CN113173736B

CN113173736B - Preparation method of high-mixing-amount plant-mixed hot recycled asphalt mixture

Info

Publication number: CN113173736B
Application number: CN202110326187.4A
Authority: CN
Inventors: 顾兴宇; 王晨
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2021-03-26
Filing date: 2021-03-26
Publication date: 2022-04-01
Anticipated expiration: 2041-03-26
Also published as: CN113173736A

Abstract

The invention discloses a preparation method of a high-volume plant-mixed hot recycled asphalt mixture, and belongs to the technical field of highway construction materials. It comprises the following steps: firstly, classifying and grading RAP materials; secondly, determining the mixing amount, wherein different types of RAP materials with different grades adopt different mixing proportions according to the classification grading result of the RAP materials; crushing and screening, namely crushing and screening RAP materials; fourthly, determining the synthetic gradation; fifthly, determining the asphalt dosage, namely selecting high-viscosity rubber modified asphalt, determining the optimal asphalt dosage by using a Marshall test method, and increasing 0.3% of the asphalt dosage on the basis of the optimal asphalt dosage to be used as the finally determined asphalt dosage; sixthly, preparing the plant-mixed hot recycling asphalt mixture with high mixing amount. The invention greatly improves the RAP material mixing amount, has remarkable social benefit and economic benefit, saves investment, reduces the construction cost, improves the traffic capacity of roads and reduces the transportation cost on the premise of ensuring the construction quality.

Description

Preparation method of high-mixing-amount plant-mixed hot recycled asphalt mixture

Technical Field

The invention belongs to the technical field of highway construction materials, and particularly relates to a preparation method of a high-volume plant-mixed hot recycled asphalt mixture.

Background

At present, the blending proportion of the RAP materials is 10% -25%, but the blending proportion can not consume all RAP materials, so that excessive accumulation and waste of the RAP materials are caused, and a large amount of economic and environmental problems are brought, therefore, ultra-high proportion recovery (the blending amount is more than 40%) of the RAP materials increasingly attracts people's attention, but meanwhile, the research on high blending plant heat regeneration is in a starting stage, the high blending amount of the RAP materials is only limited to theory, the control on the variability and quality of the RAP materials is ignored, and the problem of how to ensure the long-term road performance of the RAP materials when the RAP materials are applied to expressways is also ignored.

Meanwhile, in practical application, plant-mixed hot recycling mixing equipment is usually transformed on the basis of the existing mixing plant, and mixing production processes are different, so that most of plant-mixed hot recycling equipment is difficult to realize high-proportion mixing of RAP on the basis of ensuring the efficiency and the performance of recycled mixtures. Therefore, on the basis of the improvement of the existing plant-mixed hot recycling equipment and production process in China, the method realizes the high RAP mixing amount of plant-mixed hot recycling through correct design of the recycled mixture, and ensures and improves the long-term road performance of the recycled mixture, thereby having very important significance.

Through retrieval, the Chinese patent publication number: CN 104926233A; the publication date is as follows: 09 month and 23 days 2015; discloses a formulation of an asphalt mixture with high RAP content and a manufacturing method thereof, the formulation comprises the following components: milling and planing 40-65% of old material; 30-50% of aggregate; 1.5% of mineral powder; 1.5% of ordinary portland cement; 0.3% of polyester fibers or basalt fibers; 2.8 to 3.9 percent of base asphalt; the manufacturing method comprises the following steps: (1) preheating, milling and milling old materials; (2) adding the preheated milling old material into a hot mixing pot; (3) adding the preheated aggregate, and simultaneously adding polyester fiber or basalt fiber for mixing; (4) adding preheated matrix asphalt and mixing; (5) adding preheated mineral powder and mixing. Although the scheme of the application improves the mixing amount of the RAP material in the asphalt mixture compared with the prior art, the variability is large due to different component grades of the RAP material in the early stage, the performance of the asphalt mixture prepared by the scheme of the application is greatly influenced by the quality of the recovered old RAP material, and the method cannot be effectively applied to actual production construction.

