CN115818996B - Treatment method of waste asphalt mixture, regenerated asphalt mixture and preparation method of regenerated asphalt mixture - Google Patents
Treatment method of waste asphalt mixture, regenerated asphalt mixture and preparation method of regenerated asphalt mixture Download PDFInfo
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- 239000010426 asphalt Substances 0.000 title claims abstract description 204
- 239000000203 mixture Substances 0.000 title claims abstract description 157
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- 238000000034 method Methods 0.000 title claims abstract description 29
- 238000002360 preparation method Methods 0.000 title claims abstract description 19
- 239000002245 particle Substances 0.000 claims abstract description 229
- 238000012216 screening Methods 0.000 claims abstract description 65
- 230000005284 excitation Effects 0.000 claims abstract description 56
- 229910052500 inorganic mineral Inorganic materials 0.000 claims description 167
- 239000011707 mineral Substances 0.000 claims description 167
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- 238000005299 abrasion Methods 0.000 claims description 31
- 239000000843 powder Substances 0.000 claims description 22
- 238000010438 heat treatment Methods 0.000 claims description 18
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Abstract
The invention provides a treatment method of waste asphalt mixture, regenerated asphalt mixture and a preparation method thereof. The processing method comprises the following steps: screening the waste asphalt mixture sample to obtain a first screened product with the particle size of less than 3mm, the particle size of more than 3mm and less than 32mm and the particle size of more than 32 mm; taking a first screening product with the particle size of more than 3mm and less than 32mm for primary fine stripping to obtain a first fine stripping product; screening the first fine stripped product to obtain a second screened product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32 mm; obtaining fine stripping parameters; based on the fine peeling parameters, acquiring centrifugal excitation frequency of accurate fine peeling; and respectively carrying out accurate fine stripping on the second screening products with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm according to the centrifugal excitation frequency of the accurate fine stripping to obtain accurate fine stripped products.
Description
Technical Field
The invention relates to a treatment method of waste asphalt mixture, regenerated asphalt mixture and a preparation method thereof, in particular to a treatment method of waste asphalt mixture based on fine stripping, regenerated asphalt mixture and a preparation method thereof, belonging to the technical field of recycling of asphalt pavement of road engineering.
Background
Asphalt pavement is the main pavement structure of expressway pavement in China, and damage such as rutting, cracks and the like can occur on the asphalt pavement under the interaction of complex natural conditions and traffic load. The waste asphalt mixture (RAP) produced by major and minor repairs is over 2 hundred million tons per year, consuming 3 hundred million tons of sand and 50 hundred million liters of fuel oil, which is the most common world. The resource consumption and the environmental protection pressure are huge, the sustainable development of the traffic industry is severely restricted, and the national ecological civilization and the construction of the traffic are obviously influenced. In order to protect the environment and reduce mining, asphalt pavement regeneration is imperative.
The asphalt pavement regeneration is a green road construction technology which is to mix original waste asphalt pavement materials with a proper amount of new materials such as asphalt, stone and the like to form a regenerated asphalt mixture meeting the road performance requirements, and finally re-lay the asphalt pavement. Through the recycling of the waste asphalt mixture, waste materials can be changed into valuable materials, a large amount of resources are saved, and meanwhile, the occupation of land and the pollution to the environment caused by stacking of waste materials are avoided, so that the recycling application of the domestic asphalt pavement is increasingly popular. The plant-mixed heat regeneration technology is currently the most mainstream technology for asphalt pavement regeneration. However, the technical bottleneck of the plant-mixed thermal regeneration is that the adding proportion of the waste asphalt mixture is limited to below 30% in general, which is mainly determined by the instability of the property of the waste asphalt mixture (RAP).
The waste asphalt mixture (RAP) is a mixture of aggregate and asphalt, so that the aggregate and the asphalt are mutually wrapped and cohered into a block-shaped particle structure. Therefore, the waste asphalt mixture (RAP) is not a single particle, but is a mixed particle, and often one particle in the waste asphalt mixture (RAP) is formed by conglomerating a plurality of finer particles, so that the grading composition of the waste asphalt mixture (RAP) and the asphalt dosage have larger fluctuation. The current technical Specification for recycling highway asphalt pavement (JTG/T5521-2019) prescribes that the design and the performance of the plant-mixed hot recycling mixture meet the requirements of the common hot-mixed asphalt mixture, but the quality stability of the recycled asphalt mixture is often affected due to the adhesive particle property of the waste asphalt mixture (RAP). Because of the non-uniform quality of the reclaimed asphalt mixture, the reclaimed asphalt pavement is easy to generate local diseases, thereby forming traffic safety hidden trouble and affecting smooth and safe operation of traffic.
Disclosure of Invention
Problems to be solved by the invention
In view of the technical problems existing in the prior art, for example: the invention provides a method for treating waste asphalt mixture, which comprises the steps of mixing waste asphalt mixture in the recycled asphalt mixture in a low proportion, adding the waste asphalt mixture, and then obtaining the recycled asphalt mixture with poor quality stability and low road performance. By the treatment method, the blending proportion of the waste asphalt mixture in the reclaimed asphalt mixture is greatly improved, the quality stability of the reclaimed asphalt mixture is improved, the quality of the hot mix plant recycling technology is improved, and the waste asphalt mixture is recycled.
Furthermore, the invention also provides a regenerated asphalt mixture which has excellent quality stability, reduces the dependence of pavement materials on non-renewable resources natural sand stone materials, and reduces the damage of mass storage of waste asphalt mixtures to the ecological environment.
Furthermore, the invention also provides a preparation method of the reclaimed asphalt mixture, which is simple and feasible, is easy to obtain raw materials and is suitable for mass production.
Solution for solving the problem
The invention firstly provides a treatment method of waste asphalt mixture, which comprises the following steps:
screening the waste asphalt mixture sample to obtain a first screened product with the particle size of less than 3mm, the particle size of more than 3mm and less than 32mm and the particle size of more than 32 mm;
taking a first screening product with the particle size of more than 3mm and less than 32mm for primary fine stripping to obtain a first fine stripping product;
screening the first fine stripped product to obtain a second screened product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32 mm;
obtaining fine stripping parameters;
based on the fine peeling parameters, acquiring centrifugal excitation frequency of accurate fine peeling;
And respectively carrying out accurate fine stripping on the second screening products with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm according to the centrifugal excitation frequency of the accurate fine stripping to obtain accurate fine stripped products.
