High-dosage rubber powder composite SBS modified asphalt and preparation method thereof

Abstract

The invention discloses high-volume rubber powder composite SBS modified asphalt and a preparation method thereof, and belongs to the technical field of materials for asphalt pavements. The composite SBS modified asphalt is prepared from the following components in parts by mass: 60 to 70 parts of asphalt, 10 to 15 parts of common rubber powder, 15 to 30 parts of activated rubber powder, 2 to 2.5 parts of an SBS modifier, 1 to 2 parts of a ductility enhancer, 0.5 to 1 part of a dispersing agent and 0.1 to 0.15 part of a stabilizer. The high-volume rubber powder composite SBS modified asphalt disclosed by the invention is simple in processing technology, low in price and stable in performance, and has obvious effects on improving the low-temperature crack resistance, fatigue resistance and aging resistance of an asphalt mixture besides improving the rutting resistance of the asphalt mixture. Meanwhile, the waste tires can be effectively recycled, the method has the advantages of being ecological, environmentally friendly and the like, resource waste is directly reduced, and natural landscape and ecological environment balance are greatly maintained.

Description

Technical Field

[0001] The invention belongs to the technical field of asphalt pavement materials, and particularly relates to a high-volume rubber powder composite SBS modified asphalt and a preparation method thereof. Background Art

[0002] With economic development, the tire industry is facing an increasingly severe problem of "mass production and mass waste." Processing waste tires into rubber powder for use in road construction is one effective way to recycle waste tires. With recent improvements in rubber powder processing technology and the continuous reduction in the production cost of fine rubber powder, rubber powder has been widely used in road construction, achieving promising results. The combination of rubber powder and SBS improves the pavement's high-temperature rutting resistance, low-temperature crack resistance, water stability, and durability, extending its service life and significantly reducing road construction costs.

[0003] However, when the rubber powder content in existing technologies is low, the modified asphalt has poor shelf stability and is prone to stratification and sedimentation. This lack of stability during long-term storage or under high-temperature conditions affects construction uniformity. Furthermore, the low rubber powder content has a limited contribution to reducing the cost of the modified asphalt. Patent CN 102977621 A, "Composite modified asphalt of SBS and waste rubber powder and its preparation method," specifies 75-96 parts by weight of base asphalt and 0.5-12 parts of waste rubber powder. Patent CN 103059591 A, "Composite modified asphalt of SBS and rubber powder and its preparation method," specifies 10-15% rubber powder. Excessive rubber powder content significantly increases the viscosity of the modified asphalt, increasing construction difficulty and complicating the processing. In patent CN111393863 B "A rubber powder modified asphalt and its preparation method", the base asphalt is 50-60 parts and the rubber powder is 30-35 parts. During the preparation of the modified asphalt, the solid raw materials in the modified asphalt must first be mixed evenly and crushed to form a modified powder to reduce the particle size of the solid raw materials in the modified asphalt, ensure that the solid raw materials are evenly dispersed in the base asphalt, and increase the probability of the solid powder reacting with the base asphalt. In addition, the asphalt modification needs to be carried out in a dry inert gas atmosphere to reduce the probability of unnecessary side reactions between the modified asphalt raw materials and water vapor in the air, thereby increasing the complexity of the processing of large-amount rubber powder composite modified asphalt products. Summary of the Invention

[0004] In response to the shortcomings of the existing technology, the present invention provides a large-volume rubber powder composite SBS modified asphalt and a preparation method thereof, the purpose of which is to further increase the rubber powder content, reduce the amount of SBS and base asphalt, give full play to the advantages of both SBS and rubber powder modifiers, reduce the cost of modified asphalt, and at the same time improve the storage stability of the rubber powder composite modified asphalt and improve the durability of asphalt pavement.

