CN113582628A - Pervious concrete and preparation method thereof - Google Patents
Pervious concrete and preparation method thereof Download PDFInfo
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- CN113582628A CN113582628A CN202111010662.3A CN202111010662A CN113582628A CN 113582628 A CN113582628 A CN 113582628A CN 202111010662 A CN202111010662 A CN 202111010662A CN 113582628 A CN113582628 A CN 113582628A
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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
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/02—Granular materials, e.g. microballoons
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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
- C04B14/00—Use of inorganic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of inorganic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B14/02—Granular materials, e.g. microballoons
- C04B14/04—Silica-rich materials; Silicates
- C04B14/06—Quartz; Sand
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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
- C04B16/00—Use of organic materials as fillers, e.g. pigments, for mortars, concrete or artificial stone; Treatment of organic materials specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B16/04—Macromolecular compounds
- C04B16/06—Macromolecular compounds fibrous
- C04B16/0616—Macromolecular compounds fibrous from polymers obtained by reactions only involving carbon-to-carbon unsaturated bonds
- C04B16/0625—Polyalkenes, e.g. polyethylene
- C04B16/0633—Polypropylene
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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
- C04B22/00—Use of inorganic materials as active ingredients for mortars, concrete or artificial stone, e.g. accelerators, shrinkage compensating agents
- C04B22/06—Oxides, Hydroxides
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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
- C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
- C04B24/24—Macromolecular compounds
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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
- C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
- C04B24/24—Macromolecular compounds
- C04B24/38—Polysaccharides or derivatives thereof
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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
- C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
- C04B40/0028—Aspects relating to the mixing step of the mortar preparation
- C04B40/0039—Premixtures of ingredients
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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
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00241—Physical properties of the materials not provided for elsewhere in C04B2111/00
- C04B2111/00284—Materials permeable to liquids
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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
- 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 pervious concrete and a preparation method thereof, wherein the pervious concrete comprises, by mass, 900 parts of coarse aggregate, 200 parts of cement, 320 parts of admixture, 0.7-1.9 parts of dispersant and 60-80 parts of water. The pervious concrete provided by the invention has high concrete strength and good cement dispersibility.
Description
Technical Field
The invention belongs to the technical field of concrete, and particularly relates to pervious concrete and a preparation method thereof.
Background
The surface of modern city is covered by reinforced concrete building and asphalt concrete road surface, which causes the exhaustion of underground water and the accumulation of water on rainstorm road surface. In the 80 s of the 20 th century, developed countries and regions, the development of pervious concrete pavements was started to address this deficiency. The pervious concrete is a honeycomb structure with holes uniformly distributed by coating a thin layer of cement slurry on the surface of coarse aggregate and bonding the cement slurry, so that the pervious concrete has the characteristics of air permeability, water permeability and light weight. Pervious concrete generally does not contain fine aggregate.
The pervious concrete can make rainwater flow into the ground, effectively supplement underground water, and relieve some urban environmental problems such as rapid decline of urban underground water level. And can effectively eliminate the harm of oil compounds on the ground and the like to the environmental pollution; meanwhile, the material is an excellent paving material which can protect underground water, maintain ecological balance and relieve urban heat island effect; it is beneficial to the benign development of human living environment, the management of urban rainwater, the prevention and treatment of water pollution and the like, and has important significance.
The water-permeable concrete has good water permeability, but the mechanical properties are reduced compared with the common concrete. Because fine aggregate is lacked and the surface of the coarse aggregate is only coated with thin-layer cement paste, the pervious concrete has small bonding area and large and more pores, so that the strength of the concrete is difficult to meet the requirement, and the development of the pervious concrete is limited.
To sum up, how to design a pervious concrete can effectively improve the strength of the concrete, which is a problem that needs to be solved urgently at present.
Disclosure of Invention
The present invention is directed to solve the above problems, and an object of the present invention is to provide a pervious concrete and a method for preparing the same, which comprehensively improves the strength of the pervious concrete by pretreating a coarse aggregate, preparing a dispersant, and improving a method for preparing the pervious concrete.
The invention achieves the purpose through the following technical scheme, and the pervious concrete comprises, by mass, 1200 parts of coarse aggregate 900-.
The pretreatment method of the coarse aggregate comprises the following steps:
s1, uniformly mixing hydrated salt and the coarse aggregate, heating for 30-40min at 55-65 ℃, dispersing for 20-30min in a high-speed dispersion machine at 80-90 ℃ and 1000-1200r/min, and cooling for 1-2h at 0-5 ℃ to obtain hydrated salt crystal coated coarse aggregate;
s2, dipping the polypropylene short fibers in the glue solution for 20-40min, filtering the glue solution to obtain sticky short fibers, uniformly spraying the sticky short fibers on the surface of coarse aggregate coated by hydrated salt crystals, and standing at room temperature for 2-4h to harden the sticky short fibers into a web;
s3, heating the material obtained in the step S2 to 40-60 ℃, uniformly stirring, standing for 1-2h, and heating to 100-120 ℃ to evaporate water, thereby obtaining the pretreated coarse aggregate.
Further, the coarse aggregate is sand stone with the particle size of 4-9mm, and the admixture is fly ash or silica fume.
Further, in step S1, the mass ratio of hydrated salt to coarse aggregate is (0.06-0.1): 1, the hydrated salt is CaCl2﹒6H2O。
Further, in step S2, the diameter of the polypropylene staple fiber is 2-5 μm, the length is 3-7mm, and the glue solution comprises the following components in a mass ratio of 1: (0.1-0.2) room temperature adhesive and silicone oil, wherein the spraying amount of the viscous short fiber is 2-3%.
