Viscosity-reducing and life-prolonging type warm-mixing recycled asphalt and preparation method thereof

Abstract

The prepared composite regenerant comprises a common asphalt regenerant, an auxiliary viscosity reducer, a reaction regenerant and an anti-aging agent in a mass ratio of 100: (25-50): (1-3): (5-15). The preparation method of the viscosity-reducing and life-prolonging type warm-mixing recycled asphalt comprises the following steps: heating aged asphalt to a warm-mixing temperature of 125-150 DEG C, adding 5-10% of the composite regenerant, and mixing for 5-15 minutes to obtain the viscosity-reducing and life-prolonging type warm-mixing recycled asphalt. The method is wide in application range, has universality, and can be used for regeneration of common asphalt such as common matrix asphalt, SBS modified asphalt, rubber asphalt or polymer composite modified asphalt; the viscosity of the recycled asphalt in the mixture can be obviously reduced, the high and low temperature performance and the deformation resistance of the recycled asphalt can be synchronously improved, and meanwhile the service life of the recycled asphalt is obviously prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of road materials, and in particular to a viscosity-reducing and life-extending warm-mix recycled asphalt and a preparation method thereof. Background Art

[0002] With the acceleration of urbanization, the demand for transportation is increasing. Asphalt pavement, as the main transportation infrastructure, plays an important role in transportation. However, asphalt pavement is easily affected by climate change, traffic load and environmental factors during use, leading to problems such as aging, cracking and peeling, which seriously affect the safety and service life of the road. Asphalt is prone to aging under the action of high temperature, ultraviolet rays and oxygen, which causes changes in its physical and chemical properties, resulting in serious damage to the asphalt pavement and the generation of a large amount of waste asphalt mixture. Therefore, it is crucial to achieve high-quality and low-carbon recycling of waste asphalt mixture.

[0003] Compared with hot mix asphalt technology, warm mix asphalt technology has the advantages of low energy consumption, low emissions, and low construction temperature, which can effectively reduce the impact on the environment. Warm mix recycled asphalt technology is an extension of warm mix asphalt technology. It not only has many advantages of warm mix asphalt technology, but also can achieve the recycling of waste asphalt mixtures. However, the current warm mix recycled asphalt technology still has problems such as high viscosity resistance during the regeneration process of recycled asphalt, poor anti-aging ability, and weak adhesion and bonding. At the same time, the existing traditional asphalt regeneration agents are generally highly targeted and can often only achieve the regeneration of aged matrix asphalt materials, but have no obvious regeneration effect on other aged modified asphalts, and have poor applicability.

[0004] In summary, developing a viscosity-reducing and life-extending warm-mix asphalt regeneration agent suitable for different types of asphalt materials will help to universally improve the processing characteristics and adhesion of recycled asphalt materials, enhance their anti-aging ability, and extend the service life of asphalt pavements. Summary of the invention

[0005] The purpose of the present invention is to solve the problem that aged asphalt mixture is difficult to recycle with low carbon and high value, and the existing asphalt regeneration agents on the market have the disadvantages of low universality, large hot mix construction emissions, poor regeneration effect, poor durability, etc., and thus a viscosity-reducing and life-extending warm mix regenerated asphalt and a preparation method thereof are proposed; the method considers using ordinary asphalt regeneration agent, auxiliary viscosity reducer, reaction regeneration agent and antioxidant for premixing under certain temperature conditions, using auxiliary viscosity reducer and reaction regeneration agent to achieve the warm mixing and activity enhancement effect of regenerated asphalt, and at the same time using low melting point organic antioxidant with good compatibility with the regeneration agent to give the composite regeneration agent anti-aging properties, thereby preparing a viscosity-reducing and life-extending composite warm mix asphalt regeneration agent; using the viscosity-reducing and life-extending composite warm mix asphalt regeneration agent prepared by the present invention to warm mix regenerate different types of aged asphalt, so that the regenerated asphalt can achieve the overall goals of low-carbon and environmentally friendly regeneration, overall performance improvement, and service life extension, and has strong universality; the composite regeneration agent designed by the present invention has a simple preparation process, a low-carbon and efficient asphalt regeneration process, no equipment modification and upgrading, and a high resource utilization rate, which has significant advantages.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A viscosity-reducing and life-extending warm-mix recycled asphalt comprises the following raw materials: a common asphalt regeneration agent, an auxiliary viscosity-reducing agent, a reaction regeneration agent and an anti-aging agent, wherein the mass proportions thereof are respectively 30-60% of the common asphalt regeneration agent, 10-30% of the auxiliary viscosity-reducing agent, 2-8% of the reaction regeneration agent and 1-4% of the anti-aging agent.

