface tension of the glaze slip, so that the glaze slip can enter cracks and pores of the regenerated coarse aggregate more easily, glaze inside the regenerated coarse aggregate is improved, more glaze layers are formed, the structural strength of the regenerated coarse aggregate is improved, and the mechanical strength of the regenerated concrete is improved. The surface active agent enables the glaze slip to be more easily combined with the surface of the regenerated coarse aggregate and the inner wall of the crack, enables the glaze slip to be better attached to the regenerated coarse aggregate, reduces the glaze slip which runs off from the regenerated coarse aggregate in the airing process, stabilizes the glaze on the surface of the regenerated coarse aggregate and in the crack, enables more glaze layers to be formed in the sintering process, improves the structural strength of the regenerated coarse aggregate, and improves the mechanical strength of the regenerated concrete. The surface active agent also enables the glaze slip to be more easily attached to the surface of the regenerated coarse aggregate, prevents the glaze slip from completely wrapping the surface of the regenerated coarse aggregate to form a spherical condition with a smooth surface, stabilizes the combination of the glaze modified regenerated coarse aggregate and other raw materials, and improves the mechanical strength of the regenerated concrete.
More preferably, the glaze modified regenerated coarse aggregate obtained in the fourth step is added into a stirring tank and stirred for 20 +/-5 minutes. .
Through adopting above-mentioned technical scheme, the glaze relatively smooth glaze layer is formed on the modified regeneration coarse aggregate surface of frit, and regeneration coarse aggregate surface is originally super high with regard to roughness, more arch and shrinkage pool have, the mutual friction and collision of the modified regeneration coarse aggregate of frit among the stirring process, the bulge collision fracture on the modified regeneration coarse aggregate surface of frit drops, reduce the surface area of the modified regeneration coarse aggregate of frit, reduce with the thick liquid volume, improve the slump of regeneration concrete, make the concrete be under construction more easily, it is closely knit to vibrate more easily, reduce the cavity, the appearance of honeycomb, improve the structural strength of regeneration concrete. The glaze layer is scratched in the stirring process, the smoothness of the surface of the glaze modified regenerated coarse aggregate is reduced, the glaze modified regenerated coarse aggregate is better combined with other raw materials, and the mechanical strength of the regenerated concrete is improved.
More preferably, the residue dropped from the glaze-modified reclaimed coarse aggregate after stirring is sieved, and the powder is ground to obtain fine particles.
Through adopting above-mentioned technical scheme, after the residue screening after will falling and grinding, again use with the modified regeneration coarse aggregate of frit together, reduce the particle diameter of residue, small granule can improve the slump and the mobility of regeneration concrete mixture, makes the concrete be under construction more easily, and the densification of vibrating more easily reduces the appearance of cavity, honeycomb, improves the structural strength of regeneration concrete.
More preferably, the particle size of the fine particles after grinding is 0.1 to 0.5 μm. .
Through adopting above-mentioned technical scheme, the particle size undersize of tiny granule can increase the grinding cost, and the too big then leads to the easy fracture of tiny granule, influences recycled concrete's mechanical strength. And the tiny particles with larger particle size have little influence on the fluidity of the recycled concrete.
Further preferably, the corrosive liquid is sprayed into the stirring tank in the stirring process to carry out micro-etching on the surface of the glaze modified regenerated aggregate, and the corrosive liquid is sprayed on the surface of the glaze modified regenerated coarse aggregate through the atomizing spray head.
Through adopting above-mentioned technical scheme, the atomizer can make even drippage of corrosive liquid at the glaze modified regeneration coarse aggregate, and the glaze layer on glaze modified regeneration coarse aggregate surface appears tiny punctiform corrosion coat through the microetching, and the mar appears more easily in the glaze modified regeneration coarse aggregate surface of stirring in-process glaze modified regeneration coarse aggregate, has suitably increased the roughness on glaze modified regeneration coarse aggregate surface glaze layer of glaze, makes the bonding force of glaze modified regeneration coarse aggregate and grout. The coarse aggregate modified by glaze improves the roughness of the surface of the coarse aggregate modified by glaze while having small porosity, does not greatly increase the slurry consumption, improves the binding force between the coarse aggregate modified by glaze and cement slurry, and improves the slump and mechanical strength of recycled concrete.
More preferably, the etching solution is hydrofluoric acid or potassium hydroxide.
