PG100 modified asphalt and preparation method thereof

Abstract

The invention relates to the technical field of asphalt, in particular to PG100 modified asphalt and a preparation method thereof, and the PG100 modified asphalt comprises the following components in parts by weight: 85-93 parts of matrix asphalt; 4.5 to 6.0 parts of a polymer modifier; 1.5 to 3.0 parts of a crystallization enhancing main agent; 0.5 to 1.5 parts of a crystallization enhancing auxiliary agent; 1.0 to 4.0 parts of a viscosity reducer; 0.1 to 0.5 part of a stabilizing agent; road petroleum asphalt is used as a basic raw material, high-dosage SBS is used for modifying matrix asphalt, a silicone powder composite polyolefin carrier in a crystallization reinforcing main agent material is used for performing infiltration reinforcement on an SBS spatial network, and the high-temperature modulus and aging resistance of the SBS spatial network are improved, so that the rutting resistance of an asphalt pavement is greatly improved, and the service life of the asphalt pavement is prolonged. The service life of the asphalt pavement is prolonged, and the social and economic benefits are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt, and in particular to a PG100 modified asphalt and a preparation method thereof. Background Art

[0002] The transportation in my country's coastal areas is developing rapidly, the traffic axle load is increasing, and the high-temperature and heavy load on asphalt pavements is increasing, which puts higher requirements on the high-temperature performance of asphalt binders.

[0003] At present, there are some studies on materials related to high temperature performance of pavement at home and abroad. For example, the invention patent with publication number CN116836560A uses polysiloxane to modify 70# or 90# asphalt. The silanol of polysiloxane and the ethoxy of cross-linking agent such as ethyl orthosilicate undergo hydrolysis and condensation reaction under the catalysis of catalyst such as dibutyltin dilaurate to form a network cross-linking structure, which improves the basic performance of matrix asphalt, but the overall high temperature performance improvement is limited, and there are certain limitations in the use of asphalt pavement surface layer; the invention patent with publication number CN114702738A uses CM135 or CM140 chlorinated polyethylene (chlorine mass fraction 35% to 40%) composite rubber powder to prepare a modifier to improve the high temperature performance of modified asphalt. Although it saves costs and improves high temperature performance, the rubber asphalt has a strong odor and pollutes the environment when producing asphalt. The manufacturer is not universal and has slight limitations. Currently, there are many technical routes for high-temperature improvement of asphalt. Most of them are produced using high-modulus materials such as polyurethane, epoxy resin, rock asphalt or plastic. The high-temperature resistance needs to be improved. At the same time, there are certain differences in related processes or performance such as production, cost and storage, making it difficult to promote universally.

[0004] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a PG100 modified asphalt and a preparation method thereof. The base material is road petroleum asphalt, a high amount of SBS is used to modify the matrix asphalt, and the silicone powder composite polyolefin carrier in the crystallization enhancement main agent material is used to infiltrate and reinforce the SBS spatial network, thereby improving the high temperature modulus and aging resistance of the SBS spatial network, thereby greatly improving the anti-rutting performance of the asphalt pavement, forming a high temperature resistant modified asphalt product, extending the life of the asphalt pavement, and improving social and economic benefits.

[0006] The PG100 modified asphalt of the present invention comprises the following components calculated by weight:

[0007]

[0008] As a preferred embodiment of the present invention, the matrix asphalt is one or more of 70# straight-run matrix asphalt and 50# straight-run matrix asphalt; the above asphalt is refined and produced using heavy crude oil, with a relatively high asphaltene content, excellent high-temperature performance and aging resistance.

[0009] As a preferred embodiment of the present invention, the polymer modifier is one or more of styrene-butadiene rubber, styrene-butadiene-styrene block copolymer, and hydrogenated styrene-butadiene block copolymer.

[0010] As a preferred embodiment of the present invention, the crystallization enhancing main agent is one or more of silicone powder and silicone masterbatch;

[0011] Compared with traditional low-molecular-weight PE-based lubricants and EBS-based lubricants, silicone powder can improve the adhesion of asphalt organic matter to the surface of aggregates and has better aging resistance. Traditional low-molecular-weight PE-based lubricants and EBS lubricants will gradually degrade and precipitate at temperatures above 100 °C, losing their effectiveness. The production process of asphalt requires heating to 180 °C, and the application effect of traditional lubricants is limited. Therefore, silicone powder with better thermal stability and chemical properties is more suitable for the asphalt system and can effectively improve the high-temperature performance and weather resistance of asphalt materials.

