A modified asphalt with high content of high-viscosity powder and its preparation method

Abstract

This invention relates to a high-content, high-viscosity rubber powder modified asphalt and its preparation method, belonging to the technical field of rubber powder modified asphalt. It solves the problem of low dynamic viscosity in ultra-high-content rubber powder modified asphalt. The high-content, high-viscosity rubber powder modified asphalt, by weight, comprises: base asphalt: 23-43 parts; polymer modifier: 0-3 parts; paste-like pretreated rubber powder: 36-48 parts; first rubber powder: 6-12 parts; reinforcing agent: 5-18 parts; stabilizer: 0-1 parts; viscosity reducer: 1-7 parts. The modified asphalt of this invention achieves a high rubber powder content, improving the performance of the modified asphalt while more effectively solving the problem of recycling waste rubber powder, thus contributing to further environmental improvement.

Description

Technical Field

[0001] This invention belongs to the field of rubber powder modified asphalt technology, and particularly relates to a high-content, high-viscosity rubber powder modified asphalt and its preparation method. Background Technology

[0002] With the rapid development of my country's economy and society, the number of cars has increased dramatically. Consequently, the amount of waste tires generated has risen significantly. The large-scale accumulation of waste rubber tires has led to "black pollution," deteriorating the environment, affecting vegetation growth, and disrupting the ecological balance. Crushing waste rubber tires into rubber powder, which can be used as an asphalt modifier, can effectively solve the problem of recycling waste rubber powder.

[0003] With the increasingly widespread application of rubber-modified asphalt on highways in my country, from 2013 to the present, the application of rubber-modified asphalt on highways in Hebei Province has reached 1,600 kilometers. Among them, 20% rubber-modified asphalt is the most commonly used. The high-temperature performance, low-temperature performance, and water loss resistance of high-volume rubber-modified asphalt are all superior to those of 20% rubber-modified asphalt. Therefore, the technical research on high-performance rubber-modified asphalt with even higher volumes is more important.

[0004] Existing technologies using 28-32 mesh rubber powder can achieve rubber-modified asphalt with a content of approximately 15%-22%. However, this method produces rubber-modified asphalt with poor high-temperature storage stability, significant viscosity decay, and high energy consumption. While some methods achieve rubber powder content of 32%-37%, these require a wider variety of activators to effectively degrade the rubber powder. Furthermore, they necessitate high-temperature swelling and high-speed shearing processes, resulting in substantial energy consumption and failing to achieve energy conservation and emission reduction effects.

[0005] In addition, although high-content rubber powder modified asphalt has a high rotational viscosity, its dynamic viscosity is low, which cannot improve the water loss resistance of rubber powder modified asphalt mixtures, and the stability of rubber powder modified asphalt is poor; the adhesion and toughness properties of asphalt cannot be reflected, and the bonding performance with aggregates is poor. Summary of the Invention

[0006] Based on the above analysis and in view of the shortcomings of the prior art, the present invention improves the rubber powder content in the prior art while solving the problem of low dynamic viscosity of ultra-high rubber powder modified asphalt, and provides a high-content, high-viscosity rubber powder modified asphalt and its preparation method.

[0007] The objective of this invention is mainly achieved through the following technical solutions:

[0008] This invention provides a high-content, high-viscosity modified asphalt, in parts by weight:

[0009] Base bitumen: 23-43 parts;

[0010] Polymer modifier: 0-3 parts;

[0011] Paste-like pretreatment adhesive powder: 36-48 parts;

[0012] First rubber powder: 6-12 parts;

[0013] Reinforcing agent: 5-18 parts;

[0014] Stabilizer: 0-1 part;

[0015] Viscosity reducer: 1-7 parts.

[0016] Furthermore, the base asphalt is road petroleum asphalt; the polymer modifier is one or a mixture of several SBS, SBR, and PP polymers.

[0017] Furthermore, the paste-like pretreated rubber powder is obtained by high-speed mixing and blending of second rubber powder and aromatic oil, followed by twin-screw extrusion processing.

[0018] Furthermore, the viscosity reducer is one or more of petroleum resin, phenolic resin, and terpene resin.