By adopting the technical scheme, the glaze contains aluminum oxide, hydrofluoric acid and potassium hydroxide are easy to corrode the glaze layer containing aluminum oxide, and other strong acid or strong base can corrode the glaze layer only by high temperature.
In order to achieve the second object, the invention provides the following technical scheme:
a preparation method of recycled concrete comprises the following steps:
step one, stirring and mixing natural macadam, sand, glaze modified recycled coarse aggregate, cement and fly ash uniformly to obtain a first mixture;
and step two, uniformly mixing water and the admixture, adding the mixture into the first mixture, and uniformly stirring to obtain the recycled concrete.
By adopting the technical scheme, the glaze modified recycled concrete has the advantages of smaller porosity, lower water absorption, higher self structural strength, reduced slurry consumption, improved slump of concrete and improved mechanical strength of concrete.
In summary, compared with the prior art, the invention has the following beneficial effects:
(1) glaze modification is carried out on the regenerated coarse aggregate, a glaze layer is formed on cracks and the surface of the regenerated coarse aggregate, so that the slump and the fluidity of the regenerated concrete are improved, and the cracks are filled to ensure that the glaze modified regenerated coarse aggregate has better deformation resistance and the mechanical strength of the regenerated concrete is improved;
(2) stirring and corroding the glaze modified regenerated coarse aggregate formed after sintering, reducing the surface area of the glaze modified regenerated coarse aggregate, reducing the slurry consumption, enabling the surface of the glaze modified regenerated coarse aggregate to have certain roughness, and improving the binding power of the glaze modified regenerated coarse aggregate and cement slurry; the slump of the recycled concrete is improved, and the mechanical strength of the recycled concrete is improved;
(3) after the residues are ground, the particle size of the residues is reduced to form micro particles, the fluidity and the slump of the concrete mixture are improved, and the construction of concrete is more convenient.
Detailed Description
The present invention will be described in detail with reference to examples.
Example 1: the components and the corresponding parts by weight of the raw materials of the recycled concrete are shown in the table 1,
the glaze modified recycled coarse aggregate is prepared by the following steps:
crushing waste concrete into coarse aggregates with the thickness of 5-25mm, then washing the crushed coarse aggregates with water, and naturally drying the crushed coarse aggregates to obtain regenerated coarse aggregates;
step two, preparing glaze, namely putting 5 +/-1 part of feldspar, 5 +/-1 part of quartz, 5 +/-1 part of calcite, 17 +/-1 part of kaolin and 4 +/-1 part of alumina in parts by weight into a ball mill, grinding for 20 +/-0.5 hours, and uniformly mixing the ground raw materials to obtain the glaze;
putting the regenerated coarse aggregate into a stirring tank, adding water into glaze, uniformly stirring to obtain glaze slurry, wherein the glaze slurry comprises 30 parts and 60 parts of glaze, surfactant and water by weight, adding the glaze slurry into the stirring tank until the regenerated coarse aggregate is submerged, soaking and stirring for 30 +/-5 minutes;
and step four, fishing out the soaked dry aggregate from the glaze slurry, airing, and then putting into a sintering furnace for sintering for 20 minutes at the sintering temperature of 1100 +/-5 ℃ to obtain the glaze modified recycled coarse aggregate.
A recycled concrete is prepared by the following steps:
step one, stirring and mixing natural macadam, sand, glaze modified recycled coarse aggregate, cement and fly ash uniformly to obtain a first mixture;
and step two, uniformly mixing water and the admixture, adding the mixture into the first mixture, and uniformly stirring to obtain the recycled concrete.
In this example, the particle size of the sand is less than 5mm, and the particle size of the natural crushed stone is 5-20 mm. The mud content is 0.45 percent, the crushing index is 9 percent, the cement is ordinary Portland cement, and the additive is a polycarboxylic acid water reducing agent.
Examples 2 to 3: a recycled concrete is different from the recycled concrete in example 1 in that the raw materials and the corresponding weight parts thereof are shown in Table 1, the raw materials and the corresponding weight parts thereof of the glaze slip are shown in Table 2, and the unit kg/m in Table 13Is the unit of weight portion of the raw materials required by the recycled concrete of the invention.
TABLE 1 raw materials and parts by weight of recycled concrete in examples 1 to 3
Figure BDA0002424145010000051
TABLE 2 glaze slips of examples 1 to 3 and their weight parts
Components Example 1 Example 2 Example 3
Glaze material 30 40 38
Water (W) 60 55 55
Example 4: the difference between the recycled concrete and the example 1 is that in the third step of preparing the glaze modified recycled coarse aggregate, water and a surfactant are added into the glaze, and the glaze slurry is obtained by uniformly stirring, wherein the weight part of the surfactant is 18 parts. In this example, the surfactant is sodium dodecylbenzenesulfonate.
