CN109279843B - Environment-friendly recycled concrete and preparation method thereof - Google Patents
Environment-friendly recycled concrete and preparation method thereof Download PDFInfo
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- CN109279843B CN109279843B CN201811500592.8A CN201811500592A CN109279843B CN 109279843 B CN109279843 B CN 109279843B CN 201811500592 A CN201811500592 A CN 201811500592A CN 109279843 B CN109279843 B CN 109279843B
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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
- C04B28/02—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 containing hydraulic cements other than calcium sulfates
- C04B28/04—Portland cements
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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
- C04B20/10—Coating or impregnating
- C04B20/1055—Coating or impregnating with inorganic materials
-
- 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
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
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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 invention discloses environment-friendly recycled concrete and a preparation method thereof, and relates to the field of building materials. The raw materials of the environment-friendly recycled concrete comprise the following components in percentage by weight: 200-220kg/m water3(ii) a 440-460kg/m ordinary portland cement3(ii) a 380kg/m natural river sand3(ii) a 10-15kg/m of polycarboxylic acid water reducing agent3(ii) a Natural gravel 580kg/m3(ii) a 600-650kg/m polyvinyl alcohol modified recycled coarse aggregate3(ii) a 30-40kg/m of micro silicon powder3. The invention has the advantages of improving the compressive strength and the flexural strength, recycling the waste concrete and the waste polypropylene fiber, reducing pollution and being green and environment-friendly.
Description
Technical Field
The invention relates to the technical field of building materials, in particular to environment-friendly recycled concrete and a preparation method thereof.
Background
With the rapid development of the construction industry, the urbanization footsteps are faster and faster, meanwhile, the old city is more and more transformed, and a large amount of waste construction waste is generated. Most of the construction wastes in China are not recycled in a scientific mode. Most of the construction wastes are treated as garbage and are randomly piled in open-air suburbs or are treated in a simple landfill mode.
The invention discloses a recycled concrete doped with chopped basalt fibers and recycled coarse aggregate, which is prepared from the following raw materials in parts by weight: 100 portions of water, 300 portions of ordinary portland cement, 500 portions of medium sand, 700 portions of natural gravel, 650 portions of recycled coarse aggregate, 30-50 portions of fly ash, 1-5 portions of water reducing agent and 1-6 portions of chopped basalt fiber.
Compared with natural aggregate, the recycled coarse aggregate in the patent has the advantages that the surface of the recycled coarse aggregate is wrapped by hardened cement mortar, so the total content of the old cement mortar and the new cement mortar in recycled concrete is higher than that of common concrete, the porosity of the recycled concrete is higher than that of the natural concrete, and the untreated recycled coarse aggregate can influence the mechanical property and the durability of the concrete, so that the compressive strength and the flexural strength of the recycled concrete are poor.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide the environment-friendly recycled concrete which has the advantages of improving the compressive strength and the flexural strength.
The second purpose of the invention is to provide a preparation method of the environment-friendly recycled concrete, which has the advantages of improving the compressive strength and the flexural strength.
In order to achieve the first purpose, the invention provides the following technical scheme:
the environment-friendly recycled concrete comprises the following raw materials in parts by weight:
200-220kg/m water3；
440-460kg/m ordinary portland cement3；
380kg/m natural river sand3；
10-15kg/m of polycarboxylic acid water reducing agent3；
Natural gravel 580kg/m3；
600-650kg/m polyvinyl alcohol modified recycled coarse aggregate3；
30-40kg/m of micro silicon powder3；
The preparation method of the polyvinyl alcohol modified recycled aggregate comprises the following steps:
(1) adding carbon nanofibers into a polyvinyl alcohol aqueous solution, and stirring and mixing uniformly to obtain a mixed solution;
(2) adding the regenerated coarse aggregate into the mixed solution, simultaneously inserting an ultrasonic vibration rod into the mixed solution, vibrating for 15-30min, and soaking for 24-36 h;
(3) filtering, and drying the regenerated coarse aggregate at 50-60 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
By adopting the technical scheme, the nano carbon fibers permeate into gaps of the recycled coarse aggregate along with the polyvinyl alcohol aqueous solution, the ultrasonic vibration rod can discharge bubbles in the gaps of the recycled coarse aggregate, the permeation speed of the nano carbon fibers and the polyvinyl alcohol aqueous solution is increased, and the strength of the recycled coarse aggregate is enhanced after drying; and part of polyvinyl alcohol and nano carbon fiber form a film on the surface of the recycled coarse aggregate, so that the surface adhesion of the recycled coarse aggregate is improved, the recycled coarse aggregate is firmly adhered with cement, natural macadam and the like into a whole, and the strength of the recycled coarse aggregate is further improved.