[0019] The present invention also provides a method for preparing the high-content, high-viscosity asphalt modified by the aforementioned method, comprising the following steps:

[0020] Step 1: Weigh the high-content, high-viscosity modified asphalt raw material according to the mass ratio;

[0021] Step 2: Heat the base asphalt in the reactor to 130-170℃, add the paste-like pretreatment adhesive powder and stir and mix for 10-30 minutes;

[0022] Step 3: After the paste-like pre-treatment rubber powder is mixed, add the polymer modifier, reinforcing agent and first rubber powder in sequence, stir and mix for 20-40 minutes, and keep the temperature at 175-190℃;

[0023] Step 4: Pass the well-stirred asphalt mixture through a colloid mill for high-speed shear grinding.

[0024] Step 5: Add the stabilizer and viscosity reducer to the asphalt mixture that has been subjected to high-speed shear grinding, and stir to mix evenly;

[0025] Step 6: Pass the well-stirred asphalt mixture through a colloid mill for low-speed shear grinding.

[0026] Furthermore, in step 2, the preparation process of the paste-like pretreated rubber powder is as follows: the second rubber powder and aromatic oil are fed into a high-speed stirring reactor at a mass ratio of 10:8-10:3 and stirred at high speed for 2-4 minutes. Then, the rubber powder mixture is fed into a twin-screw extruder for high-temperature and high-pressure extrusion.

[0027] Furthermore, in step 2, the extrusion temperature is 280-310℃ and the extrusion pressure is 3.0MPa.

[0028] Furthermore, in step 4, the shearing rate is 1000-3000 rpm, the shearing time is 1-15 minutes, and the shearing temperature is 175℃-190℃.

[0029] Furthermore, in step 5, the temperature is maintained at 175℃-180℃ while stirring and mixing for 6-10 minutes.

[0030] Furthermore, in step 6, the shearing rate is 1000-2000 rpm, the shearing time is 2-10 minutes, and the shearing temperature is 170℃-185℃.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] 1. The modified asphalt of this invention achieves a high content of rubber powder, which can not only improve the performance of modified asphalt, but also more effectively solve the problem of recycling waste rubber powder, which is conducive to further environmental improvement.

[0033] 2. The asphalt material of the present invention improves the problem of low low-temperature ductility of the original rubber powder modified asphalt. The low-temperature ductility of rubber powder modified asphalt can be increased by 20%-25%, and the low-temperature flexural tensile strain of rubber powder modified asphalt mixture can be increased by 10%-15%.

[0034] 3. The rubber powder of the present invention is in the form of a paste. The rubber powder is more fully and evenly dispersed in the asphalt. The dynamic viscosity of the rubber powder modified asphalt is increased by 30%-35%, which improves the cohesion of the rubber powder modified asphalt and enhances its viscosity and toughness, thereby improving the water loss resistance of the rubber powder modified asphalt mixture.

[0035] 4. The rubber powder of this invention is pretreated by twin-screw extrusion, using 12 temperature zones, each with a temperature of about 300°C, an extrusion pressure of 3.0 MPa, and an extrusion speed of 150 kg / h-200 kg / h. This solves the problem of poor compatibility between rubber powder and asphalt caused by excessive rubber powder content. In the production process of rubber powder modified asphalt, the reaction temperature is relatively low, the production cycle is short, and the production efficiency of rubber powder modified asphalt is increased by 10%-15%.

[0036] 5. Because the second rubber powder is pretreated by twin-screw extrusion in the early stage, the harmful gases produced during the treatment process are collected. Moreover, the reaction temperature is low during the production of rubber powder modified asphalt, thus the produced rubber powder modified asphalt has a low odor and causes less environmental pollution during the later construction process.

[0037] Other features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description. Detailed Implementation

[0038] The following detailed description, in conjunction with specific embodiments, illustrates a high-content, high-viscosity modified asphalt and its preparation method. These embodiments are for illustrative purposes only, and the present invention is not limited to these embodiments.

[0039] This invention provides a high-content, high-viscosity powder modified asphalt, based on mass density:

[0040] Base bitumen: 23-43 parts;

[0041] Polymer modifier: 0-3 parts;

[0042] Paste-like pretreatment adhesive powder: 36-48 parts;

[0043] First rubber powder: 6-12 parts;

[0044] Reinforcing agent: 5-18 parts;

[0045] Stabilizer: 0-1 part;

[0046] Viscosity reducer: 1-7 parts.

