Precise separation waste asphalt mixture fine material prefabricated building block and preparation method thereof

Abstract

The invention discloses a finely separated waste asphalt mixture fine material prefabricated building block and a preparation method thereof, and belongs to the technical field of road engineering.The preparation method comprises the following steps that an asphalt pavement recycled material is refined through refining equipment, and vibratory screening is performed to obtain an asphalt pavement recycled material fine material; detecting the mass of the aged asphalt in the fine asphalt pavement reclaimed material through a combustion method; placing the fine asphalt pavement recycled material in a drying oven for preheating and heat preservation, after preheating and heat preservation are finished, placing the fine asphalt pavement recycled material in a mixing pot for heating and mixing, and adding a regenerant according to the mass of the aged asphalt for continuous mixing, so as to obtain a regenerated asphalt mixture after preheating and heat preservation are finished; and loading the regenerated asphalt mixture into a mold, loading and molding to obtain the finely separated waste asphalt mixture fine material prefabricated building block. According to the invention, full utilization and high-value recovery of the fine aggregate of the recycled asphalt mixture can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of road engineering and relates to a prefabricated building block for fine material of accurately separated waste asphalt mixture and a preparation method thereof. Background Art

[0002] Since the 21st century, China's highway infrastructure construction has been promoted at an unprecedented speed and scale. By the end of 2023, the total mileage of highways has reached more than 5.4 million kilometers. Since the design life of medium and high-grade asphalt pavements in my country is generally 12 to 15 years, a large part of the asphalt pavements built in the early stage have approached or reached their service life. In addition, under the combined effects of heavy loads, overloads and environmental factors, the pavement often suffers from many diseases before reaching its service life, seriously affecting its performance and driving safety. At present, a considerable number of asphalt pavements in China are facing large-scale maintenance and repair or even reconstruction. It is estimated that the large and medium-sized repair projects of trunk roads in my country alone can generate nearly 100 million tons of recycled asphalt pavement (RAP) each year.

[0003] The road asphalt and stone contained in RAP are both non-renewable and valuable resources with high recycling value. The refined sorting process of recycled asphalt mixture can effectively reduce the variability of RAP and improve the performance of recycled asphalt mixture. However, the fine aggregate in RAP after fine separation is large, and the surface of the fine aggregate is covered with a layer of aged asphalt. This aged asphalt not only affects the adhesion between the fine aggregate and the new asphalt, but also may cause the mixture to soften at high temperatures and crack at low temperatures. At present, recycling is achieved by adding new binders (new asphalt) to RAP, but when the RAP coarse material is completely consumed, a large amount of fine material remains unused, and the recovery rate is only about 30%.

[0004] Due to the high asphalt content and fine gradation, disposal and application have become technical challenges for RAP recycling, especially RAP fines with a particle size of less than 5 mm, in which the content of aged asphalt is several times that of coarse materials. Based on the properties of RAP fines, high-value comprehensive utilization of RAP in the field of road engineering is an urgent problem to be solved in the current road engineering field. Summary of the invention

[0005] To achieve the above purpose, the present invention provides a prefabricated building block for fine material of waste asphalt mixture separated precisely and a preparation method thereof, which solves the problem that the existing asphalt mixture recycled material has a large output of fine aggregate, resulting in a single utilization method and low comprehensive utilization efficiency.

[0006] The technical solution adopted by the present invention is a method for preparing prefabricated building blocks by finely separating waste asphalt mixture, comprising the following steps:

[0007] S1. Processing the asphalt pavement recycled material through a fine processing device, and performing vibration screening to obtain asphalt pavement recycled material fine material;

[0008] S2. Testing the quality of aged asphalt in the fine material of asphalt pavement recycling material by combustion method;

[0009] S3, placing the fine material of the recycled asphalt pavement in an oven for preheating and heat preservation, and after the preheating and heat preservation are completed, placing the fine material of the recycled asphalt pavement in a mixing pot for heating and mixing, and adding a regeneration agent according to the quality of the aged asphalt to continue mixing, and obtaining a regenerated asphalt mixture after the end;

[0010] S4, loading the recycled asphalt mixture into a mold for loading and molding, and obtaining a prefabricated building block of fine material of the finely separated waste asphalt mixture.