Disclosure of Invention

In order to solve at least one of the above technical problems, according to an aspect of the present invention, there is provided a method for preparing a high-content hot mix plant recycling asphalt mixture, comprising the steps of:

classifying and grading RAP materials, classifying the RAP materials according to different RAP material sources, storage conditions and detection conditions, and grading various RAP materials according to different mud contents, asphalt contents and asphalt penetration degrees of the RAP materials which are less than 0.075 mm;

secondly, determining the mixing amount, wherein different types of RAP materials with different grades adopt different mixing proportions according to the classification grading result of the RAP materials;

crushing and screening, namely crushing RAP, screening after crushing, and screening into a first coarse aggregate with the particle size of 0-10 mm and a second coarse aggregate with the particle size of 10-15 mm;

determining synthetic grading, wherein the first coarse aggregate and the second coarse aggregate are subjected to synthetic grading design with crushed stones and mineral powder respectively, screening RAP materials, crushed stones and mineral powder in sequence, adjusting the dosage proportion of each grade of mineral materials to enable the synthetic grading to be between the lower grading limit and the upper grading limit, and recording the data volume of each component;

fifthly, determining the asphalt dosage, namely selecting high-viscosity rubber modified asphalt, determining the optimal asphalt dosage by using a Marshall test method, and increasing 0.3% of the asphalt dosage on the basis of the optimal asphalt dosage to be used as the finally determined asphalt dosage;

and sixthly, preparing, namely preparing the high-mixing-amount plant-mixed hot recycled asphalt mixture according to the determined RAP material mixing amount, the crushed material amount, the mineral powder amount and the asphalt amount.

According to the preparation method of the high-volume plant-mixed hot recycled asphalt mixture provided by the embodiment of the invention, optionally,

in the first step, the RAP material classification basis is as follows: the RAP materials with clear sources, separated storage and detection once per 500 tons of RAP materials in each batch are a type of RAP materials; the RAP materials with unclear sources, stored in bins and detected once per 500 tons of RAP materials in each batch are two types of RAP materials; three types of RAP materials with undefined sources, non-classified storage and non-detection;

grading basis of each RAP material is as follows: the mud content is less than or equal to 1.5 percent below 0.075mm, the asphalt content is more than or equal to 3.5 percent, and the asphalt penetration is more than or equal to 35; the mud content is less than 2.0 percent under the condition that the mud content is less than 1.5 percent and less than 0.075mm, the asphalt content is less than 3.5 percent under the condition that the asphalt penetration is less than 25 and less than 35; the mud content is less than or equal to 2.5 percent and less than or equal to 0.075mm, the asphalt content is less than or equal to 3.0 percent and more than 2.5 percent, the asphalt penetration is less than 25 and more than 15, and the like; the mud content below 0.075mm is more than 2.5%, the asphalt content is less than 2.5%, the asphalt penetration is less than 15, and the like.

According to the preparation method of the high-mixing plant-mixed hot recycled asphalt mixture provided by the embodiment of the invention, optionally, the mixing proportion of different types of RAP materials with different grades is as follows:

the maximum mixing amount of the first-class RAP material in the upper layer of the municipal road is 50 percent, and the maximum mixing amount in the lower layer of the first-class RAP material is 60 percent;

the maximum mixing amount of the second grade RAP material in the upper surface layer of the municipal road is 40 percent, and the maximum mixing amount in the lower surface layer is 50 percent;

the maximum mixing amount of the three-class RAP material in the upper surface layer of the municipal road is 30 percent, and the maximum mixing amount in the lower surface layer is 40 percent;

after the four-class RAP material is subjected to necessary treatment, the maximum mixing amount in the upper layer of the municipal road is 10 percent, and the maximum mixing amount in the lower layer is 20 percent;

the maximum mixing amount of class II first-class RAP materials in an upper layer of the municipal road is 30 percent, and the maximum mixing amount of class II first-class RAP materials in a lower layer of the municipal road is 40 percent;

the maximum mixing amount of the second-class second-grade RAP material in the upper surface layer of the municipal road is 20%, and the maximum mixing amount in the lower surface layer of the municipal road is 30%;

the maximum mixing amount of the second-class, third-class and other RAP materials in the upper surface layer of the municipal road is 10%, and the maximum mixing amount of the second-class, third-class and other RAP materials in the lower surface layer of the municipal road is 20%.