[0047] It should be noted that the base asphalt is road petroleum asphalt, for example, 70# Grade A petroleum asphalt, which has a penetration of 67, a softening point of 49.0℃, and a ductility of 40cm at 10℃.

[0048] The paste-like pretreated rubber powder is obtained by high-speed mixing and blending of second rubber powder and aromatic oil, followed by twin-screw extrusion. The mass ratio of second rubber powder to aromatic oil is 10:8-10:3, and the particle size of the second rubber powder is 28-35 mesh. The twin-screw extrusion parameters are as follows: 8-12 temperature zones of equal length are used, with a temperature of 280-310℃ in each zone, an extrusion pressure of 3.0-3.5MPa, an extrusion speed of 150KG / h-200KG / h, and an extrusion temperature of 280℃-310℃.

[0049] The second rubber powder in the paste-like pretreated rubber powder can be the same as the first rubber powder, and both can be obtained by crushing waste rubber tires with a particle size of 28-35 mesh.

[0050] Compared with existing technologies, this invention pre-treats a portion of the rubber powder (i.e., the second rubber powder) into a paste before mixing it with asphalt and other components. The total amount of the pre-treated rubber powder and the first rubber powder can reach 42-60 parts. The pre-treated rubber powder can replace the gum in the four components of asphalt (saturated hydrocarbons, aromatic hydrocarbons, asphaltenes, and gums), improving the viscosity and toughness of the rubber powder-modified asphalt. In addition, rubber powder in this particle size range has excellent mechanical properties, which can minimize the damage to its mechanical properties caused by twin-screw extrusion, preferably 28-32 mesh.

[0051] The polymer modifier is one or a mixture of SBS, SBR, and PP polymers. It is mainly a thermoplastic elastomer. After high-speed shearing in a colloid mill, it can form a network structure in asphalt and improve the elastic recovery performance of rubber powder modified asphalt.

[0052] The reinforcing agent is one or more of natural asphalt, low-grade hard asphalt, and petroleum asphalt flakes. The first rubber powder and the second rubber powder adsorb the oil in the asphalt during the asphalt swelling process, which leads to an increase in the asphalt's Brookfield viscosity. The reinforcing agent can be used to further reduce viscosity and reinforce the asphalt.

[0053] The stabilizer is a vulcanization activator, such as sulfur or a mixture of sulfur and zinc stearate, zinc oxide, and thiazoles. In a high-volume, high-viscosity asphalt modified system, it can effectively achieve cross-linking of the asphalt, rubber powder, and polymer ternary structure, thereby improving the dynamic viscosity and high-temperature storage stability of the rubber powder modified asphalt.

[0054] The viscosity reducer uses one or more of petroleum resin, phenolic resin, and terpene resin. It is granular at room temperature and liquid above 130°C. It not only has a good viscosity-reducing effect on rubber-modified asphalt but also maintains high adhesion at 60°C. Existing technologies for rubber-modified asphalt use activators 980 and 480 to reduce asphalt viscosity, but these degrade rapidly at high temperatures, resulting in poor stability of the rubber-modified asphalt. Unlike existing technologies, this invention uses a resin-based viscosity reducer that not only reduces viscosity but also provides reinforcing properties.

[0055] Existing high-content rubber powder modified asphalt exhibits high Brookfield viscosity and low dynamic viscosity. During the swelling process of asphalt, rubber powder adsorbs oil from the asphalt, leading to an increase in Brookfield viscosity. Even after desulfurization and high-speed mechanical shearing, the rubber powder remains in granular form within the asphalt, and these particles are prone to sedimentation, resulting in low dynamic viscosity. The high-content, high-viscosity rubber powder modified asphalt of this invention utilizes a paste-like pretreated rubber powder processed from rubber powder using a high-temperature twin-screw extrusion process. This paste-like pretreated rubber powder allows for uniform dispersion of its adhesive properties within the asphalt, exhibiting high toughness. Therefore, the high-content, high-viscosity rubber powder modified asphalt of this invention features both low Brookfield viscosity and high dynamic viscosity.