[0008] As a further feature of the present invention, the common asphalt regeneration agent is one or more of furfural oil, aromatic oil, waste vegetable oil, waste engine oil, and waste diesel oil.

[0009] As a further feature of the present invention, the auxiliary viscosity reducing agent is one or more of solvent oil, ethylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether.

[0010] As a further feature of the present invention, the reaction regeneration agent is one or more of polymethylene polyphenyl isocyanate (or polymerized MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI).

[0011] As a further feature of the present invention, the antioxidant is at least one of 2,2,4-trimethyl-1,2-dihydroquinoline (hindered amine antioxidant RD) and 4-[(4,6-dioctylthio-1,3,5-triazine-2-yl)amino]-2,6-di(1,1-methylethyl)phenol (hindered phenol antioxidant 565).

[0012] As a further aspect of the present invention, a method for preparing a viscosity-reducing and life-extending warm-mix regenerated asphalt includes the preparation of a viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent and the preparation of a viscosity-reducing and life-extending warm-mix regenerated asphalt.

[0013] As a further aspect of the present invention, a method for preparing a viscosity-reducing and life-extending warm-mix regenerated asphalt is provided. (1) Preparation of a viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent

[0014] S1: weigh the raw materials of the common asphalt regeneration agent, auxiliary viscosity reducer, reaction regeneration agent and anti-aging agent and mix the regeneration agent at the same temperature according to the mass ratio and set aside;

[0015] S2: The raw materials weighed in S1 are mixed at a stirring speed of 300-600 rpm at 25-100°C for 10-30 min to obtain a viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent, which is then sealed and stored at room temperature.

[0016] (2) Preparation of viscosity-reducing and life-extending warm-mix recycled asphalt

[0017] S3: The new asphalt was first aged at 163°C for 85 min, and then placed in a pressure aging chamber (PAV) at 100°C and 2.1 MPa for 20 h to prepare aged asphalt;

[0018] S4: heating the aged asphalt to 125-150°C to make it have a certain fluidity after melting;

[0019] S5: Weigh 5-10% (relative to the mass of aged asphalt) of the warm mix regeneration agent involved in step S2, add it to the aged asphalt at a stirring speed of 300-600 rpm, and stir for 5-15 minutes to prepare a viscosity-reducing and life-extending warm mix regenerated asphalt.

[0020] The present invention is a viscosity-reducing and life-extending warm-mix recycled asphalt and a preparation method thereof, which has the following beneficial effects compared with the prior art:

[0021] (1) In the method described in the present invention, the common asphalt regeneration agent plays the role of dissolving asphaltene in aged asphalt and adjusting components, and the auxiliary viscosity reducer further regulates the viscosity of asphalt to improve the working characteristics of aged asphalt, so as to achieve the condition that the aged asphalt can be warm-mixed and regenerated. Furthermore, a small amount of reactive regeneration agent is added to the above components to consider using its active groups to react with functional groups such as hydroxyl and carboxyl generated in aged asphalt to achieve chemical bonding, so as to make up for the problem of insufficient high-temperature deformation resistance caused by the softening of warm-mixed regenerated asphalt by the common asphalt regeneration agent and the auxiliary viscosity reducer. Finally, an organic antioxidant preferably having good compatibility with the above components is introduced into the above composite warm-mix regeneration agent to achieve the purpose of extending the service life of warm-mixed regenerated asphalt.