Example 5: a recycled concrete which is different from example 4 in that the glaze, the surfactant and the water are 15 parts by weight, respectively.
Example 6: a recycled concrete which is different from example 4 in that 20 parts by weight of each of glaze, surfactant and water.
Example 7: a recycled concrete, which is different from example 1 in that in the fourth step of preparing the glaze-modified recycled coarse aggregate, the sintering time is 30 minutes.
Example 8: a recycled concrete, which is different from example 1 in that in the fourth step of preparing the glaze-modified recycled coarse aggregate, the sintering time is 40 minutes.
Example 9: a recycled concrete, which is different from the example 1 in that in the fourth step of preparing the glaze modified recycled coarse aggregate, the sintered glaze modified recycled coarse aggregate is added into a stirring tank and stirred for 20 +/-5 minutes.
Example 10: the difference between the recycled concrete and the example 9 is that in the fourth step of preparing the glaze modified recycled coarse aggregate, corrosive liquid is sprayed into a stirring tank in the stirring process to carry out micro-etching on the surface of the glaze modified recycled aggregate, and the corrosive liquid is sprayed on the surface of the glaze modified recycled coarse aggregate through an atomizing nozzle. The corrosive liquid is hydrofluoric acid or potassium hydroxide.
Example 11: a recycled concrete which is different from example 9 in that in the fourth step of preparing a glaze modified recycled coarse aggregate, the residue falling from the glaze modified recycled coarse aggregate after stirring is sieved out, the powder is ground to obtain fine particles, and the particle size of the fine particles is ground to 0.1 μm.
Example 12: a recycled concrete which is different from example 9 in that in the fourth step of preparing a glaze modified recycled coarse aggregate, the residue falling from the glaze modified recycled coarse aggregate after stirring is sieved out, the powder is ground to obtain fine particles, and the particle size of the fine particles is ground to 0.3 μm.
Example 13: a recycled concrete which is different from example 9 in that in the fourth step of preparing a glaze modified recycled coarse aggregate, the residue falling from the glaze modified recycled coarse aggregate after stirring is sieved out, the powder is ground to obtain fine particles, and the particle size of the fine particles is ground to 0.5 μm.
Comparative example 1: a recycled concrete is different from the concrete of example 4 in that 10 parts by weight of a surfactant is added.
Comparative example 2: a recycled concrete which is different from example 4 in that 25 parts by weight of a surfactant is added from example 4.
Comparative example 3: a recycled concrete, which is different from example 1 in that in the fourth step of preparing the glaze-modified recycled coarse aggregate, the sintering time is 10 minutes.
Comparative example 4: a recycled concrete, which is different from example 1 in that in the fourth step of preparing the glaze-modified recycled coarse aggregate, the sintering time is 50 minutes.
Comparative example 5: a recycled concrete which is different from example 9 in that in the fourth step of preparing a glaze modified recycled coarse aggregate, a residue dropped from the glaze modified recycled coarse aggregate after stirring is sieved out, the powder is ground to obtain fine particles, and the particle size of the fine particles is ground to 1 μm.
Comparative example 6: a recycled concrete, which is different from the concrete of example 1 in that, in the step one, the recycled coarse aggregate is not modified by the glaze, but the common recycled coarse aggregate is added.
Test slump test
Test samples: the concrete mixtures obtained in examples 1 to 13 were used as test samples 1 to 13, and the concrete mixtures obtained in comparative examples 1 to 6 were used as control samples 1 to 6.
The test method comprises the following steps: a horn-shaped slump bucket with an upper opening of 100mm, a lower opening of 200mm and a height of 300mm is respectively filled with test samples 1-13 and control samples 1-6, each sample is filled for three times, a tamping hammer is used for uniformly impacting 25 times along the bucket wall from outside to inside after each filling, and after tamping, the samples are leveled. And pulling up the barrel, and subtracting the height of the highest point of the concrete after the collapse by using the barrel height (300mm) to obtain a difference value, namely the slump.
And (3) test results: the test results of the test samples 1 to 13 are shown in Table 3, and the test results of the control samples 1 to 6 are shown in Table 4.
Test-compressive Strength test
Test samples: concrete mixtures obtained in examples 1 to 13 were used as test samples 1 to 13, and concrete mixtures obtained in comparative examples 1 to 5 were used as control samples 1 to 6. .