[0056] Based on the above-mentioned components of the high-content, high-viscosity asphalt modified asphalt, the following mass proportions were optimized:

[0057] Base bitumen: 30-41 parts;

[0058] Polymer modifier: 0.5-1.5 parts;

[0059] Paste-like pretreatment adhesive powder: 36-45 parts;

[0060] First rubber powder: 6-10 parts;

[0061] Reinforcing agent: 8-15 parts;

[0062] Stabilizer: 0.2-0.6 parts;

[0063] Viscosity reducer: 2-5 parts;

[0064] In addition, the present invention provides a method for preparing high-content, high-viscosity asphalt modified with adhesive powder, which specifically includes the following steps:

[0065] Step 1: Weigh the high-content, high-viscosity modified asphalt raw material according to the mass ratio;

[0066] Step 2: Heat the base asphalt in the reactor to 130-170℃, add the paste-like pretreatment adhesive powder and stir and mix for 10-30 minutes;

[0067] Step 3: After the paste-like pre-treatment rubber powder is mixed, add the polymer modifier, reinforcing agent and first rubber powder in sequence, stir and mix for 20-40 minutes, and keep the temperature at 175-190℃;

[0068] Step 4: Pass the well-stirred asphalt mixture through a colloid mill for high-speed shear grinding.

[0069] Step 5: Add stabilizer and viscosity reducer to the asphalt mixture that has been sheared and ground at high speed, and stir and mix for 5-15 minutes while maintaining the temperature at 170-185℃.

[0070] Step 6: Pass the well-stirred asphalt mixture through a colloid mill for low-speed shear grinding.

[0071] It should be noted that in step 1, the polymer modifier is in granular form, the first rubber powder is waste tire rubber powder, the reinforcing agent is in fragment form, the stabilizer is in powder form, and the viscosity reducer is in granular form.

[0072] Specifically, in step 2, the heating temperature of the base asphalt is 130℃-170℃, preferably 140℃-165℃, and the stirring time is 10-30 minutes, preferably 10-20 minutes;

[0073] Preparation process of paste-like pretreated rubber powder: The second rubber powder is waste tire rubber powder, which is mixed with aromatic oil at a mass ratio of 10:8-10:3 and fed into a high-speed stirred reactor for high-speed stirring for 2-4 minutes. Then the rubber powder mixture is fed into a twin-screw extruder for high-temperature and high-pressure extrusion. Twelve temperature zones are used, with a temperature of 280-310℃, an extrusion pressure of 3.0MPa, and an extrusion speed of 150-200KG / h.

[0074] Specifically, in step 3, the reaction temperature of the asphalt mixture is 175℃-190℃, preferably 180℃-185℃, and the reaction time is 20-40 minutes, preferably 25-35 minutes;

[0075] Specifically, in step 4, the shearing rate is 1000-3000 rpm, preferably 1500-2500 rpm, such as 1800 rpm, 2000 rpm, 2200 rpm, or 2400 rpm; the shearing time is 1-15 minutes, preferably 5-10 minutes; and the shearing temperature is 175℃-190℃, preferably 180℃-185℃, such as 182℃ or 184℃.

[0076] Specifically, in step 5, the reaction temperature of the asphalt mixture is 170℃-185℃, preferably 175℃-180℃, and the reaction time is 5-15 minutes, preferably 6-10 minutes;

[0077] Specifically, in step 6, the shearing rate is 1000-2000 rpm, preferably 1300-1500 rpm, the shearing time is 2-10 minutes, preferably 3-7 minutes, and the shearing temperature is 170℃-185℃, preferably 175℃-185℃.

[0078] It should be noted that the preparation temperature of high-content rubber powder modified asphalt in the prior art is 200℃-210℃, while the preparation temperature of rubber powder modified asphalt in this invention is 175℃-190℃. The heating system of the production equipment adopts electric heating, which results in a lower preparation temperature, effectively reducing heating time, reducing production energy consumption, saving production time, and improving production efficiency.

[0079] The high-content stabilized rubber powder modified asphalt prepared by the above process has a 20%-25% increase in ductility, a significant improvement in low-temperature performance, and a 30%-35% increase in dynamic viscosity, thereby enhancing the cohesion and toughness of the rubber powder modified asphalt and significantly improving its durability.

[0080] Example 1

[0081] Step 1: Weigh the following raw materials according to the mass ratio: 43 parts of 70# base asphalt, 36 parts of paste pretreatment rubber powder, 3.5 parts of viscosity reducer, 0.7 parts of polymer modifier, 6 parts of first rubber powder, 10.6 parts of reinforcing agent, and 0.2 parts of stabilizer.