More preferably, the mass concentration of the polyvinyl alcohol aqueous solution is 0.2 to 0.5%.
By adopting the technical scheme, the film formed by the polyvinyl alcohol aqueous solution has certain hydrophilicity, and the film on the surface can be dissolved under the action of the water in the concrete. If the concentration is too small, a film cannot be formed on the surface, and the purpose of covering pores on the surface of the recycled coarse aggregate cannot be achieved, and if the concentration is too large, the formed film cannot be dissolved due to too thick surface, so that the thickness of an interface transition region between the recycled coarse aggregate and the cement paste is increased, and the bonding force between the recycled coarse aggregate and the cement paste is influenced.
More preferably, the mass ratio of the carbon nanofibers to the polyvinyl alcohol aqueous solution is (0.5-1.0): 100.
by adopting the technical scheme, the carbon nanofibers are too few to play a role in reinforcement, and the carbon nanofibers are too many to easily cause the blockage of gaps of the recycled coarse aggregate.
More preferably, the filamentous nanocarbon has an average diameter of 100nm and a length of 60 to 100. mu.m.
By adopting the technical scheme, the carbon nanofibers can enter gaps of the recycled coarse aggregate, and meanwhile, the reinforcing effect can be achieved.
More preferably, the raw materials also comprise modified waste polypropylene fibers, and the weight ratio of the modified waste polypropylene fibers is 10-20kg/m3。
By adopting the technical scheme, the polypropylene fiber is an artificial synthetic fiber, the strength is high, the elasticity is good, the wear resistance and the corrosion resistance are realized, and the breaking strength, the crack resistance and the compressive strength of the concrete can be improved after the polypropylene fiber is added into the concrete.
More preferably, the preparation method of the modified waste polypropylene fiber comprises the following steps:
s1, crushing waste articles made of polypropylene materials to obtain waste polypropylene fibers with the diameter of 0.5-1mm and the length of 1-6 mm;
s2, performing corona treatment on the waste polypropylene fiber, wherein the corona strength is 4.0 kV/cm-4.2 kV/cm, and obtaining the modified waste polypropylene fiber.
By adopting the technical scheme, the waste articles can be fishing nets, safety nets and sewing threads, and the surface of the polypropylene fiber becomes rough after corona treatment, so that the cohesiveness of the polypropylene fiber and cement mortar is improved.
More preferably, S2 specifically includes: carrying out corona treatment on the waste polypropylene fibers, wherein the corona strength is 4.0 kV/cm-4.2 kV/cm, adding the waste polypropylene fibers subjected to corona treatment into a polyvinyl alcohol aqueous solution with the mass concentration of 0.5-1%, stirring and mixing uniformly, filtering and drying to obtain the modified waste polypropylene fibers.
By adopting the technical scheme, the polyvinyl alcohol forms a layer of film on the surface of the polypropylene fiber, so that the cohesiveness of the polypropylene fiber and cement mortar is further improved.
In order to achieve the second purpose, the invention provides the following technical scheme:
the preparation method of the environment-friendly recycled concrete comprises the following steps:
uniformly mixing natural river sand, natural macadam and polyvinyl alcohol modified recycled coarse aggregate to obtain a first mixture;
step two, uniformly mixing water, ordinary portland cement, micro silicon powder and a polycarboxylic acid water reducing agent to obtain a second mixture;
and step three, adding the first mixture into the second mixture, and uniformly mixing to obtain the environment-friendly recycled concrete.