Further, the pervious concrete also comprises 0.7-1.9 parts of a dispersing agent, wherein the dispersing agent comprises a component A and a component B, and the mass ratio of the component A to the component B is 1: (1.2-2), wherein the component A comprises alumina-lignin nano particles and chitin-chitosan nano whiskers, and the mass ratio of the alumina-lignin nano particles to the chitin-chitosan nano whiskers is 1: (1-1.5), and the component B is a polycarboxylic acid type water reducing agent.
Further, the preparation method of the alumina-lignin nanoparticles comprises the following steps: putting the lignin powder at the temperature of between 15 and 30 ℃ for vacuum drying for 4 to 8 hours, then uniformly mixing the lignin powder with the nano alumina powder, and putting the mixture in ultrasonic waves of 125-140W and 30 to 40kHZ for treatment for 4 to 5 hours to obtain the alumina-lignin nano particles.
Wherein the mass ratio of the lignin powder to the nano alumina powder is 1: (0.2-0.3).
Further, the preparation method of the chitin-chitosan nanowhisker comprises the following steps:
A. mixing chitin with 20-30 times of concentrated hydrochloric acid, stirring and refluxing at 128-135 deg.C for 7-8h, centrifuging to remove upper layer liquid after reaction, taking off the lower layer precipitate, and repeatedly centrifuging and dispersing in deionized water until the pH of the dispersion is 3;
B. transferring the dispersion liquid to a dialysis bag, dialyzing with deionized water, and replacing the deionized water until the pH of the solution outside the dialysis bag is 5-6;
C. adding chitosan into the dialysis bag, stirring for dissolving, and continuing to dialyze with deionized water until the pH of the solution outside the dialysis bag is 7, and stopping dialysis;
D. and filtering the dispersion liquid obtained by dialysis, and freeze-drying to obtain the chitin-chitosan nano crystal whisker.
Further, the mass ratio of the chitin to the chitosan is 1: (0.1-0.2).
The invention also discloses a preparation method of the pervious concrete, which comprises the following steps:
(1) evenly mixing the cement and the admixture to obtain a first material,
(2) uniformly mixing the material I and the alumina-lignin nano particles, then adding the chitin-chitosan nano whiskers, continuously uniformly mixing, adding the pretreated coarse aggregate, and uniformly stirring to obtain a material II;
(3) and adding half of water into the material II, uniformly stirring, then adding a polycarboxylic acid type water reducing agent, uniformly stirring, adding the remaining half of water and the pretreated sodium silicate, continuously stirring uniformly, and then discharging to obtain the pervious concrete.
Further, the mole ratio of the sodium silicate powder to the hydrate pretreated in the step (3) is (1-1.2): the pretreatment method comprises the following steps: adding a sodium silicate raw material into grease, soaking for 1-2h, filtering, and drying to obtain pretreated sodium silicate powder.
The invention has the beneficial effects that:
(1) because the adhesive strength between the coarse aggregate and the cement in the pervious concrete is poor and the pervious concrete is easy to separate, the coarse aggregate is pretreated, polypropylene short fibers are sprayed on the surface of the coarse aggregate, fiber nets which are overlapped in a staggered mode and bonded together are formed on the surface of the coarse aggregate, then the coarse aggregate is added into the concrete, and partial cement slurry can be fixedly wrapped around the coarse aggregate due to the action of the fiber nets on the surface of the coarse aggregate, so that the separation of the cement and the coarse aggregate is avoided, and the strength of the concrete is enhanced;
(2) when the coarse aggregate is pretreated, firstly, the surface of the coarse aggregate is coated with the crystalline hydrate, then the polypropylene short fiber is sprayed, and then the crystalline hydrate is removed by melting, so that a pore is formed between a fiber net formed in the later period and the coarse aggregate, and a space is provided for accommodating cement paste;
(3) when the coarse aggregate is pretreated, silicone oil is added into the glue solution for dipping the polypropylene short fibers, so that the smoothness of the fiber surface is enhanced, and cement can smoothly enter the fiber net;
(4) because the surface of the coarse aggregate forms a fiber net in the pretreatment process, the local distribution of concrete is easy to cause uneven, the invention also designs a dispersing agent which comprises a component A and a component B, wherein the component A is used for dispersing cement during dry mixing of the concrete, the component B is used for dispersing cement mortar, and the combination of the component A and the component B can comprehensively improve the dispersing effect of the concrete, thereby improving the fluidity of the cement mortar and the strength of the concrete and improving the water reducing rate;
(5) the component A of the dispersant contains chitin-chitosan nanowhiskers, which have positive charges and a large number of active groups, such as hydroxyl and amino, so that the nanowhiskers can be tightly adsorbed on the surface of (dry) cement, so that the (dry) cement has positive charges, the dispersibility of the cement during dry mixing is enhanced, and the component B of the dispersant is a polycarboxylic acid type water reducing agent (with anions), so that when the (dry) cement with positive charges, which adsorbs the nanowhiskers, is used for preparing concrete, the adsorption of the water reducing agent and the nanowhiskers can be promoted, and the dispersibility of cement mortar is promoted;
(6) the component A of the dispersant also comprises alumina-lignin nano particles, wherein the alumina-lignin nano particles are adsorbed on the surface of the cement in advance, and then the chitin-chitosan nano whiskers are added, and the lignin has negative charges, so that the nano whiskers are tightly combined with the cement and the nano particles in the cement mortar at the same time, and a three-dimensional structure is formed nearby the cement, so that the dispersing effect of a cement dry mixture is improved, the steric hindrance of the surface of the cement caused by the nano whiskers is avoided, and the obstruction to the hydration of the cement is avoided;
(7) because the adsorption action between solids is easy to reduce after water is added, in the cement mortar construction process, the nano particles and the nano whiskers on the surface of cement are easy to separate, and the dispersion effect is weakened, so that the nano particles of the A component of the dispersing agent disclosed by the invention contain alumina, the alumina can form chemical bond combination with cement hydrate, the binding force between the nano particles and the cement particles is enhanced, the nano whiskers contain chitosan (alkaline polysaccharide), and hydroxyl in chitosan can form chemical bond combination with the alumina and the cement hydrate, so that the nano whiskers, the nano particles and the cement particles can form chemical bond combination with each other, and the separation effect is not easy to influence;