[0082] Specifically, the ingredients are: 220g of 70# Grade A petroleum asphalt, 184.2g of paste-like pretreated rubber powder, 3.6g of SBS, 30.7g of first rubber powder, 54.2g of petroleum asphalt flakes, 0.5g of sulfur, 0.5g of zinc stearate, and 17.9g of petroleum resin.

[0083] Step 2: Heat the 70# Grade A petroleum asphalt in the reactor to 130°C, add the paste-like pre-treatment adhesive powder, and stir and mix for 10 minutes.

[0084] Preparation process of paste-like pretreated rubber powder: 28-35 mesh second rubber powder and aromatic oil are added to a high-speed stirred reactor at a mass ratio of 102.2g:81.8g and stirred at high speed for 2 minutes. Then the rubber powder mixture is fed into a twin-screw extruder for high-temperature and high-pressure extrusion. Twelve temperature zones are used, all with a temperature of 280℃, an extrusion pressure of 3.0MPa, and an extrusion speed of 150KG / h.

[0085] Step 3: After the paste-like pre-treatment rubber powder is mixed, add SBS, 28-35 mesh first rubber powder and petroleum asphalt flakes in sequence, stir and mix for 20 minutes, and keep the temperature at 175℃.

[0086] Step 4: The well-stirred asphalt mixture is subjected to high-speed shear grinding through a colloid mill at a shear rate of 1000 rpm, a shearing time of 1 minute, and a shearing temperature of 175℃.

[0087] Step 5: Add mercaptan and petroleum resin to the asphalt mixture that has been sheared and ground at high speed, and stir and mix for 5 minutes while maintaining the temperature at 170℃.

[0088] Step 6: The asphalt mixture to be stirred evenly is passed through a colloid mill for low-speed shear grinding at a shear rate of 1000 rpm, a shearing time of 2 minutes, and a shearing temperature of 170℃.

[0089] Complete the sample preparation.

[0090] Example 2

[0091] Step 1: Weigh the following high-content, high-viscosity modified asphalt raw materials according to the mass ratio: 37.6 parts of 70# base asphalt, 39 parts of paste-like pretreatment rubber powder, 3.7 parts of viscosity reducer, 1 part of polymer modifier, 7.5 parts of first rubber powder, 11 parts of reinforcing agent, and 0.2 parts of stabilizer.

[0092] Specifically, the ingredients are: 202g of 70# Grade A petroleum asphalt, 209.5g of paste-like pretreated rubber powder, 3.1g of SBS, 2.3g of PP, 40.3g of first rubber powder, 59.1g of natural asphalt, 0.5g of sulfur, 0.3g of zinc stearate, 0.3g of zinc oxide, and 19.9g of terpene resin.

[0093] Step 2: Heat the 70# Grade A petroleum asphalt in the reactor to 170℃, add the paste-like pre-treatment rubber powder, and stir and mix for 30 minutes;

[0094] Preparation process of paste-like pretreated rubber powder: 28-35 mesh second rubber powder and aromatic oil are fed into a high-speed stirred reactor at a mass ratio of 161.5:48.5 and stirred at high speed for 4 minutes. Then the rubber powder mixture is fed into a twin-screw extruder for high-temperature and high-pressure extrusion. Twelve temperature zones are used, all with a temperature of 310℃, an extrusion pressure of 3.0MPa, and an extrusion speed of 200KG / h.

[0095] Step 3: After the paste-like pre-treatment rubber powder is mixed, add SBS, PP, 28-35 mesh first rubber powder and natural asphalt in sequence, stir and mix for 40 minutes, and keep the temperature at 190℃.

[0096] Step 4: The well-stirred asphalt mixture is subjected to high-speed shear grinding through a colloid mill at a shear rate of 3000 rpm, a shearing time of 15 minutes, and a shearing temperature of 190℃.

[0097] Step 5: Add sulfide and terpene resin to the asphalt mixture that has been sheared and ground at high speed, and stir and mix at 185°C for 15 minutes.

[0098] Step 6: The asphalt mixture to be stirred evenly is passed through a colloid mill for low-speed shear grinding at a shear rate of 2000 rpm for 10 minutes and a shear temperature of 185℃.

[0099] Complete the sample preparation.