In summary, compared with the prior art, the invention has the following beneficial effects:
(1) according to the invention, the regenerated coarse aggregate is soaked by adopting the aqueous solution of the carbon nanofibers and the polyvinyl alcohol, the carbon nanofibers permeate into gaps of the regenerated coarse aggregate along with the aqueous solution of the polyvinyl alcohol, the ultrasonic vibration rod can discharge bubbles in the gaps of the regenerated coarse aggregate, the permeation speed of the carbon nanofibers and the aqueous solution of the polyvinyl alcohol is improved, and the strength of the regenerated coarse aggregate is enhanced after drying; part of polyvinyl alcohol and nano carbon fiber form a film on the surface of the recycled coarse aggregate, so that the surface adhesion of the recycled coarse aggregate is improved, the recycled coarse aggregate is firmly adhered with cement, natural macadam and the like into a whole, and the strength of the recycled coarse aggregate is improved;
(2) according to the invention, the polypropylene fiber after corona treatment is added, so that the cohesiveness of the polypropylene fiber and cement mortar is improved, and the breaking strength, the cracking resistance and the compressive strength of concrete are improved;
(3) the invention can recycle the waste concrete and the waste polypropylene fiber, reduces pollution and is green and environment-friendly.
Detailed Description
The present invention will be described in detail with reference to examples.
Example 1: the environment-friendly recycled concrete comprises the following raw materials in parts by weight:
200kg/m water3；
440kg/m ordinary portland cement3；
380kg/m natural river sand3；
10kg/m of polycarboxylic acid water reducing agent3；
Natural crushed stone 580kg/m3；
Polyvinyl alcohol modified recycled coarse aggregate 650kg/m3；
30kg/m of micro silicon powder3；
The particle strength of the natural river sand is less than 5mm, the particle size of the natural macadam is 5-20mm, the mud content is 0.45%, and the crushing index is 9%.
The preparation method of the polyvinyl alcohol modified recycled aggregate comprises the following steps:
(1) adding carbon nanofibers into a polyvinyl alcohol aqueous solution with the mass concentration of 0.2, wherein the mass ratio of the carbon nanofibers to the polyvinyl alcohol aqueous solution is 0.5: 100, the average diameter of the carbon nanofibers is 100nm, the length of the carbon nanofibers is 60 micrometers, and the carbon nanofibers are stirred and mixed uniformly to obtain a mixed solution;
(2) adding the recycled coarse aggregate with the particle size of 5-25m into the mixed solution, simultaneously inserting an ultrasonic vibration rod into the mixed solution, vibrating for 15min, and soaking for 36 h;
(3) filtering, and drying the regenerated coarse aggregate at 50 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
The preparation method of the environment-friendly recycled concrete comprises the following steps:
uniformly mixing natural river sand, natural macadam and polyvinyl alcohol modified recycled coarse aggregate, stirring for 15min, and stirring at the rotating speed of 700rpm to obtain a first mixture;
step two, uniformly mixing water, ordinary portland cement, micro silicon powder and a polycarboxylic acid water reducing agent, stirring for 20min, and stirring at the rotating speed of 900rpm to obtain a second mixture;
and step three, adding the first mixture into the second mixture, uniformly mixing for 15min, and stirring at a rotation speed of 600rpm to obtain the environment-friendly recycled concrete.