According to the preparation method of the high-volume hot mix plant-mixed recycled asphalt mixture provided by the embodiment of the invention, optionally, the necessary treatment comprises the following treatment steps:

A. heating RAP to 120 ℃ for more than 3 hours;

B. screening out the part of the RAP material with the diameter of less than 0.075 mm;

C. spraying regenerant to RAP material and mixing.

According to the preparation method of the high-doping hot mix plant-mixed recycled asphalt mixture provided by the embodiment of the invention, optionally, before the doping amount in the second step is determined, a part of the RAP material below 0.3mm is screened out.

According to the preparation method of the high-volume plant-mixed hot recycled asphalt mixture provided by the embodiment of the invention, optionally, the specific process for preparing the high-volume plant-mixed hot recycled asphalt mixture in the sixth step is as follows:

s1, preheating, namely respectively putting the RAP material, the high-viscosity rubber modified asphalt, the crushed stone material and the mineral powder into a preheating barrel, and preheating for a certain time;

s2, mixing, namely sequentially mixing, pouring the preheated RAP material into a stirring pot, adding crushed stone after mixing for a period of time, adding high-viscosity rubber modified asphalt after mixing for a period of time, and finally adding mineral powder after a period of time;

s3, preserving heat, and putting the mixed mixture into an oven for preserving heat for a certain time to obtain the plant-mixed hot recycled asphalt mixture with high mixing amount.

According to the preparation method of the high-mixing-amount plant-mixed hot recycled asphalt mixture, optionally, in S1, the preheating temperatures of the RAP material and the crushed stone material are increased along with the increase of the mixing amount of the RAP material, the preheating temperature of the high-viscosity high-glue modified asphalt is 160 ℃, the preheating temperature of the mineral powder is 180 ℃, and the preheating time is 4 hours.

According to the preparation method of the high-content hot mix plant-mixed recycled asphalt mixture provided by the embodiment of the invention, optionally, in S2, the temperature of the stirring pot is 160 ℃, and each material is added and then mixed for 60 seconds before the next operation is carried out.

According to the preparation method of the high-content hot mix plant-mixed recycled asphalt mixture provided by the embodiment of the invention, optionally, in S3, the mixed mixture is subjected to heat preservation at 135 ℃ for 4 hours.

Advantageous effects

Compared with the prior art, the invention has at least the following beneficial effects:

1. the invention sets a strict RAP material grading classification standard in the application of the hot mix plant recycling asphalt mixture, provides different applicable conditions for RAP materials with different grades, and provides the corresponding maximum mixing amount of the old materials, and performs high mixing amount application on the RAP materials on the premise of ensuring the product performance;

2. considering that the old asphalt is not utilized by 100 percent, the fusion rate and the effective utilization rate of the new asphalt are estimated, and the effective utilization rate of the hot mix plant-mixed recycled asphalt mixture with high old material mixing amount is about 80 percent, so that 0.3 percent of the new asphalt using amount is added on the basis of the new asphalt using amount determined by a Marshall test to be used as the final new asphalt using amount of the recycled mixture, and the corrected new asphalt using amount is used for forming a Marshall test piece to test and obtain the best performance;

3. the invention eliminates RAP variability as much as possible by grading RAP and screening RAP fines, improves road performance of the regenerated mixture and greatly improves RAP mixing amount by using high-adhesive high-viscosity asphalt and correcting the consumption of new asphalt by using the fusion degree parameter of new and old asphalt, has remarkable social and economic benefits, saves investment and reduces construction cost on the premise of ensuring engineering quality, improves road traffic capacity and reduces transportation cost.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below, and it is apparent that the drawings in the following description only relate to some embodiments of the present invention and are not limiting on the present invention.

FIG. 1 shows a schematic flow chart of a preparation method of the high-content hot mix plant recycling asphalt mixture.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments.

