Low-carbon high-modulus asphalt modifier, modified asphalt and preparation method of low-carbon high-modulus asphalt modifier

Abstract

The invention discloses a low-carbon high-modulus asphalt modifier, modified asphalt and a preparation method thereof, and relates to the technical field of preparation of asphalt for road engineering. The low-carbon high-modulus asphalt modifier is prepared by taking a waste toothpaste packaging material as a raw material, and comprises the following main components in percentage by weight: 70-73.75% of RPE (Resin Polyethylene) and 25-28.75% of aluminum. The modified asphalt is prepared by modifying matrix asphalt by using a low-carbon high-modulus asphalt modifier with the addition amount of 5-15wt%. The low-carbon high-modulus asphalt modifier disclosed by the invention can effectively improve the high-temperature stability and creep resistance of common petroleum asphalt, so that a green, high-performance and sustainable asphalt binder is prepared. The waste toothpaste packaging material is used as a raw material to prepare the asphalt modifier, so that the environmental problems of white pollution and the like caused by incineration and accumulation of waste toothpaste shells can be solved, harmless and resource utilization of the waste toothpaste packaging material is realized, the cost of the modified asphalt can be reduced, and double benefits of environment and economy are realized.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt materials for road engineering, and in particular to a low-carbon high-modulus asphalt modifier and modified asphalt and a preparation method thereof. Background Art

[0002] Affected by high traffic loads and extreme climate, asphalt pavement is prone to cracking and rutting. According to statistics, more than 70% of highways need major or medium repairs after about 10 years of service, resulting in huge consumption of unsustainable resources. Therefore, the development of green, durable, and high-toughness pavement materials has become a key path for the sustainable development of highways.

[0003] At the same time, with the development of social economy and the progress of industrialization, a large number of plastic products are produced and used every year. Take dental care products as an example: toothpaste, dental film, dental floss and other products have sprung up like mushrooms after rain. Although these plastic products have brought great convenience to people's lives, their improper recycling and treatment have also caused serious "white pollution". The recycling of plastic products is mainly divided into two categories: energy recovery and material recovery. Among them, the energy recovery process is simple and provides heat energy through incineration, but a large amount of toxic and harmful gases and particulate matter will be produced during the incineration process, and a large amount of carbon dioxide will be emitted. Material recovery is divided into physical recovery and chemical recovery, but most waste plastic products can no longer be used for food grade, because food grade plastic recovery has strict requirements on the appearance and color of waste plastics, and generally requires pure color waste plastics.

[0004] Waste plastic products not only pollute the environment, but also occupy a large amount of land, and road construction has a strong capacity to absorb these wastes. For example, Chinese patent document CN102337035A provides a solution for asphalt modification of waste plastics, specifically disclosing a waste plastic modified asphalt and a preparation method. The waste plastic modified asphalt is made of a mixture of matrix asphalt, waste plastics, compatibility aids and inorganic fillers. Based on 100 parts by weight of the matrix asphalt, the waste plastics are 4 to 12 parts by weight, the compatibility aids are 2 to 5 parts by weight, and the inorganic fillers are 2 to 20 parts by weight. The technical solution points out that waste low-density polyethylene and waste polypropylene are not compatible with matrix asphalt, and it is necessary to add additional inorganic substances such as talcum powder and carbon black to balance the density of waste low-density polyethylene and waste polypropylene with matrix asphalt, thereby improving compatibility, but it is necessary to add additional additives such as talcum powder, carbon black, compatibility agents, etc., which increases the cost, and the acceptability of the physical project is low.

[0005] Chinese patent document CN112266522A also discloses a scheme for using waste plastics for asphalt modification, specifically disclosing a direct-cast waste plastic asphalt modifier, whose raw materials include the following components by mass: 49-69 parts of LDPE recycled material; 30-50 parts of high-fluidity low-density polyethylene; 1 part of antioxidant. The modifier can be directly added to the asphalt mixture and mixed with the mixture. Under the high-temperature shear dispersion of the mixture, it quickly melts in the matrix asphalt to achieve micron-level dispersion, thereby solving the storage stability problem of wet-process waste plastic modified asphalt based on LDPE and improving the high-temperature rutting resistance of asphalt mixture. This scheme mainly solves the storage stability problem of existing wet-process waste plastic modified asphalt by directly modifying waste plastics, but the dry direct-cast process is difficult to give full play to the modification effect of the waste plastic modifier due to the short mixing time of the waste plastic modifier and asphalt, resulting in poor overall performance of the asphalt mixture.