[0012] Preferably, the silicone content in the silicone powder and silicone masterbatch is 20% - 40%;

[0013] In the prior art, the method of directly adding siloxane is mostly used, which has the following deficiencies: the intermolecular force of siloxane materials is relatively strong. When the siloxane content is relatively high, the viscosity of the materials is relatively high, and it is not easy to disperse evenly by physical methods such as shear dispersion; in the present invention, siloxane is introduced by adding one or more of silicone powder and silicone masterbatch. The inorganic component silicate in the silicone powder is coated on the polysiloxane in a nucleating structure. The intermolecular force of this coating structure is higher than that of the inorganic minerals of polymer additives and fillers. Therefore, when applied to asphalt materials, it can act on the swollen and stretched polymer modifier. With the assistance of the polyolefin carrier chlorinated polyethylene in the crystallization assisting agent, the compatibility of the interface between non-polar aggregates and asphalt organic matter can be greatly improved, thereby increasing the adhesion of asphalt to aggregates and enhancing the durability of asphalt pavements, and thus extending the service life of roads.

[0014] As a preferred embodiment of the present invention, the crystallization enhancing auxiliary agent is a complex of low chlorinated polyethylene and dilauryl thiodipropionate.

[0015] Preferably, the mass ratio of the crystallization enhancing main agent to the crystallization enhancing auxiliary agent is 3 - 2:1;

[0016] The crystallization-enhancing main agent, as the main enhancing component of the crystallization framework structure, can greatly exert its effect of enhancing the adhesion and compatibility of asphalt when combined with certain auxiliary agents. Therefore, the auxiliary agent will have a synergistic infiltration effect on the main agent. When the content of the main agent exceeds the above limit, it is difficult for the auxiliary agent to disperse all the main agents well, and the free silicone material will greatly increase the viscosity of the asphalt, thereby reducing the construction performance. When the auxiliary agent exceeds this limit, it is not conducive to cost control.

[0017] As a preferred embodiment of the present invention, the chlorine mass fraction of the low-chlorinated polyethylene is 16-24%;

[0018] Low-chlorinated polyethylene refers to a low chlorine mass fraction. When the chlorine mass fraction is 16-24%, the material tends to have the properties of a thermoplastic elastomer and is similar in molecular weight to the polymer modifier. According to the "like dissolves like" principle, it can improve the high and low temperature performance of the modified asphalt and is not easy to segregate; chlorine element has a strong polarity and is randomly and evenly distributed on the macromolecular chain of polyethylene after chlorination, showing a non-crystalline state. The chlorine content in the above range has typical thermoplastic elastomer properties when applied to asphalt, and can form a three-dimensional space network with the SBS space network and the matrix asphalt, interpenetrating and crosslinking with each other. When the chlorine content exceeds the above limit, the chlorinated polyethylene shows the properties of a rubber-like elastomer or even a hard polymer, with an increased modulus, which is not conducive to production infiltration.

[0019] As a polyolefin carrier, low-chlorinated polyethylene can improve the infiltration effect of silicone powder in the crystallization structure main agent on the SBS polymer modifier, effectively locking the SBS space network and the elastic structure network of chlorinated polyethylene. Dilauryl thiodipropionate (DLTP) can effectively decompose the hydroperoxide (ROOH) in the autoxidation chain reaction, achieving the purpose of interrupting the chain reaction, thereby stabilizing the anti-aging property of the three-dimensional space network under high temperature conditions, improving the anti-aging ability of the asphalt, and prolonging the service life of the asphalt.

[0020] Preferably, the average relative molecular mass of the low-chlorinated polyethylene is 100,000-160,000;

[0021] When the relative molecular mass of chlorinated polyethylene is relatively large, the viscosity is relatively high and it is not easy to produce. When the relative molecular mass is relatively low, the strength is relatively low and it is difficult to meet the high temperature requirements of the asphalt. Chlorinated polyethylene with an average relative molecular mass of 100,000-160,000 has both a relatively low viscosity and a relatively high strength.

[0022] As a preferred embodiment of the present invention, the mass ratio of chlorinated polyethylene to dilauryl thiodipropionate is 8-9:1-2;

[0023] Dilauryl thiodipropionate is an antioxidant used to enhance the antioxidant performance of chlorinated polyethylene and can, to a certain extent, improve the anti-aging performance of modified asphalt. Since its mechanism of action mainly inhibits hydroperoxides (ROOH) in the chain reaction, and the hydroperoxides (ROOH) in the chain reaction are mainly generated by the gradual thermal oxidation attenuation after the modifier is developed, only a small amount of oxidation inhibition is required in the final step. Excessive addition is not cost-effective, and a small amount may lead to poor inhibition effect, resulting in attenuation of the modification effect of asphalt due to aging.

