Green carbon-reducing modified asphalt, preparation method thereof and application of green carbon-reducing modified asphalt in high-doping-amount RAP

Abstract

The invention belongs to the technical field of recycled asphalt, and discloses green carbon-reducing modified asphalt as well as a preparation method and application thereof in high-dosage RAP. The green carbon-reducing modified asphalt is prepared from the following raw materials in parts by mass: 3-6 parts of an SBS modifier, 70-90 parts of asphalt, 4-8 parts of a warm mixing agent, 5-10 parts of a viscosity reducer, 7-20 parts of a regenerant and 3-5 parts of a stabilizer. According to the present invention, the major breakthrough of the traditional asphalt material is achieved on the technical level, and the significant beneficial effects are provided in the aspects of environmental protection, resource saving, economic feasibility, industry development and the like, such that the method is the important technical innovation for achieving the sustainable development target in the road construction field.

Description

Technical Field

[0001] The present invention relates to the technical field of recycled asphalt, and in particular to a green carbon-reducing modified asphalt, a preparation method thereof, and an application thereof in high-dosage RAP. Background Art

[0002] In the future, the development trend of new road transportation materials will focus more on functional products and forward-looking technologies, and green and low-carbon transportation new materials will also usher in rapid development. In recent years, with the rapid development of my country's highway construction and the need for renovation and reconstruction of a large number of high-grade highway asphalt pavements, the recycling of old asphalt pavement materials has regained attention and received widespread attention.

[0003] Over the past few decades, countries around the world have increasingly recycled recycled asphalt pavement (RAP). RAP contains a rich amount of aged asphalt and crushed mineral aggregates, and its recycling can significantly reduce the demand for new asphalt and aggregates, thus bringing significant environmental and economic benefits.

[0004] Aged asphalt in RAP is usually stiffer than new asphalt, so it can provide better high-temperature stability for asphalt pavement. On the other hand, higher RAP content may lead to problems such as workability, mixing efficiency of new and old asphalt, and fatigue cracking, so the current use of RAP in asphalt pavement is controlled within 15%.

[0005] Asphalt is a viscoelastic material. Based on this characteristic of asphalt, people heat the elastic asphalt at room temperature to a higher temperature to reduce its viscosity and improve its fluidity. When the viscosity value is reduced to a certain range, it can be mixed, spread, and rolled with raw materials such as stone. During the construction process, asphalts of different properties have different viscoelastic performances, and the temperature range suitable for construction is naturally different. Under normal circumstances, the mixing temperature of SBS modified asphalt mixture is about 175-185℃, and the mixing temperature of ordinary asphalt mixture is about 150℃.

[0006] In order to control the mixing temperature of asphalt mixture within the above range, a large amount of energy is needed to heat the raw materials such as asphalt and stone, which not only produces a large amount of carbon emissions, but also increases the emission of asphalt smoke. Therefore, reducing the mixing temperature of asphalt mixture has become a key research direction, which is called warm mix asphalt technology in the industry.

[0007] In order to save energy and reduce smoke emissions, warm mix asphalt technology generally reduces the mixing temperature. For example, the mixing temperature of SBS modified asphalt mixture is controlled below 175°C. However, when the mixing temperature is reduced, the performance of SBS modified asphalt mixture is often reduced.

[0008] In order to balance the defects of the above two technologies and promote the development of green pavement technology, researchers have tried to combine the two technologies in recent years. The resulting new technology is called warm mix recycling technology. Since warm mix technology can reduce the viscosity of asphalt, a higher content of RAP can be recycled. Therefore, the development of green carbon reduction modified asphalt dedicated to high-content RAP is of great significance. Summary of the invention

[0009] The purpose of the present invention is to provide a green carbon-reducing modified asphalt and a preparation method thereof and application in high-dosage RAP to solve the problems existing in the prior art.

[0010] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0011] The present invention provides a green carbon reduction modified asphalt, comprising the following raw materials in parts by weight:

[0012] 3-6 parts of SBS modifier, 70-90 parts of asphalt, 4-8 parts of warm mix agent, 5-10 parts of viscosity reducer, 7-20 parts of regeneration agent and 3-5 parts of stabilizer.