Example 2: the environment-friendly recycled concrete is different from the concrete in the embodiment 1 in that the raw materials comprise the following components in percentage by weight:
205kg/m water3；
Ordinary portland cement 445kg/m3；
Natural river sand 385kg/m3；
Polycarboxylic acid water reducing agent 11g/m3；
585g/m of natural macadam3；
630g/m polyvinyl alcohol modified recycled coarse aggregate3；
Microsilica 32g/m3。
Example 3: the environment-friendly recycled concrete is different from the concrete in the embodiment 1 in that the raw materials comprise the following components in percentage by weight:
210kg/m water3；
Ordinary Portland cement 450/m3；
Natural river sand 390/m3；
Polycarboxylic acid water reducing agent 13g/m3；
Natural broken stone 590/m3；
620g/m polyvinyl alcohol modified recycled coarse aggregate3；
Micro silicon powder 35kg/m3。
Example 4: the environment-friendly recycled concrete is different from the concrete in the embodiment 1 in that the raw materials comprise the following components in percentage by weight:
215kg/m of water3；
Ordinary portland cement 455/m3；
Natural river sand 395/m3；
Polycarboxylate superplasticizer 14g/m3；
Natural crushed stone 595/m3；
Polyvinyl alcohol modified recycled coarse aggregate 610/m3；
Micro silicon powder 38g/m3。
Example 5: the environment-friendly recycled concrete is different from the concrete in the embodiment 1 in that the raw materials comprise the following components in percentage by weight:
220kg/m water3；
Ordinary Portland cement 460kg/m3；
Natural river sand 400kg/m3；
Polycarboxylate superplasticizer 15kg/m3；
600kg/m natural macadam3；
600kg/m polyvinyl alcohol modified recycled coarse aggregate3；
Micro silicon powder 40kg/m3。
Example 6: the environment-friendly recycled concrete is different from the embodiment 1 in that the preparation method of the polyvinyl alcohol modified recycled aggregate is as follows:
(1) adding carbon nanofibers into a polyvinyl alcohol aqueous solution with the mass concentration of 0.3%, wherein the mass ratio of the carbon nanofibers to the polyvinyl alcohol aqueous solution is 0.8: 100, the average diameter of the carbon nanofibers is 100nm, the length of the carbon nanofibers is 80 microns, and the carbon nanofibers are stirred and mixed uniformly to obtain a mixed solution;
(2) adding the recycled coarse aggregate with the particle size of 5-25m into the mixed solution, simultaneously inserting an ultrasonic vibration rod into the mixed solution, vibrating for 15min, and soaking for 36 h;
(3) filtering, and drying the regenerated coarse aggregate at 50 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
Example 7: the environment-friendly recycled concrete is different from the embodiment 1 in that the preparation method of the polyvinyl alcohol modified recycled aggregate is as follows:
(1) adding carbon nanofibers into a polyvinyl alcohol aqueous solution with the mass concentration of 0.5%, wherein the mass ratio of the carbon nanofibers to the polyvinyl alcohol aqueous solution is 1: 100, the average diameter of the carbon nanofibers is 100nm, the length of the carbon nanofibers is 100 microns, and the carbon nanofibers are stirred and mixed uniformly to obtain a mixed solution;
(2) adding the recycled coarse aggregate with the particle size of 5-25m into the mixed solution, simultaneously inserting an ultrasonic vibration rod into the mixed solution, vibrating for 15min, and soaking for 36 h;
(3) filtering, and drying the regenerated coarse aggregate at 50 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
Example 8: the environment-friendly recycled concrete is different from the embodiment 1 in that the preparation method of the polyvinyl alcohol modified recycled aggregate is as follows:
(1) adding carbon nanofibers into a polyvinyl alcohol aqueous solution with the mass concentration of 0.2, wherein the mass ratio of the carbon nanofibers to the polyvinyl alcohol aqueous solution is 0.5: 100, the average diameter of the carbon nanofibers is 100nm, the length of the carbon nanofibers is 60 micrometers, and the carbon nanofibers are stirred and mixed uniformly to obtain a mixed solution;
(2) adding the recycled coarse aggregate with the particle size of 5-25m into the mixed solution, simultaneously inserting an ultrasonic vibration rod into the mixed solution, vibrating for 20min, and soaking for 30 h;
(3) filtering, and drying the regenerated coarse aggregate at 50 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
Example 9: the environment-friendly recycled concrete is different from the embodiment 1 in that the preparation method of the polyvinyl alcohol modified recycled aggregate is as follows:
(1) adding carbon nanofibers into a polyvinyl alcohol aqueous solution with the mass concentration of 0.2, wherein the mass ratio of the carbon nanofibers to the polyvinyl alcohol aqueous solution is 0.5: 100, the average diameter of the carbon nanofibers is 100nm, the length of the carbon nanofibers is 60 micrometers, and the carbon nanofibers are stirred and mixed uniformly to obtain a mixed solution;
(2) adding the recycled coarse aggregate with the particle size of 5-25m into the mixed solution, simultaneously inserting an ultrasonic vibration rod into the mixed solution, vibrating for 30min, and soaking for 24 h;
(3) filtering, and drying the regenerated coarse aggregate at 50 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
Example 10: environment-friendly regenerative coagulationThe soil is different from the soil in the embodiment 1 in that the raw material also comprises modified waste polypropylene fiber, and the weight ratio of the modified waste polypropylene fiber is 10kg/m3；
The preparation method of the modified waste polypropylene fiber comprises the following steps:
s1, crushing waste articles made of polypropylene materials to obtain waste polypropylene fibers with the diameter of 0.5-1mm and the length of 1-6 mm;
s2, carrying out corona treatment on the waste polypropylene fiber, wherein the corona strength is 4.0kV/cm, and obtaining the modified waste polypropylene fiber.