[0024] As a preferred embodiment of the present invention, the organic viscosity reducer is one or more of aromatic oil, naphthenic oil, DOA, and DOS;

[0025] Aromatic oil is derived from petroleum refining and has the same origin as petroleum asphalt. It has a better molten state, which is beneficial to the melting of the polymer modifier and the chlorinated polyolefin swelling agent. Moreover, aromatic oil plasticizes the chlorinated polyolefin, making up for the low-temperature damage caused by the crystallization network to a certain extent;

[0026] Due to its special cyclic molecular structure, naphthenic oil can effectively reduce the viscosity of asphalt and improve the workability of the mixture, making the mixture easier to lay and compact;

[0027] DOA and DOS can endow the colloid with good cold resistance when applied to thermoplastic colloids, and are very suitable for the situation where both heat resistance and low temperature resistance are required. Therefore, when applied to thermoplastic systems such as SBS modifiers and chlorinated polyethylene, they can improve the high and low temperature performance of asphalt materials, thereby improving the high and low temperature performance of asphalt pavements and extending the service life.

[0028] As a preferred embodiment of the present invention, the stabilizer is sulfur or sulfur-containing stabilizers;

[0029] The main sulfur component in sulfur or sulfur-containing stabilizers undergoes a displacement reaction with the hydrogen bonds in the modifier in asphalt, thereby stabilizing the polymer network structure after high-temperature swelling, making the modified asphalt less likely to undergo thermal decomposition and segregation, and improving the storage stability of the modified asphalt.

[0030] The preparation method of the PG100 modified asphalt of the present invention includes the following steps:

[0031] S1 Preheat part of the base asphalt to a flowing state, add the polymer modifier and the crystallization enhancement main agent, stir evenly, pass through a grinding and shearing process, and then stir and develop; the grinding and shearing process uses a colloid mill to shear and disperse the polymer modifier to improve its dispersion uniformity in the asphalt binder and ensure the modification effect;

[0032] S2 Add the organic viscosity reducer and stir and develop;

[0033] S3 Add a stabilizer and stir for development;

[0034] S4 Add a crystallization enhancement adjuvant, supplement the remaining matrix asphalt, and after stirring for development, obtain PG100 modified asphalt.

[0035] For the preparation method of the PG100 modified asphalt of the present invention, the reasons for adding the matrix asphalt in S1 and S4 respectively are as follows: First, it conforms to the production process; Second, it can reduce asphalt aging to a certain extent; The production process of the modified asphalt of the present invention is generated by partial asphalt miscible modifier over-grinding, and then pumped into the development tank to supplement the remaining asphalt for development. After adding the stabilizer and developing, the last step is to add auxiliary additives. In this step, the asphalt needs to flush the auxiliary additives floating on the surface of the asphalt into the asphalt in S1, and then the whole is miscible and developed. If the asphalt and the modifier are completely miscible at one time, the later-added low-chlorinated polyethylene light powdery substance is easy to float on the upper layer of the asphalt and has not been over-ground and sheared, so it is difficult to be miscible in the asphalt in a short time, and it is difficult to exert its effect;

[0036] The preparation method of the present invention promotes the formation of a spatial network by adding a crystallization enhancement main agent and a polymer modifier in advance for melting development, then adds an organic viscosity reducer to reduce the melt viscosity, and supplements light components (the remaining matrix asphalt) to promote the dispersion of the polymer modifier and the crystallization enhancement main agent, promote the swelling of the polymer modifier material spatial network, and at the same time adsorb and solidify with the crystallization enhancement main agent, greatly improving the asphalt performance. Then add a stabilizer to react with the crystallization enhancement adjuvant to stabilize the spatial network, comprehensively improve the dispersion effect, compound the spatial network structure, and improve the anti-aging property and durability of the asphalt.