[0011] Furthermore, in step S1, the vibration frequency is 40-50 Hz, and the particle size of the fine material of the asphalt pavement recycling material is within 5 mm.

[0012] Furthermore, in step S3, the preheating and heat preservation is to place the fine asphalt pavement recycled material in an oven, heat it to 110-150° C., and then keep it warm for 1.5-2 hours.

[0013] Furthermore, in step S3, the heating mixing is to place the fine material of the asphalt pavement recycled material in a mixing pot and mix it at a temperature of 160 to 180° C. for 60 to 90 seconds, and continue mixing for 60 to 90 seconds after adding the regeneration agent.

[0014] Furthermore, in step S3, the regeneration agent includes component A and component B, wherein component A includes kerosene and waste cooking oil mixed in any proportion, and component B includes modified fatty amine curing agent and styrene-butadiene-styrene block copolymer mixed in any proportion.

[0015] Furthermore, in step S3, the regeneration agent is 4% to 10% of the mass of the aged asphalt.

[0016] Furthermore, in step S4, the loading molding includes any one of compaction method, vibration compaction molding method and static pressure molding method.

[0017] Furthermore, in step S3, the mass ratio of component A to component B is 2.0-2.5:0.3-0.6.

[0018] Furthermore, step S4 further includes:

[0019] If the compaction method is used, compact both sides 50 to 75 times;

[0020] If the vibration compaction molding method is adopted, the vibration force is controlled to be 5.0kN~6.0kN, and the vibration frequency is 45Hz~65Hz;

[0021] If the static pressure forming method is adopted, the static pressure load is 30-40 kN, which is maintained for 3-4 minutes before unloading.

[0022] Another technical solution adopted by the present invention is a prefabricated building block of fine material of waste asphalt mixture separated accurately. The prefabricated building block of fine material of waste asphalt mixture separated accurately is prepared by the above-mentioned preparation method.

[0023] The beneficial effects of the present invention are:

[0024] (1) The present invention uses a regeneration agent to form a good solvation layer around the asphalt particles, increase the content of the supplementary solvent component, improve the stability of the asphalt colloidal system, refine and disperse the wax crystal particles, and improve the plasticity and deformation resistance of the asphalt, thereby reversing its properties and activating the aged asphalt in the finely separated RAP. Without adding any new binder, the RAP fine material can be fully recycled. The regeneration agent can also increase the light component to adjust the ratio of the asphalt discrete phase to the continuous phase, reduce the aged asphalt clusters, improve the dispersibility of the discrete phase, increase the molecular fluidity, improve the viscosity, brittleness and ductility of the regenerated asphalt, and improve the comprehensive performance of the material.

[0025] (2) The present invention provides a prefabricated block made of finely separated waste asphalt mixture. The existing cement concrete blocks need to be cured after molding, and the requirements for the curing environment and conditions are relatively high. The curing period of the whole process under various curing conditions is generally greater than 7 days (it is recommended to ensure more than 28 days) to ensure strength. The asphalt mixture has a short molding time and the strength is formed quickly. Generally, the strength can be formed within 24 hours after molding in an ordinary environment. In the same time, the production efficiency of the present invention is higher. At the same time, during the installation process, cement concrete blocks need to reserve expansion joints for relative movement. Due to the elasticity and deformation capacity of asphalt itself, the present invention can be directly laid without expansion joints, which simplifies the construction steps. Compared with existing highway cement blocks, the recycled asphalt mixture prefabricated parts used in the present invention have a simple molding process, high production efficiency, fast and convenient installation, and low difficulty in later maintenance.

[0026] (3) Compared with existing highway cement blocks, the present invention applies mechanical impact loads to compact the material, and repeated impacts rearrange and compact the fine materials, thereby improving the density of the prefabricated blocks and greatly improving their mechanical properties. At the same time, the incorporation of bio-based regeneration agents in the present invention is conducive to improving the adhesion of old asphalt in the fine materials, thereby improving its durability and stability under natural conditions, and having excellent resistance to water damage and salt erosion.