(8) when the alumina-lignin nano particles are prepared, firstly, lignin is frozen and dried to form a porous structure, and then, nano alumina powder is added for ultrasonic treatment together, so that the nano alumina powder can be effectively combined with pores of the lignin to prepare the alumina-lignin nano particles in the process of forming the nano particles by the porous lignin;
(9) when the chitin-chitosan nano whisker is prepared, firstly, chitin is acidolyzed to form chitin whisker dispersion liquid, then the dispersion liquid is adjusted to be weak acid to dissolve chitosan, and finally, filtration and freeze drying are carried out to ensure that the chitosan is precipitated on the surface of the chitin whisker, so that the chitosan and the chitin are effectively compounded;
(10) because the surface of the coarse aggregate forms a fiber net in the pretreatment process of the coarse aggregate, and the addition of the dispersing agent enhances the fluidity of the mixture, so that the mixture is not easy to be fixed in the fiber net of the coarse aggregate, in order to solve the problem, the invention adds pretreated sodium silicate when the remaining half of water is added in the step (3) of the preparation method of the pervious concrete, and because calcium chloride is absorbed in the pores of the pretreated coarse aggregate, the added sodium silicate can be rapidly cured with the calcium chloride, so that the mixture is fixed in the fiber net, the strength of the concrete is further enhanced, but the hardening of the cement can be rapidly promoted after the sodium silicate is added, so that the sodium silicate can not effectively contact with the coarse aggregate, therefore, the invention also carries out grease pretreatment on the sodium silicate, coats a layer of oil film on the surface of the sodium silicate, improves the hydrophobicity of the sodium silicate, and slows down the promotion effect of the sodium silicate on the hardening of the cement, so that the sodium silicate can be smoothly combined with calcium chloride on the surface of the coarse aggregate and coagulated and fixed.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The embodiment provides pervious concrete which comprises, by mass, 900 parts of coarse aggregate, 200 parts of cement, 30 parts of fly ash and 60 parts of water. The coarse aggregate is sand stone with the particle size of 4 mm.
The pretreatment method of the coarse aggregate comprises the following steps:
s1, uniformly mixing hydrated salt and coarse aggregate, heating at 55 ℃ for 40min, dispersing in a high-speed dispersion machine at 80 ℃ and 1000r/min for 30min, and cooling at 0 ℃ for 1h to obtain hydrated salt crystal coated coarse aggregate;
s2, dipping the polypropylene short fibers in the glue solution for 20min, filtering the glue solution to obtain sticky short fibers, uniformly spraying the sticky short fibers on the surface of coarse aggregate coated by hydrated salt crystals, and standing at room temperature for 2h to harden the sticky short fibers into a net;
s3, heating the material obtained in the step S2 to 40 ℃, uniformly stirring, standing for 1h, heating to 100 ℃ and evaporating water to obtain the pretreated coarse aggregate.
In step S1, the mass ratio of hydrated salt to coarse aggregate is 0.06: 1, the hydrated salt is CaCl2﹒6H2O。
In step S2, the diameter of the polypropylene staple fiber is 2 μm, the length is 3mm, and the glue solution comprises the following components in a mass ratio of 1: 0.1 of room temperature adhesive and silicone oil, and the spraying amount of the viscous short fiber is 2 percent.
Example 2
On the basis of embodiment 1, this embodiment also provides a pervious concrete, which includes, by mass, 900 parts of coarse aggregate, 200 parts of cement, 30 parts of fly ash, 0.7 part of a dispersant, and 60 parts of water.
The dispersing agent comprises a component A and a component B, and the mass ratio of the component A to the component B is 1: 1.2, the component A comprises alumina-lignin nano particles and chitin-chitosan nano whiskers, and the mass ratio of the alumina-lignin nano particles to the chitin-chitosan nano whiskers is 1: 1, the component B is a polycarboxylic acid type water reducing agent.
The preparation method of the alumina-lignin nanoparticles comprises the following steps: and (3) putting the lignin powder into a vacuum drying chamber at the temperature of-15 ℃ for 8h, then uniformly mixing the lignin powder with the nano alumina powder, and putting the mixture into ultrasonic waves of 125W and 30kHZ for treatment for 5h to obtain the alumina-lignin nano particles.
Wherein the mass ratio of the lignin powder to the nano alumina powder is 1: 0.2.
the preparation method of the chitin-chitosan nano crystal whisker comprises the following steps:
A. mixing chitin with 20 times of concentrated hydrochloric acid, stirring and refluxing at 128 deg.C for 8 hr, centrifuging to remove upper layer liquid after reaction, taking the lower layer precipitate, and repeatedly centrifuging and dispersing in deionized water until pH of the dispersion is 3;
B. transferring the dispersion liquid to a dialysis bag, dialyzing with deionized water, and replacing the deionized water until the pH of the solution outside the dialysis bag is 5;
C. adding chitosan into the dialysis bag, stirring for dissolving, and continuing to dialyze with deionized water until the pH of the solution outside the dialysis bag is 7, and stopping dialysis;
D. and filtering the dispersion liquid obtained by dialysis, and freeze-drying to obtain the chitin-chitosan nano crystal whisker.
The mass ratio of the chitin to the chitosan is 1: 0.1.
the rest is the same as in example 1.
Example 3
On the basis of embodiment 2, the embodiment also discloses a preparation method of the pervious concrete, which comprises the following steps:
(1) evenly mixing the cement and the admixture to obtain a first material,
(2) uniformly mixing the material I and the alumina-lignin nano particles, then adding the chitin-chitosan nano whiskers, continuously uniformly mixing, adding the pretreated coarse aggregate, and uniformly stirring to obtain a material II;
(3) and adding half of water into the material II, uniformly stirring, then adding a polycarboxylic acid type water reducing agent, uniformly stirring, adding the remaining half of water and the pretreated sodium silicate, continuously stirring uniformly, and then discharging to obtain the pervious concrete.