[0022] (2) The viscosity-reducing and life-extending warm-mix asphalt regeneration agent prepared by the present invention is not a special regeneration agent for a single type of aged asphalt. It has a good regeneration effect on common asphalts such as ordinary base asphalt, SBS modified asphalt, rubber asphalt or polymer composite modified asphalt, has good universality and good application prospects.

[0023] (3) The viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent prepared by the present invention can perform high-quality, low-carbon warm-mix regeneration of waste asphalt at a relatively low temperature, thereby promoting energy conservation and emission reduction in the regenerated asphalt preparation process, improving engineering performance, and extending service life, with significant economic, environmental and social benefits.

[0024] (4) The viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent and its regenerated asphalt designed by the present invention are simple in preparation process, and the preparation equipment does not need to be modified or upgraded. The resource utilization rate is high, and it can effectively solve the problem of efficient and high-quality recycling of waste asphalt mixtures. DETAILED DESCRIPTION

[0025] The content of the present invention can be more easily understood by selecting the following detailed description of the preferred implementation method of the present invention and the embodiments included. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those of ordinary skill in the art to which the present invention belongs. When there is a conflict, the definition in this specification shall prevail.

[0026] As used herein, the term "prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0027] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0028] When amount, concentration or other value or parameter is expressed as range, preferred range or a series of upper preferred value and lower preferred value limit range, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when disclosing range "1 to 5", described range should be interpreted as including range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5" etc. When numerical range is described in this article, unless otherwise stated, the range is intended to include its end value and all integers and fractions within the range.

[0029] Singular forms include plural references unless the context clearly indicates otherwise. "Optional" or "either" means that the subsequently described event or incident may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

[0030] Approximate terms in the specification and claims are used to modify quantities, indicating that the present invention is not limited to the specific quantity, but also includes acceptable and modified parts close to the quantity without causing changes in the relevant basic functions. Accordingly, the use of "about", "approximately", etc. to modify a numerical value means that the present invention is not limited to the exact numerical value. In some examples, the approximate terms may correspond to the accuracy of the instrument for measuring the numerical value. In the specification and claims of this application, range limitations can be combined and / or interchanged, and if not otherwise stated, these ranges include all subranges contained therein.

[0031] In addition, the indefinite articles "a" and "an" before the elements or components of the present invention have no restrictions on the quantity requirements (i.e. the number of occurrences) of the elements or components. Therefore, "a" or "an" should be interpreted as including one or at least one, and the elements or components in the singular form also include the plural form, unless the number is obviously intended to be in the singular form.

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0033] The first aspect of the present invention provides a viscosity-reducing and life-extending warm-mix asphalt regeneration agent, wherein the weight ratio of the common asphalt regeneration agent, the auxiliary viscosity-reducing agent, the reaction regeneration agent, and the anti-aging agent in the components is 100:(25-50):(1-3):(5-15); the common asphalt regeneration agent is one or more of furfural oil, aromatic oil, waste vegetable oil, waste engine oil, and waste diesel oil; the auxiliary viscosity-reducing agent is one or more of solvent oil, ethylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether; the reaction regeneration agent is one or more of the following: The regeneration agent is one or more of polymethylene polyphenyl isocyanate (or polymerized MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI); the antioxidant is at least one of 2,2,4-trimethyl-1,2-dihydroquinoline (hindered amine antioxidant RD) and 4-[(4,6-dioctylthio-1,3,5-triazine-2-yl)amino]-2,6-di(1,1-methylethyl)phenol (hindered phenol antioxidant 565).

[0034] The second aspect of the present invention provides a method for preparing the viscosity-reducing and life-extending warm-mix asphalt regeneration agent according to the first aspect of the present invention, comprising the following steps:

[0035] S1: weigh the raw materials of the common asphalt regeneration agent, auxiliary viscosity reducer, reaction regeneration agent and anti-aging agent and mix the regeneration agent at the same temperature according to the mass ratio and set aside;

[0036] S2: The raw materials weighed in S1 are mixed at a stirring speed of 300-600 rpm at 25-100°C for 10-30 min to obtain a viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent, which is then sealed and stored at room temperature.