[0027] (4) The prefabricated blocks with finely separated waste asphalt mixtures proposed in the present invention improve the disease problems of traditional cement blocks. After being subjected to the freeze-thaw effect of the surrounding environment, traditional cement blocks will suffer from diseases such as exposure, breakage and powdering. At the same time, the erosion of deicing salt and snow-melting agents in winter will accelerate the development of cement block diseases. The mass loss rate of the regenerated asphalt mixture of the present invention under the same freeze-thaw cycle conditions is about one-tenth of that of cement materials, indicating that it has excellent resistance to water damage compared to cement blocks. At the same time, since the main components of asphalt are organic compounds such as asphaltene, aromatic hydrocarbons and aliphatic compounds, these components have low solubility and are not easy to react chemically with water and salt. In addition, the structure of asphalt is compact and can effectively prevent the penetration of water and salt, thereby reducing the direct corrosion of salt to the substrate, which can effectively improve the disease problems of traditional cement blocks. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is a comparison chart of the mass loss of the prefabricated building blocks of fine material of refined separation of waste asphalt mixture proposed by the present invention and traditional cement concrete during freeze-thaw cycles.

[0030] Figure 2 This is a comparison chart of the mass loss of the prefabricated building blocks of fine material of refined separation of waste asphalt mixture proposed by the present invention and traditional cement concrete in the salt-freezing cycle. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The present invention provides a method for preparing a prefabricated building block by finely separating waste asphalt mixture, comprising the following steps:

[0033] S1. Recycled asphalt pavement material (RAP) is refined by fine processing equipment, and vibrated and sieved to obtain recycled asphalt pavement material fine material with a particle size of less than 5 mm, and the vibration frequency is 40 to 50 Hz;

[0034] S2. Testing the quality of aged asphalt in the fine material of asphalt pavement recycling material by combustion method;

[0035] S3, placing the fine material of the recycled asphalt pavement in an oven for preheating and heat preservation at 110-150°C for 1.5-2h, after the preheating and heat preservation, placing the fine material of the recycled asphalt pavement in a mixing pot for heating and mixing at 160-180°C for 60s-90s, adding a regeneration agent according to 4%-10% of the mass of the aged asphalt and continuing to mix for 60s-90s, and obtaining a recycled asphalt mixture after the end;

[0036] The regeneration agent includes component A and component B, wherein component A is a light oil, including kerosene and waste cooking oil mixed in any proportion, and component B includes a modified fatty amine curing agent and styrene-butadiene-styrene block copolymer (SBS) mixed in any proportion, and the mass ratio of component A to component B is 2.0-2.5:0.3-0.6; the modified fatty amine curing agent is prepared by addition reaction of diethylenetriamine and butyl glycidyl ether, and its structural formula is

[0037] S4, loading the recycled asphalt mixture into a mold for loading and molding, and obtaining a prefabricated building block of fine material of the finely separated waste asphalt mixture.

[0038] Loading molding methods include: compaction method, vibration compaction molding method, and static pressure molding method, which can achieve material density.

[0039] If the compaction method is used, compact both sides 50 to 75 times;

[0040] If the vibration compaction molding method is adopted, the vibration force is controlled to be 5.0kN~6.0kN, and the vibration frequency is 45Hz~65Hz;

[0041] If the static pressure forming method is adopted, the static pressure load is 30-40 kN, which is maintained for 3-4 minutes before unloading.

[0042] The refinement treatment of the present invention specifically utilizes the mutual striking, shearing and grinding series of actions between the internal components of the refinement equipment and the RAP to refine the RAP with the milling material and separate the asphalt from the surface of the RAP with larger particle size.

[0043] In the rejuvenating agent of the present invention, component A can supplement the light components of aged asphalt to activate the aged asphalt; the modified fatty amine curing agent in component B can undergo a curing reaction with the resin in the aged asphalt at room temperature, react with the resin and SBS to generate a three-dimensional network molecular structure, strengthen the interface effect, and further increase the viscosity of the asphalt mixture, thereby improving the bonding performance; and the ends of the SBS molecules are mainly chain hydrocarbon groups or single benzene ring structures, which can ensure that the ends thereof invade into the interior of the asphalt in a short time, thereby playing a reinforcing and restraining role.