[0005] A high-content rubber powder composite SBS modified asphalt, comprising the following components in parts by mass:

[0006] Asphalt 60-70 parts, ordinary rubber powder 10-15 parts, activated rubber powder 15-30 parts, SBS modifier 2-2.5 parts, retardant 1-2 parts, dispersant 0.5-1 part, stabilizer 0.1-0.15 parts;

[0007] The modified asphalt has a needle penetration of ≥60 (0.1 mm), a softening point of ≥70°C, an elongation at 5°C of ≥15 cm, a kinematic viscosity of 1.5 Pa·s to 3.5 Pa·s at 180°C, a flash point of ≥230°C, a viscosity-toughness of ≥10 N·m, a difference between segregation and softening points of ≤5°C, an elastic recovery of ≥80%, a change in the mass of the residue after RTFOT of ≤±0.8%, a residual needle penetration ratio of ≥60%, and a residual elongation of ≥10 cm at 5°C.

[0008] in:

[0009] The asphalt is Grade A No. 90 road petroleum asphalt.

[0010] The ordinary rubber powder is processed from waste tires and has a particle size of 40 to 60 meshes.

[0011] The activated rubber powder is made from common rubber powder through surface activation, has a particle size of 40-60 meshes, a carbon black content of ≥28%, and a rubber hydrocarbon content of ≥42%.

[0012] The SBS modifier is linear; the stabilizer is sulfur, and the effective component content is ≥95%.

[0013] The retardant is one or a mixture of rubber oil, aromatic oil, and naphthenic oil, and the proportions of the multiple retardants are arbitrary.

[0014] The dispersant is one or a mixture of zinc stearate, stearic acid amide, and vinyl bis-stearic acid amide, and the proportions of the multiple dispersants are arbitrary.

[0015] The preparation method of the above-mentioned high-content rubber powder composite SBS modified asphalt specifically comprises the following steps:

[0016] (1) Preheating the asphalt to 145°C to 155°C according to the mass fraction, adding ordinary rubber powder, activated rubber powder, SBS modifier, retardant and dispersant, then heating and performing high-speed shear dispersion to obtain a mixture;

[0017] (2) A stabilizer is added to the mixture, and after development, a large amount of rubber powder composite SBS modified asphalt is obtained.

[0018] in:

[0019] In the step (1), the temperature of the high-speed shear dispersion is 220° C. to 230° C., the rotation speed is 7000 r / min to 8000 r / min, and the dispersion time is 1.5 h to 2 h.

[0020] In the step (2), the development temperature is 180° C. to 185° C., and the development time is 50 min to 70 min.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The high-content rubber powder-compounded SBS modified asphalt of the present invention features a simple processing process, low cost, and stable performance. In addition to improving the rutting resistance of asphalt mixtures, it also significantly enhances the low-temperature crack resistance, fatigue resistance, and aging resistance of asphalt mixtures. Furthermore, it allows for the effective recycling of waste tires, offering environmental advantages, directly reducing resource waste, and significantly maintaining the balance of the natural landscape and ecological environment. This aligns with the national policy of building a resource-conserving and environmentally friendly society, resulting in excellent social and environmental benefits. DETAILED DESCRIPTION

[0023] The present invention is further described below with reference to the examples.

[0024] In the embodiment of the present invention, ordinary rubber powder is processed from waste tires, and the particle size is 40-60 mesh.

[0025] In the embodiment of the present invention, the activated rubber powder is made from ordinary rubber powder through surface activation, has a particle size of 40-60 mesh, a carbon black content of ≥28%, and a rubber hydrocarbon content of ≥42%.

[0026] In the embodiment of the present invention, the stabilizer is sulfur, and the content of the active ingredient is ≥95%.

[0027] Example 1

[0028] A method for preparing a high-content rubber powder composite SBS modified asphalt specifically comprises the following steps:

[0029] (1) Prepare the ingredients according to the following weight ratios: 70 parts of Class A No. 90 road petroleum asphalt, 15 parts of ordinary rubber powder, 15 parts of activated rubber powder, 2 parts of linear SBS modifier, 1 part of aromatic oil, 0.7 parts of vinyl bis-hard amide, and 0.15 parts of sulfur.

