CN113861706B - Modified asphalt containing nano material and application thereof - Google Patents
Modified asphalt containing nano material and application thereof Download PDFInfo
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- CN113861706B CN113861706B CN202111211300.0A CN202111211300A CN113861706B CN 113861706 B CN113861706 B CN 113861706B CN 202111211300 A CN202111211300 A CN 202111211300A CN 113861706 B CN113861706 B CN 113861706B
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L95/00—Compositions of bituminous materials, e.g. asphalt, tar, pitch
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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
- C04B26/00—Compositions of mortars, concrete or artificial stone, containing only organic binders, e.g. polymer or resin concrete
- C04B26/02—Macromolecular compounds
- C04B26/26—Bituminous materials, e.g. tar, pitch
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2201/00—Properties
- C08L2201/08—Stabilised against heat, light or radiation or oxydation
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Abstract
The invention relates to modified asphalt containing a nano material, which comprises 100 parts of SBS modified asphalt and 0.002-0.02 part of modified nano graphene oxide, wherein the modified nano graphene oxide is prepared by mixing polyvinylpyrrolidone and nano graphene oxide powder in a mass ratio of 1: (2.5-3.5) mixing and preparing. The modified asphalt provided by the invention is prepared by mixing SBS modified asphalt and a certain amount of nano graphene oxide prepared by a specific method, and the temperature sensitivity, viscosity, plasticity, ageing resistance and the like are improved to a certain extent, so that the modified asphalt has practical application value.
Description
Technical Field
The invention relates to the technical field of road engineering materials, in particular to modified asphalt containing a nano material.
Background
With the development of economy and the increase of traffic demands, the traffic volume and the axle load of China increase year by year. Meanwhile, with the change of global climate, extreme weather events such as ultra-high temperature weather and sleet frost weather frequently occur in recent years. However, in the face of complex road conditions and natural environments, unmodified asphalt cannot bear increasing axle loads and severe weather environments, and the service life of the asphalt pavement is seriously influenced. Therefore, there is an urgent need to develop new asphalt materials to enhance the performance of road asphalt pavement to ensure longer service life under complicated and severe service conditions.
The SBS modified asphalt has the advantages of good elasticity, large ductility, high low-temperature flexibility, high thermal stability, good weather resistance and the like, and is one of the most widely applied modified asphalt in the world at present. The SBS modifier is a copolymer formed by polymerization reaction of butadiene and styrene serving as monomers, has the performances of resin and rubber, and can obviously improve the high-low temperature performance, the ageing resistance and the like of the asphalt pavement. However, the SBS-modified asphalt still has the problems of poor system compatibility and storage stability, and the like, and the comprehensive properties thereof need to be further improved.
In the prior art, nano graphene oxide is adopted to improve the performance of asphalt. However, the nano graphene oxide has a very large specific surface area and a relatively high surface energy, and thus spontaneous agglomeration often occurs, and the nano graphene oxide cannot be well dispersed in asphalt, so that the modification effect of the nano graphene oxide on the asphalt is greatly reduced.
At present, development of modified asphalt which is modified by multiple means and has excellent comprehensive performance is urgently needed.
Disclosure of Invention
The first purpose of the invention is to provide modified asphalt containing nano materials. The modified asphalt provided by the invention has excellent comprehensive performance and has better effects in the aspects of temperature sensitivity, viscosity, plasticity, aging resistance and the like.
Specifically, the invention provides modified asphalt containing nano materials, which comprises the following components: 100 parts of SBS modified asphalt and 0.002-0.02 part of modified nano graphene oxide.
In some embodiments of the invention, the modified asphalt containing the nanomaterial comprises 0.008 to 0.01 part of modified nano graphene oxide.
In some embodiments of the present invention, the SBS modified asphalt contains 4.5 to 5.5% of a linear SBS modifier. The modified nano graphene oxide provided by the invention can be well dispersed in SBS modified asphalt, and especially can be cooperated with SBS modified asphalt containing 4.5-5.5% of linear SBS modifier to play a role, so that modified asphalt with excellent comprehensive performance is obtained.