The mole ratio of the sodium silicate powder pretreated in the step (3) to the hydrate is 1: the pretreatment method comprises the following steps: adding a sodium silicate raw material into grease, soaking for 1h, filtering and drying to obtain pretreated sodium silicate powder.
The rest is the same as in example 2.
Example 4
The embodiment provides pervious concrete which comprises 1050 parts by mass of coarse aggregate, 260 parts by mass of cement, 40 parts by mass of fly ash, 1.3 parts by mass of a dispersant and 70 parts by mass of water. The coarse aggregate is sand with the grain diameter of 6.5 mm.
The pretreatment method of the coarse aggregate comprises the following steps:
s1, uniformly mixing hydrated salt with the coarse aggregate, heating at 60 ℃ for 35min, dispersing in a high-speed dispersion machine at 85 ℃ and 1100r/min for 25min, and cooling at 2.5 ℃ for 1.5h to obtain hydrated salt crystal coated coarse aggregate;
s2, dipping the polypropylene short fibers in the glue solution for 30min, filtering the glue solution to obtain sticky short fibers, uniformly spraying the sticky short fibers on the surface of coarse aggregate coated by hydrated salt crystals, and standing at room temperature for 3h to harden the sticky short fibers into a net;
s3, heating the material obtained in the step S2 to 50 ℃, uniformly stirring, standing for 1.5h, and heating to 110 ℃ to evaporate water to obtain the pretreated coarse aggregate.
In step S1, the mass ratio of hydrated salt to coarse aggregate is 0.08: 1, the hydrated salt is CaCl2﹒6H2O。
In step S2, the diameter of the polypropylene staple fiber is 3.5 μm, the length is 5mm, and the glue solution comprises the following components in a mass ratio of 1: 0.15 of room temperature adhesive and silicone oil, and the spraying amount of the viscous short fiber is 2.5 percent.
The dispersing agent comprises a component A and a component B, and the mass ratio of the component A to the component B is 1: 1.6, the component A comprises alumina-lignin nano particles and chitin-chitosan nano whiskers, and the mass ratio of the alumina-lignin nano particles to the chitin-chitosan nano whiskers is 1: 1.25, and the component B is a polycarboxylic acid type water reducing agent.
The preparation method of the alumina-lignin nanoparticles comprises the following steps: putting the lignin powder into a vacuum drying chamber at the temperature of minus 22 ℃ for 6h, then uniformly mixing the lignin powder with the nano alumina powder, and putting the mixture into ultrasonic waves of 132W and 35kHZ for treatment for 4.5h to obtain the alumina-lignin nano particles.
Wherein the mass ratio of the lignin powder to the nano alumina powder is 1: 0.25.
the preparation method of the chitin-chitosan nano crystal whisker comprises the following steps:
A. mixing chitin with 25 times of concentrated hydrochloric acid, stirring and refluxing at 131 deg.C for 7.5h, centrifuging to remove upper layer liquid after reaction, taking lower layer precipitate, and repeatedly centrifuging and dispersing in deionized water until pH of the dispersion is 3;
B. transferring the dispersion liquid to a dialysis bag, dialyzing with deionized water, and replacing the deionized water until the pH of the solution outside the dialysis bag is 5.5;
C. adding chitosan into the dialysis bag, stirring for dissolving, and continuing to dialyze with deionized water until the pH of the solution outside the dialysis bag is 7, and stopping dialysis;
D. and filtering the dispersion liquid obtained by dialysis, and freeze-drying to obtain the chitin-chitosan nano crystal whisker.
The mass ratio of the chitin to the chitosan is 1: 0.15.
the invention also discloses a preparation method of the pervious concrete, which comprises the following steps:
(1) evenly mixing the cement and the admixture to obtain a first material,
(2) uniformly mixing the material I and the alumina-lignin nano particles, then adding the chitin-chitosan nano whiskers, continuously uniformly mixing, adding the pretreated coarse aggregate, and uniformly stirring to obtain a material II;
(3) and adding half of water into the material II, uniformly stirring, then adding a polycarboxylic acid type water reducing agent, uniformly stirring, adding the remaining half of water and the pretreated sodium silicate, continuously stirring uniformly, and then discharging to obtain the pervious concrete.
The mole ratio of the sodium silicate powder pretreated in the step (3) to the hydrate is 1.1: the pretreatment method comprises the following steps: adding the sodium silicate raw material into the grease, soaking for 1.5h, filtering and drying to obtain pretreated sodium silicate powder.
Example 5
The embodiment provides pervious concrete which comprises 1200 parts of coarse aggregate, 320 parts of cement, 50 parts of silica fume, 1.9 parts of a dispersing agent and 80 parts of water in parts by mass. The coarse aggregate is sand with the grain diameter of 9 mm.
The pretreatment method of the coarse aggregate comprises the following steps:
s1, uniformly mixing the hydrated salt and the coarse aggregate, heating at 65 ℃ for 30min, dispersing in a high-speed dispersion machine at 90 ℃ and 1200r/min for 20min, and cooling at 5 ℃ for 2h to obtain hydrated salt crystal coated coarse aggregate;
s2, dipping the polypropylene short fibers in the glue solution for 40min, filtering the glue solution to obtain sticky short fibers, uniformly spraying the sticky short fibers on the surface of coarse aggregate coated by hydrated salt crystals, and standing at room temperature for 4h to harden the sticky short fibers into a net;
s3, heating the material obtained in the step S2 to 60 ℃, uniformly stirring, standing for 2 hours, heating to 120 ℃ and evaporating water to obtain the pretreated coarse aggregate.