[0030] Class A No. 90 road petroleum asphalt was preheated to 150°C, and ordinary rubber powder, activated rubber powder, linear SBS modifier, aromatic oil, and vinyl bis-stearamide were added thereto. The mixture was then heated to 220°C and subjected to high-speed shear dispersion at a speed of 7000 r / min for 2 hours to obtain a mixture.

[0031] (2) Sulfur was added to the mixture and developed at 185°C for 60 minutes to obtain a high-content rubber powder composite SBS modified asphalt.

[0032] The test indicators of the high-content rubber powder composite SBS modified asphalt prepared in this example are shown in Table 1.

[0033] Table 1 Test indicators of SBS modified asphalt with high content of rubber powder

[0034]

[0035] To verify the performance of the modified asphalt prepared in this example, the modified asphalt was used to prepare an AC-20C asphalt mixture. According to the requirements of the Ministry of Transport's "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004), the asphalt mixture was tested for high-temperature rutting resistance, low-temperature cracking resistance, water damage resistance, and fatigue resistance. The test results were compared with those of an SBS modified asphalt mixture.

[0036] The test results show that after using the high-content rubber powder composite SBS modified asphalt of this embodiment, the dynamic stability, failure strain, residual strength ratio, and fatigue number performance indicators of the asphalt mixture are compared with the test results of the SBS modified asphalt mixture. All indicators are greatly improved. The test results of the road performance of the asphalt mixture are shown in Table 2, and the results of the fatigue test of the asphalt mixture are shown in Table 3.

[0037] Table 2 Asphalt mixture road performance test results

[0038]

[0039] Table 3 Asphalt mixture fatigue test results

[0040]

[0041] Example 2

[0042] A method for preparing a high-content rubber powder composite SBS modified asphalt specifically comprises the following steps:

[0043] (1) Prepare the ingredients in parts by mass: 70 parts of Class A No. 90 road petroleum asphalt, 10 parts of ordinary rubber powder, 20 parts of activated rubber powder, 2.5 parts of linear SBS modifier, 1.5 parts of aromatic oil, 0.5 parts of vinyl bis-hard amide, and 0.15 parts of sulfur.

[0044] Class A No. 90 road petroleum asphalt was preheated to 148°C, and ordinary rubber powder, activated rubber powder, linear SBS modifier, aromatic oil, and vinyl bis-stearamide were added thereto. The mixture was then heated to 225°C and subjected to high-speed shear dispersion at a speed of 7500 r / min for 1.5 hours to obtain a mixture.

[0045] (2) Sulfur was added to the mixture and developed at 180°C for 50 minutes to obtain SBS modified asphalt with a large amount of rubber powder.

[0046] The test indicators of the high-content rubber powder composite SBS modified asphalt prepared in this example are shown in Table 4.

[0047] Table 4 Test indicators of high-content rubber powder composite SBS modified asphalt

[0048]

[0049]

[0050] To verify the performance of the modified asphalt prepared in this example, the modified asphalt was used to prepare an AC-20C asphalt mixture. According to the requirements of the Ministry of Transport's "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004), the asphalt mixture was tested for high-temperature rutting resistance, low-temperature cracking resistance, water damage resistance, and fatigue resistance. The test results were compared with those of an SBS modified asphalt mixture.

[0051] After testing, after using the high-content rubber powder composite SBS modified asphalt of the present invention, the dynamic stability, failure strain, residual strength ratio, and fatigue number performance indicators of the asphalt mixture were compared with the test results of the SBS modified asphalt mixture. All indicators were greatly improved. The test results of the road performance of the asphalt mixture are shown in Table 5, and the results of the fatigue test of the asphalt mixture are shown in Table 6.