[0037] The third aspect of the present invention provides a method for preparing a viscosity-reducing and life-extending warm-mix recycled asphalt, comprising the following steps:

[0038] S3: The new asphalt was first aged at 163°C for 85 min, and then placed in a pressure aging chamber (PAV) at 100°C and 2.1 MPa for 20 h to prepare aged asphalt;

[0039] In step S3, the new asphalt is selected from common base asphalt, SBS modified asphalt, rubber asphalt or polymer composite modified asphalt;

[0040] S4: heating the aged asphalt to 125-150°C to make it have a certain fluidity after melting;

[0041] S5: Weigh 5-10% (relative to the mass of aged asphalt) of the warm mix regeneration agent involved in step S2, add it to the aged asphalt at a stirring speed of 300-600 rpm, and stir for 5-15 minutes to prepare a viscosity-reducing and life-extending warm mix regenerated asphalt.

[0042] The fourth aspect of the present invention provides a viscosity-reducing and life-extending warm-mix regenerated asphalt, which comprises the viscosity-reducing and life-extending warm-mix asphalt regeneration agent provided by the first aspect of the present invention and aged asphalt, wherein the aged asphalt is an aging product of the aforementioned new asphalt.

[0043] The present invention proposes a method for preparing a viscosity-reducing and life-extending warm-mix recycled asphalt, which can not only significantly reduce the viscosity of the recycled asphalt in the mixture, but also help to achieve the simultaneous improvement of the high and low temperature performance and deformation resistance of the recycled asphalt, and at the same time significantly extend the service life of the recycled asphalt. The present invention has a wide range of applications and is universal, and can be used for the regeneration of common asphalts such as ordinary matrix asphalt, SBS modified asphalt, rubber asphalt or polymer composite modified asphalt.

[0044] The composite regeneration agent prepared by the present invention comprises a common asphalt regeneration agent, an auxiliary viscosity reducing agent, a reaction regeneration agent and an anti-aging agent, and the mass ratio thereof is 100:(25-50):(1-3):(5-15). The present invention relates to a method for preparing a viscosity-reducing and life-extending warm-mix regenerated asphalt: the aged asphalt is heated to a warm-mixing temperature of 125 to 150°C, 5 to 10% of the above composite regeneration agent is added externally, and the mixture is mixed for 5 to 15 minutes to obtain a viscosity-reducing and life-extending warm-mix regenerated asphalt; the inventors have found that the use of the above composite regeneration agent can reduce the viscosity of the aged asphalt, significantly restore the high and low temperature performance, significantly enhance the deformation resistance, and improve the aging resistance, which greatly solves the low-carbon regeneration problem and the durable service problem of the aged asphalt mixture.

[0045] The composite regeneration agent designed in the present invention has a simple preparation process, a low-carbon and efficient asphalt regeneration process, no equipment modification or upgrading is required, and the resource utilization rate is high, thus having significant economic, environmental and social benefits.

[0046] Example 1

[0047] The preparation process of warm-mix asphalt regeneration agent is as follows: according to the mass ratio of 100:25:1:0, the raw materials of warm-mix regeneration agent of furfural oil, solvent oil, polymerized MDI and hindered amine type antioxidant RD are weighed, and mixed at a stirring speed of 300 rpm at 25°C for 30 minutes to obtain a viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent, which is sealed and stored at room temperature.

[0048] The preparation process of the viscosity-reducing and life-extending warm-mix regenerated asphalt is as follows: first, a new No. 70 ordinary base asphalt is aged at 163°C for 85 minutes and then placed in a pressure aging chamber (PAV) at 100°C and 2.1MPa for 20 hours to prepare aged asphalt; the aged asphalt is heated to 150°C so that it has a certain fluidity after melting; 5% (relative to the mass of aged asphalt) of the warm-mix asphalt regeneration agent prepared above is weighed and added to the aged asphalt at a stirring speed of 600rpm, and stirred for 15 minutes to prepare the viscosity-reducing and life-extending warm-mix regenerated asphalt.