[0006] The main components of toothpaste packaging shells are polyethylene plastic (abbreviated as PE) and metal aluminum, but there is no related literature report on the use of toothpaste packaging materials for asphalt modification in the prior art. The technical solutions disclosed in the above-mentioned prior art documents CN102337035A and CN112266522A cannot provide feasibility guidance for the use of toothpaste packaging materials for asphalt modification. The present invention intends to provide a method for preparing modified asphalt using toothpaste packaging materials as the main modifier to achieve harmless and resourceful utilization of toothpaste packaging materials. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a low-carbon high-modulus asphalt modifier and modified asphalt and a preparation method thereof. The present invention uses waste toothpaste packaging materials (i.e. waste toothpaste packaging shells) as raw materials to prepare a low-carbon high-modulus asphalt modifier, which is used for asphalt modification and can effectively improve the high-temperature stability and creep resistance of ordinary petroleum asphalt.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a low-carbon high-modulus asphalt modifier, which is prepared using waste toothpaste packaging materials as raw materials, and its main components are 70-73.75% RPE (i.e., waste polyethylene recovered from toothpaste packaging materials) and 25-28.75% aluminum.

[0010] Furthermore, the particle size of the asphalt modifier is ≤220 mesh.

[0011] In a second aspect, the present invention provides a method for preparing the above-mentioned low-carbon and high-modulus asphalt modifier, wherein the preparation method specifically comprises washing the recycled waste toothpaste packaging materials to remove surface stains and drying them; then crushing, grinding, and sieving them to obtain a low-carbon and high-modulus asphalt modifier with a preset particle size.

[0012] Furthermore, in the method, the flushing time of the waste toothpaste packaging material is generally 2 hours to 6 hours.

[0013] Furthermore, in the method, the drying conditions of the waste toothpaste packaging materials are: drying at 75°C to 90°C for 2h to 4h.

[0014] Furthermore, in the method, the dried toothpaste packaging material is crushed by a turbine pulverizer, and then sieved after grinding to obtain a low-carbon high-modulus asphalt modifier with a particle size of ≤220 mesh. Because the traditional impact pulverizer cannot effectively crush the aluminum film in the waste toothpaste packaging material, the present invention uses a turbine pulverizer.

[0015] In a third aspect, the present invention provides a modified asphalt, which is obtained by modifying base asphalt with the above-mentioned low-carbon high modulus asphalt modifier or the low-carbon high modulus asphalt modifier obtained by the above-mentioned method, and the addition amount of the low-carbon high modulus asphalt modifier is 5~15wt% of the base asphalt.

[0016] In a fourth aspect, the present invention further provides a method for preparing modified asphalt, comprising the following steps:

[0017] S1. Preparing a low-carbon high-modulus asphalt modifier: preparing a low-carbon high-modulus asphalt modifier by the preparation method according to any one of claims 3 to 5;

[0018] S2, heat and melt the base asphalt, then add 5-15wt% of the low-carbon high-modulus asphalt modifier prepared by S1, control the temperature at 165-180°C, and stir preliminarily;

[0019] S3. After preliminary stirring, the mixed material is subjected to high-speed shearing for 45-60 minutes, and the temperature is controlled at 165-180°C;

[0020] S4. Further high-speed dispersion stirring is performed at a rate of 400-500 rad / min to obtain.

[0021] In the method of the present invention, the low-carbon high-modulus asphalt modifier is initially dispersed in the matrix asphalt by preliminary stirring, and the preliminary stirring adopts low-speed stirring, such as manual stirring. The preliminary stirring can avoid the separation and stratification of the components of the modifier and the matrix asphalt in the next high-speed shearing process due to the different densities of the modifier and the matrix asphalt, which weakens the shearing effect. Further high-speed shearing can further grind the low-carbon high-modulus asphalt modifier, and the high-speed shearing process is generally carried out using a high-speed shearing instrument. Further high-speed stirring can make the asphalt modifier after high-speed shearing grinding further dispersed in the matrix asphalt, and the high-speed stirring and dispersing process is generally carried out in a high-speed agitator.

[0022] Furthermore, in step S2, the base asphalt is heated at 130-140° C. for 30-35 minutes to melt it.