The preparation method of the environment-friendly recycled concrete comprises the following steps:
uniformly mixing natural river sand, natural macadam and polyvinyl alcohol modified recycled coarse aggregate, stirring for 15min, and stirring at the rotating speed of 700rpm to obtain a first mixture;
step two, uniformly mixing water, ordinary portland cement, micro silicon powder and a polycarboxylic acid water reducing agent, stirring for 20min, and stirring at the rotating speed of 900rpm to obtain a second mixture;
and step three, adding the first mixture into the second mixture, uniformly mixing, adding the modified waste polypropylene fibers, stirring for 15min, and stirring at a rotating speed of 600rpm to obtain the environment-friendly recycled concrete.
Example 11: an environment-friendly recycled concrete which is different from the concrete in example 10 in that the weight ratio of the modified waste polypropylene fibers is 15kg/m3。
Example 12: an environment-friendly recycled concrete which is different from the concrete in example 10 in that the weight ratio of the modified waste polypropylene fibers is 20kg/m3。
Example 13: the difference between the environment-friendly recycled concrete and the embodiment 10 is that the preparation method of the modified waste polypropylene fiber comprises the following steps:
s1, crushing waste articles made of polypropylene materials to obtain waste polypropylene fibers with the diameter of 0.5-1mm and the length of 1-6 mm;
s2, carrying out corona treatment on the waste polypropylene fiber, wherein the corona strength is 4.1kV/cm, and obtaining the modified waste polypropylene fiber.
Example 14: the difference between the environment-friendly recycled concrete and the embodiment 10 is that the preparation method of the modified waste polypropylene fiber comprises the following steps:
s1, crushing waste articles made of polypropylene materials to obtain waste polypropylene fibers with the diameter of 0.5-1mm and the length of 1-6 mm;
s2, carrying out corona treatment on the waste polypropylene fiber, wherein the corona strength is 4.2kV/cm, and obtaining the modified waste polypropylene fiber.
Example 15: the difference between the environment-friendly recycled concrete and the embodiment 10 is that the preparation method of the modified waste polypropylene fiber comprises the following steps:
s1, crushing waste articles made of polypropylene materials to obtain waste polypropylene fibers with the diameter of 0.5-1mm and the length of 1-6 mm;
s2, performing corona treatment on the waste polypropylene fibers, wherein the corona strength is 4.0kV/cm, adding the waste polypropylene fibers subjected to corona treatment into a polyvinyl alcohol aqueous solution with the mass concentration of 0.5%, uniformly stirring and mixing, filtering, and drying to obtain the modified waste polypropylene fibers.
Example 16: the difference between the environment-friendly recycled concrete and the embodiment 10 is that the preparation method of the modified waste polypropylene fiber comprises the following steps:
s1, crushing waste articles made of polypropylene materials to obtain waste polypropylene fibers with the diameter of 0.5-1mm and the length of 1-6 mm;
s2, performing corona treatment on the waste polypropylene fibers, wherein the corona strength is 4.0kV/cm, adding the waste polypropylene fibers subjected to corona treatment into a polyvinyl alcohol aqueous solution with the mass concentration of 0.7%, uniformly stirring and mixing, filtering, and drying to obtain the modified waste polypropylene fibers.