[0049] Example 2

[0050] In this embodiment, only the proportion of polymerized MDI in the composite regeneration agent in embodiment 1 is adjusted. After the adjustment, the mass ratio of furfural oil, solvent oil, polymerized MDI and hindered amine type antioxidant RD in the composite regeneration agent is 100:25:2:0. The other steps are consistent with embodiment 1.

[0051] Example 3

[0052] In this embodiment, only the proportion of polymerized MDI in the composite regeneration agent in embodiment 1 is adjusted. After the adjustment, the mass ratio of furfural oil, solvent oil, polymerized MDI and hindered amine type antioxidant RD in the composite regeneration agent is 100:25:3:0. The other steps are consistent with embodiment 1.

[0053] Example 4

[0054] This embodiment only adjusts the proportion of solvent oil in the composite regeneration agent in Example 3. After the adjustment, the mass ratio of furfural oil, solvent oil, polymeric MDI and hindered amine type antioxidant RD in the composite regeneration agent is 100:50:3:0. The other steps are consistent with Example 3.

[0055] Example 5

[0056] In this embodiment, only the ratio of the hindered amine antioxidant RD in the composite regeneration agent in embodiment 4 is adjusted. After the adjustment, the mass ratio of furfural oil, solvent oil, polymeric MDI and hindered amine antioxidant RD in the composite regeneration agent is 100:50:3:5. The other steps are consistent with embodiment 4.

[0057] Example 6

[0058] In this embodiment, only the ratio of the hindered amine antioxidant RD in the composite regeneration agent in embodiment 5 is adjusted. After the adjustment, the mass ratio of furfural oil, solvent oil, polymeric MDI and hindered amine antioxidant RD in the composite regeneration agent is 100:50:3:10. The other steps are consistent with embodiment 5.

[0059] Example 7

[0060] In this embodiment, only the ratio of the hindered amine antioxidant RD in the composite regeneration agent in embodiment 5 is adjusted. After the adjustment, the mass ratio of furfural oil, solvent oil, polymeric MDI and hindered amine antioxidant RD in the composite regeneration agent is 100:50:3:15. The other steps are consistent with embodiment 5.

[0061] Example 8

[0062] This example uses the composite regeneration agent prepared in Example 6, the difference being that the dosage of the warm mix regeneration agent is adjusted to 7.5%, and the other steps are consistent with Example 6.

[0063] Example 9

[0064] This example uses the composite regeneration agent prepared in Example 6, the difference being that the dosage of the warm mix regeneration agent is adjusted to 10%, and the other steps are consistent with Example 6.

[0065] Example 10

[0066] In this embodiment, the polymeric MDI in the composite regeneration agent described in Example 6 is replaced by an isocyanate mixture (polymeric MDI:TDI=2:1). The difference is that the dosage of the warm mix regeneration agent is adjusted to 7.5%, and the other steps are consistent with Example 6.

[0067] Embodiment 11

[0068] In this embodiment, the polymeric MDI in the composite regeneration agent described in Example 6 is replaced by an isocyanate mixture (polymeric MDI:TDI=1:2). The difference is that the dosage of the warm mix regeneration agent is adjusted to 7.5%, and the other steps are consistent with Example 6.

[0069] Example 12

[0070] The difference of this embodiment is that the regeneration object in Example 8 is adjusted to aged SBS modified asphalt, and the other steps remain unchanged.

[0071] Embodiment 13

[0072] The difference of this embodiment is that the regeneration object in Example 8 is adjusted to aged rubber asphalt, and the other steps remain unchanged.

[0073] Example 14 (Excessive amount of auxiliary viscosity reducing agent "solvent oil")

[0074] The difference of this embodiment is that an excess amount of solvent oil is used to adjust the mass ratio of furfural oil, solvent oil, polymeric MDI and hindered amine antioxidant RD in the composite regeneration agent to 100:80:3:10, and the other steps are consistent with Example 8.