The processing method according to the present invention, wherein the step of acquiring the fine peeling parameter includes:
screening the waste asphalt mixture sample to obtain a third screened product with the particle size of less than 3mm, the particle size of more than 3mm and less than 32mm and the particle size of more than 32 mm;
taking a third screening product with the particle size of more than 3mm and less than 32mm, centrifugally stripping, recovering waste mineral aggregate with the particle size of more than 3mm and less than 32mm, and testing the angularity, crushing value and abrasion value of the waste mineral aggregate, and the mass ratio of the waste mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32 mm;
taking a third screening product with the particle size of more than 3mm and less than 32mm for primary fine stripping to obtain a second fine stripping product;
screening the second fine stripped product to obtain a fourth screened product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32 mm;
Respectively carrying out secondary fine stripping on the fourth screening products with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm under different centrifugal excitation frequencies to obtain a third fine stripping product;
centrifugally stripping the third fine stripped product, recovering fine stripped product mineral aggregate with the grain diameter of more than 3mm and less than 32mm, and testing the angular property, crushing value, abrasion value and mass ratio of the fine stripped product mineral aggregate with the grain diameter of more than 3mm and less than 13mm and the grain diameter of more than 13mm and less than 32 mm;
obtaining the relative difference of the edges and angles of the fine stripped product mineral aggregate and the waste mineral aggregate, the relative difference of the crushing value and the abrasion value according to the edges and angles, the crushing value and the abrasion value of the fine stripped product mineral aggregate and the edges and angles, the crushing value and the abrasion value of the waste mineral aggregate;
acquiring a cohesiveness index according to the mass ratio of the respective waste mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm, and the mass ratio of the respective fine stripping product mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32 mm;
based on the angular relative difference, the crush value relative difference, the abrasion value relative difference, and the cohesiveness index, the fine peeling parameter is obtained.
The processing method according to the present invention, wherein the fine peeling parameters include:
the viscosity index is less than 1.5%;
the relative difference of the edges and corners of the fine stripping product mineral aggregate and the waste mineral aggregate is less than 10 percent;
the crushing value of the fine stripping product mineral aggregate and the crushing value of the waste mineral aggregate are relatively poor less than 6%;
the abrasion value of the fine stripping product mineral aggregate and the waste mineral aggregate is relatively less than 10 percent.
The treatment method of the invention, wherein, the frequency of centrifugal excitation for secondary fine stripping of the fourth screening product with the grain diameter of more than 3mm and less than 13mm is 35-50Hz, and the time of centrifugal excitation is 15-30 s; the frequency of centrifugal excitation for secondary fine stripping of the fourth screening product with the grain diameter of more than 13mm and less than 32mm is 20-35Hz, and the time of the centrifugal excitation is 15-30 s.
The treatment method of the invention, wherein the frequency of the centrifugal excitation of the fine stripping is 40-50Hz, and the time of the centrifugal excitation is 5-10 s; and/or the precise fine peeling time is 5-10 s.
The present invention also provides a reclaimed asphalt mixture comprising a mixed aggregate, wherein the mixed aggregate comprises the precisely fine-stripped product and mineral aggregate obtained by the treatment method according to any one of claims 1 to 5; preferably, the content of the precisely fine-peeled product is 60% or more and the content of the mineral aggregate is 40% or less, based on 100% of the total mass of the mixed aggregate.
The reclaimed asphalt mixture of the invention, wherein the precisely fine stripping product contains precisely fine stripping products with the grain diameter of less than 3mm, precisely fine stripping products with the grain diameter of more than 3mm and less than 5mm, precisely fine stripping products with the grain diameter of more than 5mm and less than 10mm, precisely fine stripping products with the grain diameter of more than 10mm and less than 20mm and precisely fine stripping products with the grain diameter of more than 20mm and less than 30mm after being screened;
preferably, the total content of the precisely fine-peeled product having a particle diameter of more than 5mm and 10mm or less, the precisely fine-peeled product having a particle diameter of more than 10mm and 20mm or less, the precisely fine-peeled product having a particle diameter of more than 20mm and 30mm or less is 50% to 65%, the content of the precisely fine-peeled product having a particle diameter of more than 3mm and 5mm or less is 0 to 10%, and the content of the precisely fine-peeled product having a particle diameter of 3mm or less is 10 to 15%, based on 100% of the total mass of the mixed aggregate.
The reclaimed asphalt mixture of the invention, wherein the mineral aggregate comprises mineral powder, mineral aggregate with the particle size of less than 5mm and mineral aggregate with the particle size of more than 20mm and less than 30 mm; preferably, the total mass of the mixed aggregate is 100%, the content of mineral powder is 2% -5%, the content of mineral materials with the particle size of less than 5mm is 0% -13%, and the content of mineral materials with the particle size of more than 20mm and less than 30mm is 8% -22%.
The reclaimed asphalt mixture of the invention, wherein the reclaimed asphalt mixture further comprises matrix asphalt and a reclaiming agent; preferably, the content of the matrix asphalt is 1.5% -3.5% based on 100% of the total mass of the mixed aggregate; the content of the regenerant is 0.1-0.3%.
The invention also provides a preparation method of the reclaimed asphalt mixture, which comprises the step of mixing the components of the reclaimed asphalt mixture;
preferably, the preparation method comprises the following steps:
mixing and heating the accurate fine stripping product with the grain diameter of more than 3mm and less than 5mm, the accurate fine stripping product with the grain diameter of more than 5mm and less than 10mm, the accurate fine stripping product with the grain diameter of more than 10mm and less than 20mm, the accurate fine stripping product with the grain diameter of more than 20mm and less than 30mm, mineral aggregate with the grain diameter of less than 5mm and mineral aggregate with the grain diameter of more than 20mm and less than 30mm to obtain a premixed product;
respectively heating the precise and fine stripping product with the particle size of less than 3mm and mineral powder;
mixing the premixed product, and then mixing the premixed product with matrix asphalt and a regenerant to obtain a premixed product;
mixing the pre-mixed product with the heated precise and fine stripping product with the particle size of less than 3mm, and then mixing with the heated mineral powder to obtain the reclaimed asphalt mixture.
ADVANTAGEOUS EFFECTS OF INVENTION
The treatment method of the waste asphalt mixture can greatly improve the blending proportion of the waste asphalt mixture in the reclaimed asphalt mixture, improve the quality stability of the reclaimed asphalt mixture, improve the quality of the hot-mix plant recycling technology and realize the recycling of the waste asphalt mixture.
The regenerated asphalt mixture has excellent quality stability, reduces the dependence of pavement materials on non-renewable resources natural sand materials, and reduces the damage of mass storage waste asphalt mixtures to ecological environment.
The preparation method of the regenerated asphalt mixture is simple and feasible, raw materials are easy to obtain, and the regenerated asphalt mixture is suitable for mass production.