Example 1

The preparation method of the high-content hot mix plant recycling asphalt mixture of the embodiment is shown in fig. 1, and comprises the following specific steps:

step one, classifying and grading RAP materials, classifying the RAP materials according to different RAP material sources, storage conditions and detection conditions, and grading various RAP materials according to different mud contents, asphalt contents and asphalt penetration degrees of the RAP materials which are less than 0.075 mm.

The basis for the classification of RAP classes is shown in table 1.

TABLE 1 RAP classification grading basis table

For classification of RAP material, the provider may be queried or the relevant record determination queried at the time the RAP material is purchased.

And step two, determining the doping amount, wherein different types of RAP materials with different grades adopt different doping proportions according to the classification grading result of the RAP materials.

The part of less than 0.3mm in the RAP material is screened out in advance, and then the blending ratio of the RAP material is determined according to the classification grading result of the step one.

The specific blending standard of the RAP material is as follows:

the maximum mixing amount of the second-class, third-class and other RAPs in the upper surface layer of the municipal road is 10 percent, and the maximum mixing amount in the lower surface layer is 20 percent;

performing necessary treatment on the second-class fourth-class RAP materials;

performing necessary treatment on the three types of RAP materials;

after necessary treatment is carried out on the second-class fourth-class RAP materials and the third-class RAP materials, the road performance of the regenerated mixture is checked through an indoor test, and then the range of the dosage of the RAP which can be used is determined.

The above-mentioned necessary treatment specifically includes the steps of:

A. heating RAP to 120 ℃, and then preserving heat for at least 3 hours to reduce the water content of RAP material;

C. spraying regenerant to RAP material and mixing.

And step three, crushing the RAP material, screening after crushing, screening into a first coarse aggregate with the particle size of 0-10 mm and a second coarse aggregate with the particle size of 10-15 mm, and performing classified stacking and storage.

And step four, determining synthetic grading, wherein the first coarse aggregate and the second coarse aggregate are respectively subjected to synthetic grading design with crushed stones and mineral powder, the RAP materials, the crushed stones and the mineral powder are sequentially screened, the synthetic grading is between a lower grading limit and an upper grading limit by adjusting the dosage proportion of each grade of mineral materials, and the data volume of each component is recorded.

And (3) taking the RAP materials with different thicknesses processed in the step three as a raw material of the recycled asphalt mixture, and performing synthetic grading design on crushed stone and mineral powder, sequentially screening the RAP materials, the crushed stone and the mineral powder, counting the passing rates of aggregates corresponding to different sieve pores of 16mm, 13.2mm, 9.5mm, 4.75mm, 2.36mm, 1.18mm, 0.6mm, 0.3mm, 0.075mm and the like after screening, adjusting the dosage proportion of each grade of mineral materials according to the obtained passing rate value by combining a table 2 according to the requirements of road engineering asphalt and asphalt mixture test regulations (JTG E20-2011), determining that the synthetic grading is between a lower grading limit and a grading upper limit, and recording the data volume of each component.

TABLE 2 lower and upper grading limits

Mesh size (mm)	16	13.2	9.5	4.75	2.36	1.18	0.6	0.3	0.15	0.075
											Grading Upper Limit (%)	100	100	85	68	50	38	28	20	15	8
Grading lower limit (%)	100	90	68	38	24	15	10	7	5	4

And step five, determining the asphalt dosage, namely selecting high-viscosity rubber modified asphalt, wherein the use of the high-viscosity rubber modified asphalt improves the integral anti-rutting performance, anti-cracking performance, water damage resistance and durability of the regenerated mixture, determining the optimal asphalt dosage by using a Marshall test method, and increasing 0.3% of the asphalt dosage as the finally determined asphalt dosage on the basis.

In this example, the high viscosity and high viscosity rubber modified asphalt should be selected to meet the technical indexes in table 3.