[0044] Example 1

[0045] S1. Process the RAP through fine processing equipment and perform vibration screening to obtain asphalt pavement recycled material fine material with a particle size of less than 5 mm, with a vibration frequency of 40 Hz;

[0046] S2. Testing the quality of aged asphalt in the fine material of asphalt pavement recycling material by combustion method;

[0047] S3, placing the fine material of the recycled asphalt pavement in an oven for preheating at 120°C for 2 hours. After the preheating and insulation, placing the fine material of the recycled asphalt pavement in a mixing pot for heating and mixing at 175°C for 90 seconds, adding a regeneration agent according to 4% of the mass of the aged asphalt and continuing to mix for 90 seconds, and obtaining a recycled asphalt mixture after the end;

[0048] The regeneration agent includes component A and component B in a mass ratio of 2.2:0.5, component A includes kerosene and waste cooking oil in a mass ratio of 1.2:1, and component B includes a curing agent and SBS polymer in a mass ratio of 1.4:1;

[0049] S4. The recycled asphalt mixture obtained in S3 is placed into a mold and a test piece is formed by compaction method, with both sides compacted 75 times.

[0050] Example 2

[0051] S1. Process the RAP through fine processing equipment and perform vibration screening to obtain asphalt pavement recycled material fine material with a particle size of less than 5 mm, with a vibration frequency of 45 Hz;

[0052] S2. Testing the quality of aged asphalt in the fine material of asphalt pavement recycling material by combustion method;

[0053] S3, placing the fine material of the recycled asphalt pavement in an oven for preheating at 120°C for 2 hours. After the preheating and insulation, placing the fine material of the recycled asphalt pavement in a mixing pot for heating and mixing at 175°C for 90 seconds, adding a regeneration agent according to 8% of the mass of the aged asphalt and continuing to mix for 90 seconds, and obtaining a recycled asphalt mixture after the end;

[0054] The regeneration agent includes component A and component B in a mass ratio of 2.2:0.5, component A includes kerosene and waste cooking oil in a mass ratio of 1.2:1, and component B includes a curing agent and SBS polymer in a mass ratio of 1.4:1;

[0055] S4. The recycled asphalt mixture obtained in S3 is placed into a mold and a test piece is formed by compaction method, with both sides compacted 75 times.

[0056] Example 3

[0057] S1. Process the RAP through fine processing equipment and perform vibration screening to obtain asphalt pavement recycled material fine material with a particle size of less than 5 mm, with a vibration frequency of 50 Hz;

[0058] S2. Testing the quality of aged asphalt in the fine material of asphalt pavement recycling material by combustion method;

[0059] S3, placing the fine material of the recycled asphalt pavement in an oven for preheating at 135°C for 2 hours. After the preheating and insulation, placing the fine material of the recycled asphalt pavement in a mixing pot for heating and mixing at 175°C for 90 seconds, adding a regeneration agent according to 4% of the mass of the aged asphalt and continuing to mix for 90 seconds, and obtaining a recycled asphalt mixture after the end;

[0060] The regeneration agent includes component A and component B in a mass ratio of 2.3:0.4, component A includes kerosene and waste cooking oil in a mass ratio of 1.2:1, and component B includes a curing agent and SBS polymer in a mass ratio of 1.4:1;

[0061] S4. The recycled asphalt mixture obtained in S3 is placed into a mold and a test piece is formed by compaction method, with both sides compacted 75 times.

[0062] Example 4

[0063] S1. Process the RAP through fine processing equipment and perform vibration screening to obtain asphalt pavement recycled material fine material with a particle size of less than 5 mm, with a vibration frequency of 45 Hz;

[0064] S2. Testing the quality of aged asphalt in the fine material of asphalt pavement recycling material by combustion method;

[0065] S3, placing the fine material of the recycled asphalt pavement in an oven for preheating at 150°C for 2 hours. After the preheating and insulation, placing the fine material of the recycled asphalt pavement in a mixing pot for heating and mixing at 175°C for 90 seconds, adding a regeneration agent according to 4% of the mass of the aged asphalt and continuing to mix for 90 seconds, and obtaining a recycled asphalt mixture after the end;

[0066] The regeneration agent includes component A and component B in a mass ratio of 2.3:0.4, component A includes kerosene and waste cooking oil in a mass ratio of 1.2:1, and component B includes a curing agent and SBS polymer in a mass ratio of 1.4:1;

[0067] S4. The recycled asphalt mixture obtained in S3 is placed into a mold and a test piece is formed by compaction method, with both sides compacted 75 times.