[0100] Example 3

[0101] Step 1: Weigh the high-content, high-viscosity modified asphalt raw materials according to the following mass ratio: 36.1 parts of 70# Grade A road asphalt, 43 parts of paste-like pretreatment rubber powder, 3.5 parts of viscosity reducer, 0.7 parts of polymer modifier, 7 parts of first rubber powder, 9.5 parts of reinforcing agent, and 0.2 parts of stabilizer.

[0102] Specifically, the following materials are used: 240g of 70# Grade A petroleum asphalt, 285.9g of paste-like pretreatment rubber powder, 4.7g of SBR, 46.5g of first rubber powder, 63.2g of low-grade hard asphalt, 1.3g of sulfur, and 23.3g of phenolic resin.

[0103] Step 2: Heat the 70# Grade A petroleum asphalt in the reactor to 140℃, add the paste-like pre-treatment rubber powder, and stir and mix for 20 minutes.

[0104] Preparation process of paste-like pretreated rubber powder: 28-32 mesh second rubber powder and aromatic oil are fed into a high-speed stirred reactor at a mass ratio of 179g:107g and stirred at high speed for 3 minutes. Then the rubber powder mixture is fed into a twin-screw extruder for high-temperature and high-pressure extrusion. Twelve temperature zones are used, all with a temperature of 300℃, an extrusion pressure of 3.0MPa, and an extrusion speed of 160KG / h.

[0105] Step 3: After the paste-like pretreatment rubber powder is mixed, add SBR, 28-32 mesh first rubber powder and low grade hard asphalt in sequence, stir and mix for 25 minutes, and keep the temperature at 180℃.

[0106] Step 4: The well-stirred asphalt mixture is subjected to high-speed shear grinding through a colloid mill at a shear rate of 1500 rpm, a shearing time of 5 minutes, and a shearing temperature of 180℃.

[0107] Step 5: Add sulfur and phenolic resin to the asphalt mixture that has been subjected to high-speed shear grinding, and stir and mix at 175°C for 6 minutes.

[0108] Step 6: The asphalt mixture to be stirred evenly is passed through a colloid mill for low-speed shear grinding at a shear rate of 1300 rpm for 3 minutes and a shear temperature of 175℃.

[0109] Complete the sample preparation.

[0110] Example 4

[0111] Step 1: Weigh the high-content, high-viscosity modified asphalt raw materials according to the following mass ratio: 33.9 parts of 70# base asphalt, 45 parts of paste-like pretreatment rubber powder, 3.2 parts of viscosity reducer, 0.7 parts of polymer modifier, 9 parts of first rubber powder, 8 parts of reinforcing agent, and 0.2 parts of stabilizer.

[0112] Specifically, the following components are used: 204g of 70# Grade A petroleum asphalt, 270.8g of paste-like pretreatment rubber powder, 4.2g of PP, 54.2g of first-grade rubber powder, 48.1g of low-grade hard asphalt, 1.2g of sulfur, and 19.3g of petroleum resin.

[0113] Step 2: Heat the 70# Grade A petroleum asphalt in the reactor to 165℃, add the paste-like pre-treatment rubber powder, and stir and mix for 20 minutes;

[0114] Preparation process of paste-like pretreated rubber powder: 28-32 mesh second rubber powder and aromatic oil are added to a high-speed stirred reactor at a mass ratio of 180.5g:90.3g and stirred at high speed for 3 minutes. Then the rubber powder mixture is fed into a twin-screw extruder for high-temperature and high-pressure extrusion. Twelve temperature zones are used, all with a temperature of 290℃, an extrusion pressure of 3.0MPa, and an extrusion speed of 180KG / h.

[0115] Step 3: After the paste-like pre-treatment rubber powder is mixed, add PP, 28-32 mesh first rubber powder and low grade hard asphalt in sequence, stir and mix for 35 minutes, and keep the temperature at 185℃.

[0116] Step 4: The well-stirred asphalt mixture is subjected to high-speed shear grinding through a colloid mill at a shear rate of 2500 rpm, a shearing time of 10 minutes, and a shearing temperature of 185℃.

[0117] Step 5: Add sulfur and petroleum resin to the asphalt mixture that has been sheared and ground at high speed, and stir and mix for 10 minutes while maintaining the temperature at 180℃.