TABLE 3 technical index requirements of high viscosity high gum modified asphalt

After the asphalt is selected, the optimal asphalt dosage is determined by a Marshall test method, the determination method comprises the steps of estimating the new asphalt dosage as a median value, forming 5 groups of Marshall test pieces at intervals of 0.5, respectively measuring the stability MS and the flow value FL according to the Marshall test method, respectively measuring the gross volume relative density of the test pieces at 25 ℃ by a surface-drying method, calculating the isovolumetric indexes of the void ratio VV, the mineral aggregate clearance ratio VMA and the effective asphalt saturation ratio VFA, and finally, taking the asphalt ratio as a horizontal coordinate and each performance index of the test pieces as a vertical coordinate, smoothly connecting the test results by four curves to finally obtain the optimal asphalt ratio data of the Marshall test method.

Since the effective utilization rate of the old asphalt in the hot mix plant recycling asphalt mixture is about 80%, the new asphalt dosage of the final recycling mixture is 0.3% added on the basis of the new asphalt dosage determined by the marshall test.

Step six, preparing the plant-mixed hot recycling asphalt mixture with high mixing amount, wherein the specific process comprises the following steps:

s1, preheating, namely respectively putting the RAP material, the high-viscosity rubber modified asphalt, the crushed stone material and the mineral powder into a preheating barrel, wherein the preheating temperatures of the RAP material and the crushed stone material are shown in Table 4, the preheating temperature of the high-viscosity rubber modified asphalt is 160 ℃, the preheating temperature of the mineral powder is 180 ℃, and the preheating time is 4 hours;

s2, mixing sequentially, pouring the preheated RAP material into a stirring pot at 160 ℃, mixing for 60 seconds, adding crushed stone, mixing for 60 seconds, adding high-viscosity rubber modified asphalt, mixing for 60 seconds, finally adding mineral powder, and mixing for 60 seconds to complete the mixing of the mixture;

s3, preserving heat, and putting the mixed mixture into a 135 ℃ oven to preserve heat for 4 hours to obtain the plant-mixed hot recycled asphalt mixture with high mixing amount.

TABLE 4 RAP material and crushed stone preheating temperatures corresponding to different RAP material mixing amounts

S1, the preheating temperature of the RAP material is limited, the RAP material can be aged again when the temperature is higher than the limited temperature, and the AP material can not be effectively mixed with the crushed stone when the temperature is lower than the limited temperature.

In S1, the preheating temperature of the crushed stone and the ore powder is limited, the asphalt is rapidly aged when the temperature is higher than the limited temperature during mixing, and the asphalt cannot be wrapped when the temperature is lower than the limited temperature.

The preheating temperature of the high-viscosity high-rubber modified asphalt in the S1 is limited, the asphalt is aged when the temperature is higher than the limited temperature, and the asphalt cannot become liquid and is difficult to mix when the temperature is lower than the limited temperature.

In the S2, RAP materials, crushed stone materials, high-viscosity rubber modified asphalt and mineral powder need to be added in sequence for mixing, if the RAP materials, the crushed stone materials and the asphalt cannot be perfectly mixed, and the mixing degree of the new asphalt and the old asphalt is influenced, so that the performance of the finally prepared regenerated asphalt mixture is influenced.

Example 2

This example shows a method for preparing an AC-13C type reclaimed asphalt mixture.

The AC-13C type recycled asphalt mixture of the embodiment comprises the following components in parts by weight: 55 parts of class II first-grade recycled asphalt pavement reclaimed materials; 40 parts by weight of crushed stone; 2.4 parts of mineral powder; 2.6 parts of high-viscosity asphalt.

Classifying and grading the obtained old asphalt reclaimed materials according to the specification, finally determining the old asphalt reclaimed materials to be two-class first-class RAP materials, and then screening out the parts below 0.3mm in the RAP materials to determine the mixing amount of the RAP materials.

And secondly, mechanically mixing the RAP materials, crushing, and then screening to obtain 30% of first coarse aggregate with the particle size of 0-10 mm and 70% of second coarse aggregate with the particle size of 10-15 mm, wherein the parts below 0.3mm are screened.

And thirdly, screening the RAP material, the crushed stone material and the mineral powder in sequence, adjusting the dosage proportion of each grade to ensure that the synthetic gradation is between the specified lower gradation limit and the upper gradation limit, and recording the data volume of each component.