[0023] Furthermore, in step S2, the initial stirring time is 10 to 20 minutes.

[0024] Furthermore, the high-speed shear rate in step S3 is 4500-5000 r / min.

[0025] Furthermore, in step S4, the time of high-speed dispersing and stirring is controlled within 25-30 minutes, and the temperature is controlled within 175-180°C.

[0026] The present invention has the following beneficial effects:

[0027] 1. The present invention provides a low-carbon, high-modulus asphalt modifier made from waste toothpaste packaging materials, which is used to modify ordinary petroleum asphalt. The needle penetration of the modified asphalt is lower than that before modification; the softening point can be greatly improved; and the 60°C dynamic viscosity is also greatly improved. This shows that the low-carbon, high-modulus asphalt modifier provided by the present invention can effectively improve the high-temperature stability and creep resistance of ordinary petroleum asphalt, thereby producing a green, high-performance, and sustainable asphalt binder. At the same time, the preparation of asphalt modifiers using waste toothpaste packaging materials as raw materials can solve the environmental problems caused by the "white pollution" caused by the incineration and accumulation of waste toothpaste shells; it can achieve the harmless and resourceful utilization of waste toothpaste packaging materials, and at the same time reduce the cost of modified asphalt, achieving both environmental and economic benefits.

[0028] 2. The low-carbon high-modulus asphalt modifier prepared from waste toothpaste packaging materials of the present invention mainly comprises RPE and aluminum film. RPE exists in the form of a polymer chain in the high-molecular polymer matrix asphalt, which provides the possibility for the formation of the RPE network structure and its adsorption of light components in the matrix asphalt. The adsorption reduces the relative content of free light components in the modified asphalt, thereby improving the high-temperature performance of the asphalt. At the same time, a small amount of extremely small-particle aluminum powder in the high-modulus asphalt modifier made from waste toothpaste shells reacts with acidic substances such as asphalt acid and asphalt anhydride in asphalt to form organic aluminum salts, which play a nucleation role on RPE and promote the crystallization of RPE in the matrix asphalt. After crystallization, the crystallite size and long period of RPE molecules become smaller, and the specific surface area increases, making the contact with the matrix asphalt more complete, which improves the high-temperature performance of the modified asphalt; secondly, aluminum powder that appears as inorganic matter exists as a filler in the modified asphalt, which can improve the density difference between RPE and the matrix asphalt and stabilize the interface between RPE and asphalt, thereby reducing the droplet size of RPE and increasing the viscosity of the asphalt phase. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The rutting factor variation curves of the modified asphalt or asphalt of each embodiment and comparative example of the present invention at different temperatures.

[0030] Figure 2 The graphs are the change curves of the irreversible creep compliance of the modified asphalt or asphalt in various embodiments and comparative examples of the present invention.

[0031] Figure 3 The infrared spectrum (FT-IR) data diagram of the modified asphalt or asphalt of each embodiment and comparative example of the present invention. DETAILED DESCRIPTION

[0032] As used herein:

[0033] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0034] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0035] When a parameter is expressed as a range, a preferred range, or a range limited by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0036] In these examples, parts and percentages are by mass unless otherwise indicated.

[0037] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing the specific embodiments and are not intended to limit the present invention. In the embodiments, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0039] Example 1 (Preparation Example of Asphalt Modifier from Waste Toothpaste Packaging Material)

[0040] This embodiment provides a method for preparing a low-carbon high-modulus asphalt modifier using waste toothpaste packaging materials as raw materials, comprising the following steps:

[0041] (1) Rinse the waste toothpaste packaging materials (packaging shells) collected from the waste plastic recycling plant until the surface stains are removed; the general rinsing time is 2 to 6 hours; in this embodiment, the rinsing time is 5 hours.

[0042] (2) The rinsed waste toothpaste tubes are placed in an oven. The drying temperature is generally controlled at 75°C to 90°C for 2h to 4h. In this embodiment, the drying temperature is controlled at 80°C for 3h.

[0043] (3) The dried waste toothpaste shells are crushed and ground using a turbine grinder, and then sieved to obtain a low-carbon high-modulus modifier with a particle size of ≤220 mesh.

[0044] The main components of the recycled waste toothpaste packaging materials (packaging shells) are 70-73.75% RPE and 25-28.75% aluminum. As those skilled in the art can understand, in addition to the main components RPE and aluminum, the waste toothpaste packaging materials also contain a small amount of molding aids.