Drawings
FIG. 1 shows a schematic representation of the measured perimeter of a spent mineral aggregate or finely exfoliated product mineral aggregate of the present invention and its polygonal perimeter.
Detailed Description
The following describes the present invention in detail. The following description of the technical features is based on the representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:
in the present specification, the numerical range indicated by the term "numerical value a to numerical value B" means a range including the end point numerical value A, B.
In the present specification, unless specifically stated otherwise, "a plurality" of "a plurality of" etc. means a numerical value of 2 or more.
In this specification, the terms "substantially", "substantially" or "substantially" mean that the error is less than 5%, or less than 3% or less than 1% compared to the relevant perfect or theoretical standard.
In the present specification, "%" means mass% unless otherwise specified.
In the present specification, the meaning of "can" includes both the meaning of performing a certain process and the meaning of not performing a certain process.
In this specification, "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.
Reference throughout this specification to "some specific/preferred embodiments," "other specific/preferred embodiments," "an embodiment," and so forth, means that a particular element (e.g., feature, structure, property, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the elements may be combined in any suitable manner in the various embodiments.
In the present specification, the "normal temperature" may be 10 to 40 ℃.
<First aspect>
The first aspect of the invention provides a method for treating a waste asphalt mixture, which comprises the following steps:
screening the waste asphalt mixture sample to obtain a first screened product with the particle size of less than 3mm, the particle size of more than 3mm and less than 32mm and the particle size of more than 32 mm;
taking a first screening product with the particle size of more than 3mm and less than 32mm for primary fine stripping to obtain a first fine stripping product; specifically, the frequency of the centrifugal excitation of the fine peeling is 40-50Hz, for example: 42Hz, 45Hz, 48Hz, etc.; the time of centrifugal excitation is 5-10s, for example: 6s, 7s, 8s, 9s, etc.
Screening the first fine stripped product to obtain a second screened product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32 mm;
obtaining fine stripping parameters;
based on the fine peeling parameters, acquiring centrifugal excitation frequency of accurate fine peeling;
according to the centrifugal excitation frequency of the precise and fine stripping, respectively performing precise and fine stripping on the second screening products with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm to obtain precise and fine stripping products; specifically, the precise fine peeling time is 5 to 10s, for example: 6s, 7s, 8s, 9s, etc.
The treatment method of the waste asphalt mixture can greatly improve the blending proportion of the waste asphalt mixture in the reclaimed asphalt mixture, improve the quality stability of the reclaimed asphalt mixture, improve the quality of the hot-mix plant recycling technology and realize the recycling of the waste asphalt mixture.
In some specific embodiments, the step of obtaining the fine lift-off parameter comprises:
screening the waste asphalt mixture sample to obtain a third screened product with the particle size of less than 3mm, the particle size of more than 3mm and less than 32mm and the particle size of more than 32 mm; the third screening product with the particle size of more than 32mm is generally small in proportion and can be used as the third screening product;
taking a third screening product with the particle size of more than 3mm and less than 32mm, centrifugally stripping, recovering waste mineral aggregate with the particle size of more than 3mm and less than 32mm, and testing the angularity, crushing value and abrasion value of the waste mineral aggregate, and the mass ratio of the waste mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32 mm;
taking a third screening product with the particle size of more than 3mm and less than 32mm for primary fine stripping to obtain a second fine stripping product; the purpose of primary fine stripping is to carry out primary stripping on the waste mineral aggregate, and avoid excessive refinement of the waste mineral aggregate; specifically, the frequency of centrifugal excitation for one fine stripping is 40-50Hz, and the time of centrifugal excitation is 5-10 s.
Screening the second fine stripped product to obtain a fourth screened product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32 mm; wherein, the fourth screening product with the grain diameter of less than 3mm is mixed with the third screening product with the grain diameter of less than 3mm, and the mixture is directly stored for standby;
respectively carrying out secondary fine stripping on the fourth screening products with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm under different centrifugal excitation frequencies to obtain a third fine stripping product; in some specific embodiments, the frequency of the centrifugal excitation of the secondary fine exfoliation of the fourth screened product having a particle size greater than 3mm and less than 13mm is between 35 and 50Hz, for example: 38Hz, 40Hz, 42Hz, 45Hz, 48Hz, etc.; the time of centrifugal excitation is 15-30 s, for example: 18s, 21s, 24s, 27s, etc.; the frequency of the centrifugal excitation of the secondary fine stripping of the fourth screening product with the grain diameter of more than 13mm and less than 32mm is 20-35Hz, for example: 22Hz, 25Hz, 28Hz, 30Hz, 32Hz, etc.; the time of centrifugal excitation is 15-30 s, for example: 18s, 21s, 24s, 27s, etc.
The fourth screened product, which generally has a particle size of greater than 3mm and less than 13mm and a particle size of greater than 13mm and less than 32mm, may be tested by selecting three different centrifugal excitation frequencies, for example: for the fourth screening product with the grain diameter of more than 3mm and less than 13mm, centrifugal excitation frequencies of 35Hz, 40Hz and 45Hz can be selected to respectively carry out secondary fine stripping on the fourth screening product with the grain diameter of more than 3mm and less than 13mm, wherein when the centrifugal excitation frequency is 35Hz, the time of centrifugal excitation is 5-10 s, for example: 6s, 7s, 8s, 9s, etc.; when the centrifugal excitation frequency is 40Hz, the centrifugal excitation time is 5-10 s, for example: 6s, 7s, 8s, 9s, etc.; when the centrifugal excitation frequency is 45Hz, the centrifugal excitation time is 5-10 s, for example: 6s, 7s, 8s, 9s, etc.
For the fourth screening product with the grain diameter of more than 13mm and less than 32mm, the fourth screening products with the grain diameters of more than 13mm and less than 32mm can be selected for secondary fine stripping by centrifugal excitation frequencies of 20Hz, 25Hz and 30Hz, wherein when the centrifugal excitation frequency is 20Hz, the time of centrifugal excitation is 5-10 s, for example: 6s, 7s, 8s, 9s, etc.; when the centrifugal excitation frequency is 25Hz, the centrifugal excitation time is 5-10 s, for example: 6s, 7s, 8s, 9s, etc.; when the centrifugal excitation frequency is 30Hz, the centrifugal excitation time is 5-10 s, for example: 6s, 7s, 8s, 9s, etc.