Example 17: the difference between the environment-friendly recycled concrete and the embodiment 10 is that the preparation method of the modified waste polypropylene fiber comprises the following steps:
s1, crushing waste articles made of polypropylene materials to obtain waste polypropylene fibers with the diameter of 0.5-1mm and the length of 1-6 mm;
s2, performing corona treatment on the waste polypropylene fibers, wherein the corona strength is 4.0kV/cm, adding the waste polypropylene fibers subjected to corona treatment into a polyvinyl alcohol aqueous solution with the mass concentration of 1%, uniformly stirring and mixing, filtering, and drying to obtain the modified waste polypropylene fibers.
Comparative example 1: the environment-friendly recycled concrete is different from the concrete in the embodiment 1 in that the raw materials comprise the following components in percentage by weight:
200kg/m water3；
440kg/m ordinary portland cement3；
380kg/m natural river sand3；
10kg/m of polycarboxylic acid water reducing agent3；
Natural crushed stone 580kg/m3；
Ordinary recycled coarse aggregate 650kg/m3；
30kg/m of micro silicon powder3；
The particle size of the natural river sand is less than 5mm, the particle size of the natural macadam is 5-20mm, the mud content is 0.45%, and the crushing index is 9%.
The preparation method of the environment-friendly recycled concrete comprises the following steps:
uniformly mixing natural river sand, natural macadam and common recycled coarse aggregate, stirring for 15min, and stirring at the rotating speed of 700rpm to obtain a first mixture;
step two, uniformly mixing water, ordinary portland cement, micro silicon powder and a polycarboxylic acid water reducing agent, stirring for 20min, and stirring at the rotating speed of 900rpm to obtain a second mixture;
and step three, adding the first mixture into the second mixture, uniformly mixing for 15min, and stirring at a rotation speed of 600rpm to obtain the environment-friendly recycled concrete.
Comparative example 2: the environment-friendly recycled concrete is different from the embodiment 1 in that the preparation method of the polyvinyl alcohol modified recycled aggregate is as follows:
(1) adding regenerated coarse aggregate with the particle size of 5-25m into a polyvinyl alcohol aqueous solution with the mass concentration of 0.2, and soaking for 36 h;
(2) filtering, and drying the regenerated coarse aggregate at 50 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
Comparative example 3: the environment-friendly recycled concrete is different from the embodiment 1 in that the preparation method of the polyvinyl alcohol modified recycled aggregate is as follows:
(1) adding regenerated coarse aggregate with the particle size of 5-25m into a polyvinyl alcohol aqueous solution with the mass concentration of 0.2, simultaneously inserting an ultrasonic vibration rod into the mixed solution, vibrating for 15min, and soaking for 36 h;
(2) filtering, and drying the regenerated coarse aggregate at 50 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
Comparative example 4: the environment-friendly recycled concrete is different from the concrete in the embodiment 1 in that the raw materials comprise the following components in percentage by weight:
200kg/m water3；
440kg/m ordinary portland cement3；
380kg/m natural river sand3；
10kg/m of polycarboxylic acid water reducing agent3；
Natural crushed stone 580kg/m3；
Ordinary recycled coarse aggregate 650kg/m3；
30kg/m of micro silicon powder3；
10kg/m of waste polypropylene fiber with the diameter of 0.5-1mm and the length of 1-6mm3；
The particle size of the natural river sand is less than 5mm, the particle size of the natural macadam is 5-20mm, the mud content is 0.45%, and the crushing index is 9%.
The preparation method of the environment-friendly recycled concrete comprises the following steps:
uniformly mixing natural river sand, natural macadam and common recycled coarse aggregate, stirring for 15min, and stirring at the rotating speed of 700rpm to obtain a first mixture;
step two, uniformly mixing water, ordinary portland cement, micro silicon powder and a polycarboxylic acid water reducing agent, stirring for 20min, and stirring at the rotating speed of 900rpm to obtain a second mixture;
and step three, adding the first mixture into the second mixture, adding the waste polypropylene fibers, uniformly mixing, stirring for 15min, and stirring at a rotating speed of 600rpm to obtain the environment-friendly recycled concrete.