[0037] More specifically, in S1, heat the matrix asphalt to a flowing state at a temperature of 170°C ± 2°C, then stir and preheat in a stirring kettle for 0.5 h, add a polymer modifier and a crystallization enhancement main agent, stir and mix for 0.5 h, perform over-grinding and shearing at 175 ± 2°C, pump into the development tank, and then stir and develop at 175 ± 5°C for 2 h;

[0038] The temperature of 170°C ± 2°C can avoid asphalt aging during the heating process;

[0039] During shearing, a certain temperature is required for over-grinding. With the high temperature produced by instantaneous over-grinding, the SBS modifier can be sheared and crushed more finely. Therefore, the temperature is raised to 175 ± 2°C. The development time and the purpose of the organic viscosity reducer are to promote the swelling and development of SBS. At a higher temperature, the molecular movement is more intense and the development time is faster;

[0040] S2 Add an organic viscosity reducer and stir and develop at 175°C ± 5°C for 1 - 2 h;

[0041] S3 Add a stabilizer and stir and develop at 170 ± 5 °C for 3 - 5 h; after the addition of the stabilizer, the SBS network system gradually develops and stabilizes. Therefore, the temperature is reduced to the range of 175 ± 5 °C, and there is no need to heat to maintain a high temperature. Otherwise, the developed modifier network will gradually decay and lose its effect;

[0042] S4 Add a crystallization enhancement adjuvant to supplement the remaining asphalt mass, stir and develop for 3 - 5 h to obtain PG100 modified asphalt;

[0043] More specifically, the crystallization enhancement adjuvant is added in a direct injection manner, and there is no strict requirement for the remaining asphalt mass. Generally, it is sufficient to dissolve all the SBS modifiers in it; the reason for adding the crystallization enhancement adjuvant at the end is that if the crystallization enhancement adjuvant is directly mixed, on the one hand, the SBS modifier network is not fully developed and cannot enhance the network infiltration effect, and on the other hand, if the crystallization enhancement adjuvant is added too early, it is prone to aging under long-term high-temperature stirring, which is not conducive to the performance of the modifier.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) The high-temperature resistant PG100 modified asphalt provided by the present invention is different from using high-molecular auxiliaries such as resins and cured epoxy to improve the high-temperature performance of asphalt. Based on the SBS modifier spatial network structure on the basis of traditional SBS modified asphalt, a strong molecular force material such as silicone powder or silicone masterbatch is used to adsorb and enhance the SBS spatial network. The enhancement mechanism of silicone powder mainly lies in that its main component contains silicon or silicate, and this component is wrapped by polysiloxane in the form of a nucleus. Its molecular force is stronger than that of the polymer and inorganic substances themselves. With the help of a chlorinated polyolefin material with a specific molecular weight range as the infiltration and dispersion carrier, the infiltration and dispersion ability of the silicone material is improved. After the nucleus infiltrates into the SBS spatial network, it can greatly increase the network strength and anti-aging property of the SBS modifier, thereby greatly improving the high-temperature rutting resistance of asphalt; in addition to the dispersion and infiltration effect, the chlorinated polyolefin carrier with a specific chlorine content also has elastomeric properties. It swells and develops under high-temperature conditions and forms a composite network structure with SBS intertwined and crosslinked, with the matrix asphalt as the continuous phase and SBS and chlorinated polyolefin as the dispersed phases. Compared with the single SBS spatial network, the composite network has more excellent high-temperature performance;

[0045] 2) Due to its polydimethylsiloxane-wrapped core structure, silicone powder material can serve as a supplementary reinforcing agent for chlorinated polyolefin carriers. The two complement each other. Its high-strength molecular force can adsorb to a certain extent on the surrounding polyolefin carriers under the action of chlorinated polyolefin, reducing the content of free polyolefin and thus enhancing the overall strength of the asphalt material. The relatively narrow molecular weight distribution of chlorinated polyolefin results in lower viscosity under low-shear conditions and higher viscosity under high-shear stress conditions. Therefore, when applied to high-temperature and heavy-load pavement conditions, the possibility of rutting diseases is reduced. Combining with the chain-breaking reaction effect of the vulcanizing agent DLTP can extend the service life of the pavement asphalt material;

[0046] 3) The viscosity of the PG100 modified asphalt prepared by compounding silicone powder material with corresponding auxiliary additives is greater than 300,000 Pa·s, the softening point is greater than 95 °C, and the elastic recovery is ≥ 98%. The PG grading reaches PG100 at high temperature. Compared with the PG76 or PG82 in general high-temperature and heavy-load areas, its high-temperature performance is better and its rutting resistance performance is better, meeting the development trend of social transportation and having social and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic flow chart of the preparation method of the PG100 modified asphalt of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0048] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following detailed description of the specific embodiments of the present invention will be given in conjunction with the drawings of the specification.