The test method comprises the following steps: the concrete mixtures of the test samples 1 to 13 are prepared into concrete test blocks, the concrete mixtures of the reference samples 1 to 6 are prepared into concrete test blocks, and the 28d compressive strength (MPa) of the recycled concrete is detected according to the compressive strength test in GB/T50081-2002 Standard test method for mechanical properties of common concrete.
The test instrument: pressure testing machine
And (3) test results: the test results of the test samples 1 to 13 are shown in Table 3, and the test results of the control samples 1 to 6 are shown in Table 4.
As can be seen from tables 3 and 4, when the test sample 1, the test sample 2, the test sample 3, and the control sample 6 were compared, and the slip of the concrete mixture obtained after the glaze modification was performed on the recycled coarse aggregate was increased, the compressive strength of the concrete test block was increased, which indicates that a glaze layer was formed in the crack and on the surface of the glaze-modified recycled concrete, and the compressive strength and the slip of the recycled concrete were improved.
As can be seen from tables 3 and 4, when the test sample 4, the test sample 5, the test sample 6, the test sample 1, the control sample 1, and the control sample 2 are compared, and a proper amount of surfactant is added in the process of preparing the glaze slip, the slump and the compressive strength of the obtained recycled concrete are increased; the addition of a proper amount of the surface active agent can promote the glaze slip to enter the cracks and be better combined with the inner walls and the surfaces of the cracks of the regenerated coarse aggregates, and the slump and the mechanical strength of the regenerated concrete are improved. When the surfactant is added in excess of 20 parts, the slump and compressive strength of the resulting recycled concrete are hardly changed.
As can be seen from tables 3 and 4, when the test sample 1, the test sample 7, the test sample 8, the control sample 3 and the control sample 4 are compared, when the sintering time is less than 20 minutes and more than 40 minutes, the compressive strength of the obtained concrete is reduced, which indicates that when the sintering time is less than 20 minutes, the glaze slip is not completely hardened, the strength of the glaze modified recycled coarse aggregate is affected, and when the sintering time exceeds 40 minutes, the self structure of the recycled coarse aggregate is deteriorated due to long-time high temperature, the strength is deteriorated, and the strength of the glaze modified recycled coarse aggregate is affected.
It can be known from table 3 and table 4 that, compare test sample 1, test sample 9, stir the modified regeneration coarse aggregate of glaze after sintering, the slump of the recycled concrete that obtains increases, explains that the modified regeneration coarse aggregate of glaze rubs and collides each other in the stirring process, makes the protruding part on the modified regeneration coarse aggregate surface of glaze collision fracture drop, reduces the surface area of the modified regeneration coarse aggregate of glaze, reduces with the thick liquid volume, improves the slump of recycled concrete. The increase of the compressive strength of the obtained recycled concrete shows that the glaze layer can be scratched in the stirring process, the smoothness of the surface of the glaze modified recycled coarse aggregate is reduced, the glaze modified recycled coarse aggregate is better combined with other raw materials, and the mechanical strength of the recycled concrete is improved.
It can be seen from tables 3 and 4 that, when comparing the test samples 9 and 10, the compressive strength of the recycled concrete obtained after the microetching during the stirring process is increased, which indicates that the microetching causes a tiny punctate corrosion layer to appear on the glaze layer on the surface of the glaze modified recycled coarse aggregate, scratches are more likely to appear on the surface of the glaze modified recycled coarse aggregate during the stirring process, the adhesive force between the glaze modified recycled coarse aggregate and the cement slurry is improved without greatly increasing the amount of the slurry, the mechanical strength of the recycled concrete is improved as can be seen from tables 3 and 4, when comparing the test samples 1, 11, 12, 13 and 5, the slump and compressive strength of the recycled concrete obtained after the coarse stirring of the glaze modified recycled aggregate are ground, and the particle size of the residue is reduced, the slump and the fluidity of the recycled concrete mixture can be improved, so that the concrete is easier to construct, the concrete is easier to vibrate compactly, the appearance of cavities and honeycomb phenomena is reduced, and the structural strength of the recycled concrete is improved. When the particle size is larger than 0.5 micron, the obtained concrete has obviously reduced falling degree and reduced fluidity.
TABLE 3 test sample 1-13 slump and compressive Strength test results
Figure BDA0002424145010000081
Figure BDA0002424145010000091
TABLE 4 slump and compressive Strength test results for control samples 1-6
Figure BDA0002424145010000092
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims (9)