The modified nano graphene oxide is prepared by the method comprising the following steps:
(1) Mixing and stirring graphite, concentrated sulfuric acid and phosphoric acid, slowly adding potassium permanganate, and stirring for reaction;
(2) Adding deionized water into the reaction liquid obtained in the step (1), adding a hydrogen peroxide solution for reaction, repeatedly washing and centrifuging the obtained reaction product to strip graphite oxide and form nano graphene oxide gel, and drying to obtain nano graphene oxide powder;
(3) Mixing a polyvinylpyrrolidone (PVP) water solution with the nano graphene oxide powder, wherein the mass ratio of the PVP to the nano graphene oxide powder is 1: (2.5-3.5), ultrasonic dispersing uniformly, stirring for reaction, washing and drying.
In some embodiments of the present invention, the stirring reaction in step (1) is performed in an ice bath, a water bath at 30-50 ℃ and a water bath at 80-95 ℃ in sequence. Under the conditions, the nano graphene oxide with proper and uniform particle size can be formed.
In some embodiments of the present invention, the repeated washing in step (2) is performed with an acidic aqueous solution, preferably an aqueous solution having a pH of 5.3 to 5.7. Under the conditions, the nano graphene oxide with proper and uniform particle size can be formed.
The invention limits the mass ratio of the polyvinylpyrrolidone in the polyvinylpyrrolidone aqueous solution in the step (3) to the nano graphene oxide powder to be 1: (2.5 to 3.5), more preferably 1:3. according to the invention, through optimizing the mass ratio of the polyvinylpyrrolidone to the nano graphene oxide powder, the polyvinylpyrrolidone modified nano graphene oxide powder can be dispersed in SBS asphalt in the best state and the best dispersion degree, and can perform the synergistic action with the SBS modifier, so that the optimum modification effect on the SBS asphalt is generated.
In some embodiments of the present invention, the stirring reaction in step (3) is performed at 35-40 ℃ and pH 7.6-8, and then at 25-30 ℃ and pH 7.1-7.5. According to the invention, by optimizing the conditions of the mixing reaction of the polyvinylpyrrolidone and the nano graphene oxide powder, the particle size of the polyvinylpyrrolidone modified nano graphene oxide powder is more uniform and the property is more stable, so that the optimal modification effect on SBS asphalt is generated.
In some embodiments of the present invention, the modified nano graphene oxide powder is prepared by a method comprising the following specific steps:
(1) Mixing 0.15 part of graphite, 34 parts of concentrated sulfuric acid and 3 parts of concentrated phosphoric acid, mechanically stirring for 10 minutes in an ice bath, slowly adding 0.9 part of potassium permanganate, keeping the temperature at 0 ℃, stirring and reacting for 2 hours in the ice bath, then stirring and reacting for 60 minutes in a water bath at 40 ℃, and then adjusting the temperature of the water bath to 95 ℃, and stirring and reacting for 60 minutes;
(2) Suspending the reaction product obtained in the step (1) in water, adding 11 parts of hydrogen peroxide for reaction, repeatedly washing and centrifuging the reaction product for 5 times by using a water solution with the pH of 5.5, stripping graphite oxide in the washing process to form nano graphene oxide gel, and drying at 60 ℃ to obtain nano graphene oxide powder;
(3) Adding the nano graphene oxide powder obtained in the step (2) into a PVP (polyvinyl pyrrolidone) aqueous solution, wherein the mass ratio of the PVP to the nano graphene oxide powder is 1: and 3, obtaining a uniformly dispersed colloidal solution through ultrasonic dispersion, firstly carrying out stirring reaction in a water bath at 38 ℃ and at a pH value of 7.8, then carrying out stirring reaction in a water bath at 28 ℃ and at a pH value of 7.2, washing the colloid obtained after the reaction is finished with deionized water and ethanol, and drying to obtain the modified nano graphene oxide powder.