Comparative example 5: recycled concrete was prepared using example 1 of the chinese invention patent publication No. CN 107010896A.
Performance test samples: the recycled concrete obtained in examples 1 to 17 was used as test samples 1 to 17, and the recycled concrete obtained in comparative examples 1 to 5 was used as control samples 1 to 5.
The test method comprises the following steps: the 28-day compressive strength and flexural strength of the test samples 1 to 17 and the control samples 1 to 5 were measured according to the method prescribed in Standard test methods for mechanical Properties of ordinary concrete GB/T50081-2002.
Test results and analysis: the test results of the test samples 1 to 17 and the control samples 1 to 5 are shown in Table 1. As can be seen from table 1, after the recycled concrete is modified by polyvinyl alcohol and carbon nanofibers, the compressive strength and the flexural strength of the recycled concrete are both greatly improved, bubbles in gaps of the recycled coarse aggregate can be discharged through vibration treatment of the ultrasonic vibration rod, the permeation speed of the carbon nanofibers and the polyvinyl alcohol aqueous solution is improved, and the strength of the recycled coarse aggregate is enhanced after drying; particularly, after the modified waste polypropylene fibers are added, the modified waste polypropylene fibers and the polyvinyl alcohol modified recycled concrete have synergistic effect, the compressive strength and the flexural strength of the recycled concrete are remarkably improved, and the mechanical property of the recycled concrete is increased to the maximum extent after the waste polypropylene fibers are subjected to corona treatment and polyvinyl alcohol modification at the same time.
TABLE 1 test results of test samples 1-17 and control samples 1-5
| Sample numbering | Compressive strength/MPa | Flexural strength/MPa |
| Test sample 1 | 48.5 | 15.0 |
| Test sample 2 | 48.2 | 15.2 |
| Test sample 3 | 48.5 | 15.6 |
| Test sample 4 | 48.3 | 15.3 |
| Test sample 5 | 48.6 | 15.4 |
| Test sample 6 | 49.2 | 16.0 |
| Test sample 7 | 49.3 | 16.2 |
| Test sample 8 | 49.6 | 16.5 |
| Test sample 9 | 49.5 | 16.1 |
| Test sample 10 | 55.0 | 18.3 |
| Test sample 11 | 56.2 | 29.2 |
| Test sample 12 | 57.1 | 20.1 |
| Test sample 13 | 55.6 | 18.6 |
| Test sample 14 | 55.8 | 18.8 |
| Test sample 15 | 59.2 | 22.0 |
| Test sample 16 | 59.4 | 22.2 |
| Test sample 17 | 59.6 | 22.3 |
| Control sample 1 | 25.0 | 5.2 |
| Control sample 2 | 26.5 | 6.3 |
| Control sample 3 | 28.1 | 7.5 |
| Control sample 4 | 27.2 | 7.3 |
| Control sample 5 | 22.3 | 4.2 |
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 (5)
1. The environment-friendly recycled concrete is characterized by comprising the following raw materials in parts by weight:
200-220kg/m water3 ；
440-460kg/m ordinary portland cement3 ；
380kg/m natural river sand3 ；
10-15kg/m of polycarboxylic acid water reducing agent3 ；
Natural gravel 580kg/m3 ；
600-650kg/m polyvinyl alcohol modified recycled coarse aggregate3 ；
30-40kg/m of micro silicon powder3 ；
The preparation method of the polyvinyl alcohol modified recycled aggregate comprises the following steps:
(1) adding carbon nanofibers into a polyvinyl alcohol aqueous solution with the mass concentration of 0.2-0.5%, and stirring and mixing uniformly to obtain a mixed solution; the mass ratio of the carbon nanofibers to the polyvinyl alcohol aqueous solution is (0.5-1.0): 100, respectively; the average diameter of the nano carbon fiber is 100nm, and the length of the nano carbon fiber is 60-100 mu m;
(2) adding the regenerated coarse aggregate into the mixed solution, simultaneously inserting an ultrasonic vibration rod into the mixed solution, vibrating for 15-30min, and soaking for 24-36 h;
(3) filtering, and drying the regenerated coarse aggregate at 50-60 ℃ to obtain the polyvinyl alcohol modified regenerated coarse aggregate.