Then, centrifugally stripping the third fine stripped product, recovering fine stripped product mineral aggregate with the grain diameter of more than 3mm and less than 32mm, and testing the angular character, crushing value, abrasion value and mass ratio of the fine stripped product mineral aggregate with the grain diameter of more than 3mm and less than 13mm and the grain diameter of more than 13mm and less than 32 mm;
obtaining the relative difference of the edges and angles of the fine stripped product mineral aggregate and the waste mineral aggregate, the relative difference of the crushing value and the abrasion value according to the edges and angles, the crushing value and the abrasion value of the fine stripped product mineral aggregate and the edges and angles, the crushing value and the abrasion value of the waste mineral aggregate;
Acquiring a cohesiveness index according to the mass ratio of the respective waste mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm, and the mass ratio of the respective fine stripping product mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32 mm;
based on the angular relative difference, the crush value relative difference, the abrasion value relative difference, and the cohesiveness index, the fine peeling parameter is obtained.
Specifically, the fine peeling parameters include:
the viscosity index is less than 1.5%;
the relative difference of the edges and corners of the fine stripping product mineral aggregate and the waste mineral aggregate is less than 10 percent;
the crushing value of the fine stripping product mineral aggregate and the crushing value of the waste mineral aggregate are relatively poor less than 6%;
the abrasion value of the fine stripping product mineral aggregate and the waste mineral aggregate is relatively less than 10 percent.
If the centrifugal excitation frequency of the fine stripping parameters is multiple, the minimum frequency is selected as the fine stripping parameter of the waste mineral aggregate. If the requirements of the fine stripping parameters are not met, the application grade of the separated waste asphalt mixture is reduced, and the waste asphalt mixture can be used for pavement base layers and the like.
The impact of angularity, crush value, and abrasion value on asphalt mix performance is significant, wherein:
The angularity is used for determining the rutting resistance of the asphalt mixture at high temperature. It can be characterized by the square of the ratio of the measured perimeter of the mineral aggregate to the perimeter of its polygon (as shown in fig. 1). Specifically, the method can be obtained by calculation according to the following formula (1):
wherein: l-angularity of the mineral aggregate;
n is the actual measured perimeter of the mineral aggregate;
m—polygonal perimeter of mineral aggregate.
In general, the larger the angular value is, the more the angular value of the mineral aggregate is, the better the embedding capacity of the asphalt mixture framework is, and therefore, the better the high-temperature rutting resistance of the asphalt mixture is. The relative difference in angularity is the percentage of the absolute value of the difference in angularity of the finely exfoliated product mineral material to the spent mineral material to the angularity of the spent mineral material.
The crush value is a measure for determining the running crush resistance of asphalt mixtures, and can be measured according to the test method in Highway engineering aggregate test procedure (JTG E42-2005). The relative difference in crush values is the percentage of the ratio of the absolute value of the difference in crush values of the finely exfoliated product mineral material to the spent mineral material to the angular character of the spent mineral material.
The abrasion value is used for determining the running abrasion resistance of the asphalt mixture, and can be detected according to the detection method in the highway engineering aggregate test procedure (JTG E42-2005). The relative difference in abrasion values is the percentage of the ratio of the absolute value of the difference in abrasion values of the finely exfoliated product mineral material to the spent mineral material to the angular properties of the spent mineral material.
The viscosity index can be calculated according to the mass ratio of the fine stripping product mineral aggregate and the waste mineral aggregate in the particle size range to be measured according to the following formula (2).
In the formula (2):
I c -an indicator of cohesiveness;
P i b -the mass ratio of the waste mineral aggregate in the particle size range to be measured;
P i a -the mass ratio of the finely exfoliated product mineral material of the particle size range to be measured;
n-the number of particle sizes.
Wherein I is c The smaller the value of (C) indicates that the less the agglomerate particles in the waste asphalt mixture are, the better the fine stripping effect is.
In the present application, the particle size range to be measured may be a particle size of more than 3mm and 13mm or less and a particle size of more than 13mm and 32mm or less, i.e., n may be 2 and P i b The mass ratio of the waste mineral aggregate corresponding to the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm is two values; p (P) i a The cohesiveness index was calculated by the above formula corresponding to two values of the mass ratio of the fine-exfoliated product mineral aggregate having a particle diameter of more than 3mm and 13mm or less and a particle diameter of more than 13mm and 32mm or less.
<Second aspect>
A second aspect of the present invention provides a reclaimed asphalt mix comprising a mixed aggregate, wherein the mixed aggregate comprises the precision fine peel product and mineral aggregate of the first aspect of the present invention; preferably, the sum of the contents of the precise fine-stripped products is 60% or more and the content of the mineral aggregate is 40% or less, based on 100% of the total mass of the mixed aggregate.
In some specific embodiments, the precisely fine exfoliated product after sieving comprises a precisely fine exfoliated product having a particle size of 3mm or less, a precisely fine exfoliated product having a particle size of greater than 3mm and 5mm or less, a precisely fine exfoliated product having a particle size of greater than 5mm and 10mm or less, a precisely fine exfoliated product having a particle size of greater than 10mm and 20mm or less, and a precisely fine exfoliated product having a particle size of greater than 20mm and 30mm or less.
Preferably, the total content of the precisely fine-peeled product having a particle diameter of more than 5mm and 10mm or less, the precisely fine-peeled product having a particle diameter of more than 10mm and 20mm or less, and the precisely fine-peeled product having a particle diameter of more than 20mm and 30mm or less is 50% to 80%, based on 100% of the total mass of the mixed aggregate, for example: 55%, 65%, 70%, 75%, etc.; the content of the precise fine peeled product having a particle diameter of more than 3mm and 5mm or less is 0 to 10%, for example: 2%, 5%, 8%, etc.; the content of the precise fine peeled product having a particle diameter of 3mm or less is 10 to 15%, for example: 11%, 12%, 13%, 14%, etc.
The content of each of the precisely fine peeled product having a particle diameter of more than 5mm and 10mm or less, the precisely fine peeled product having a particle diameter of more than 10mm and 20mm or less, and the precisely fine peeled product having a particle diameter of more than 20mm and 30mm or less is not particularly limited, and the present invention may be appropriately added as required. Specifically, the content of the precise fine peeled product having a particle diameter of more than 5mm and 10mm or less may be 10 to 20%, for example: 12%, 15%, 18%, etc.; the content of the fine peeled product having a particle diameter of more than 10mm and 20mm or less may be 30 to 40%, for example: 32%, 35%, 38%, etc.; the precise fine peel product having a particle size of more than 20mm and 30mm or less may be 10 to 20%, for example: 12%, 15%, 18%, etc.
Further, the mineral aggregate according to the invention means a newly added mineral aggregate. Wherein the mineral aggregate comprises mineral powder, mineral aggregate with the particle size of less than 5mm and mineral aggregate with the particle size of more than 20mm and less than 30 mm; preferably, the mineral powder is contained in an amount of 2% -5% based on 100% of the total mass of the mixed aggregate, for example: 3%, 4%, etc.; the mineral aggregate having a particle diameter of 5mm or less is contained in an amount of 0 to 13%, for example: 2%, 5%, 8%, 10%, 12%, etc.; the mineral aggregate having a particle diameter of more than 20mm and 30mm or less is contained in an amount of 8 to 22%, for example: 10%, 12%, 15%, 18%, 20%, etc.