[0075] Example 15 (Excessive Regeneration Agent)

[0076] The difference of this embodiment is that an excess amount of reaction regeneration agent is used, so that the mass ratio of furfural oil, solvent oil, polymeric MDI and hindered amine antioxidant RD in the composite regeneration agent is adjusted to 100:50:20:10, and the other steps are consistent with Example 8.

[0077] Comparative Example 1

[0078] The difference of this comparative example is that a commercially available warm mix asphalt regeneration agent is used to warm mix the aged base asphalt, and its dosage is controlled to be 7.5% (relative to the mass of the aged asphalt). The other steps are consistent with Example 1.

[0079] Comparative Example 2

[0080] The difference of this comparative example is that the regeneration object in comparative example 1 is adjusted to aged SBS modified asphalt, and the other steps remain unchanged.

[0081] Comparative Example 3

[0082] The difference of this comparative example is that the regeneration object in comparative example 1 is adjusted to aged rubber asphalt, and the other steps remain unchanged.

[0083] Test example:

[0084] Softening point: According to the test method of "Testing Procedures for Asphalt and Asphalt Mixtures for Highway Engineering" (JTG E20-2011 T 0606), the softening point of the warm-mixed recycled asphalt in the embodiment and the comparative example was tested by the ring and ball method. The main experimental conditions are: (1) water as the medium; (2) the initial insulation temperature is 5℃±0.5℃; (3) the heating rate is controlled to be 5℃±0.5℃.

[0085] Ductility: According to the test method of "Testing Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011 T 0605), the ductility of the warm-mixed recycled asphalt in the examples and comparative examples was tested. Main experimental conditions: (1) The test temperature was controlled at 5°C (recycled SBS modified asphalt and recycled rubber asphalt) and 5°C (recycled base asphalt), respectively; (2) The tensile speed was 5 cm / min±0.25 cm / min.

[0086] Viscosity: According to the test method of "Testing Procedures for Asphalt and Asphalt Mixtures for Highway Engineering" (JTG E20-2011 T 0625), the working characteristics of the warm-mixed recycled asphalt in the examples and comparative examples were tested. Main experimental conditions: (1) The test temperature was controlled at 135°C (recycled base asphalt, recycled SBS modified asphalt and recycled rubber asphalt) and 150°C (recycled rubber asphalt); (2) The insulation time was 1.5 h.

[0087] The softening point, ductility and viscosity of the warm mix regenerated asphalt and aged base asphalt, aged SBS modified asphalt and aged rubber asphalt prepared in Examples 1-15 and Comparative Examples 1-3 were measured respectively. The results are shown in Table 1.

[0088]

[0089]

[0090] It can be seen from the data in Table 1 that the warm-mix asphalt regeneration agent prepared by the present invention is used to regenerate aged base asphalt. The softening point of the warm-mix regenerated base asphalt in Examples 1-11 does not show a cliff-like downward trend, the ductility is significantly improved, and the viscosity at 135°C is significantly reduced. This shows that the prepared warm-mix asphalt regeneration agent has a good effect of inhibiting the degradation of the high-temperature performance of the aged base asphalt and improving the ductility, while the processing characteristics are significantly improved.

[0091] Comparative Examples 8, 12 and 13, the prepared warm mix asphalt regeneration agent was used for aged base asphalt, aged SBS modified asphalt and aged rubber asphalt, all of which showed similar regeneration effects, indicating that the regeneration agent has a certain universality for different types of aged asphalt.

[0092] Compared with Example 8, Example 14 contains excessive solvent oil, which causes a serious decrease in the softening point of the regenerated asphalt, while Example 15 contains excessive reaction regeneration agent, which causes a significant increase in the softening point of the regenerated asphalt and a significant decrease in the ductility. This shows that excessive solvent oil or reaction regeneration agent in the warm mix asphalt regeneration agent will have an adverse effect on the physical properties of the regenerated asphalt.

[0093] By comparing Examples 1-13 with Comparative Examples 1-3, it was found that a certain commercially available asphalt regeneration agent only had a good regeneration effect on aged base asphalt, but had no obvious regeneration effect on aged SBS modified asphalt and aged rubber asphalt, which indicates that the prepared warm mix asphalt regeneration agent has good universality.