[0118] Step 6: The asphalt mixture to be stirred evenly is passed through a colloid mill for low-speed shear grinding at a shear rate of 1500 rpm, a shearing time of 7 minutes, and a shearing temperature of 185℃.

[0119] Complete the sample preparation.

[0120] Example 5

[0121] Step 1: Weigh the high-content, high-viscosity modified asphalt raw materials according to the following mass ratio: 25 parts of 70# base asphalt, 48 parts of paste pretreatment rubber powder, 5.8 parts of viscosity reducer, 0.5 parts of polymer modifier, 12 parts of first rubber powder, 10.2 parts of reinforcing agent, and 0.2 parts of stabilizer.

[0122] Specifically, the following materials are used: 156g of 70# Grade A petroleum asphalt, 299.5g of paste-like pretreated rubber powder, 3.1g of SBS, 74.9g of first rubber powder, 63.6g of petroleum asphalt flakes, 1.2g of sulfur, and 36.2g of petroleum resin.

[0123] Step 2: Heat the 70# Grade A petroleum asphalt in the reactor to 170℃, add the paste-like pre-treatment rubber powder, and stir and mix for 30 minutes;

[0124] Preparation process of paste-like pretreated rubber powder: 28-32 mesh second rubber powder and aromatic oil are added to a high-speed stirred reactor at a mass ratio of 214g:85.7g and stirred at high speed for 4 minutes. Then the rubber powder mixture is fed into a twin-screw extruder for high-temperature and high-pressure extrusion. Twelve temperature zones are used, all with a temperature of 300℃, an extrusion pressure of 3.0MPa, and an extrusion speed of 190KG / h.

[0125] Step 3: After the paste-like pre-treatment rubber powder is mixed, add SBS, 28-32 mesh first rubber powder and petroleum asphalt flakes in sequence, stir and mix for 30 minutes, and keep the temperature at 182℃.

[0126] Step 4: The well-stirred asphalt mixture is subjected to high-speed shear grinding through a colloid mill at a shear rate of 2000 rpm, a shearing time of 8 minutes, and a shearing temperature of 182℃.

[0127] Step 5: Add sulfur and petroleum resin to the asphalt mixture that has been sheared and ground at high speed, and stir and mix for 8 minutes while maintaining the temperature at 178°C.

[0128] Step 6: The asphalt mixture to be stirred evenly is passed through a colloid mill for low-speed shear grinding at a shear rate of 1400 rpm, a shearing time of 5 minutes, and a shearing temperature of 180℃.

[0129] Complete the sample preparation.

[0130] Comparative example:

[0131] Step 1: Weigh the high-content rubber powder modified raw materials according to the following mass ratio: 57 parts of 70# base asphalt, 35 parts of first rubber powder, 1 part of SBS, 1.1 parts of activating viscosity reducer, 0.3 parts of stabilizer, and 5.6 parts of reinforcing agent;

[0132] Specifically, the following ingredients are used: 300g of 70# Grade A petroleum asphalt, 184g of first rubber powder, 5.3g of SBS, 5.8g of activating viscosity reducer 480, 1.6g of sulfur, and 29.5g of natural asphalt.

[0133] Step 2: Heat the 70# Grade A petroleum asphalt in the reactor to 150°C, add SBS and activating viscosity reducer 480, and stir and mix for 10 minutes.

[0134] Step 3: After the asphalt mixture is fully mixed, add 28-32 mesh first rubber powder and stir for 40 minutes. The reaction temperature is 205℃ and the stirring time is 40 minutes.

[0135] Step 4: The well-stirred asphalt mixture is subjected to high-speed shear grinding through a colloid mill. The shearing temperature is maintained at 205℃, the shearing rate is 2000 rpm, and the shearing time is 15 minutes.

[0136] Step 5: Add the asphalt mixture that has been sheared and ground at high speed to sulfur and natural asphalt, keep the shear temperature at 195°C, and stir for 15 minutes.

[0137] Step 6: The asphalt mixture to be stirred evenly is passed through a colloid mill for low-speed shear grinding. The shearing temperature is maintained at 195℃, the shearing rate is 2000 rpm, and the shearing time is 5 minutes.

[0138] Complete the sample preparation.