Further, in the present invention, the reclaimed asphalt mixture further comprises a base asphalt and a reclaiming agent; preferably, the matrix asphalt is present in an amount of 1.5% to 3.5% based on 100% total mass of the mixed aggregate, for example: 2%, 2.5%, 3%, etc.; the content of the regenerant is 0.1% -0.3%, for example: 0.15%, 2%, 0.25%, etc.
The base asphalt is not particularly limited in the present invention, and may be one commonly used in the art. For example: road petroleum asphalt, etc. Further, the road petroleum asphalt includes one or a combination of two or more of low-grade road petroleum asphalt (for example, 25# road petroleum asphalt, 35# road petroleum asphalt, 50# road petroleum asphalt, etc.), 70# to 200# road petroleum asphalt, etc. The present invention preferably uses 70# road petroleum asphalt as the base asphalt.
The recycling agent is not particularly limited, and any commercially available asphalt recycling agent may be used. As long as the technical index of the regenerant meets the requirements of the Highway asphalt pavement regeneration technical Specification.
The regenerated asphalt mixture provided by the invention contains a large amount of waste asphalt mixture, but has excellent quality stability, so that the dependence of pavement materials on non-renewable resources natural sand materials is reduced, and the damage of mass storage of the waste asphalt mixture to the ecological environment is reduced.
<Third aspect of the invention>
The present invention provides a method for producing a reclaimed asphalt mixture according to the second aspect of the present invention, comprising the step of mixing the components of the reclaimed asphalt mixture;
in some specific embodiments, the preparation method comprises the steps of:
mixing and heating the precise fine stripping product with the grain diameter of more than 3mm and less than 5mm, the precise fine stripping product with the grain diameter of more than 5mm and less than 10mm, the precise fine stripping product with the grain diameter of more than 10mm and less than 20mm, the precise fine stripping product with the grain diameter of more than 20mm and less than 30mm, mineral aggregate with the grain diameter of less than 5mm and mineral aggregate with the grain diameter of more than 20mm and less than 30mm to obtain a premixed product;
Respectively heating the precise and fine stripping product with the particle size of less than 3mm and mineral powder;
mixing the premixed product, and then mixing the premixed product with matrix asphalt and a regenerant to obtain a premixed product;
mixing the pre-mixed product with the heated precise and fine stripping product with the particle size of less than 3mm, and then mixing with the heated mineral powder to obtain the reclaimed asphalt mixture.
Specifically, the preparation method comprises the following steps:
mixing and heating fine-peeled products with particle diameters of more than 3mm and less than 5mm, fine-peeled products with particle diameters of more than 5mm and less than 10mm, fine-peeled products with particle diameters of more than 10mm and less than 20mm, fine-peeled products with particle diameters of more than 20mm and less than 30mm, mineral materials with particle diameters of less than 5mm and mineral materials with particle diameters of more than 20mm and less than 30mm to obtain a premixed product; by the method for obtaining the premixed product, the internal weak interface formed by pre-mixing the new mineral aggregate and all waste mineral aggregates caused by the traditional method can be reduced, and the performance of the regenerated asphalt mixture is reduced. In particular, the temperature of the heating may be 160-180 ℃, for example: 165 ℃, 170 ℃, 175 ℃ and the like; the heating time is 220-260min, for example: 230min, 240min, 250min, etc.
Respectively heating the precise and fine stripping product with the particle size of less than 3mm and mineral powder; the accurate fine stripping product with the grain diameter of less than 3mm has higher asphalt content, increases specific surface area of asphalt, is not suitable for heating together with other accurate fine stripping products, and is easy to age asphalt. Thus, the precisely fine peeled product having a particle diameter of 3mm or less was heated alone. Thus, secondary aging of the asphalt which is an accurate fine stripping product with the particle size of less than 3mm can be avoided, and the performance of the reclaimed asphalt mixture is influenced. In particular, the temperature of the heating may be 80-100 ℃, for example: 85 ℃, 90 ℃, 95 ℃ and the like; the heating time is 65-85min, for example: 68min, 70min, 72min, 75min, 78min, 80min, 82min, etc. Likewise, the heating temperature of the ore powder may be 80-100 ℃, for example: 85 ℃, 90 ℃, 95 ℃ and the like; the heating time is 65-85min, for example: 68min, 70min, 72min, 75min, 78min, 80min, 82min, etc.
Mixing the premixed product, and then mixing the premixed product with matrix asphalt and a regenerant to obtain a premixed product; specifically, the matrix asphalt can be heated and then mixed with the premixed product and the regenerant. Specifically, the heating temperature of the matrix asphalt may be 130 to 150 ℃, for example: 135 ℃, 140 ℃, 145 ℃, etc.; the heating time is 210-250min, for example: 210min, 220min, 230min, 240min, etc. The regenerant does not need to be heated.
Specifically, the premixed product is firstly mixed for 3-5s, then matrix asphalt and a regenerant are added, the mixture is mixed for 70-80s, then the heated precise and fine stripping product with the particle size of less than 3mm is added, the mixture is mixed for 30-50s, then the heated mineral powder is added, the mixture is mixed for 60-80s, and the mixture is uniformly mixed to prepare the regenerated asphalt mixture.
Examples
Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.
Examples:
(1) And collecting the waste asphalt mixture milled from the pavement, pre-screening the waste asphalt mixture into third screening products with the particle size of less than 3mm, the particle size of more than 3mm and less than 32mm and the particle size of more than 32mm in three different particle size ranges, and then respectively storing the third screening products. Wherein the waste asphalt mixture with the particle size of less than 3mm is directly stored for standby without fine stripping treatment; the waste asphalt mixture with the particle size larger than 32mm has small proportion and is reserved for other purposes.
(2) Specific test methods are used for reference to highway engineering asphalt and asphalt mixture test procedure (JTG E20-2011): asphalt content test (centrifugal separation method) in asphalt mixture of T0722-1993, 1500g of third screening product with particle size more than 3mm and less than 32mm is treated, waste mineral aggregate in the third screening product with particle size more than 3mm and less than 32mm is recovered, and the corner angle, crushing value and abrasion value of the waste mineral aggregate and the mass ratio of the waste mineral aggregate with particle size more than 3mm and less than 13mm and particle size more than 13mm and less than 32mm are respectively tested. And the test results are shown in table 1 (the specific calculation mode is referred to in the specific embodiment and will not be described here again) based on the performance standard of the waste asphalt mixture.