In step S1, the mass ratio of hydrated salt to coarse aggregate is 0.1: 1, the hydrated salt is CaCl2﹒6H2O。
In step S2, the diameter of the polypropylene staple fiber is 5 μm, the length is 7mm, and the glue solution comprises the following components in a mass ratio of 1: 0.2 of room temperature adhesive and silicone oil, and the spraying amount of the viscous short fiber is 3 percent.
The dispersing agent comprises a component A and a component B, and the mass ratio of the component A to the component B is 1: 2, the component A comprises alumina-lignin nano particles and chitin-chitosan nano whiskers, and the mass ratio of the alumina-lignin nano particles to the chitin-chitosan nano whiskers is 1: 1.5, and the component B is a polycarboxylic acid type water reducing agent.
The preparation method of the alumina-lignin nanoparticles comprises the following steps: putting the lignin powder into vacuum drying at-30 ℃ for 4h, then uniformly mixing with the nano alumina powder, and putting the mixture into ultrasonic waves of 140W and 40kHZ for treatment for 4h to obtain the alumina-lignin nano particles.
Wherein the mass ratio of the lignin powder to the nano alumina powder is 1: 0.3.
the preparation method of the chitin-chitosan nano crystal whisker comprises the following steps:
A. mixing chitin with 30 times of concentrated hydrochloric acid, stirring and refluxing at 135 deg.C for 7h, centrifuging to remove upper layer liquid after reaction, taking the lower layer precipitate, and repeatedly centrifuging and dispersing in deionized water until pH of the dispersion is 3;
B. transferring the dispersion liquid to a dialysis bag, dialyzing with deionized water, and replacing the deionized water until the pH of the solution outside the dialysis bag is 6;
C. adding chitosan into the dialysis bag, stirring for dissolving, and continuing to dialyze with deionized water until the pH of the solution outside the dialysis bag is 7, and stopping dialysis;
D. and filtering the dispersion liquid obtained by dialysis, and freeze-drying to obtain the chitin-chitosan nano crystal whisker.
The mass ratio of the chitin to the chitosan is 1: 0.2.
the invention also discloses a preparation method of the pervious concrete, which comprises the following steps:
(1) evenly mixing the cement and the admixture to obtain a first material,
(2) uniformly mixing the material I and the alumina-lignin nano particles, then adding the chitin-chitosan nano whiskers, continuously uniformly mixing, adding the pretreated coarse aggregate, and uniformly stirring to obtain a material II;
(3) and adding half of water into the material II, uniformly stirring, then adding a polycarboxylic acid type water reducing agent, uniformly stirring, adding the remaining half of water and the pretreated sodium silicate, continuously stirring uniformly, and then discharging to obtain the pervious concrete.
The mole ratio of the sodium silicate powder pretreated in the step (3) to the hydrate is 1.2: the pretreatment method comprises the following steps: adding a sodium silicate raw material into grease, soaking for 2 hours, filtering and drying to obtain pretreated sodium silicate powder.
Comparative example 1
The comparative example differs from example 3 in that the method of pre-treatment of the coarse aggregate is:
and soaking the polypropylene short fibers in the glue solution for 20min, filtering the glue solution to obtain adhesive short fibers, uniformly spraying the adhesive short fibers onto the surface of the coarse aggregate, standing at room temperature for 2h to harden the adhesive short fibers into a net, and thus obtaining the pretreated coarse aggregate.
Comparative example 2
The comparative example differs from example 3 in that the method of pre-treatment of the coarse aggregate is:
s1, uniformly mixing hydrated salt and coarse aggregate, heating at 55 ℃ for 40min, dispersing in a high-speed dispersion machine at 80 ℃ and 1000r/min for 30min, and cooling at 0 ℃ for 1h to obtain hydrated salt crystal coated coarse aggregate;
and S2, dipping the polypropylene short fibers in the glue solution for 20min, filtering the glue solution to obtain sticky short fibers, uniformly spraying the sticky short fibers on the surface of the coarse aggregate coated by the hydrated salt crystals, and standing at room temperature for 2h to harden the sticky short fibers into a net, thereby obtaining the pretreated coarse aggregate.
Comparative example 3
The present comparative example differs from example 3 in that the pretreatment method for coarse aggregate, step S2, is: soaking the polypropylene short fiber in water for 20min, filtering to remove water to obtain viscous short fiber, uniformly spraying the viscous short fiber on the surface of coarse aggregate coated with hydrated salt crystals, and standing at room temperature for 2h to dry the viscous short fiber into a net.
Comparative example 4
This comparative example is different from example 3 in that polypropylene short fibers are replaced with ceramic short fibers in the pretreatment method of coarse aggregate.
Comparative example 5
This comparative example is different from example 3 in that polypropylene short fibers are replaced with polyester fibers in the pretreatment method of the coarse aggregate.
Comparative example 6
The present comparative example differs from example 3 in that the pretreatment method for coarse aggregate, step S3, is: and (5) washing the material obtained in the step (S2) with water at 40 ℃, and heating to 100 ℃ to evaporate water to obtain the pretreated coarse aggregate.
Comparative example 7
This comparative example differs from example 3 in that in the method of pre-treatment of coarse aggregate, the hydrated salt is sodium sulfate decahydrate.
Comparative example 8
This comparative example differs from example 3 in that in the method of pre-treatment of the coarse aggregate, the hydrated salt is sodium acetate trihydrate.
Comparative example 9
The comparative example is different from example 3 in that in the pretreatment method of the coarse aggregate, the glue solution is a room temperature glue.
Comparative example 10
The present comparative example differs from example 3 in that in the preliminary treatment method for coarse aggregate, step S1, the mass ratio of hydrated salt to coarse aggregate was 0.04: 1.
comparative example 11
The present comparative example differs from example 3 in that in the preliminary treatment method for coarse aggregate, step S1, the mass ratio of hydrated salt to coarse aggregate was 0.12: 1.
comparative example 12
The present comparative example is different from example 3 in that the sprayed amount of the viscous short fibers is 1% in the step S2 of the coarse aggregate pretreatment method.