[0013] Preferably, in the above-mentioned green carbon reduction modified asphalt, the SBS modifier is styrene-butadiene-styrene block copolymer;

[0014] The SBS modifier is one or both of linear and star types;

[0015] The asphalt is 70# asphalt.

[0016] Preferably, in the above-mentioned green carbon reduction modified asphalt, the warm mix agent is polyethylene wax;

[0017] The viscosity reducing agent is a divalent acid ester.

[0018] Preferably, in the above-mentioned green carbon reduction modified asphalt, the regeneration agent is a mixture of 70 to 85 parts of methyl styrene block copolymer and 10 to 30 parts of volatility enhancer;

[0019] The stabilizer is sulfur.

[0020] The present invention also provides a method for preparing green carbon-reducing modified asphalt, comprising the following steps:

[0021] (1) shearing and mixing the SBS modifier and asphalt to obtain a base material;

[0022] (2) adding a warm mix agent, a viscosity reducer and a regeneration agent into a base material and mixing them to obtain a mixture;

[0023] (3) Adding a stabilizer into the mixture and stirring it to obtain green carbon-reducing modified asphalt.

[0024] Preferably, in the above-mentioned method for preparing green carbon-reducing modified asphalt, the shear mixing conditions in step (1) are: temperature of 170-190° C., speed of 2500-4000 rpm, and time of 15-20 min;

[0025] The stirring conditions in step (2) are as follows: temperature of 160-180° C., speed of 2500-4000 rpm, and time of 140-180 min;

[0026] The stirring conditions in step (3) are: temperature of 160-180° C., speed of 2500-4000 rpm, and time of 140-180 min.

[0027] The present invention also provides an application of green carbon-reducing modified asphalt in high-dosage RAP.

[0028] Preferably, in the above application, the application method comprises the following steps:

[0029] The green carbon reduction modified asphalt is mixed with stone to obtain an asphalt mixture.

[0030] Preferably, in one of the above applications, the mass ratio of the green carbon-reducing modified asphalt to stone is 4 to 7:100.

[0031] The asphalt mixture obtained by the present invention has a low mixing temperature and high performance. When the mixing temperature is 155°C, the residual stability of the warm-mix asphalt mixture is above 88%, the freeze-thaw crack strength ratio is above 85%, the dynamic stability is above 3500 times / mm, and the low-temperature bending failure strain is above 2500με.

[0032] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0033] (1) Significantly reduce carbon emissions: The present invention uses optimized modification technology and multiple modifiers such as regeneration agents and viscosity reducers to effectively utilize a high proportion of RAP (waste asphalt mixture materials that are usually difficult to handle and easily cause environmental burdens), greatly reducing the demand for new asphalt materials, thereby significantly reducing carbon emissions during asphalt production and road construction, which is in line with the development trend of global carbon reduction and circular economy.

[0034] (2) Improving asphalt performance: The use of specially designed green modifiers closely combined with RAP materials not only overcomes the problem of reduced road performance caused by the high dosage of traditional recycled asphalt, such as anti-rutting ability, low-temperature crack resistance and durability, but also improves the overall performance of the asphalt mixture to a certain extent, ensuring the quality and safety of road projects.

[0035] (3) Enhanced material adaptability: The modified asphalt can adapt to a wider range of RAP sources and quality differences. Even in cases where the quality requirements for waste asphalt materials vary, the ideal use effect can be achieved by adjusting the modified formula, thereby enhancing the versatility and practicality of the material.

[0036] (4) Promote resource recycling: The use of high dosage of RAP effectively promotes the resource utilization of construction waste, reduces the pressure on solid waste landfills, plays a positive role in protecting the natural environment and saving natural resources, and promotes the construction of a circular economy system.

[0037] (5) Economic benefits: By reducing the reliance on new asphalt raw materials, the present invention helps to reduce road construction costs. At the same time, the reuse of waste asphalt materials also creates new economic value for related industries, achieving a win-win situation of environmental protection and economic benefits.