[0049] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0050] Secondly, the so-called "embodiment" herein refers to specific features, structures or characteristics that can be included in at least one implementation manner of the present invention. The phrase "in an embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that mutually excludes other embodiments.

[0051] In the embodiments of the present invention, the matrix asphalt is sourced from Jiangsu Zhongyitong Road New Materials Co., Ltd., and the sources of commercially available materials are as follows:

[0052] SBS modifier: Ningbo Jinhai Chenguang Chemical Co., Ltd.

[0053] Silicone powder: Hangzhou Kajie Plastic Technology Co., Ltd.

[0054] Chlorinated polyethylene CPE (chlorine mass fraction is 20%): Dongguan Shanyi Plastic Co., Ltd.

[0055] Chlorinated polyethylene CPE (chlorine mass fraction is 35%): Dongguan Shanyi Plastic Co., Ltd.

[0056] Dilauryl thiodipropionate (DLTP): Shanghai Aladdin Biochemical Technology Co., Ltd.

[0057] Aromatic oil: Shandong Furunda Chemical Co., Ltd.

[0058] Sulfur stabilizer: Luoyang Yuchen Petrochemical Products Co., Ltd.

[0059] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0060] Example 1

[0061] A kind of PG100 modified asphalt, calculated by weight parts, includes the following components:

[0062]

[0063] This embodiment provides a preparation method of PG100 modified asphalt. The specific preparation steps include:

[0064] S1. Heat 8 kg of Shuanglong 70# base asphalt to a flowing state at a temperature of 170°C ± 2°C, then stir and preheat it in a stirring kettle for 0.5 h. Add 450 g of linear Jinhai Chenguang 7302 HSBS and 300 g of silicone powder, stir and mix them for 0.5 h, perform over-grinding and shearing at 175 ± 2°C, then pump it into a development tank, and then stir and develop it at 175 ± 5°C for 2 h;

[0065] S2. Add 400 g of aromatic oil, and stir and develop it at 175°C ± 5°C for 1 - 2 h;

[0066] S3. Add 10 g of sulfur stabilizer, and stir and develop it at 170 ± 5°C for 3 - 5 h;

[0067] S4. Add 135 g of chlorinated polyethylene (chlorine mass fraction is 20%) and 15 g of DLTP, supplement 0.69 kg of Shuanglong 70# base asphalt, and stir and develop it for 3 - 5 h to obtain PG100 modified asphalt.

[0068] Example 2 (except for the different addition amounts of each component, the rest are the same as in Example 1)

[0069] A kind of PG100 modified asphalt, calculated by weight parts, includes the following components:

[0070]

[0071] This embodiment provides a method for preparing PG100 modified asphalt, and the specific preparation steps include:

[0072] S1. Heat 8kg of Shuanglong 70# matrix asphalt at 170℃±2℃ to a fluid state, then stir and preheat in a stirring kettle for 0.5h, add 600g of linear Jinhai Chenguang 7302HSBS and 150g of silicone powder, stir and mix for 0.5h, grind and shear at 175±2℃, drive into a development tank, and then stir and develop at 175±5℃ for 2h;

[0073] S2. Add 400g aromatic oil and stir at 175℃±5℃ for 1-2h;

[0074] S3. Add 20g of sulfur stabilizer and stir at 170±5℃ for 3-5h;

[0075] S4. Add 40g of chlorinated polyethylene (chlorine mass fraction is 20%) and 10g of DLTP, supplement with 0.78kg of Shuanglong 70# base asphalt, stir and develop for 3 to 5 hours to obtain PG100 modified asphalt.

[0076] Example 3 (Except for the different addition amounts of each component, the rest is the same as Example 1)

[0077] A PG100 modified asphalt, calculated by weight, includes the following components:

[0078]

[0079] This embodiment provides a method for preparing PG100 modified asphalt, and the specific preparation steps include:

[0080] S1. Heat 8kg of Shuanglong 70# base asphalt at 170℃±2℃ to a fluid state, then stir and preheat in a stirring kettle for 0.5h, add 450g of linear Jinhai Chenguang 7302HSBS and 200g of silicone powder, stir and mix for 0.5h, grind and shear at 175±2℃, drive into a development tank, and then stir and develop at 175±5℃ for 2h;

[0081] S2. Add 200g aromatic oil and stir at 175℃±5℃ for 1-2h;

[0082] S3. Add 10g of sulfur stabilizer and stir at 170±5℃ for 3-5h;

[0083] S4. Add 80g of chlorinated polyethylene (chlorine mass fraction is 20%) and 20g of DLTP, supplement with 1.04kg of Shuanglong 70# base asphalt, stir and develop for 3 to 5 hours to obtain PG100 modified asphalt.