Comparative example 13
The present comparative example is different from example 3 in that the sprayed amount of the viscous short fibers is 4% in the step S2 of the coarse aggregate pretreatment method.
Comparative example 14
The comparative example is different from example 4 in that the dispersant contains only component B, i.e., a polycarboxylic acid type water reducing agent.
Comparative example 15
This comparative example differs from example 4 in that the dispersant contains only component a.
Comparative example 16
This comparative example differs from example 4 in that component a of the dispersant is alumina-lignin nanoparticles.
Comparative example 17
The difference between this comparative example and example 4 is that component a of the dispersant is chitin-chitosan nanowhiskers.
Comparative example 18
This comparative example differs from example 4 in that the alumina-lignin nanoparticles in component a of the dispersant were changed to lignin nanoparticles.
Comparative example 19
The present comparative example is different from example 4 in that the chitin-chitosan nanowhiskers in component a of the dispersant were changed to chitosan nanowhiskers.
Comparative example 20
The comparative example differs from example 4 in that the mass ratio of components a and B is 1: 1.
comparative example 21
The comparative example differs from example 4 in that the mass ratio of components a and B is 1: 2.2.
comparative example 22
The comparative example differs from example 4 in that the preparation method of the alumina-lignin nanoparticles is: uniformly mixing lignin powder and nano alumina powder, and treating for 4.5h in ultrasonic waves of 132W and 35kHZ to obtain the alumina-lignin nano particles.
Comparative example 23
The difference between the comparative example and the example 4 is that the preparation method of the chitin-chitosan nano whisker comprises the following steps:
A. mixing chitin, chitosan and 25 times of concentrated hydrochloric acid, stirring and refluxing at 131 deg.C for 7.5h, centrifuging to remove upper layer liquid after reaction, taking lower layer precipitate, placing in deionized water, and repeatedly centrifuging and dispersing until pH of the dispersion is 3;
B. transferring the dispersion liquid to a dialysis bag, dialyzing with deionized water, and replacing the deionized water until the pH of the solution outside the dialysis bag is 7, and stopping dialysis;
C. and filtering the dispersion liquid obtained by dialysis, and freeze-drying to obtain the chitin-chitosan nano crystal whisker.
Comparative example 24
The difference between the comparative example and the example 4 is that the preparation method of the chitin-chitosan nano whisker comprises the following steps: transferring the dispersion to a dialysis bag, dialyzing with deionized water, and replacing the deionized water until the pH of the solution outside the dialysis bag is 4.5.
Comparative example 25
The difference between the comparative example and the example 4 is that the preparation method of the chitin-chitosan nano whisker comprises the following steps: transferring the dispersion to a dialysis bag, dialyzing with deionized water, and replacing the deionized water until the pH of the solution outside the dialysis bag is 6.5.
Comparative example 26
The comparative example differs from example 5 in that the method of preparing pervious concrete comprises the following steps:
(1) evenly mixing the cement and the admixture to obtain a first material,
(2) adding the pretreated coarse aggregate into the first material, and uniformly stirring to obtain a second material;
(3) and adding half of water into the material II, uniformly stirring, then adding the alumina-lignin nanoparticles, the chitin-chitosan nanowhiskers and the polycarboxylic acid type water reducing agent, uniformly stirring, adding the remaining half of water and the pretreated sodium silicate, continuously uniformly stirring, and discharging to obtain the pervious concrete.
Comparative example 27
The comparative example is different from example 5 in that the preparation method of the pervious concrete comprises the following step (2): and uniformly mixing the material I with the alumina-lignin nano-particles and the chitin-chitosan nano-whiskers, adding the pretreated coarse aggregate, and uniformly stirring to obtain a material II.
Comparative example 28
The comparative example is different from example 5 in that the preparation method of the pervious concrete comprises the following step (3): and adding water into the material II, uniformly stirring, then adding a polycarboxylic acid type water reducing agent, continuously uniformly stirring, and then discharging to obtain the pervious concrete.
Comparative example 29
This comparative example differs from example 5 in that the pervious concrete was prepared without pretreating sodium silicate in step (3).
Comparative example 30
The comparative example provides pervious concrete which comprises 900 parts of coarse aggregate, 200 parts of cement, 30 parts of fly ash and 60 parts of water in parts by mass. The coarse aggregate is sand stone with the particle size of 4 mm.
Firstly, the strength performance of the pervious concrete prepared by the invention
Pervious concrete was prepared according to the methods of examples 1-5 and comparative examples 1-30 of the present invention, wherein P.O 42.5 Portland cement was used as the cement, and the strength properties of pervious concrete were measured according to the method specified in the technical Specification for pervious Cement concrete pavement (CJJ/T135-2019) industry Standard, and the results are shown in Table 1.
TABLE 1
The results in table 1 show that the pervious concrete prepared in examples 3-5 of the present invention has a compressive strength and a bending strength higher than the performance requirements of the C30 strength class, and reaches more than 56 MPa, and the bending strength reaches more than 6.4MPa, thus showing excellent strength performance.
Wherein, the comparative example 30 is used as a prior art control group, compared with examples 1-3, the strength parameter is example 3> example 2> comparative example 30> example 1, and the difference between example 2 and comparative example 30 is small, which shows that the strength of the pervious concrete can be comprehensively improved only by preparing the pervious concrete by the method of the present invention, and by the pretreatment of the coarse aggregate, the preparation of the dispersant and the improvement of the preparation method of the pervious concrete.
As is also apparent from the results in Table 1, the pervious concretes prepared in comparative examples 1 to 29 exhibited lower values of both compressive strength and flexural tensile strength than those of examples 3 to 5 of the present invention, indicating a decrease in strength properties.