[0068] Example 5

[0069] S1. Process the RAP through fine processing equipment and perform vibration screening to obtain asphalt pavement recycled material fine material with a particle size of less than 5 mm, with a vibration frequency of 50 Hz;

[0070] S2. Testing the quality of aged asphalt in the fine material of asphalt pavement recycling material by combustion method;

[0071] S3, placing the fine material of the recycled asphalt pavement in an oven for preheating at 130°C for 2 hours. After the preheating and insulation, placing the fine material of the recycled asphalt pavement in a mixing pot for heating and mixing at 180°C for 90 seconds, adding a regeneration agent according to 7% of the mass of the aged asphalt and continuing to mix for 90 seconds, and obtaining a recycled asphalt mixture after the end;

[0072] The regeneration agent includes component A and component B in a mass ratio of 2.3:0.4, component A includes kerosene and waste cooking oil in a mass ratio of 1.2:1, and component B includes a curing agent and SBS polymer in a mass ratio of 1.4:1;

[0073] S4. The recycled asphalt mixture obtained in S3 is placed into a mold and a test piece is formed by compaction method, with both sides compacted 75 times.

[0074] Example 6

[0075] The difference from Example 5 is:

[0076] In S3, the fine material of the recycled asphalt pavement is placed in an oven at 110°C for preheating and insulation; the fine material of the recycled asphalt pavement is placed in a mixing pot at 160°C for heating and mixing for 75 seconds; a regeneration agent is added according to 4% of the mass of the aged asphalt; the mass ratio of component A to component B is 2.0:0.6; and stirring is continued for 75 seconds after the addition of the regeneration agent.

[0077] In S4, the double-sided compaction is performed 50 times. The remaining steps are the same as those in Example 5.

[0078] Example 7

[0079] The difference from Example 5 is:

[0080] The fine material of the recycled asphalt pavement is placed in an oven at 150°C for preheating and heat preservation for 1.5 hours; the fine material of the recycled asphalt pavement is placed in a mixing pot for heating and mixing for 60 seconds; a regeneration agent is added according to 10% of the mass of the aged asphalt; the mass ratio of component A to component B is 2.5:0.3; stirring is continued for 60 seconds after the regeneration agent is added. The remaining steps are the same as those in Example 5.

[0081] Example 8

[0082] The difference from Example 5 is:

[0083] In S4, a vibration compaction molding method is used, and the vibration force is controlled to be 5.0 kN and the vibration frequency is 45 Hz. The remaining steps are the same as those in Example 5.

[0084] Example 9

[0085] The difference from Example 5 is:

[0086] In S4, a vibration compaction molding method is used, and the vibration force is controlled to be 6.0 kN and the vibration frequency is 65 Hz. The remaining steps are the same as those in Example 5.

[0087] Example 10

[0088] The difference from Example 5 is:

[0089] In S4, static pressure molding is adopted, the load is 30 kN, and the load is maintained for 3 minutes before unloading. The remaining steps are the same as those in Example 5.

[0090] Embodiment 11

[0091] The difference from Example 5 is:

[0092] In S4, static pressure molding is adopted, the load is 40 kN, and the load is maintained for 4 minutes before unloading. The remaining steps are the same as those in Example 5.

[0093] Comparative Example 1

[0094] The difference from Example 1 is:

[0095] In S3, no regeneration agent is added, and the fine material of the asphalt pavement recycled material is placed in a mixing pot and heated and stirred for 180 seconds. The remaining steps are the same as in Example 1.

[0096] Comparative Example 2

[0097] The difference from Example 4 is:

[0098] In S3, no regeneration agent is added, and the fine material of the asphalt pavement recycled material is placed in a mixing pot and heated and stirred for 180 seconds. The remaining steps are the same as those in Example 4.

[0099] Comparative Example 3

[0100] The difference from Example 5 is:

[0101] In S3, the fine asphalt pavement recycled material is placed in an oven and preheated at 100° C. The remaining steps are the same as in Example 5.