In some embodiments of the invention, the modified asphalt containing the nano material is prepared by shearing, stirring and mixing the SBS modified asphalt and the nano graphene oxide at 150-180 ℃ and 2000-5000 r/min.
In a second aspect, the present invention protects an asphalt mixture comprising the modified asphalt comprising nanomaterial of the first aspect.
The asphalt mixture is a uniform mixture prepared by mixing a mineral mixture which comprises coarse aggregate, fine aggregate and filler and is composed according to gradation with the modified asphalt containing the nano material. Wherein, the coarse aggregate can be selected from broken stone, broken gravel, screened gravel, slag and the like with grading and particle size meeting requirements; the fine aggregate can be natural sand, artificial sand, stone chips and the like with grading and particle size meeting requirements; the filler is generally mineral powder and the like, the filler plays a role in filling and improving the asphalt performance in the asphalt mixture, and the mineral powder can be obtained by grinding limestone or strong basic rock in rock pulp rock with gradation and particle size meeting requirements.
The mineral mixture in the asphalt mixture can be selected according to the actual requirements (such as weather conditions, traffic properties, construction conditions and the like) of asphalt pavement construction by referring to national standards and methods disclosed in the prior art.
In some embodiments of the invention, the mineral mixture and the modified asphalt containing the nano material are mixed for 45-60 s at the temperature of 180-200 ℃ to obtain the asphalt mixture.
In a third aspect, the invention protects the application of the modified asphalt of the first aspect or the asphalt mixture of the second aspect in asphalt pavement construction.
Compared with the prior art, the modified asphalt provided by the invention is formed by mixing SBS modified asphalt and a small amount of nano graphene oxide prepared by a specific method, achieves certain improvement in temperature sensitivity, viscosity, plasticity, aging resistance and the like, and has practical application value.
Detailed Description
The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.
The SBS modified asphalt employed in each of the following examples was a finished SBS modified asphalt containing 5% of an SBS modifier; the SBS modifier is of a linear structure, and S/B =30/70.
Example 1
The embodiment provides a modified asphalt, which specifically comprises the following components: 100g of SBS modified asphalt and 0.01g of modified nano graphene oxide;
the modified nano graphene oxide is prepared by the following method:
(1) Mixing 0.15g of graphite with 34g of concentrated sulfuric acid and 3g of concentrated phosphoric acid, mechanically stirring for 10 minutes in an ice bath, slowly adding 0.9g of potassium permanganate, keeping the temperature at 0 ℃, stirring and reacting for 2 hours in the ice bath, then stirring and reacting for 60 minutes in a water bath at 40 ℃, and then adjusting the temperature of the water bath to 95 ℃, and stirring and reacting for 60 minutes;
(2) Suspending the reaction product obtained in the step (1) in water, adding 11g of hydrogen peroxide for reaction, repeatedly washing and centrifuging the reaction product for 5 times by using a water solution with the pH of 5.5, stripping graphite oxide in the washing process to form nano graphene oxide gel, and drying at 60 ℃ to obtain nano graphene oxide powder;
(3) Adding the nano graphene oxide powder obtained in the step (2) into a PVP (polyvinyl pyrrolidone) aqueous solution, wherein the mass ratio of the PVP to the nano graphene oxide powder is 1: and 3, obtaining a uniformly dispersed colloidal solution through ultrasonic dispersion, firstly carrying out stirring reaction in a water bath at 38 ℃ and at a pH value of 7.8, then carrying out stirring reaction in a water bath at 28 ℃ and at a pH value of 7.2, washing the colloid obtained after the reaction is finished with deionized water and ethanol, and drying to obtain the modified nano graphene oxide powder.