[0045] Generally, the recycled waste toothpaste packaging material comprises a polyethylene plastic toothpaste nozzle, and an aluminum film and a polyethylene layer form a toothpaste tube. As a person skilled in the art, it can be understood that the composition of the recycled waste toothpaste packaging shell is not limited to this type, and the protection scope of the present invention cannot be limited thereto. This embodiment takes this type of toothpaste packaging material as an example, and calculates the content of RPE and aluminum in the low-carbon high modulus modifier obtained from the recycled waste toothpaste packaging material according to the following method.

[0046] First, split and weigh the mass of the plastic toothpaste mouthpiece, then measure the thickness of the polyethylene layer and the aluminum film layer of the toothpaste tube respectively, then calculate the volume of the aluminum film layer and the polyethylene layer according to the circumference and length of the toothpaste tube, and calculate the mass of the aluminum film layer and the polyethylene layer by combining their respective volumes with the density of polyethylene and aluminum. According to the addition ratio of the molding agent in the existing conventional toothpaste packaging material, the mass of the molding agent is removed to calculate the mass of the polyethylene and aluminum film in the toothpaste packaging material. The mass of the aluminum film is the mass of the aluminum in the recycled material, and the mass of the polyethylene in the toothpaste tube plus the mass of the toothpaste mouthpiece is the mass of RPE. Finally, the mass percentage of the main components RPE and aluminum in the waste toothpaste packaging material (i.e., the low-carbon high modulus modifier made with it as raw material) can be calculated by weighing the total mass of the toothpaste tube and the calculated mass of RPE and aluminum.

[0047] According to the above method, it is calculated that the main components of the low-carbon high-modulus modifier prepared from the waste toothpaste packaging materials recycled in this embodiment are 73.52% RPE and 25.23% aluminum.

[0048] Example 2 (Preparation Example of Modified Asphalt)

[0049] This embodiment provides a method for preparing low-carbon high-modulus modified asphalt, which specifically includes the following steps:

[0050] (1) Heat 70# base asphalt at 135℃ for 30 minutes to melt it;

[0051] (2) Add 5% of the low-carbon high-modulus modifier prepared in Example 1 to the melted 70# base asphalt, control the temperature at 170°C, and stir manually for 15 minutes;

[0052] (3) After preliminary manual stirring, the mixed material is subjected to high-speed shearing for 50 min, with the shear rate controlled at 4500 r / min and the temperature controlled at 170 °C;

[0053] (4) Further high-speed stirring and dispersing is performed at a rate of 450 rad / min, the time is controlled at 30 min, and the temperature is controlled at 175° C., thereby obtaining the low-carbon high-modulus modified asphalt.

[0054] Example 3

[0055] This embodiment provides a method for preparing low-carbon high-modulus modified asphalt, which specifically includes the following steps:

[0056] (1) Heat 70# base asphalt at 130℃ for 35 minutes to melt it;

[0057] (2) Add 5% of the low-carbon high-modulus modifier prepared in Example 1 to the melted 70# base asphalt, control the temperature at 165°C, and stir manually for 10 minutes;

[0058] (3) After preliminary manual stirring, the mixed material was subjected to high-speed shearing for 45 min, with the shear rate controlled at 4500 r / min and the temperature controlled at 165 °C;

[0059] (4) Further high-speed stirring and dispersing is performed at a rate of 400 rad / min, the time is controlled at 20 min, and the temperature is controlled at 175° C., thereby obtaining the low-carbon high-modulus modified asphalt.

[0060] Example 4

[0061] This embodiment provides a method for preparing low-carbon high-modulus modified asphalt, which specifically includes the following steps:

[0062] (1) Heat 70# base asphalt at 140℃ for 35 minutes to melt it;

[0063] (2) Add 5% of the low-carbon high-modulus modifier prepared in Example 1 to the melted 70# base asphalt, control the temperature at 180°C, and stir manually for 20 minutes;

[0064] (3) After preliminary manual stirring, the mixed material is subjected to high-speed shearing for 60 min, with the shear rate controlled at 5000 r / min and the temperature controlled at 180 °C;

[0065] (4) Further, high-speed stirring and dispersion is performed at a rate of 450 rad / min, the time is controlled at 30 min, and the temperature is controlled at 180° C., thereby obtaining the low-carbon high-modulus modified asphalt.