[0038] (6) Demonstration and leadership: As a green innovative technology, the application of this patent will set an example of carbon reduction and environmental protection for the road construction industry, encourage more companies and research institutions to invest in the research and development of sustainable building materials, and jointly promote the green transformation of global transportation infrastructure.

[0039] In summary, the invention of this high-dosage RAP-specific green carbon-reducing modified asphalt not only achieved a major breakthrough in traditional asphalt materials at the technical level, but also showed significant beneficial effects in environmental protection, resource conservation, economic feasibility and industry development. It is an important technological innovation for achieving sustainable development goals in the field of road construction. DETAILED DESCRIPTION

[0040] The present invention provides a green carbon reduction modified asphalt, comprising the following raw materials in parts by weight:

[0041] 3-6 parts of SBS modifier, 70-90 parts of asphalt, 4-8 parts of warm mix agent, 5-10 parts of viscosity reducer, 7-20 parts of regeneration agent and 3-5 parts of stabilizer.

[0042] In the present invention, the mass fraction of the SBS modifier is preferably 3 to 6 parts, more preferably 3.5 to 5.5 parts, and even more preferably 4 to 5 parts.

[0043] In the present invention, the mass fraction of the asphalt is preferably 70 to 90 parts, more preferably 75 to 85 parts, and even more preferably 78 to 80 parts.

[0044] In the present invention, the mass fraction of the warm mix agent is preferably 4 to 8 parts, more preferably 5 to 7 parts, and even more preferably 6 to 6.5 parts.

[0045] In the present invention, the mass fraction of the viscosity reducer is preferably 5 to 10 parts, more preferably 6 to 9 parts, and even more preferably 7 to 8 parts.

[0046] In the present invention, the mass fraction of the regeneration agent is preferably 7 to 20 parts, more preferably 10 to 18 parts, and even more preferably 12 to 15 parts.

[0047] In the present invention, the weight percentage of the stabilizer is preferably 3 to 5 parts, more preferably 3.5 to 4.5 parts, and even more preferably 3.8 to 4 parts.

[0048] In the present invention, the SBS modifier is preferably a styrene-butadiene-styrene block copolymer.

[0049] In the present invention, the SBS modifier is preferably one or both of linear and star types; it can improve the high temperature stability, low temperature crack resistance, aging resistance and water stability of the asphalt mixture.

[0050] In the present invention, the asphalt is preferably 70# asphalt; 70# asphalt has a needle penetration (25°C, 5s, 100g) of 60-80dmm according to my country's asphalt grading method (needle penetration grading).

[0051] In the present invention, the warm-mix agent is preferably polyethylene wax;

[0052] The polyethylene wax is in the form of white powder with a diameter of 4 mm and a density of 0.85 to 0.95 g / cm at 25°C. 3 .

[0053] In the present invention, the viscosity reducer is preferably a dibasic acid ester; the dibasic acid ester can be purchased and can be obtained from Jiangsu Jierui Chemical Co., Ltd., and the model is dibasic acid ester DBE.

[0054] In the present invention, the regeneration agent is preferably a mixture of 70 to 85 parts of methyl styrene block copolymer and 10 to 30 parts of volatility enhancer. ;

[0055] The methyl styrene block copolymer is prepared by referring to patent CN202111118503.5 “An α-methyl styrene copolymer and its preparation method and application”;

[0056] The volatile enhancer is prepared with reference to patent CN202411203339.1 “A composite enhancer for asphalt pavement and its preparation method”.

[0057] In the present invention, the stabilizer is preferably sulfur.

[0058] The present invention also provides a method for preparing green carbon-reducing modified asphalt, comprising the following steps:

[0059] (1) shearing and mixing the SBS modifier and asphalt to obtain a base material;

[0060] (2) adding a warm mix agent, a viscosity reducer and a regeneration agent into a base material and mixing them to obtain a mixture;

[0061] (3) Adding a stabilizer into the mixture and stirring it to obtain green carbon-reducing modified asphalt.