(3) Carrying out primary fine stripping treatment on 1500g of waste asphalt mixture with the particle size of more than 3mm and less than 32mm by adopting asphalt mixture fine separation equipment, wherein the frequency of centrifugal excitation of primary fine stripping is 45Hz, the time of centrifugal excitation is 8s, and the primary fine stripping aims at carrying out primary stripping on the waste asphalt mixture, and meanwhile, avoiding excessive refinement of the waste asphalt mixture to obtain a second fine stripping product.
(4) Screening the second fine stripping product into a fourth screening product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32mm in three different particle size ranges, wherein the fourth screening product with the particle size of less than 3mm is mixed with the waste asphalt mixture with the particle size of less than 3mm of the third screening product, and directly stored for standby.
(5) And carrying out secondary fine stripping on the fourth screening products with the particle sizes of more than 3mm and less than 13mm and the particle sizes of more than 13mm and less than 32mm, wherein the centrifugal excitation frequency of the fourth screening products with the particle sizes of more than 3mm and less than 13mm is respectively set to be 35Hz, 40Hz and 45Hz, the time for carrying out centrifugal excitation each time is 8s, the centrifugal excitation frequency range of the fourth screening products with the particle sizes of more than 13mm and less than 32mm is respectively set to be 20Hz, 25Hz and 30Hz, and the time for carrying out centrifugal excitation each time is 8s, so as to obtain the third fine stripped products.
(6) After secondary fine stripping with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm is completed, collecting third fine stripped products with different stripping parameters, and adopting a specific test method to refer to the test procedure of highway engineering asphalt and asphalt mixture (JTG E20-2011): testing the asphalt content in the T0722-1993 asphalt mixture (centrifugal separation method), recovering to obtain a fine stripping product mineral aggregate, and then testing the angularity, crushing value and abrasion value of the mineral aggregate; and the respective fine exfoliated product mineral masses having a particle diameter of greater than 3mm and 13mm or less and a particle diameter of greater than 13mm and 32mm or less were examined for the mass ratio. And obtaining a cohesiveness index according to the mass ratio of the respective waste mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm, and the mass ratio of the respective fine stripping product mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32 mm. The test results are shown in table 1 (the specific calculation mode is referred to in the specific embodiment and will not be described here again).
TABLE 1 results of tests on the properties of the values of the angularity, crushing value, abrasion value and cohesiveness index of finely exfoliated product mineral aggregates
TABLE 2 results of the tests for the properties of the fine peel products, including angularity, crush value and abrasion value, are relatively poor (%)
(7) Determining a precise fine peeling frequency according to a method for determining a fine peeling parameter of a fine peeling product based on four-factor level control, wherein the fine peeling parameter of the fine peeling product is determined as follows:
the viscosity index is less than 1.5%;
the relative difference of the edges and corners of the fine stripping product mineral aggregate and the waste mineral aggregate is less than 10 percent;
the crushing value of the fine stripping product mineral aggregate and the crushing value of the waste mineral aggregate are relatively poor less than 6%;
the abrasion value of the fine stripping product mineral aggregate and the waste mineral aggregate is relatively less than 10 percent.
From the fine peeling parameters described above, it can be determined that: the fine peeling products having a particle diameter of more than 3mm and 13mm or less have a suitable precise fine peeling frequency of 35Hz, and the fine peeling products having a particle diameter of more than 13mm and 32mm or less have a suitable precise fine peeling frequency of 25Hz.
(8) After the fine stripping parameters of the waste asphalt mixture are determined, the waste asphalt mixture can be processed by adopting the fine stripping process and the parameters, and the specific steps are as follows:
Pre-screening a waste asphalt mixture sample milled from a road surface to obtain a first screened product with the particle size of less than 3mm, the particle size of more than 3mm and less than 32mm and the particle size of more than 32 mm;
specific test methods are used for reference to highway engineering asphalt and asphalt mixture test procedure (JTG E20-2011): asphalt content test (centrifugation) in T0722-1993 asphalt mixture for first sieving product with particle size of more than 3mm and below 32 mm;
taking a first screening product with the particle size of more than 3mm and less than 32mm, and carrying out primary fine stripping by adopting asphalt mixture fine separation equipment, wherein the frequency of centrifugal excitation of the primary fine stripping is 45Hz, and the time of the centrifugal excitation is 8s, so as to obtain a first fine stripping product;
screening the first fine stripped product to obtain a second screened product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32 mm;
and then carrying out precise fine stripping on the second screening product according to the centrifugal excitation frequency of the precise fine stripping, wherein the second screening product with the grain diameter of more than 3mm and less than 13mm is treated for 8s under the condition that the precise fine stripping frequency is 35Hz, and the second screening product with the grain diameter of more than 13mm and less than 32mm is treated for 8s under the condition that the precise fine stripping frequency is 25Hz, so as to obtain the precise fine stripping product.
And uniformly screening the precise fine stripping products into precise fine stripping products with the particle size of less than 3mm, the particle size of more than 3mm and less than 5mm, the particle size of more than 5mm and less than 10mm, the particle size of more than 10mm and less than 20mm and the particle size of more than 20mm and less than 30mm for later use.
(II) preparation of regenerated asphalt mixture
(1) And (3) carrying out a mixing proportion design of the reclaimed asphalt mixture, wherein the addition proportion of three precise fine stripping products with the grain diameter of more than 5mm and less than 10mm, the grain diameter of more than 10mm and less than 20mm and the grain diameter of more than 20mm and less than 30mm in the precise fine stripping products is respectively 15%, 35% and 15%, the addition proportion of the precise fine stripping products with the grain diameter of more than 3mm and less than 5mm is 5%, and the addition proportion of the precise fine stripping products with the grain diameter of less than 3mm is 10%.
(2) Preparing mineral powder, wherein the adding proportion of the mineral powder is 4%; a new mineral aggregate with a grain diameter of less than 5mm, wherein the addition proportion of the new mineral aggregate is 6%, and the addition proportion of the new mineral aggregate with a grain diameter of more than 20mm and less than 30mm is 10%; preparation of regenerant (Jiangsu Su Bote New Material Co., ltd.)Asphalt recycling agent) in an addition ratio of 0.2% (mass ratio of all mixed aggregates); a 70# road petroleum asphalt was prepared with an addition ratio of 2.4% (mass ratio of all mixed aggregates). The mixed aggregate is a mixture of the precisely fine-stripped product and the new mineral aggregate.