Comparative examples 1 to 13 changed the pretreatment method of the coarse aggregate, respectively, compared with example 3; comparative examples 14 to 25 changed the preparation raw material and method of the dispersant, respectively, compared with example 4; as a result, the compressive strength and the flexural tensile strength of comparative examples 1 to 25 were reduced to various degrees, which indicates that the strength properties of the pervious concrete could be effectively improved only by pretreating the coarse aggregate and preparing the dispersant strictly according to the method of the present invention.
Comparative examples 26 to 29, in comparison with example 5, changed the preparation method of the pervious concrete of the present invention, respectively, and the strength was also decreased, indicating that the preparation method of the concrete of the present invention can improve the strength properties.
Secondly, the fluidity test of the pervious concrete mixture
The pervious concrete prepared in examples 1-5 of the present invention and comparative examples 14-27 and 30 were subjected to fluidity measurement according to the method specified in national Standard for testing the Performance of pervious concrete mixes (GB/T50080 + 2016), wherein the fluidity is expressed by slump, and the higher the slump, the better the fluidity, and the cement is Portland cement P + O42.5. The results are shown in Table 2.
TABLE 2
The slump of the pervious concrete is generally low and is between 20 and 50 mm. After the coarse aggregate is pretreated, the invention influences the dispersion of concrete, so that the fluidity of the concrete is poor and the slump is lower. This test was designed in order to study the effect of the dispersant prepared according to the present invention and the process for preparing pervious concrete on the flowability of concrete mixtures.
As is clear from Table 1, the slump values of examples 3 to 5 of the present invention were between 45 and 48, which are higher than those of comparative examples 14 to 27 and 30.
Example 1 increased the pretreatment of the coarse aggregate as compared with comparative example 30, resulting in a problem of dispersibility, resulting in a decrease in slump of example 1.
Compared with example 1, the slump of the mixture is obviously improved by adding the dispersant in the example 2 of the invention, which shows that the addition of the dispersant improves the fluidity of the mixture.
Compared with the example 2, the preparation method of the pervious concrete is designed in the example 3, the using method of the dispersing agent is limited, and the slump of the mixture is improved as a result, which shows that the fluidity of the mixture can be further improved by adopting the preparation method of the pervious concrete.
Comparative examples 14 to 25 changed the preparation raw materials and methods of the dispersant, respectively, as compared with example 4, and resulted in different degrees of slump loss, indicating that only the dispersant prepared according to the present invention was effective in improving the fluidity of pervious concrete.
Compared with example 5, comparative examples 26 and 27 respectively change the use method of the dispersant in the process of preparing the pervious concrete, and the slump is obviously reduced, which shows that the fluidity of the concrete can be effectively improved only by using the dispersant by the method of the invention.
Thirdly, the dispersant of the invention has the water reducing effect on pervious concrete
The dispersing agents prepared in the embodiments 2-5 and the comparative examples 14-25 of the invention are applied to pervious concrete, and the workability of pervious concrete mixtures is measured according to the national standard of the homogeneity test method of concrete admixtures (GB/T8077-. Wherein the cement is ordinary portland cement with P £ O42.5. The results are shown in Table 3.
TABLE 3
As is clear from Table 3, examples 3 to 5 of the present invention had a water reducing ratio of about 28% and excellent water reducing effect.
Compared with the example 2, the example 3 designs the preparation method of the pervious concrete, limits the using method of the dispersing agent, and obviously improves the water reducing rate.
Comparative examples 14 to 25, in which the raw materials and the method for preparing the dispersant were changed, respectively, as compared with example 4, resulted in a different degree of reduction in the water-reducing rate of the pervious concrete, indicating that the workability of the pervious concrete could be effectively improved by placing the dispersant prepared according to the present invention.
The invention has the beneficial effects that: according to the pervious concrete provided by the invention, the strength of the pervious concrete is comprehensively improved and the problem of dispersibility is solved through the pretreatment of the coarse aggregate, the preparation of the dispersing agent and the improvement of the preparation method of the pervious concrete.
Finally, it should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and not intended to limit the present invention, and although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications and equivalents can be made in the technical solutions described in the foregoing embodiments, or some technical features thereof can be replaced. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The pervious concrete is characterized in that: the cement mortar comprises, by mass, 900-1200 parts of coarse aggregate, 200-320 parts of cement, 30-50 parts of admixture and 60-80 parts of water;
the pretreatment method of the coarse aggregate comprises the following steps:
s1, uniformly mixing hydrated salt and the coarse aggregate, heating for 30-40min at 55-65 ℃, dispersing for 20-30min in a high-speed dispersion machine at 80-90 ℃ and 1000-1200r/min, and cooling for 1-2h at 0-5 ℃ to obtain hydrated salt crystal coated coarse aggregate;
s2, dipping the polypropylene short fibers in the glue solution for 20-40min, filtering the glue solution to obtain sticky short fibers, uniformly spraying the sticky short fibers on the surface of coarse aggregate coated by hydrated salt crystals, and standing at room temperature for 2-4h to harden the sticky short fibers into a web;
s3, heating the material obtained in the step S2 to 40-60 ℃, uniformly stirring, standing for 1-2h, and heating to 100-120 ℃ to evaporate water, thereby obtaining the pretreated coarse aggregate.
2. The pervious concrete of claim 1, wherein: the coarse aggregate is sand with the particle size of 4-9mm, and the admixture is fly ash or silica fume.
3. The pervious concrete of claim 1, wherein: in step S1, the mass ratio of hydrated salt to coarse aggregate is (0.06-0.1): 1, the hydrated salt is CaCl2﹒6H2O。
4. The pervious concrete of claim 1, wherein: in step S2, the diameter of the polypropylene short fiber is 2-5 μm, the length is 3-7mm, and the glue solution comprises the following components in mass ratio of 1: (0.1-0.2) room temperature adhesive and silicone oil, wherein the spraying amount of the viscous short fiber is 2-3%.