[0052] Table 5 Asphalt mixture road performance test results

[0053]

[0054] Table 6 Asphalt mixture fatigue test results

[0055]

[0056] Example 3

[0057] A method for preparing a high-content rubber powder composite SBS modified asphalt specifically comprises the following steps:

[0058] (1) Ingredients are prepared according to the following mass proportions: 65 parts of Class A No. 90 road petroleum asphalt, 12 parts of ordinary rubber powder, 23 parts of activated rubber powder, 2.2 parts of linear SBS modifier, 1.5 parts of aromatic oil, 0.75 parts of vinyl bis-hard amide, and 0.12 parts of sulfur.

[0059] Class A No. 90 road petroleum asphalt was preheated to 155°C, and ordinary rubber powder, activated rubber powder, linear SBS modifier, aromatic oil, and vinyl bis-stearamide were added thereto. The mixture was then heated to 230°C and subjected to high-speed shear dispersion at a speed of 8000 r / min for 2 hours to obtain a mixture.

[0060] (2) Sulfur was added to the mixture and developed at 182°C for 55 minutes to obtain a high-content rubber powder composite SBS modified asphalt.

[0061] The test indicators of the high-content rubber powder composite SBS modified asphalt prepared in this example are shown in Table 7.

[0062] Table 7 Test indicators of high-content rubber powder composite SBS modified asphalt

[0063]

[0064] To verify the performance of the modified asphalt prepared in this example, the modified asphalt was used to prepare an AC-20C asphalt mixture. According to the requirements of the Ministry of Transport's "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004), the asphalt mixture was tested for high-temperature rutting resistance, low-temperature cracking resistance, water damage resistance, and fatigue resistance. The test results were compared with those of an SBS modified asphalt mixture.

[0065] After testing, after using the high-content rubber powder composite SBS modified asphalt of the present invention, the dynamic stability, failure strain, residual strength ratio, and fatigue number performance indicators of the asphalt mixture were compared with the test results of the SBS modified asphalt mixture. All indicators were greatly improved. The test results of the road performance of the asphalt mixture are shown in Table 8, and the results of the fatigue test of the asphalt mixture are shown in Table 9.

[0066] Table 8 Asphalt mixture road performance test results

[0067]

[0068] Table 9 Asphalt mixture fatigue test results

[0069]

[0070] Example 4

[0071] A method for preparing a high-content rubber powder composite SBS modified asphalt specifically comprises the following steps:

[0072] (1) Prepare the ingredients according to the following weight ratios: 65 parts of Class A No. 90 road petroleum asphalt, 10 parts of ordinary rubber powder, 25 parts of activated rubber powder, 2 parts of linear SBS modifier, 1.2 parts of aromatic oil, 1 part of vinyl bis-hard amide, and 0.1 part of sulfur.

[0073] Class A No. 90 road petroleum asphalt was preheated to 145°C, and ordinary rubber powder, activated rubber powder, linear SBS modifier, aromatic oil, and vinyl bis-stearamide were added thereto. The mixture was then heated to 225°C and subjected to high-speed shear dispersion at a speed of 7800 r / min for 1.5 hours to obtain a mixture.

[0074] (2) Sulfur was added to the mixture and developed at 180°C for 70 minutes to obtain a high-content rubber powder composite SBS modified asphalt.

[0075] The test indicators of the high-content rubber powder composite SBS modified asphalt prepared in this example are shown in Table 10.

[0076] Table 10 Test indicators of high-content rubber powder composite SBS modified asphalt

[0077]

[0078] To verify the performance of the modified asphalt prepared in this example, the modified asphalt was used to prepare an AC-20C asphalt mixture. According to the requirements of the Ministry of Transport's "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004), the asphalt mixture was tested for high-temperature rutting resistance, low-temperature cracking resistance, water damage resistance, and fatigue resistance. The test results were compared with those of an SBS modified asphalt mixture.

[0079] After testing, after using the high-content rubber powder composite SBS modified asphalt of the present invention, the dynamic stability, failure strain, residual strength ratio, and fatigue number performance indicators of the asphalt mixture were compared with the test results of the SBS modified asphalt mixture. All indicators were greatly improved. The test results of the road performance of the asphalt mixture are shown in Table 11, and the results of the fatigue test of the asphalt mixture are shown in Table 12.