Example 2
This example provides a modified asphalt that differs from example 1 only in that: the dosage of the modified nano graphene oxide is 0.002g.
Example 3
This example provides a modified asphalt that differs from example 1 only in that: the dosage of the modified nano graphene oxide is 0.02g.
Example 4
This example provides a modified asphalt that differs from example 1 only in that: in the process of preparing the modified nano graphene oxide, the stirring reaction in the step (3) is only carried out in water bath at 30 ℃ and under the condition of pH value of 7.5.
Comparative example 1
This comparative example provides a modified asphalt that differs from example 1 only in that: in the process of preparing the modified nano graphene oxide, the mass ratio of the polyvinylpyrrolidone to the modified nano graphene oxide powder in the step (3) is 1:4.
comparative example 2
This comparative example provides a modified asphalt that differs from example 1 only in that: polyvinylpyrrolidone (PVP) adopted in the preparation of the modified nano graphene oxide is replaced by Cetyl Trimethyl Ammonium Bromide (CTAB).
Comparative example 3
This comparative example provides a modified asphalt that differs from example 1 only in that: and replacing polyvinylpyrrolidone (PVP) adopted in the preparation of the modified nano graphene oxide with N, N-dimethyl amide (DMF).
Examples of the experiments
The modified asphalt prepared in each example of the present invention and comparative example was tested for softening point, ductility, penetration and penetration ratio according to the relevant regulations of road engineering asphalt and asphalt mixture test protocol (JTJE 20-2011). Wherein:
the softening point is the temperature of the modified asphalt when the modified asphalt is converted from a solid state to a viscous state, reflects the temperature sensitivity of the modified asphalt, and is detected by a ring and ball method.
The penetration degree reflects the ability of the modified asphalt to resist deformation under the action of external force or self-weight. The smaller the penetration, the greater the viscosity of the modified asphalt.
The ductility reflects the property that the modified asphalt is deformed without being damaged when external force is applied, and the deformed shape is still maintained after the external force is removed, and also reflects the self-healing performance of the modified asphalt. Specifically, the sample was prepared into a standard 8-letter mold (with a middle minimum cross-sectional area of 1 cm) 2 ) The length of the film when the film is broken at a drawing speed of 5cm/min and at a temperature of 25 ℃ or 10 ℃ is the ductility. The greater the ductility, the more plastic the modified asphalt.
The penetration ratio after evaporation reflects the degree of stable performance of the asphalt due to aging resistance, and specifically refers to the percentage of the penetration ratio of the asphalt after evaporation to the penetration ratio before evaporation. The greater the penetration ratio after evaporation, the better the atmospheric stability of the bitumen and the slower the ageing.
The test results are shown in table 1.
Table 1: modified asphalt Performance test results
From the above results, the modified asphalt provided by the invention has the parameters of softening point, penetration degree, ductility and the like which all meet the related technical requirements of technical Specification for road asphalt pavement construction (JTG F40-2004). Among them, the modified asphalt provided in example 1 has the best overall effect.
Although the invention has been described in detail hereinabove by way of general description, specific embodiments and experiments, it will be apparent to those skilled in the art that modifications and improvements can be made thereto without departing from the scope of the invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.
Claims (10)
1. Modified asphalt containing nanomaterial, characterized by comprising: 100 parts of SBS modified asphalt and 0.002 to 0.02 part of modified nano graphene oxide;
the modified nano graphene oxide is prepared by the following steps:
(1) Mixing and stirring graphite, concentrated sulfuric acid and concentrated phosphoric acid, slowly adding potassium permanganate, and stirring for reaction;
(2) Adding deionized water into the reaction liquid obtained in the step (1), adding a hydrogen peroxide solution for reaction, repeatedly washing and centrifuging the obtained reaction product to strip graphite oxide and form nano graphene oxide gel, and drying to obtain nano graphene oxide powder;
(3) Mixing a polyvinylpyrrolidone aqueous solution with the nano graphene oxide powder, wherein the mass ratio of the polyvinylpyrrolidone to the nano graphene oxide powder is 1: (2.5 to 3.5), uniformly dispersing by ultrasonic, stirring for reaction, washing and drying;
the stirring reaction in the step (3) is carried out under the conditions of temperature of 35 to 40 ℃ and pH value of 7.6 to 8, and then under the conditions of temperature of 25 to 30 ℃ and pH value of 7.1 to 7.5.