[0066] Example 5

[0067] The difference between this embodiment and embodiment 2 is that the dosage of the low carbon high modulus modifier in step (2) is 7.5%.

[0068] Example 6

[0069] The difference between this embodiment and embodiment 2 is that the dosage of the low carbon high modulus modifier in step (2) is 10%.

[0070] Example 7

[0071] The difference between this embodiment and embodiment 2 is that the dosage of the low carbon high modulus modifier in step (2) is 12.5%.

[0072] Example 8

[0073] The difference between this embodiment and embodiment 2 is that the dosage of the low carbon high modulus modifier in step (2) is 15%.

[0074] Comparative Example 1

[0075] According to the method in Example 2, different dosages of high modulus modifiers were replaced by different dosages of PE (polyethylene material) in different mass percentages (5%, 7.5%, 10%, 12.5%, and 15%), and the mass percentage of PE was converted through the RPE content in the high modulus modifier of approximately 73.52%, that is, the dosages of PE were 3.7%, 5.5%, 7.4%, 9.2%, and 11.0% respectively, to obtain PE modified asphalts, which were respectively recorded as Comparative Example 1.1, Comparative Example 1.2, Comparative Example 1.3, Comparative Example 1.4, and Comparative Example 1.5.

[0076] Comparative Example 2

[0077] According to the method in Example 2, different amounts of high modulus modifier were replaced by different amounts of PE in different mass percentages (5%, 7.5%, 10%, 12.5%, 15%), and the mass percentage of PE was converted through the RPE content in the high modulus modifier of about 73.52%, that is, the corresponding amounts of PE were 3.7%, 5.5%, 7.4%, 9.2%, and 11.0%, and aluminum powder was added. The aluminum powder used was larger than 100 mesh, and the corresponding amounts of aluminum powder were 1.3%, 1.9%, 2.5%, 3.2%, and 3.8% to prepare PE+aluminum powder composite modified asphalt, which were respectively recorded as Comparative Example 2.1, Comparative Example 2.2, Comparative Example 2.3, Comparative Example 2.4, and Comparative Example 2.5.

[0078] Comparative Example 3

[0079] Unmodified 70# base asphalt was used as a blank control group, recorded as Comparative Example 3.

[0080] In order to verify the feasibility and effectiveness of the present invention, the following performance tests were performed on the modified asphalts prepared in the above embodiments and comparative examples:

[0081] 1. The modified asphalt or asphalt prepared in the above examples and comparative examples were subjected to asphalt penetration test, ductility test, softening point test (ring and ball method), 60°C dynamic viscosity test and segregation test according to the "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The test results are shown in Table 1. The modified asphalt or asphalt prepared in the above examples and comparative examples were subjected to asphalt dynamic shear rheology (DSR) test and multiple stress creep recovery (MSCR) test according to the "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering". The test results are shown in Table 1. Figure 1 , Figure 2 shown.

[0082] Table 1 Basic performance test results of modified asphalt or asphalt in various embodiments and comparative examples

[0083] 2. The modified asphalt prepared in the above Example 2 and Comparative Example 1.1 was subjected to infrared spectroscopy (FI-TR) test according to the General Rules for Infrared Spectroscopy Analysis Methods. The infrared spectroscopy results are as follows: Figure 3 As shown. It can be understood by those skilled in the art that the modifier composition is consistent, and the infrared spectrum Figure 1 In the present invention, Example 2 (modifier dosage is 15%) and Comparative Example 1.1 with the corresponding PE dosage are used as examples for experimental analysis.

[0084] The results of the above tests are analyzed as follows:

[0085] From the data in Table 1, it can be seen that when the base asphalt is modified by the low-carbon high-modulus asphalt modifier prepared from waste toothpaste packaging materials of the present invention, the needle penetration of the modified asphalt is reduced by 11.4%, 24.9%, 34.5%, 46.8% and 55.4% respectively compared with that before modification; the softening point is increased by 16.85%, 56.3%, 90.1%, 116.8% and 152.3% respectively; the 60°C dynamic viscosity is increased by 2.83, 5.01, 6.91, 9.30 and 10.73 times respectively compared with that before modification. Explanation: The high modulus modifier provided by the present invention can significantly improve the high temperature performance of ordinary petroleum asphalt.