[0080] Table 11 Asphalt mixture road performance test results

[0081]

[0082]

[0083] Table 12 Asphalt mixture fatigue test results

[0084]

[0085] Example 5

[0086] A method for preparing a high-content rubber powder composite SBS modified asphalt specifically comprises the following steps:

[0087] (1) Prepare the ingredients according to the following weight ratios: 60 parts of Class A No. 90 road petroleum asphalt, 15 parts of ordinary rubber powder, 25 parts of activated rubber powder, 2.5 parts of linear SBS modifier, 2 parts of aromatic oil, 1 part of vinyl bis-hard amide, and 0.1 part of sulfur.

[0088] Class A No. 90 road petroleum asphalt was preheated to 152°C, and ordinary rubber powder, activated rubber powder, linear SBS modifier, aromatic oil, and vinyl bis-stearamide were added thereto. The mixture was then heated to 228°C and subjected to high-speed shear dispersion at a speed of 7600 r / min for 110 minutes to obtain a mixture.

[0089] (2) Sulfur was added to the mixture and developed at 182°C for 55 minutes to obtain a high-content rubber powder composite SBS modified asphalt.

[0090] The test indicators of the high-content rubber powder composite SBS modified asphalt prepared in this example are shown in Table 13.

[0091] Table 13 Test indicators of high-content rubber powder composite SBS modified asphalt

[0092]

[0093] To verify the performance of the modified asphalt prepared in this example, the modified asphalt was used to prepare an AC-20C asphalt mixture. According to the requirements of the Ministry of Transport's "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004), the asphalt mixture was tested for high-temperature rutting resistance, low-temperature cracking resistance, water damage resistance, and fatigue resistance. The test results were compared with those of an SBS modified asphalt mixture.

[0094] After testing, after using the high-content rubber powder composite SBS modified asphalt of the present invention, the dynamic stability, failure strain, residual strength ratio, and fatigue number performance indicators of the asphalt mixture were compared with the test results of the SBS modified asphalt mixture. All indicators were greatly improved. The test results of the road performance of the asphalt mixture are shown in Table 14, and the results of the fatigue test of the asphalt mixture are shown in Table 15.

[0095] Table 14 Asphalt mixture road performance test results

[0096]

[0097] Table 15 Asphalt mixture fatigue test results

[0098]

[0099] Example 6

[0100] A method for preparing a high-content rubber powder composite SBS modified asphalt specifically comprises the following steps:

[0101] (1) Prepare the ingredients according to the following weight proportions: 60 parts of Class A No. 90 road petroleum asphalt, 10 parts of ordinary rubber powder, 30 parts of activated rubber powder, 2.5 parts of linear SBS modifier, 1.7 parts of aromatic oil, 0.5 parts of vinyl bis-hard amide, and 0.1 parts of sulfur.

[0102] Class A No. 90 road petroleum asphalt was preheated to 147°C, and ordinary rubber powder, activated rubber powder, linear SBS modifier, aromatic oil, and vinyl bis-stearamide were added thereto. The mixture was then heated to 227°C and subjected to high-speed shear dispersion at a speed of 7300 r / min for 2 hours to obtain a mixture.

[0103] (2) Sulfur was added to the mixture and developed at 183°C for 65 minutes to obtain a high-content rubber powder composite SBS modified asphalt.

[0104] The test indicators of the high-content rubber powder composite SBS modified asphalt prepared in this example are shown in Table 16.

[0105] Table 16 Test indicators of high-content rubber powder composite SBS modified asphalt

[0106]

[0107]

[0108] To verify the performance of the modified asphalt prepared in this example, the modified asphalt was used to prepare an AC-20C asphalt mixture. According to the requirements of the Ministry of Transport's "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004), the asphalt mixture was tested for high-temperature rutting resistance, low-temperature cracking resistance, water damage resistance, and fatigue resistance. The test results were compared with those of an SBS modified asphalt mixture.