(3) After fine stripping, since the pitch content of the precisely fine stripped product having a particle diameter of more than 3mm and less than 5mm, a particle diameter of more than 5mm and less than 10mm, a particle diameter of more than 10mm and less than 20mm and a particle diameter of more than 20mm and less than 30mm is low, the precisely fine stripped product having a particle diameter of more than 3mm and less than 5mm, a particle diameter of more than 5mm and less than 10mm, a particle diameter of more than 10mm and less than 20mm and a particle diameter of more than 20mm and less than 30mm is directly mixed with a new mineral aggregate (a particle diameter of less than 5mm and a particle diameter of more than 20mm and less than 30 mm) in advance, and heated in an oven at 170 ℃ for 240min to obtain a premixed mineral aggregate.
(4) The precisely fine exfoliated product with particle size below 3mm was heated separately at 90 ℃ for 70min while adding mineral powder into the oven, and also heated.
(5) The 70# road petroleum asphalt is heated in a 140 ℃ oven for 230min, and the regenerant is not required to be heated.
(6) Taking out the heated premixed mineral aggregate, putting the premixed mineral aggregate into a mixing pot, firstly mixing for 4s, then adding the heated 70# road petroleum asphalt and the regenerant, mixing for 75s, then adding the heated precise stripping product with the particle size of less than 3mm, mixing for 40s, and then adding the heated mineral powder for 70s, so that the mixture is uniformly mixed, and finally the preparation of the regenerated asphalt mixture is finished.
Comparative example 1
(1) Collecting waste asphalt mixture milled from a road surface, and then directly screening the waste asphalt mixture into two grades with the grain diameter of less than 10mm and the grain diameter of more than 10mm and less than 25 mm;
(2) The adding proportion of the waste mineral aggregate with the particle size of less than 10mm is 10 percent, and the adding proportion of the waste mineral aggregate with the particle size of more than 10mm and less than 25mm is 20 percent based on 100 percent of the total mass of the mixed aggregate;
(3) Preparing mineral powder, wherein the adding proportion of the mineral powder is 5%; a new mineral aggregate with a particle size of less than 5mm, wherein the addition proportion of the new mineral aggregate is 32%, and the addition proportion of the new mineral aggregate with a particle size of more than 20mm and less than 30mm is 23%; preparation of regenerant (Jiangsu Su Bote New Material Co., ltd.)Asphalt recycling agent) in an addition ratio of 0.2% (mass ratio of all mixed aggregates); a 70# road petroleum asphalt was prepared with an addition ratio of 2.4% (mass ratio of all mixed aggregates). The mixed aggregate is a mixture of an accurate fine stripping product and new mineral aggregate;
(4) The regenerated asphalt mixture is prepared according to the relevant regulations of the Highway asphalt pavement regeneration technical Specification (JTG/T5521-2019), wherein the use amount of the waste asphalt mixture is 30%.
Comparative example 2
(1) Collecting waste asphalt mixture milled from a road surface, and then directly screening the waste asphalt mixture into two grades with the grain diameter of less than 10mm and the grain diameter of more than 10 and less than 25 mm;
(2) The adding proportion of the waste mineral aggregate with the particle size of less than 10mm is 30 percent, and the adding proportion of the waste mineral aggregate with the particle size of more than 10mm and less than 25mm is 50 percent based on 100 percent of the total mass of the mixed aggregate;
(3) Preparing mineral powder, wherein the adding proportion of the mineral powder is 4%; a new mineral aggregate with a grain diameter of less than 5mm, wherein the addition proportion of the new mineral aggregate is 6%, and the addition proportion of the new mineral aggregate with a grain diameter of more than 20mm and less than 30mm is 10%; preparation of regenerant (Jiangsu Su Bote New Material Co., ltd.)Asphalt recycling agent) in an addition ratio of 0.2% (mass ratio of all mixed aggregates); a 70# road petroleum asphalt was prepared with an addition ratio of 2.4% (mass ratio of all mixed aggregates). The mixed aggregate is a mixture of an accurate fine stripping product and new mineral aggregate;
(4) The regenerated asphalt mixture is prepared according to the relevant regulations of the Highway asphalt pavement regeneration technical Specification (JTG/T5521-2019), wherein the use amount of the waste asphalt mixture is 80%.
Performance testing
The performance of the reclaimed asphalt mixture was tested with reference to Highway asphalt pavement construction Specification (JTG F40-2004), and the performance comparison is shown in Table 3. The mass tolerance in the table reflects mainly the mass instability of the asphalt mix.
Table 3 performance comparison
As shown in the test results of Table 3, each index of the regenerated asphalt mixture prepared by the method of the invention meets the specification requirements. The road performance of the regenerated asphalt mixture (80%) prepared by the method of the invention is greatly improved in quality stability and is obviously better than that of comparative example 1 due to the waste asphalt mixture treated by the method of the invention.
In addition, the preparation method (heating parameters, mixing sequence, mixing time and the like) of the regenerated asphalt mixture is properly optimized, so that secondary aging of asphalt is reduced, weak interfaces in the asphalt mixture are reduced, and the performance of the regenerated asphalt mixture is additionally improved on the basis of improving the quality stability. The road performance of comparative example 2 is poor, especially the low-temperature crack resistance (trabecular low-temperature bending damage strain) and the water damage resistance (freeze thawing splitting strength ratio) are poor, and the quality allowance deviation does not meet the standard requirement, which indicates that the regenerated asphalt mixture has large quality instability and is extremely easy to generate quality segregation, which is also the main reason for limiting the adding proportion of waste mineral aggregate in the regenerated asphalt mixture, namely the quality allowance deviation is not easy to meet the standard requirement.
It should be noted that, although the technical solution of the present invention is described in specific examples, those skilled in the art can understand that the present invention should not be limited thereto.
The foregoing description of embodiments of the invention has been presented for purposes of illustration and description, and is not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the various embodiments described. The terminology used herein was chosen in order to best explain the principles of the embodiments, the practical application, or the technical improvements in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.