[0086] Compared with comparative examples 1.1 to 1.5, the low-carbon high modulus modifier provided by the present invention is better than the PE asphalt modifier in compatibility with the matrix asphalt, which is manifested in that the temperature difference caused by the segregation of the modified asphalt obtained by the low-carbon high modulus modifier of the present invention is smaller than that of the modified asphalt obtained by the PE asphalt modifier (the smaller the temperature difference, the better), which may be because the aluminum film reacts with the active substances such as asphalt acid and asphalt anhydride in the matrix asphalt, and the ionic bond between the product and the asphalt promotes the formation of a three-dimensional network structure. At the same time, the product may play the role of a nucleating agent in the PE melt recrystallization process, making the crystallite size and long period of the system smaller, that is, the addition of a nucleating agent can refine the matrix crystals in the system and increase the number of crystallites.

[0087] Compared with comparative examples 2.1 to 2.5, it can be seen that the composite modification of PE and aluminum powder also showed segregation, but it was also better than PE single modified asphalt, which further illustrates that aluminum powder can improve the compatibility of PE or RPE of the present invention in asphalt, and the two can play a synergistic role. Compared with comparative examples 2.1 to 2.5, there is no significant difference in high and low temperature performance and compatibility between Examples 2 to 8 of the present invention and Comparative Examples 2.1 to 2.5, but the present invention uses waste recycled materials, and aluminum powder is difficult to purchase as a hazardous controlled product, so the former is superior to the latter in terms of economy, ecology and production.

[0088] Depend on Figure 1It can be seen that the rutting factor increases with the increase of the dosage of the high modulus modifier of the present invention. When the dosage of the high modulus modifier of the present invention is 5%, 7.5%, 10%, 12.5%, and 15%, the rutting factor of ordinary petroleum asphalt is increased by 0.5, 0.7, 2.0, 3.1, and 3.9 times, respectively. This shows that the high modulus modifier of the present invention can greatly improve the deformation resistance of ordinary petroleum asphalt, thereby improving the high temperature performance of ordinary petroleum asphalt. Compared with the PE single modified asphalt prepared by each group of the low-carbon high modulus modified asphalt prepared by each embodiment of the present invention, the rutting factors of the two are relatively small before the dosage is 10%, but on the whole, the rutting factors of the low-carbon high modulus modified asphalt prepared by each group of the present invention are higher than those of the PE single modified asphalt. This may be because compared with PE modified asphalt, the low carbon high modulus modified asphalt of the present invention contains aluminum powder. When the dosage is small, the aluminum powder only plays a role of fine material filling, increasing the internal friction resistance of the modified asphalt, so it is slightly higher than PE modified asphalt. Compared with the low carbon high modulus modified asphalt prepared by each embodiment of the present invention and the PE+Al composite modified asphalt prepared by each group of comparative example 2, the performance of the modified asphalt of each group corresponding to the two is not much different, indicating that the asphalt modifier provided by the present invention is used for asphalt modification, and the component aluminum in the modifier plays a more critical role.

[0089] Depend on Figure 2 It can be seen that the irrecoverable creep compliance of asphalt increases with the increase in the content of the high modulus modifier of the present invention. When the content of the high modulus modifier of the present invention is 5%, 7.5%, 10%, 12.5%, and 15%, the recovery rate of ordinary petroleum asphalt is reduced by 72.3%, 92.9%, 95.3%, 97.0%, and 98.2%, respectively. It is shown that the addition of the high modulus modifier provided by the present invention has a large degree of modification on the elastic recovery of ordinary petroleum asphalt, thereby improving the road performance of ordinary petroleum asphalt pavement.