[0084] Example 4 (Except for the different addition amounts of each component, the rest is the same as Example 1)

[0085] A PG100 modified asphalt, calculated by weight, includes the following components:

[0086]

[0087] This embodiment provides a method for preparing PG100 modified asphalt, and the specific preparation steps include:

[0088] S1. Heat 8kg of Shuanglong 70# base asphalt at 170℃±2℃ to a fluid state, then stir and preheat in a stirring kettle for 0.5h, add 500g of linear Jinhai Chenguang 7302HSBS and 200g of silicone powder, stir and mix for 0.5h, grind and shear at 175±2℃, drive into a development tank, and then stir and develop at 175±5℃ for 2h;

[0089] S2. Add 250g aromatic oil and stir at 175℃±5℃ for 1-2h;

[0090] S3. Add 15g of sulfur stabilizer and stir at 170±5℃ for 3-5h;

[0091] S4. Add 90g of chlorinated polyethylene (chlorine mass fraction is 20%) and 10g of DLTP, supplement with 0.935kg of Shuanglong 70# base asphalt, stir and develop for 3 to 5 hours to obtain PG100 modified asphalt.

[0092] Comparative Example 1 (different from Example 4, using the same weight of base asphalt instead of the crystallization enhancement main agent and the crystallization enhancement auxiliary agent)

[0093] The modified asphalt provided in this comparative example has the following specific quality ratios:

[0094]

[0095] The specific preparation steps include:

[0096] S1. Heat 8kg of Shuanglong 70# base asphalt at 170℃±2℃ to a fluid state, then stir and preheat in a stirring kettle for 0.5h, add 500g of linear Jinhai Chenguang 7302HSBS, stir and mix for 0.5h, grind and shear at 175±2℃, drive into a development tank, and then stir and develop at 175±5℃ for 2h;

[0097] S2. Add 250 g of aromatic oil and stir and develop at 175°C ± 5°C for 1 - 2 h;

[0098] S3. Add 15 g of sulfur stabilizer and stir and develop at 170 ± 5°C for 3 - 5 h; Supplement 1.235 kg of Shuanglong 70# base asphalt and stir and develop for 3 - 5 h to obtain the modified asphalt of Comparative Example 1.

[0099] Comparative Example 2 (differing from Example 4 in that the same weight of base asphalt is used instead of the crystallization enhancement main agent)

[0100] The modified asphalt provided in this comparative example has the following specific mass ratios:

[0101]

[0102] The specific preparation steps include:

[0103] S1. Heat 8 kg of Shuanglong 70# base asphalt to a flowing state at a temperature of 170°C ± 2°C, then stir and preheat in a stirring kettle for 0.5 h, add 500 g of linear Jinhai Chenguang 7302 HSBS, stir and dissolve for 0.5 h, perform over-grinding shear at 175 ± 2°C, transfer to a development tank, and then stir and develop at 175 ± 5°C for 2 h;

[0104] S2. Add 250 g of aromatic oil and stir and develop at 175°C ± 5°C for 1 - 2 h;

[0105] S3. Add 15 g of sulfur stabilizer and stir and develop at 170 ± 5°C for 3 - 5 h;

[0106] S4. Add 90 g of chlorinated polyethylene (chlorine mass fraction is 20%) and 10 g of DLTP, supplement 1.135 kg of Shuanglong 70# base asphalt, and stir and develop for 3 - 5 h to obtain the modified asphalt of Comparative Example 2.

[0107] Comparative Example 3 (differing from Example 4 in that the same weight of base asphalt is used instead of the crystallization enhancement auxiliary agent)

[0108] The modified asphalt provided in this comparative example has the following specific mass ratios:

[0109]

[0110] The specific preparation steps include:

[0111] S1. Heat 8 kg of Shuanglong 70# base asphalt to a flowing state at a temperature of 170°C ± 2°C, then stir and preheat in a stirring kettle for 0.5 h, add 500 g of linear Jinhai Chenguang 7302 HSBS and 200 g of silicone powder, stir and dissolve for 0.5 h, perform over-grinding shear at 175 ± 2°C, transfer to a development tank, and then stir and develop at 175 ± 5°C for 2 h;

[0112] S2. Add 250 g of aromatic oil and stir and develop at 175°C ± 5°C for 1 - 2 h;

[0113] S3. Add 15 g of sulfur stabilizer and stir and develop at 170 ± 5°C for 3 - 5 h; Supplement 1.035 kg of Shuanglong 70# matrix asphalt and stir and develop for 3 - 5 h to obtain the modified asphalt of Comparative Example 3.