[0139] Table 1 shows the test results of various properties of the high-content, high-viscosity rubber powder modified asphalt in Examples 1-5 and the comparative example. The test results in Table 1 show that, compared with existing high-content stabilized rubber powder modified asphalt, the present invention improves the ductility of the rubber powder modified asphalt and significantly improves its low-temperature performance. Analysis of the dynamic viscosity test results shows that the dynamic viscosity of the high-content, high-viscosity rubber powder modified asphalt is significantly increased, thereby enhancing the cohesion and toughness of the asphalt. This also significantly improves the durability of the rubber powder modified asphalt.

[0140] Table 1. Test results of various properties of high-content, high-viscosity asphalt modified with Example 1-5 and comparative examples.

[0141]

[0142] The high-content, high-viscosity powder modified asphalt of this invention has good durability and improved road performance. Therefore, the high-content, high-viscosity powder modified asphalt of this invention has a very broad application prospect in the field of road materials.

Claims

1. A high content high viscose powder modified asphalt, characterized in that, The high-content high-viscosity rubber powder modified asphalt is prepared by mixing the following components by weight: Matrix asphalt: 23-36.1 parts; Polymer modifier: 0.7-3 parts; Pasty pretreated rubber powder: 43-48 parts; First rubber powder: 7-12 parts; Reinforcing agent: 9.5-18 parts; Stabilizer: 0.2-1 part; Viscosity reducer: 3.5-7 parts. The preparation process of the pasty pretreated rubber powder is as follows: the second rubber powder and aromatic oil are mixed in a high-speed stirring reactor at a mass ratio of 179:107-10:3, and then the mixture is put into a double-screw extrusion device for high-temperature and high-pressure extrusion. The reinforcing agent is one or more of natural asphalt, low-grade hard asphalt, and petroleum asphalt sheet. The viscosity reducer is one or more of petroleum resin, phenolic resin, and terpene resin.

2. The high volume high viscose powder modified asphalt according to claim 1, characterized in that, The matrix asphalt is road petroleum asphalt, and the polymer modifier is one or more of SBS, SBR, and PP polymer.

3. The method for preparing high-content, high-viscosity asphalt according to any one of claims 1-2, characterized in that, The method comprises the following steps: Step 1: weighing the high-content high-viscosity rubber powder modified asphalt raw materials according to the mass ratio; Step 2: heating the matrix asphalt in the reactor to 130-170℃, and adding the pasty pretreated rubber powder for stirring and blending for 10-30 minutes; Step 3: after the mixing of the pasty pretreated rubber powder is completed, the polymer modifier, reinforcing agent, and first rubber powder are added in sequence, and stirring and mixing are performed for 20-40 minutes, with the temperature maintained at 175-190℃; Step 4: passing the uniformly stirred asphalt mixture through a glue mill for high-speed shearing and grinding; Step 5: adding the stabilizer and viscosity reducer to the asphalt mixture subjected to high-speed shearing and grinding, and stirring and mixing uniformly; Step 6: passing the uniformly stirred asphalt mixture through a glue mill for low-speed shearing and grinding.

4. The method for preparing high-content, high-viscosity asphalt according to claim 3, characterized in that, In step 2, the preparation process of the pasty pretreated rubber powder is as follows: the second rubber powder and aromatic oil are mixed in a high-speed stirring reactor at a mass ratio of 179:107-10:3, and then the mixture is put into a double-screw extrusion device for high-temperature and high-pressure extrusion.

5. The method according to claim 4, wherein the high content of high viscosity pulp is 20- 30% by weight of the total weight of the asphalt. In step 2, the extrusion temperature is 280-310℃, and the extrusion pressure is 3.0 MPa. ​ 6. The method of claim 3, wherein the high content of the viscose powder is 10-30 wt% of the total weight of the asphalt. 5 In step 4, the shearing rate is 1000-3000 rpm, the shearing time is 1-15 minutes, and the shearing temperature is 175℃-190℃.

7. The method for preparing high-content, high-viscosity asphalt according to claim 3, characterized in that, In step 5, the temperature is maintained at 175℃-180℃ for stirring and mixing for 6-10 minutes.

8. The method for preparing high-content, high-viscosity asphalt according to claim 3, characterized in that, In step 6, the shearing rate is 1000-2000 rpm, the shearing time is 2-10 minutes, and the shearing temperature is 170℃-185℃.

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