[0109] After testing, after using the high-content rubber powder composite SBS modified asphalt of the present invention, the dynamic stability, failure strain, residual strength ratio, and fatigue number performance indicators of the asphalt mixture were compared with the test results of the SBS modified asphalt mixture. All indicators were greatly improved. The test results of the road performance of the asphalt mixture are shown in Table 17, and the results of the fatigue test of the asphalt mixture are shown in Table 18.

[0110] Table 17 Asphalt mixture road performance test results

[0111]

[0112] Table 18 Asphalt mixture fatigue test results

[0113]

[0114] The present invention has been described through the above embodiments. However, it should be understood that the above embodiments are for illustrative and illustrative purposes only and are not intended to limit the present invention to the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the above embodiments and that various variations and modifications may be made based on the teachings of the present invention, all of which fall within the scope of the present invention.

Claims

1. A high-content rubber powder composite SBS modified asphalt, characterized in that: Calculated by mass, it includes the following components: Asphalt 60-70 parts, ordinary rubber powder 10-15 parts, activated rubber powder 15-30 parts, SBS modifier 2-2.5 parts, retardant 1-2 parts, dispersant 0.5-1 part, stabilizer 0.1-0.15 parts; The modified asphalt has a needle penetration of ≥60 (0.1 mm), a softening point of ≥70°C, an elongation at 5°C of ≥15 cm, a kinematic viscosity of 1.5 Pa·s to 3.5 Pa·s at 180°C, a flash point of ≥230°C, a viscosity-toughness of ≥10 N·m, a difference between segregation and softening points of ≤5°C, an elastic recovery of ≥80%, a change in the mass of the residue after RTFOT of ≤±0.8%, a residual needle penetration ratio of ≥60%, and a residual elongation of ≥10 cm at 5°C.

2. The SBS modified asphalt with a large amount of rubber powder according to claim 1, characterized in that: The asphalt is Grade A No. 90 road petroleum asphalt.

3. The SBS modified asphalt with a large amount of rubber powder according to claim 1, characterized in that: The ordinary rubber powder is processed from waste tires and has a particle size of 40 to 60 meshes.

4. The SBS modified asphalt with a large amount of rubber powder according to claim 1, characterized in that: The activated rubber powder is made from common rubber powder through surface activation, has a particle size of 40-60 meshes, a carbon black content of ≥28%, and a rubber hydrocarbon content of ≥42%.

5. The SBS modified asphalt with a large amount of rubber powder according to claim 1, characterized in that: The SBS modifier is linear; the stabilizer is sulfur, and the effective component content is ≥95%.

6. The SBS modified asphalt with a large amount of rubber powder according to claim 1, characterized in that: The retardant is one or a mixture of rubber oil, aromatic oil, and naphthenic oil, and the proportions of the multiple retardants are arbitrary.

7. The SBS modified asphalt with a large amount of rubber powder according to claim 1, characterized in that: The dispersant is one or a mixture of zinc stearate, stearic acid amide, and vinyl bis-stearic acid amide, and the proportions of the multiple dispersants are arbitrary.

8. The method for preparing a high-content rubber powder composite SBS modified asphalt according to claim 1, characterized in that: The specific steps include: (1) Preheating the asphalt to 145°C to 155°C according to the mass fraction, adding ordinary rubber powder, activated rubber powder, SBS modifier, retardant and dispersant, then heating and performing high-speed shear dispersion to obtain a mixture; (2) A stabilizer is added to the mixture, and after development, a large amount of rubber powder composite SBS modified asphalt is obtained.

9. The method for preparing a high-content rubber powder composite SBS modified asphalt according to claim 8, characterized in that: In the step (1), the temperature of the high-speed shear dispersion is 220° C. to 230° C., the rotation speed is 7000 r / min to 8000 r / min, and the dispersion time is 1.5 h to 2 h.

10. The method for preparing a high-content rubber powder composite SBS modified asphalt according to claim 8, characterized in that: In the step (2), the development temperature is 180° C. to 185° C., and the development time is 50 min to 70 min.

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