1. The recycled concrete is characterized by comprising the following raw materials in parts by weight:
cement 280-300kg/m3
70-90kg/m of fly ash3
Sand 800-3
790 kg/m glaze modified recycled coarse aggregate3
190-kg/m natural gravel3
Additive 8-10kg/m3
155-155 kg/m water3
2. The recycled concrete of claim 1, wherein the glaze-modified recycled coarse aggregate is prepared by the following steps:
crushing waste concrete into coarse aggregates with the thickness of 5-25mm, then washing the crushed coarse aggregates with water, and naturally drying the crushed coarse aggregates to obtain regenerated coarse aggregates;
step two, preparing glaze, namely putting 5 +/-1 part of feldspar, 5 +/-1 part of quartz, 5 +/-1 part of calcite, 17 +/-1 part of kaolin and 4 +/-1 part of alumina in parts by weight into a ball mill, grinding for 20 +/-0.5 hours, and uniformly mixing the ground raw materials to obtain the glaze;
putting the regenerated coarse aggregate into a stirring tank, adding water into glaze, uniformly stirring to obtain glaze slurry, wherein the glaze slurry and the water are 30-40 parts and 50-60 parts by weight respectively, adding the glaze slurry into the stirring tank until the regenerated coarse aggregate is submerged, soaking and stirring for 30 +/-5 minutes;
and step four, fishing out the soaked dry aggregate from the glaze slurry, airing, and then putting into a sintering furnace for sintering for 20-40 minutes at the sintering temperature of 1100 +/-5 ℃ to obtain the glaze modified recycled coarse aggregate.
3. The recycled concrete of claim 2, wherein in the third step, water and a surfactant are added into the glaze material, and the glaze slip is obtained by uniformly stirring, wherein the weight part of the surfactant is 15-20 parts.
4. The recycled concrete of claim 2, wherein the glaze-modified recycled coarse aggregate obtained in the fourth step is added into a stirring tank and stirred for 20 ± 5 minutes.
5. The recycled concrete of claim 4, wherein the residue falling from the glaze-modified recycled coarse aggregate after stirring is sieved, and the powder is ground to obtain fine particles.
6. The recycled concrete of claim 5, wherein said fine particles after grinding have a particle size of 0.1 to 0.5 μm.
7. The recycled concrete of claim 4, wherein the stirring process sprays corrosive liquid into the stirring tank to microetch the surface of the glaze modified recycled aggregate, and the corrosive liquid is sprayed on the surface of the glaze modified recycled coarse aggregate through an atomizing nozzle.
8. The recycled concrete of claim 7, wherein said corrosive liquid is hydrofluoric acid or potassium hydroxide.
9. The preparation method of the recycled concrete is characterized by comprising the following steps of:
step one, stirring and mixing natural macadam, sand, glaze modified recycled coarse aggregate, cement and fly ash uniformly to obtain a first mixture;
and step two, uniformly mixing water and the admixture, adding the mixture into the first mixture, and uniformly stirring to obtain the recycled concrete.
CN202010215135.5A 2020-03-24 2020-03-24 Recycled concrete and preparation method thereof Expired - Fee Related CN111423174B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010215135.5A CN111423174B (en) 2020-03-24 2020-03-24 Recycled concrete and preparation method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010215135.5A CN111423174B (en) 2020-03-24 2020-03-24 Recycled concrete and preparation method thereof