5. The pervious concrete of claim 1, wherein: the paint also comprises 0.7-1.9 parts of a dispersant, wherein the dispersant comprises a component A and a component B, and the mass ratio of the component A to the component B is 1: (1.2-2), wherein the component A comprises alumina-lignin nano particles and chitin-chitosan nano whiskers, and the mass ratio of the alumina-lignin nano particles to the chitin-chitosan nano whiskers is 1: (1-1.5), and the component B is a polycarboxylic acid type water reducing agent.
6. The pervious concrete of claim 5, wherein: the preparation method of the alumina-lignin nanoparticles comprises the following steps: putting the lignin powder at the temperature of between 15 and 30 ℃ for vacuum drying for 4 to 8 hours, then uniformly mixing the lignin powder with the nano alumina powder, and putting the mixture in ultrasonic waves of 125-140W and 30 to 40kHZ for treatment for 4 to 5 hours to obtain alumina-lignin nano particles;
wherein the mass ratio of the lignin powder to the nano alumina powder is 1: (0.2-0.3).
7. The pervious concrete of claim 5, wherein: the preparation method of the chitin-chitosan nano crystal whisker comprises the following steps:
A. mixing chitin with 20-30 times of concentrated hydrochloric acid, stirring and refluxing at 128-135 deg.C for 7-8h, centrifuging to remove upper layer liquid after reaction, taking off the lower layer precipitate, and repeatedly centrifuging and dispersing in deionized water until the pH of the dispersion is 3;
B. transferring the dispersion liquid to a dialysis bag, dialyzing with deionized water, and replacing the deionized water until the pH of the solution outside the dialysis bag is 5-6;
C. adding chitosan into the dialysis bag, stirring for dissolving, and continuing to dialyze with deionized water until the pH of the solution outside the dialysis bag is 7, and stopping dialysis;
D. and filtering the dispersion liquid obtained by dialysis, and freeze-drying to obtain the chitin-chitosan nano crystal whisker.
8. The pervious concrete of claim 7, wherein: the mass ratio of the chitin to the chitosan is 1: (0.1-0.2).
9. A method of producing a pervious concrete according to any of claims 1 to 8, characterized in that: the method comprises the following steps:
(1) evenly mixing the cement and the admixture to obtain a first material,
(2) uniformly mixing the material I and the alumina-lignin nano particles, then adding the chitin-chitosan nano whiskers, continuously uniformly mixing, adding the pretreated coarse aggregate, and uniformly stirring to obtain a material II;
(3) and adding half of water into the material II, uniformly stirring, then adding a polycarboxylic acid type water reducing agent, uniformly stirring, adding the remaining half of water and the pretreated sodium silicate, continuously stirring uniformly, and then discharging to obtain the pervious concrete.
10. The method for preparing pervious concrete according to claim 9, characterized in that: the mole ratio of the sodium silicate powder pretreated in the step (3) to the hydrate is (1-1.2): the pretreatment method comprises the following steps: adding a sodium silicate raw material into grease, soaking for 1-2h, filtering, and drying to obtain pretreated sodium silicate powder.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006282479A (en) * | 2005-04-04 | 2006-10-19 | Kao Corp | Recycled aggregate-modifying agent |
| CN101863631A (en) * | 2010-06-21 | 2010-10-20 | 东南大学 | Stone aggregate wrapped by microfine fibre polymer mortar thin layer and preparation method thereof |
| CN103708792A (en) * | 2013-12-01 | 2014-04-09 | 内蒙古大学 | Preparation method for water permeable concrete |
| CN108793876A (en) * | 2018-06-29 | 2018-11-13 | 禹智环保科技（深圳）有限公司 | Using discarded concrete as the pervious concrete of aggregate, preparation method and application |
| CN110818330A (en) * | 2019-11-23 | 2020-02-21 | 青岛汇鑫混凝土有限公司 | Recycled aggregate concrete and preparation method thereof |
| CN111943600A (en) * | 2020-08-19 | 2020-11-17 | 瑞洲建设集团有限公司 | Town road pervious concrete and construction method thereof |
-
2021
- 2021-08-31 CN CN202111010662.3A patent/CN113582628B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2006282479A (en) * | 2005-04-04 | 2006-10-19 | Kao Corp | Recycled aggregate-modifying agent |
| CN101863631A (en) * | 2010-06-21 | 2010-10-20 | 东南大学 | Stone aggregate wrapped by microfine fibre polymer mortar thin layer and preparation method thereof |
| CN103708792A (en) * | 2013-12-01 | 2014-04-09 | 内蒙古大学 | Preparation method for water permeable concrete |
| CN108793876A (en) * | 2018-06-29 | 2018-11-13 | 禹智环保科技（深圳）有限公司 | Using discarded concrete as the pervious concrete of aggregate, preparation method and application |
| CN110818330A (en) * | 2019-11-23 | 2020-02-21 | 青岛汇鑫混凝土有限公司 | Recycled aggregate concrete and preparation method thereof |
| CN111943600A (en) * | 2020-08-19 | 2020-11-17 | 瑞洲建设集团有限公司 | Town road pervious concrete and construction method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 常大勇等: "净浆裹骨料工艺增强机理探讨", 《混凝土》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115159928A (en) * | 2022-07-25 | 2022-10-11 | 贵阳中建西部建设有限公司 | Low-carbon green lightweight concrete aggregate and preparation method thereof |
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Denomination of invention: A pervious concrete and its preparation method Effective date of registration: 20221109 Granted publication date: 20220603 Pledgee: Jiangxi Taihe Rural Commercial Bank Co.,Ltd. Pledgor: Jiangxi Shengyuan Commercial Concrete Co.,Ltd. Registration number: Y2022980021325 |