[0062] In the present invention, the shear mixing conditions in step (1) are: the temperature is preferably 170-190°C, more preferably 175-188°C, and more preferably 185°C; the speed is preferably 2500-4000rpm, more preferably 2800-3500rpm, and more preferably 3000rpm; the time is preferably 15-20min, more preferably 16-19min, and more preferably 17-18min.

[0063] In the present invention, the stirring conditions in step (2) are: the temperature is preferably 160-180°C, more preferably 165-178°C, and more preferably 175°C; the speed is 2500-4000rpm, more preferably 2800-3500rpm, and more preferably 3000rpm; the time is preferably 140-180min, more preferably 150-175min, and more preferably 160-170min.

[0064] In the present invention, the stirring conditions in step (3) are: the temperature is preferably 160-180°C, more preferably 165-178°C, and more preferably 175°C; the speed is preferably 2500-4000rpm, more preferably 2800-3500rpm, and more preferably 3000rpm; the time is preferably 140-180min, more preferably 150-175min, and more preferably 160-170min.

[0065] The present invention also provides an application of green carbon-reducing modified asphalt in high-dosage RAP.

[0066] In the present invention, the application method comprises the following steps:

[0067] The green carbon reduction modified asphalt is mixed with stone to obtain an asphalt mixture.

[0068] In the present invention, the mass ratio of the green carbon-reducing modified asphalt to stone is preferably 4 to 7:100, more preferably 4.5 to 6:100, and more preferably 5 to 5.5:100.

[0069] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] Example 1

[0071] A method for preparing green carbon-reducing modified asphalt comprises the following steps:

[0072] (1) 3 parts of SBS modifier styrene-butadiene-styrene block copolymer and 70 parts of 70# asphalt were shear mixed at 185° C. and 3000 rpm for 15 min to obtain a base material;

[0073] (2) adding 4 parts of polyethylene wax as a warm-mix agent, 5 parts of dibasic acid ester as a viscosity reducer, and 7 parts of a mixture of a methyl styrene block copolymer and a modifier as a regeneration agent (the mass ratio of the methyl styrene block copolymer to the modifier is 8.5:1.5) into the base material and stirring at 175° C. and 3000 rpm for 140 minutes to obtain a mixture;

[0074] (3) 3 parts of stabilizer sulfur were added into the mixture and stirred at 175° C. and 3000 rpm for 140 min to obtain green carbon-reducing modified asphalt.

[0075] Example 2

[0076] A method for preparing green carbon-reducing modified asphalt comprises the following steps:

[0077] (1) 3 parts of SBS modifier styrene-butadiene-styrene block copolymer and 71 parts of 70# asphalt were shear mixed at 185° C. and 3000 rpm for 15 min to obtain a base material;

[0078] (2) adding 6 parts of polyethylene wax as a warm-mix agent, 7 parts of dibasic acid ester as a viscosity reducer, and 10 parts of a mixture of a methyl styrene block copolymer and a modifier as a regeneration agent (the mass ratio of the methyl styrene block copolymer to the modifier is 8.5:1.5) into the base material and stirring at 175° C. and 3000 rpm for 140 minutes to obtain a mixture;

[0079] (3) 3 parts of stabilizer sulfur were added into the mixture and stirred at 175° C. and 3000 rpm for 140 min to obtain green carbon-reducing modified asphalt.

[0080] Example 3

[0081] A method for preparing green carbon-reducing modified asphalt comprises the following steps:

[0082] (1) 3 parts of SBS modifier styrene-butadiene-styrene block copolymer and 70 parts of 70# asphalt were shear mixed at 185° C. and 3000 rpm for 15 to 20 minutes to obtain a base material;

[0083] (2) adding 4 parts of polyethylene wax as a warm-mix agent, 5 parts of dibasic acid ester as a viscosity reducer, and 15 parts of a mixture of a methyl styrene block copolymer and a modifier as a regeneration agent (the mass ratio of the methyl styrene block copolymer to the modifier is 8:2) into the base material and stirring at 175° C. and 3000 rpm for 140 minutes to obtain a mixture;

[0084] (3) 3 parts of stabilizer sulfur were added into the mixture and stirred at 175° C. and 3000 rpm for 140 min to obtain green carbon-reducing modified asphalt.