2. The environment-friendly recycled concrete according to claim 1, wherein the raw materials further comprise modified waste polypropylene fibers, and the weight ratio of the modified waste polypropylene fibers is 10-20kg/m3 。
3. The environment-friendly recycled concrete according to claim 2, wherein the preparation method of the modified waste polypropylene fiber comprises the following steps:
s1, crushing waste articles made of polypropylene materials to obtain waste polypropylene fibers with the diameter of 0.5-1mm and the length of 1-6 mm;
s2, carrying out corona treatment on the waste polypropylene fibers, wherein the corona strength is 4.0 kV/cm-4.2 kV/cm, and obtaining the modified waste polypropylene fibers.
4. The environment-friendly recycled concrete according to claim 3, wherein the S2 specifically comprises: carrying out corona treatment on the waste polypropylene fibers, wherein the corona strength is 4.0 kV/cm-4.2 kV/cm, adding the waste polypropylene fibers subjected to corona treatment into a polyvinyl alcohol aqueous solution with the mass concentration of 0.5-1%, stirring and mixing uniformly, filtering and drying to obtain the modified waste polypropylene fibers.
5. A method for preparing the environmentally friendly recycled concrete of any one of claims 1 to 4, comprising the steps of:
uniformly mixing natural river sand, natural macadam and polyvinyl alcohol modified recycled coarse aggregate to obtain a first mixture;
step two, uniformly mixing water, ordinary portland cement, micro silicon powder and a polycarboxylic acid water reducing agent to obtain a second mixture;
step three, adding the first mixture into the second mixture, and uniformly mixing to obtain the environment-friendly recycled concrete;
if modified waste polypropylene fibers exist in the raw materials, the modified waste polypropylene fibers are added after the first mixture and the second mixture are uniformly mixed in the step three.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5681194A (en) * | 1992-06-09 | 1997-10-28 | Baker; Richard | Recycled fibre reinforced resin containing product |
| CN105218840A (en) * | 2015-09-16 | 2016-01-06 | 长春博超汽车零部件股份有限公司 | A kind of low VOC natural-fiber composite material, preparation method and application thereof |
| CN105777012A (en) * | 2016-03-24 | 2016-07-20 | 西京学院 | Recycled concrete with highly effective damping property |
| CN108276023A (en) * | 2018-01-23 | 2018-07-13 | 合肥梵腾环保科技有限公司 | A kind of energy-saving environment-friendly light partition plate and preparation method thereof |
| CN108726956A (en) * | 2018-08-08 | 2018-11-02 | 宝辰永宇（滁州）新材料科技有限公司 | A kind of modification regeneration concrete and preparation method thereof |
-
2018
- 2018-12-08 CN CN201811500592.8A patent/CN109279843B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5681194A (en) * | 1992-06-09 | 1997-10-28 | Baker; Richard | Recycled fibre reinforced resin containing product |
| CN105218840A (en) * | 2015-09-16 | 2016-01-06 | 长春博超汽车零部件股份有限公司 | A kind of low VOC natural-fiber composite material, preparation method and application thereof |
| CN105777012A (en) * | 2016-03-24 | 2016-07-20 | 西京学院 | Recycled concrete with highly effective damping property |
| CN108276023A (en) * | 2018-01-23 | 2018-07-13 | 合肥梵腾环保科技有限公司 | A kind of energy-saving environment-friendly light partition plate and preparation method thereof |
| CN108726956A (en) * | 2018-08-08 | 2018-11-02 | 宝辰永宇（滁州）新材料科技有限公司 | A kind of modification regeneration concrete and preparation method thereof |
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