Publications (2)

Publication Number Publication Date
CN111423174A true CN111423174A (en) 2020-07-17
CN111423174B CN111423174B (en) 2021-12-10

Family

ID=71549390

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010215135.5A Expired - Fee Related CN111423174B (en) 2020-03-24 2020-03-24 Recycled concrete and preparation method thereof

Country Status (1)

Country Link
CN (1) CN111423174B (en)

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2481275C1 (en) * 2011-12-29 2013-05-10 Юлия Алексеевна Щепочкина Mixture for making glaze
CN104649720A (en) * 2015-02-10 2015-05-27 山东建筑大学 Ceramic glaze prepared from waste concrete powder and preparation method of ceramic glaze
CN107129317A (en) * 2017-05-14 2017-09-05 江苏常大绿恒环境工程有限公司 A kind of preparation method of hydrophobicity light ceramic
CN107663074A (en) * 2017-07-04 2018-02-06 深圳市华威环保建材有限公司 A kind of manufacturing process of regeneration aggregate art brick
CN108191392A (en) * 2017-12-22 2018-06-22 广东科达洁能股份有限公司 A kind of sintering brick permeable to water being not easy to plug and preparation method thereof
CN109265087A (en) * 2018-09-29 2019-01-25 莆田学院 A kind of highway recycled aggregate pervious concrete and preparation method thereof
CN109456002A (en) * 2018-12-08 2019-03-12 曙光装配式建筑科技(浙江)有限公司 A kind of High Strength Regenerated Concrete and preparation method thereof
CN110436837A (en) * 2019-08-26 2019-11-12 厦门美益兴业建材有限公司 A kind of renewable concrete and preparation method thereof
CN110451860A (en) * 2019-08-26 2019-11-15 厦门美益兴业建材有限公司 A kind of energy-saving high-temperature-resistant concrete and preparation method thereof
CN112047688A (en) * 2020-09-09 2020-12-08 咸阳东大洋混凝土有限公司 Recycled aggregate concrete and preparation method thereof