The crushed stone comprises 10% of basalt with the grain size of 10-15 mm, 45% of limestone with the grain size of 5-10 mm and 45% of limestone with the grain size of 0-5 mm; the mineral powder is basalt ground mineral powder.

And fourthly, selecting the high-viscosity rubber modified asphalt, wherein the detection results of the selected asphalt in the embodiment are shown in the table 5.

Table 5 shows the results of testing the high viscosity and high viscosity modified asphalt of this example

Determination of the optimum oilstone ratio using the marshall test: and (3) forming 5 groups of Marshall test pieces by taking the estimated new asphalt dosage as a median and 0.5 as an interval, forming the AC-13C type asphalt mixture by taking 4.0, 4.5, 5.0, 5.5 and 6.0 as the total asphalt dosage, carrying out Marshall test on the formed test pieces, respectively measuring the stability MS and the flow value FL of the test pieces, respectively drawing a stability, flow value, void ratio, saturation, density and oilstone ratio relation curve chart according to the Marshall test and the calculation result, and determining the optimal oilstone ratio.

And adding 0.3% of new asphalt dosage as the final new asphalt dosage of the new asphalt mixture of the regeneration mixture on the basis of the optimal asphalt-stone ratio and asphalt dosage determined by a Marshall test, wherein the new asphalt dosage is 2.6 parts by weight.

Fifthly, placing 15 parts by weight of first coarse aggregate and 40 parts by weight of second coarse aggregate in a preheating barrel, wherein the preheating temperature is 120 ℃, the heating temperature of crushed stone and mineral powder is 180 ℃, the heating temperature of new asphalt is 160 ℃, and the heating time is 4 hours.

Sixthly, pouring the preheated RAP material into a stirring pot at 160 ℃, and stirring for 60 s; then adding crushed stone and mixing for 60 s; then adding high-viscosity rubber modified asphalt and mixing for 60 s; and adding mineral powder, and stirring for 60s to finish stirring of the thermal regeneration asphalt mixture.

And seventhly, placing the mixed material after the mixing into a 135 ℃ drying oven for heat preservation for 4 hours to obtain the high-old-material-mixing-amount AC-13C type plant-mixed hot recycled asphalt mixture.

Example 3

This example illustrates a method for preparing an AC-20C reclaimed asphalt mix.

The AC-20C type recycled asphalt mixture of the embodiment comprises the following components in parts by weight: 65 parts of class II first-grade recycled asphalt pavement reclaimed materials; 32 parts by weight of crushed stone; 0.5 part by weight of mineral powder; 2.4 parts of high-viscosity asphalt.

The crushed stone comprises 45% of basalt with the grain size of 10-20 mm, 45% of limestone with the grain size of 5-10 mm and 10% of limestone with the grain size of 0-5 mm; the mineral powder is basalt ground mineral powder.

And fourthly, selecting high-viscosity rubber modified asphalt, wherein the detection result of the selected asphalt in the embodiment is the same as that in the table 5.

Determination of the optimum oilstone ratio using the marshall test: and (3) forming 5 groups of Marshall test pieces by taking the estimated new asphalt dosage as a median and 0.5 as an interval, forming the AC-20C type asphalt mixture by taking 3.5, 4.0, 4.5, 5.0 and 5.5 as the total asphalt dosage, carrying out Marshall test on the formed test pieces, respectively measuring the stability MS and the flow value FL of the test pieces, respectively drawing a relation curve graph of the stability, the flow value, the void ratio, the saturation, the density and the oilstone ratio according to the Marshall test and the calculation result, and determining the optimal oilstone ratio.

And adding 0.3% of new asphalt dosage as the final new asphalt dosage of the new asphalt mixture of the regeneration mixture on the basis of the optimal asphalt-stone ratio and asphalt dosage determined by a Marshall test, wherein the new asphalt dosage is 2.3 parts by weight.