[0114] Comparative Example 4 (differing from Example 4 in that the chlorine mass fraction of chlorinated polyethylene is 35%)

[0115] The modified asphalt provided by this comparative example has the following specific mass ratios:

[0116]

[0117] The specific preparation steps include:

[0118] S1. Heat 8 kg of Shuanglong 70# matrix asphalt to a flowing state at a temperature of 170°C ± 2°C and then stir and preheat in a stirring kettle for 0.5 h. Add 500 g of linear Jinhai Chenguang 7302 HSBS and 200 g of silicone powder, stir and dissolve for 0.5 h, perform over-grinding and shearing at 175 ± 2°C, pump into a development tank, and then stir and develop at 175 ± 5°C for 2 h;

[0119] S2. Add 250 g of aromatic oil and stir and develop at 175°C ± 5°C for 1 - 2 h;

[0120] S3. Add 15 g of sulfur stabilizer and stir and develop at 170 ± 5°C for 3 - 5 h;

[0121] S4. Add 90 g of chlorinated polyethylene (chlorine mass fraction is 35%) and 10 g of DLTP, supplement 0.935 kg of Shuanglong 70# matrix asphalt, stir and develop for 3 - 5 h to obtain the modified asphalt of Comparative Example 4.

[0122] The test results of the above examples and comparative examples are shown in Table 1 below.

[0123] Table 1 Performance test results of the modified asphalt prepared in each example and comparative example

[0124]

[0125] Among them, RTFOT is the abbreviation of "Rotatory Film Oven Test", which is usually translated into Chinese as Rotating Thin-Film Oven Test. It is a test method for evaluating the aging performance of asphalt materials. By simulating the short-term aging conditions that asphalt may experience during actual road paving, RTFOT can predict the behavior and performance changes of asphalt under these conditions.

[0126] Table 2 Technical indicators of the modified asphalt prepared in Comparative Example 1 and Example 4

[0127]

[0128] In Comparative Example 1 compared with Example 4, the crystallization network additives (crystallization-enhancing main agent silicone powder, auxiliary agent chlorinated polyethylene, and DLTP) were removed from the composition. The crystallization network additives can infiltrate and reinforce the SBS modifier. It can be clearly seen that compared with Example 4, the penetration ratio of Comparative Example 1 increased significantly, the softening point decreased, and the viscosity decreased significantly. The reason is that there is less crystallization network reinforcement, infiltration enhancement of polyolefin materials, and anti-aging effect. The high-temperature performance of the asphalt deteriorated. At the same time, according to the penetration ratio results and DSR results, the aging resistance of the asphalt deteriorated, and the rutting factor decreased to a large extent, indicating that without the crystallization additives, the overall rutting resistance and aging resistance of the asphalt both deteriorated and did not meet the requirements of the high-temperature grade of 100 °C in the PG grading.

[0129] Table 3 Technical indicators of the modified asphalt prepared in Comparative Example 2 and Example 4

[0130]

[0131] In Table 3, in Comparative Example 2 compared with Example 4, the crystallization-enhancing main agent (silicone powder) was reduced in the composition. The viscosity of the asphalt in Comparative Example 2 at 60 °C increased significantly compared with Comparative Example 1. The reason is that the chlorinated polyolefin material in the crystallization-enhancing auxiliary agent can form a network to enhance the asphalt viscosity to a certain extent, but compared with Example 4, there is still a large attenuation, indicating that a single crystallization network auxiliary agent has an improvement effect on the asphalt, but still cannot meet the required high rutting resistance performance requirements. The DSR index after aging increased slightly, which should be due to its own crystallization network enhancement and the anti-aging effect brought by DLTP in its own additives, resulting in an increase in the DSR and penetration ratio values and DSR. However, according to the DSR experiment after aging, the overall performance of the asphalt still does not meet the technical index requirements of PG100 modified asphalt.