[0090] from Figure 3 It can be seen that compared with the base asphalt, the low carbon high modulus modified asphalt of the present invention increases the -1 With 1030cm -1 There are two infrared characteristic absorption peaks. The transmittance of these two characteristic absorption peaks is between 78% and 82%. After consulting the literature, it is known that 1076cm -1 The absorption peak at 1030cm may be that of ether, ester or anhydride. -1It is the absorption peak of sulfoxide. From the composition of the prepared low-carbon high-modulus modifier, it can be seen that all functional groups of PE are -CH2 methylene, and no other groups will be generated when it is added to the matrix asphalt. Then the characteristic peak here should be caused by the aluminum film. This may be because the recycled toothpaste shell packaging material has been abandoned for a long time, and the oxygen in the air gradually penetrates the gap in the PE shell and undergoes an oxidation reaction with the aluminum shell to generate aluminum oxide. The asphalt acid and asphalt anhydride in the matrix asphalt contain active and acidic carboxyl groups, which can undergo an esterification reaction with aluminum oxide to generate organic aluminum salts during the heating and high-speed shear mixing process, and finally caused by the stretching vibration of the CO bond in -COOR. The same PE+Al composite modified asphalt increases the peak at 1076cm -1 With 1030cm -1 Two characteristic infrared absorption peaks further verify that the low-carbon high-modulus modified asphalt has better performance than PE modified asphalt, among which the aluminum component in the asphalt modifier plays a more critical role.

[0091] In summary, the scheme of the present invention can promote the recycling of existing waste plastics, provide a new idea for the recycling of plastic products that cannot be efficiently separated from waste plastics and their attachments, reduce the cost of recycling waste plastics, and realize the comprehensive resource utilization of waste plastics, turning waste into treasure, so as to increase the added value of waste plastics. Therefore, the scheme of the present invention can solve the problem that waste plastic products in the form of PE plastic attached to metal films, such as waste toothpaste shell guarantee materials, are difficult to recycle. By applying it to asphalt modification, it can also greatly improve the comprehensive performance of ordinary petroleum asphalt, especially the high temperature performance of asphalt materials, and can also improve the problem of poor compatibility between waste plastics and matrix asphalt to a certain extent, thereby increasing the service life of asphalt pavement.

[0092] The above descriptions are only some preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A low carbon high modulus asphalt modifier, It is characterized in that The asphalt modifier is prepared from waste toothpaste packaging materials, and its main components are 70-73.75% of RPE and 25-28.75% of aluminum.

2. A low carbon high modulus asphalt modifier according to claim 1, It is characterized in that The particle size of the asphalt modifier is ≤220 meshes.

3. A method for preparing the low carbon high modulus asphalt modifier as claimed in claim 1, It is characterized in that The preparation method specifically comprises the following steps: washing the recycled waste toothpaste packaging materials to remove surface stains and drying them; and then crushing, grinding and screening them to obtain a low-carbon high-modulus asphalt modifier with a preset particle size.

4. The method for preparing the low carbon high modulus asphalt modifier according to claim 3, It is characterized in that The drying conditions for waste toothpaste packaging materials are: drying at 75℃~90℃ for 2h~4h.

5. The method for preparing the low carbon high modulus asphalt modifier according to claim 3, It is characterized in that The dried toothpaste packaging material is crushed by a turbine crusher, and then sieved after grinding to obtain a low-carbon high-modulus asphalt modifier with a particle size of ≤220 mesh.

6. A modified asphalt, It is characterized in that The modified asphalt is obtained by modifying base asphalt with the low-carbon high modulus asphalt modifier described in claim 1 or 2 or the low-carbon high modulus asphalt modifier obtained by any of the methods described in claims 3 to 5, and the addition amount of the low-carbon high modulus asphalt modifier is 5 to 15 wt % of the base asphalt.

7. A method for preparing modified asphalt, It is characterized in that The following steps are involved: S1. Preparing a low-carbon high-modulus asphalt modifier: preparing a low-carbon high-modulus asphalt modifier by the preparation method according to any one of claims 3 to 5; S2, heat and melt the base asphalt, then add 5-15wt% of the low-carbon high-modulus asphalt modifier prepared by S1, control the temperature at 165-180°C, and stir preliminarily; S3. After preliminary stirring, the mixed material is subjected to high-speed shearing for 45-60 minutes, and the temperature is controlled at 165-180°C; S4. Further high-speed dispersion stirring is performed at a rate of 400-500 rad / min to obtain.

8. The method for preparing modified asphalt according to claim 7, It is characterized in that In step S2, the base asphalt is heated at 130-140°C for 30-35 minutes to melt it; the initial stirring time is 10-20 minutes.

9. The method for preparing modified asphalt according to claim 7, It is characterized in that The high-speed shear rate in step S3 is 4500-5000 r / min.

10. The preparation method according to claim 7, It is characterized in that The time of high-speed dispersing and stirring in step S4 is controlled at 25-30 minutes, and the temperature is controlled at 175-180°C.

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