Fifthly, placing 15 parts by weight of first coarse aggregate and 45 parts by weight of second coarse aggregate in a preheating barrel, wherein the preheating temperature is 120 ℃, the heating temperature of crushed stone and mineral powder is 180 ℃, the heating temperature of new asphalt is 160 ℃, and the heating time is 4 hours.

And seventhly, placing the mixed material after the mixing into a 135 ℃ drying oven for heat preservation for 4 hours to obtain the AC-20C type plant-mixed hot recycled asphalt mixture with high old material mixing amount.

Samples of examples 2 and 3 were taken, and the high temperature performance and the low temperature cracking resistance of the samples were tested by rutting test and dynamic creep test at 60 ℃ and the low temperature bending trabecula test at-10 ℃ respectively, and the water damage resistance of the samples was verified by freeze-thaw splitting test and scattering test, and the final results are shown in table 6.

Table 6, example 2 and example 3 high-content hot mix plant recycling asphalt mixture performance indexes

The examples described herein are merely illustrative of the preferred embodiments of the present invention and do not limit the spirit and scope of the present invention, and various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the design concept of the present invention shall fall within the protection scope of the present invention.

Claims

1. A preparation method of a high-mixing-amount plant-mixed hot recycled asphalt mixture is characterized by comprising the following steps:

the RAP material classification basis is as follows: the RAP materials with clear sources, separated storage and detection once per 500 tons of RAP materials in each batch are a type of RAP materials; the RAP materials with unclear sources, stored in bins and detected once per 500 tons of RAP materials in each batch are two types of RAP materials; three types of RAP materials with undefined sources, non-classified storage and non-detection;

grading basis of each RAP material is as follows: the mud content is less than or equal to 1.5 percent below 0.075mm, the asphalt content is more than or equal to 3.5 percent, and the asphalt penetration is more than or equal to 35; the mud content is less than 2.0 percent under the condition that the mud content is less than 1.5 percent and less than 0.075mm, the asphalt content is less than 3.5 percent under the condition that the asphalt penetration is less than 25 and less than 35; the mud content is less than or equal to 2.5 percent and less than or equal to 0.075mm, the asphalt content is less than or equal to 3.0 percent and more than 2.5 percent, the asphalt penetration is less than 25 and more than 15, and the like; the mud content is more than 2.5 percent below 0.075mm, the asphalt content is less than 2.5 percent, the asphalt penetration is less than 15, and the like;

2. The preparation method of the high-mix hot mix plant mix recycled asphalt mixture according to claim 1, wherein the mixing proportion of different types of RAP materials with different grades is as follows:

3. The preparation method of the high-volume plant-mixed hot recycling asphalt mixture according to claim 2, characterized in that the necessary treatment comprises the following treatment steps:

A. heating RAP to 120 ℃ for more than 3 hours;

C. spraying regenerant to RAP material and mixing.

4. The preparation method of the high-volume plant-mixed hot recycling asphalt mixture according to claim 1, characterized by comprising the following steps: and step two, screening the part of the RAP material with the diameter less than 0.3mm before determining the doping amount.

5. The preparation method of the high-content hot mix plant-mixed recycled asphalt mixture according to claim 1, wherein the specific process for preparing the high-content hot mix plant-mixed recycled asphalt mixture in the sixth step is as follows:

6. The preparation method of the high-volume plant-mixed hot recycling asphalt mixture according to claim 5, characterized by comprising the following steps: in S1, the preheating temperature of the RAP material and the crushed stone material is increased along with the increase of the mixing amount of the RAP material, the preheating temperature of the high-viscosity rubber modified asphalt is 160 ℃, the preheating temperature of the mineral powder is 180 ℃, and the preheating time is 4 hours.

7. The preparation method of the high-volume plant-mixed hot recycling asphalt mixture according to claim 5, characterized by comprising the following steps: in S2, the temperature of the stirring pot was 160 ℃, and the next operation was performed after each material was added and mixed for 60 seconds.

8. The preparation method of the high-volume plant-mixed hot recycling asphalt mixture according to claim 5, characterized by comprising the following steps: in S3, the mixed mixture is kept at 135 ℃ for 4 hours.