[0132] Table 4 Technical indicators of the modified asphalt prepared in Comparative Example 3 and Examples 1-4

[0133]

[0134] In Comparative Example 3 in Table 4, compared with Examples 1 to 4, the crystallization enhancement adjuvant was reduced in the composition. The 60°C viscosity of the modified asphalt in Comparative Example 3 increased compared with that in Comparative Example 1 and was also better than the data in Comparative Example 2. It can be seen that the crystallization enhancement main agent has a greater effect on viscosity improvement than the crystallization enhancement adjuvant, and at the same time, the softening point of the asphalt is higher. However, after aging, the penetration ratio of the material is lower than that in Comparative Example 2. It can be seen that the anti-aging performance of the modified asphalt has not been improved to a large extent, indicating that the crystallization enhancement adjuvant has a better effect on improving the anti-aging performance of the asphalt material. The DSR of Comparative Example 3 is lower than that of Comparative Example 2, and the DSR has also decreased to a large extent compared with other examples, indicating that although a single crystallization enhancement main agent can improve the high-temperature performance of the asphalt, the anti-aging performance has not been improved to a large extent, and the high-temperature performance does not meet the PG grading requirements.

[0135] Technical indicators of the modified asphalt prepared in Comparative Example 4 and Example 4 in Table 5

[0136]

[0137]

[0138] It should be noted that in Comparative Example 4 in Table 5, compared with Example 4, the low chlorinated polyethylene (20%) in the crystallization enhancement adjuvant was replaced with chlorinated polyethylene (35%). According to the data, the penetration of Comparative Example 4 increased slightly, the softening point decreased, the elastic recovery decreased greatly and no longer met the index requirements, and the kinematic viscosity decreased greatly. It can be seen that although chlorinated polyethylene can improve the high-temperature performance of the asphalt, the improvement effect is lower than that brought by the infiltration of low chlorinated polyethylene. The reason is that although the free high-modulus component can improve the high-temperature performance of the asphalt, its effect is lower than the skeleton enhancement effect brought by infiltrating and interlocking the SBS modifier. And according to the decrease in the penetration ratio after aging and the decrease in DSR at 100°C, it can be seen that the free high-temperature performance is not resistant to aging, and the performance of the asphalt is greatly lost after mixing.

[0139] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered by the scope of the claims of the present invention.

Claims

1. A PG100 modified asphalt, characterized in that: Calculated by weight, it includes the following components: 85-93 parts of base asphalt; 4.5~6.0 parts of polymer modifier; 1.5~3.0 parts of crystallization enhancing agent; 0.5~1.5 parts of crystallization enhancing auxiliary agent; 1.0~4.0 parts of viscosity reducer; Stabilizer 0.1~0.5 parts.

2. The PG100 modified asphalt according to claim 1, characterized in that: The base asphalt is one or more of 70# straight-run base asphalt and 50# straight-run base asphalt.

3. The PG100 modified asphalt according to claim 1, characterized in that: The polymer modifier is one or more of styrene-butadiene rubber, styrene-butadiene-styrene block copolymer and hydrogenated styrene-butadiene block copolymer.

4. The PG100 modified asphalt according to claim 1, characterized in that: The crystallization enhancing main agent is one or more of silicone powder and silicone masterbatch.

5. The PG100 modified asphalt according to claim 1, characterized in that: The crystallization enhancement auxiliary agent is a composite of low-chlorinated polyethylene and dilauryl thiodipropionate.

6. The PG100 modified asphalt according to claim 5, characterized in that: The chlorine mass fraction of the low-chlorinated polyethylene is 16-24%.

7. The PG100 modified asphalt according to claim 5, characterized in that: The mass ratio of the chlorinated polyethylene to dilauryl thiodipropionate is 8-9:1-2.

8. The PG100 modified asphalt according to claim 1, characterized in that: The organic viscosity reducer is one or more of aromatic oil, naphthenic oil, DOA and DOS.

9. The PG100 modified asphalt according to claim 1, characterized in that: The stabilizer is sulfur or a sulfur-containing stabilizer.

10. The method for preparing PG100 modified asphalt according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1 preheating part of the matrix asphalt to a fluid state, adding the polymer modifier and the crystallization enhancement main agent, stirring evenly, grinding and shearing, and then stirring and growing; S2 adds the organic viscosity reducer and stirs to develop; S3 adds the stabilizer and stirs for growth; S4 adds the crystallization enhancement auxiliary agent, supplements the remaining base asphalt, and after stirring and developing, obtains the PG100 modified asphalt.

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