[0085] Application Example 1

[0086] The green carbon-reducing modified asphalt prepared in Example 1 and stone are mixed in a weight ratio of 4 to 7:100 to prepare an asphalt mixture.

[0087] Application Example 2

[0088] The green carbon-reducing modified asphalt prepared in Example 2 and stone are mixed at a weight ratio of 4 to 7:100 to prepare an asphalt mixture.

[0089] Application Example 3

[0090] The green carbon-reducing modified asphalt prepared in Example 3 and stone are mixed in a weight ratio of 4 to 7:100 to prepare an asphalt mixture.

[0091] Performance Testing

[0092] The green carbon-reducing modified asphalt and mixture prepared in Examples 1-3 and Application Examples 1-3 were subjected to performance tests, wherein Examples 1-3 tested three major indicators, 135°C kinematic viscosity, segregation, elastic recovery, mass loss, needle penetration ratio and residual elongation; Application Examples 1-3 tested Marshall stability, dynamic stability, and water stability (residual stability and residual strength ratio of freeze-thaw splitting test).

[0093] Performance test results:

[0094]

[0095]

[0096] The performance test results show that the comprehensive performance of the green carbon reduction modified asphalt prepared in Example 2 is much better than that of Example 1 and Example 2. The proportion of regeneration agent in the raw materials of Example 1 leads to the better performance of the asphalt index of the prepared green carbon reduction modified asphalt in the three examples, but the best effect is achieved in the mixture performance. It can be seen that the optimal proportion of regeneration agent used in the actual pavement application of green carbon reduction modified asphalt is 10 parts.

[0097] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A green carbon reduction modified asphalt, characterized in that: Contains the following raw materials by weight: 3-6 parts of SBS modifier, 70-90 parts of asphalt, 4-8 parts of warm mix agent, 5-10 parts of viscosity reducer, 7-20 parts of regeneration agent and 3-5 parts of stabilizer.

2. The green carbon reduction modified asphalt according to claim 1, characterized in that: The SBS modifier is a styrene-butadiene-styrene block copolymer; The SBS modifier is one or both of linear and star types; The asphalt is 70# asphalt.

3. The green carbon reduction modified asphalt according to claim 2, characterized in that: The warm mix agent is polyethylene wax; The viscosity reducing agent is a divalent acid ester.

4. The green carbon reduction modified asphalt according to claim 3, characterized in that: The regeneration agent is a mixture of 70 to 85 parts of methyl styrene block copolymer and 10 to 30 parts of volatility enhancer; The stabilizer is sulfur.

5. The method for preparing green carbon-reducing modified asphalt according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) shearing and mixing the SBS modifier and asphalt to obtain a base material; (2) adding a warm mix agent, a viscosity reducer and a regeneration agent into a base material and mixing them to obtain a mixture; (3) Adding a stabilizer into the mixture and stirring it to obtain green carbon-reducing modified asphalt.

6. The method for preparing green carbon-reducing modified asphalt according to claim 5, characterized in that: The shear mixing conditions in step (1) are as follows: temperature of 170-190° C., speed of 2500-4000 rpm, and time of 15-20 min; The stirring conditions in step (2) are as follows: temperature of 160-180° C., speed of 2500-4000 rpm, and time of 140-180 min; The stirring conditions in step (3) are: temperature of 160-180° C., speed of 2500-4000 rpm, and time of 140-180 min.

7. Use of the green carbon-reducing modified asphalt described in any one of claims 1 to 4 in high-dosage RAP.

8. The use according to claim 7, characterized in that: The application method comprises the following steps: The green carbon reduction modified asphalt is mixed with stone to obtain an asphalt mixture.

9. The use according to claim 8, characterized in that: The mass ratio of the green carbon-reducing modified asphalt to stone is 4 to 7:100.

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