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2481275C1 (en) * 2011-12-29 2013-05-10 Юлия Алексеевна Щепочкина Mixture for making glaze
CN104649720A (en) * 2015-02-10 2015-05-27 山东建筑大学 Ceramic glaze prepared from waste concrete powder and preparation method of ceramic glaze
CN107129317A (en) * 2017-05-14 2017-09-05 江苏常大绿恒环境工程有限公司 A kind of preparation method of hydrophobicity light ceramic
CN107663074A (en) * 2017-07-04 2018-02-06 深圳市华威环保建材有限公司 A kind of manufacturing process of regeneration aggregate art brick
CN108191392A (en) * 2017-12-22 2018-06-22 广东科达洁能股份有限公司 A kind of sintering brick permeable to water being not easy to plug and preparation method thereof
CN109265087A (en) * 2018-09-29 2019-01-25 莆田学院 A kind of highway recycled aggregate pervious concrete and preparation method thereof
CN109456002A (en) * 2018-12-08 2019-03-12 曙光装配式建筑科技(浙江)有限公司 A kind of High Strength Regenerated Concrete and preparation method thereof
CN110436837A (en) * 2019-08-26 2019-11-12 厦门美益兴业建材有限公司 A kind of renewable concrete and preparation method thereof
CN110451860A (en) * 2019-08-26 2019-11-15 厦门美益兴业建材有限公司 A kind of energy-saving high-temperature-resistant concrete and preparation method thereof
CN112047688A (en) * 2020-09-09 2020-12-08 咸阳东大洋混凝土有限公司 Recycled aggregate concrete and preparation method thereof

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
徐小敏等: "上釉技术对氧化钇稳定四方相氧化锆多晶陶瓷粘接及力学性能的影响", 《中国组织工程研究》 *
谢雄敏等: "喷釉法制备烧结页岩装饰砖及其性能研究", 《砖瓦》 *

Also Published As

Publication number Publication date
CN111423174B (en) 2021-12-10

Similar Documents

Publication Publication Date Title
CN113929390B (en) Environment-friendly green concrete and preparation method thereof
Zhou et al. Feasibility of incorporating recycled fine aggregate in high performance green lightweight engineered cementitious composites
Limbachiya et al. Performance of granulated foam glass concrete
Mageswari et al. The use of sheet glass powder as fine aggregate replacement in concrete
CN104153512B (en) A kind of processing method of building waste foamed concrete composite heat insulation block
Huang et al. Effect of recycled fine aggregates on alkali-activated slag concrete properties
US8617438B1 (en) Fly ash-based cementitious mixture
CN110395963B (en) Construction waste recycled concrete
Mohammed et al. Utilization of construction and demolition waste and synthetic aggregates
CN112830811B (en) Light high-strength geopolymer material and preparation method thereof
CN107572936A (en) Polymer foamed concrete and its production and use
CN106082901B (en) A kind of the green concrete prefabricated pile and construction method of strengthening soft foundation
CN113087427A (en) Recycled aggregate soaked based on metakaolin slurry and modification method thereof
Frankovič et al. Up-scaling and performance assessment of façade panels produced from construction and demolition waste using alkali activation technology
CN113264702A (en) Multipurpose pulp wrapping material and application thereof
CN107759156A (en) A kind of concrete formulation and preparation method and its concrete regenerating technique
CN111423174B (en) Recycled concrete and preparation method thereof
CN115259893B (en) Light environment-friendly building material
CN113185169A (en) Recycled aggregate soaked based on metakaolin slurry and modification method thereof
KR102509234B1 (en) Ultra-fine powdered super-fast hardening cement concrete composition and the construction method for road pavement using the same
CN112174613A (en) Concrete containing waste brick powder
CN112408906A (en) Novel dry-mixed masonry mortar and preparation method thereof
Wang et al. Influence of recycled concrete fines content on the dynamic mechanical properties of coal mine roadway support mortar
CN110981541A (en) Light partition board and preparation method thereof
CN108484082A (en) A kind of building waste residue regeneration floor tile and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20211210