Claims (13)
1. The treatment method of the waste asphalt mixture is characterized by comprising the following steps of:
screening the waste asphalt mixture sample to obtain a first screened product with the particle size of less than 3mm, the particle size of more than 3mm and less than 32mm and the particle size of more than 32 mm;
taking a first screening product with the particle size of more than 3mm and less than 32mm for primary fine stripping to obtain a first fine stripping product;
screening the first fine stripped product to obtain a second screened product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32 mm;
Obtaining fine stripping parameters;
based on the fine peeling parameters, acquiring centrifugal excitation frequency of accurate fine peeling;
according to the centrifugal excitation frequency of the precise and fine stripping, respectively performing precise and fine stripping on the second screening products with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm to obtain precise and fine stripping products;
the step of obtaining the fine peeling parameter comprises the following steps:
screening the waste asphalt mixture sample to obtain a third screened product with the particle size of less than 3mm, more than 3mm and less than 32mm and more than 32 mm;
taking a third screening product with the particle size of more than 3mm and less than 32mm, centrifugally stripping, recovering waste mineral aggregate with the particle size of more than 3mm and less than 32mm, and testing the angularity, crushing value and abrasion value of the waste mineral aggregate, and the mass ratio of the waste mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32 mm;
taking a third screening product with the particle size of more than 3mm and less than 32mm for primary fine stripping to obtain a second fine stripping product;
screening the second fine stripped product to obtain a fourth screened product with a particle size of less than 3mm, a particle size of more than 3mm and less than 13mm and a particle size of more than 13mm and less than 32 mm;
Respectively carrying out secondary fine stripping on the fourth screening products with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm under different centrifugal excitation frequencies to obtain a third fine stripping product;
centrifugally stripping the third fine stripped product, recovering fine stripped product mineral aggregate with the grain diameter of more than 3mm and less than 32mm, and testing the angular property, crushing value, abrasion value and mass ratio of the fine stripped product mineral aggregate with the grain diameter of more than 3mm and less than 13mm and the grain diameter of more than 13mm and less than 32 mm;
obtaining the relative difference of the edges and angles of the fine stripped product mineral aggregate and the waste mineral aggregate, the relative difference of the crushing value and the abrasion value according to the edges and angles, the crushing value and the abrasion value of the fine stripped product mineral aggregate and the edges and angles, the crushing value and the abrasion value of the waste mineral aggregate;
acquiring a cohesiveness index according to the mass ratio of the respective waste mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32mm, and the mass ratio of the respective fine stripping product mineral aggregate with the particle size of more than 3mm and less than 13mm and the particle size of more than 13mm and less than 32 mm;
acquiring a fine peeling parameter based on the angular relative difference, the crushing value relative difference, the abrasion value relative difference and the cohesiveness index;
The fine peeling parameters include:
the viscosity index is less than 1.5%;
the relative difference of the edges and corners of the fine stripping product mineral aggregate and the waste mineral aggregate is less than 10 percent;
the crushing value of the fine stripping product mineral aggregate and the crushing value of the waste mineral aggregate are relatively poor less than 6%;
the abrasion value of the fine stripping product mineral aggregate and the waste mineral aggregate is relatively less than 10 percent.
2. The method according to claim 1, wherein the frequency of the centrifugal excitation for secondary fine separation of the fourth screening product having a particle diameter of more than 3mm and 13mm or less is 35 to 50Hz, and the time of the centrifugal excitation is 15 to 30s; the frequency of centrifugal excitation for secondary fine stripping of the fourth screening product with the grain diameter of more than 13mm and less than 32mm is 20-35Hz, and the time of the centrifugal excitation is 15-30 s.
3. The method according to claim 1 or 2, wherein the frequency of the centrifugal excitation for the fine peeling is 40-50Hz, and the time of the centrifugal excitation is 5-10 s; and/or the precise fine peeling time is 5-10 s.
4. A reclaimed asphalt mix, characterized by comprising a mixed aggregate, wherein the mixed aggregate comprises a precisely fine-exfoliated product obtained by the treatment method according to any one of claims 1 to 3 and mineral aggregate.
5. The reclaimed asphalt mixture as claimed in claim 4, wherein the content of the precisely fine-peeled product is 60% or more and the content of the mineral aggregate is 40% or less based on 100% of the total mass of the mixed aggregate.
6. The reclaimed asphalt mixture as claimed in claim 4, wherein the precisely fine-peeled product after sieving comprises a precisely fine-peeled product having a particle diameter of 3mm or less, a precisely fine-peeled product having a particle diameter of more than 3mm and 5mm or less, a precisely fine-peeled product having a particle diameter of more than 5mm and 10mm or less, a precisely fine-peeled product having a particle diameter of more than 10mm and 20mm or less, and a precisely fine-peeled product having a particle diameter of more than 20mm and 30mm or less.
7. The reclaimed asphalt mixture as claimed in claim 6, wherein the total content of the precisely fine-peeled product having a particle diameter of more than 5mm and 10mm or less, the precisely fine-peeled product having a particle diameter of more than 10mm and 20mm or less, the precisely fine-peeled product having a particle diameter of more than 20mm and 30mm or less is 50 to 65%, the content of the precisely fine-peeled product having a particle diameter of more than 3mm and 5mm or less is 0 to 10%, and the content of the precisely fine-peeled product having a particle diameter of 3mm or less is 10 to 15%, based on 100% of the total mass of the mixed aggregate.
8. The reclaimed asphalt mixture of any one of claims 4-7, wherein the mineral ore comprises mineral ore, mineral ore having a particle size of 5mm or less and mineral ore having a particle size of greater than 20mm and 30mm or less.
9. The reclaimed asphalt mixture as claimed in claim 8, wherein the content of the mineral powder is 2% -5%, the content of the mineral aggregate having a particle size of 5mm or less is 0% -13%, and the content of the mineral aggregate having a particle size of more than 20mm and 30mm or less is 8% -22% based on 100% of the total mass of the mixed aggregate.
10. The reclaimed asphalt mixture of any one of claims 4-7, wherein the reclaimed asphalt mixture further comprises a base asphalt and a regener.
11. The reclaimed asphalt mixture as claimed in claim 10, wherein the matrix asphalt content is 1.5 to 3.5% based on 100% of the total mass of the mixed aggregate; the content of the regenerant is 0.1-0.3%.
12. A method of preparing a reclaimed asphalt mixture as defined in any one of claims 4 to 11, comprising the step of mixing the components of the reclaimed asphalt mixture.
13. The preparation method according to claim 12, characterized in that the preparation method comprises the steps of:
Mixing and heating the accurate fine stripping product with the grain diameter of more than 3mm and less than 5mm, the accurate fine stripping product with the grain diameter of more than 5mm and less than 10mm, the accurate fine stripping product with the grain diameter of more than 10mm and less than 20mm, the accurate fine stripping product with the grain diameter of more than 20mm and less than 30mm, mineral aggregate with the grain diameter of 0-5mm and mineral aggregate with the grain diameter of more than 20mm and less than 30mm to obtain a premixed product;
respectively heating the precise and fine stripping product with the particle size of less than 3mm and mineral powder;
mixing the premixed product, and then mixing the premixed product with matrix asphalt and a regenerant to obtain a premixed product;
mixing the pre-mixed product with the heated precise and fine stripping product with the particle size of less than 3mm, and then mixing with the heated mineral powder to obtain the reclaimed asphalt mixture.
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