[0102] Comparative Example 4

[0103] The difference from Example 5 is:

[0104] In S3, the fine asphalt pavement recycled material is placed in an oven and preheated at 165° C. The remaining steps are the same as in Example 5.

[0105] Comparative Example 5

[0106] The difference from Example 5 is:

[0107] In S3, the fine material of the recycled asphalt pavement is placed in an oven for preheating and heat preservation for 1 hour. The remaining steps are the same as those in Example 5.

[0108] Comparative Example 6

[0109] The difference from Example 5 is:

[0110] In S3, the fine material of the asphalt pavement recycling material is placed in an oven for preheating and heat preservation for 4 hours. The remaining steps are the same as those in Example 5.

[0111] Comparative Example 7

[0112] The difference from Example 5 is:

[0113] In S3, the fine material of the asphalt pavement recycling material is placed in a mixing pot and heated and mixed at 150° C. The remaining steps are the same as those in Example 5.

[0114] Comparative Example 8

[0115] The difference from Example 5 is:

[0116] In S3, the fine material of the asphalt pavement recycling material is placed in a mixing pot and heated and mixed at 190° C. The remaining steps are the same as those in Example 5.

[0117] Comparative Example 9

[0118] The difference from Example 5 is:

[0119] In S3, the fine material of the asphalt pavement recycling material is placed in a mixing pot and heated and mixed for 50 seconds. The remaining steps are the same as those in Example 5.

[0120] Comparative Example 10

[0121] The difference from Example 5 is:

[0122] In S3, a regeneration agent is added according to 2% of the mass of the aged asphalt. The remaining steps are the same as in Example 5.

[0123] Comparative Example 11

[0124] The difference from Example 5 is:

[0125] In S3, a regeneration agent is added according to 15% of the mass of the aged asphalt. The remaining steps are the same as those in Example 5.

[0126] Comparative Example 12

[0127] The difference from Example 5 is:

[0128] In S3, the mass ratio of component A to component B in the regeneration agent is 2:1. The remaining steps are the same as in Example 5.

[0129] Comparative Example 13

[0130] The difference from Example 5 is:

[0131] In S3, the mass ratio of component A to component B in the regeneration agent is 3:0.2. The remaining steps are the same as in Example 5.

[0132] The performance test of the prefabricated building blocks based on waste asphalt mixture fine material prepared in the embodiment of the present invention and the comparative example is carried out, and the performance test data are shown in Table 1:

[0133] Table 1 Performance test data

[0134]

[0135]

[0136] According to Table 1, no regeneration agent was added to Comparative Examples 1 and 2, resulting in seriously insufficient activation of the aged asphalt in the RAP fine material, insufficient bonding strength between the aggregates of the prepared prefabricated blocks, lower density of the compacted mixture, poor adhesion, relatively small freeze-thaw splitting residual strength and large mass loss due to scattering, making it easier to fall off and drop particles in actual use, and having a large porosity, which is easily eroded by water and salt penetration.

[0137] Comparative Examples 3, 5 and 7 have low preheating and mixing temperatures and insufficient insulation time, so the softening effect on the aged asphalt in RAP is not good enough, which affects the fusion between the regeneration agent and the aged asphalt, thereby reducing the activation degree of the aged asphalt and the performance of the formed blocks is poor; on the contrary, Comparative Examples 4, 6 and 8 have high preheating and mixing temperatures and long insulation time, which will cause secondary aging of the asphalt components, reduce its performance, and further cause performance degradation of the recycled asphalt mixture.

[0138] The mixing time of Comparative Example 9 is too short, resulting in uneven contact between the regeneration agent and the surface of the RAP material and insufficient temperature transfer time, which deteriorates the regeneration effect and makes the performance of the regenerated asphalt mixture unsatisfactory.

[0139] The difference in material properties between Comparative Examples 10 and 11 is mainly caused by the amount of regeneration agent used. In Comparative Example 10, the amount of regeneration agent added is too small, which is insufficient to achieve the ideal activation effect of aged asphalt. In Comparative Example 11, the amount of regeneration agent added is too large, which will cause the asphalt to be over-softened and even reduce the necessary adhesion, making the combination between the mixture particles loose, thereby affecting the density of the mixture and further reducing its durability and ability to resist water damage.