2. The nanomaterial-containing modified asphalt according to claim 1, wherein the modified nano graphene oxide is contained in an amount of 0.008 to 0.01 part.
3. The modified asphalt containing the nano-materials as claimed in claim 1, wherein the SBS modified asphalt contains 4.5-5.5% of linear SBS modifier.
4. The modified asphalt containing the nanomaterial according to claim 1, wherein the stirring reaction in step (1) is performed in an ice bath, a water bath at 30 to 50 ℃ and a water bath at 80 to 95 ℃ in this order.
5. The modified asphalt containing nano-materials as claimed in claim 1, wherein the repeated washing in step (2) is performed with an acidic aqueous solution.
6. The modified asphalt containing the nanomaterial as defined in claim 5, wherein the acidic aqueous solution is an aqueous solution having a pH of 5.3 to 5.7.
7. The modified asphalt containing nano-materials according to claim 1, wherein the modified nano graphene oxide powder is prepared by a method comprising the following steps:
(1) Mixing 0.15 part of graphite, 34 parts of concentrated sulfuric acid and 3 parts of concentrated phosphoric acid, mechanically stirring for 10 minutes in an ice bath, slowly adding 0.9 part of potassium permanganate, keeping the temperature at 0 ℃, stirring and reacting for 2 hours in the ice bath, then stirring and reacting for 60 minutes in a water bath at 40 ℃, and then adjusting the temperature of the water bath to 95 ℃, and stirring and reacting for 60 minutes;
(2) Suspending the reaction product obtained in the step (1) in water, adding 11 parts of hydrogen peroxide for reaction, repeatedly washing and centrifuging the reaction product for 5 times by using a water solution with the pH of 5.5, stripping graphite oxide in the washing process to form nano graphene oxide gel, and drying at 60 ℃ to obtain nano graphene oxide powder;
(3) Adding the nano graphene oxide powder obtained in the step (2) into a PVP (polyvinyl pyrrolidone) aqueous solution, wherein the mass ratio of the PVP to the nano graphene oxide powder is 1: and 3, obtaining a uniformly dispersed colloidal solution through ultrasonic dispersion, firstly carrying out stirring reaction in a water bath at 38 ℃ under the condition of a pH value of 7.8, then carrying out stirring reaction in a water bath at 28 ℃ under the condition of a pH value of 7.2, washing colloid obtained after the reaction is finished with deionized water and ethanol, and drying to obtain the modified nano graphene oxide powder.
8. The modified asphalt containing nanomaterial as claimed in any of claims 1~7, wherein the asphalt is prepared by mixing SBS modified asphalt and nano graphene oxide at 150-180 deg.C and 2000-5000 r/min under shearing and stirring.
9. An asphalt mixture comprising the modified asphalt containing nanomaterial of any of claims 1~8.
10. Use of the modified asphalt containing nanomaterial of any one of claims 1~8 or the asphalt mixture of claim 9 in asphalt pavement construction.
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| CN202111211300.0A CN113861706B (en) | 2021-10-18 | 2021-10-18 | Modified asphalt containing nano material and application thereof |
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| CN108424663A (en) * | 2018-03-22 | 2018-08-21 | 燕园众欣纳米科技（北京）有限公司 | A kind of SBS modified pitch and preparation method thereof containing graphene |
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| CN109401349B (en) * | 2018-11-26 | 2020-11-10 | 长沙理工大学 | Graphene oxide modified asphalt and preparation method thereof |
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