[0140] The main reason for the problems in Examples 12 and 13 is that the composition ratio of the regeneration agent is not scientific enough, which reduces the diffusion and viscosity-increasing effects of the regeneration agent and the activation efficiency for the aged asphalt is insufficient, thus resulting in poor performance improvement of the regenerated asphalt mixture.

[0141] like Figure 1 , Figure 2 As shown, the asphalt mixture precast blocks prepared using Example 5 of the present invention and the existing cement concrete precast blocks were subjected to freeze-thaw cycle tests and salt-freeze cycle tests respectively. It can be seen that the mass loss rate of the recycled asphalt mixture under the same freeze-thaw cycle conditions is about one-tenth of the cement material, indicating that its resistance to water damage and salt erosion is significantly improved.

[0142] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A method for preparing prefabricated building blocks by finely separating waste asphalt mixture fine materials, characterized in that: The following steps are involved: S1. Processing the asphalt pavement recycled material through a fine processing device, and performing vibration screening to obtain asphalt pavement recycled material fine material; S2. Testing the quality of aged asphalt in the fine material of asphalt pavement recycling material by combustion method; S3, placing the fine material of the recycled asphalt pavement in an oven for preheating and heat preservation, and after the preheating and heat preservation are completed, placing the fine material of the recycled asphalt pavement in a mixing pot for heating and mixing, and adding a regeneration agent according to the quality of the aged asphalt to continue mixing, and obtaining a regenerated asphalt mixture after the end; S4, loading the recycled asphalt mixture into a mold for loading and molding, and obtaining a prefabricated building block of fine material of the finely separated waste asphalt mixture.

2. The method for preparing a prefabricated building block by finely separating waste asphalt mixture according to claim 1, characterized in that: In step S1, the vibration frequency is 40-50 Hz, and the particle size of the fine material of the asphalt pavement recycling material is within 5 mm.

3. The method for preparing a prefabricated building block by finely separating waste asphalt mixture according to claim 1, characterized in that: In step S3, the preheating and heat preservation is to place the fine asphalt pavement recycled material in an oven, heat it to 110-150° C., and then keep it warm for 1.5-2 hours.

4. The method for preparing a prefabricated building block by finely separating waste asphalt mixture according to claim 1, characterized in that: In step S3, the heating mixing is to place the fine material of the asphalt pavement recycled material in a mixing pot and mix it at a temperature of 160 to 180° C. for 60 to 90 seconds, and continue mixing for 60 to 90 seconds after adding the regeneration agent.

5. The method for preparing prefabricated building blocks by finely separating waste asphalt mixture according to claim 1, characterized in that: In step S3, the regeneration agent includes component A and component B, wherein component A includes kerosene and waste cooking oil mixed in any proportion, and component B includes modified fatty amine curing agent and styrene-butadiene-styrene block copolymer mixed in any proportion.

6. The method for preparing prefabricated building blocks by finely separating waste asphalt mixture according to claim 1, characterized in that: In step S3, the regeneration agent is 4% to 10% of the mass of the aged asphalt.

7. The method for preparing prefabricated building blocks by finely separating waste asphalt mixture according to claim 1, characterized in that: In step S4, the loading molding includes any one of compaction method, vibration compaction molding method and static pressure molding method.

8. The method for preparing prefabricated building blocks by finely separating waste asphalt mixture according to claim 5, characterized in that: In step S3, the mass ratio of component A to component B is 2.0-2.5:0.3-0.

6.

9. The method for preparing prefabricated building blocks by finely separating waste asphalt mixture according to claim 7, characterized in that: Step S4 also includes: If the compaction method is used, compact both sides 50 to 75 times; If the vibration compaction molding method is adopted, the vibration force is controlled to be 5.0kN~6.0kN, and the vibration frequency is 45Hz~65Hz; If the static pressure forming method is adopted, the static pressure load is 30-40 kN, which is maintained for 3-4 minutes before unloading.

10. A prefabricated building block for fine separation of waste asphalt mixture, characterized in that: The prefabricated building blocks of fine material from finely separated waste asphalt mixture are prepared by the preparation method according to any one of claims 1 to 9.

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