[0094] Furthermore, the softening point growth rate and ductility loss rate were used as anti-aging indicators of the viscosity-reducing and life-extending warm-mix recycled asphalt, and the results are shown in Table 2.

[0095]

[0096]

[0097] It can be seen from the data in Table 1 that when the warm-mix asphalt regeneration agent prepared by the present invention is used to regenerate aged base asphalt, the softening point growth rate of the warm-mix regenerated base asphalt in Examples 5-11 is significantly lower (except for Example 5 which reaches 15.3%, the others are all lower than 9.0%), and the ductility loss rate (all lower than 33%) is significantly smaller, while the softening point growth rate and ductility loss rate of the warm-mix regenerated base asphalt in Comparative Example 1 are as high as 41.2% and 89.6%, respectively.

[0098] This shows that the prepared warm-mix asphalt regeneration agent has a significant life extension effect on the aged base asphalt after regeneration, which is significantly better than a certain commercially available warm-mix asphalt regeneration agent.

[0099] By comparing Examples 12-13 and Comparative Examples 2-3, it was found that the prepared warm-mix asphalt regeneration agent showed similar effects on promoting the extension of the service life of the regenerated asphalt on both aged SBS modified asphalt and aged rubber asphalt, while a certain commercially available warm-mix asphalt regeneration agent had no obvious effect. This indicates that the prepared warm-mix asphalt regeneration agent has the universality to extend the service life of different types of regenerated asphalt.

[0100] It is divided into three categories: base asphalt, SBS modified asphalt and rubber asphalt, as shown in Table 3. The details are as follows:

[0101] The composite regeneration agent prepared in the present invention comprises a common asphalt regeneration agent, an auxiliary viscosity reducer, a reaction regeneration agent and an anti-aging agent, and the mass proportions thereof are 100:(25-50):(1-3):(5-15) respectively.

[0102] The present invention relates to a method for preparing viscosity-reducing and life-extending warm-mix regenerated asphalt: the aged asphalt is heated to a warm-mix temperature of 125-150° C., 5-10% of the above-mentioned composite regeneration agent is added externally, and the mixture is mixed for 5-15 minutes.

[0103] Preferably, the common asphalt regeneration agent is one or more of aromatic oil, waste vegetable oil, waste engine oil, waste diesel oil, and furfural oil.

[0104] Preferably, the auxiliary viscosity reducing agent is one or more of solvent oil, ethylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether.

[0105] Preferably, the reaction regeneration agent is one or more of polymethylene polyphenyl isocyanate (or polymerized MDI), toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI).

[0106] Preferably, the antioxidant is at least one of 2,2,4-trimethyl-1,2-dihydroquinoline (hindered amine antioxidant RD) and 4-[(4,6-dioctylthio-1,3,5-triazine-2-yl)amino]-2,6-di(1,1-methylethyl)phenol (hindered phenol antioxidant 565).

[0107]

[0108]

[0109]

[0110]

[0111] The examples referred to herein are merely illustrative and are used to explain some features of the method of the present invention. The appended claims are intended to claim the widest possible range that can be imagined, and the embodiments presented herein are only illustrations of selected implementations according to the combination of all possible embodiments. Therefore, it is the applicant's intention that the appended claims are not limited by the selection of examples that illustrate the features of the present invention. Some numerical ranges used in the claims also include sub-ranges within them, and changes in these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. A viscosity-reducing and life-extending warm-mix recycled asphalt, characterized in that: The raw materials include common asphalt regeneration agent, auxiliary viscosity reducer, reaction regeneration agent and anti-aging agent, with the mass proportions of common asphalt regeneration agent being 30-60%, auxiliary viscosity reducer being 10-30%, reaction regeneration agent being 2-8% and anti-aging agent being 1-4%.

2. The viscosity-reducing and life-extending warm mix recycled asphalt according to claim 1, characterized in that: The common asphalt regeneration agent is one or more of furfural oil, aromatic oil, waste vegetable oil, waste engine oil, and waste diesel oil.

3. The viscosity-reducing and life-extending warm mix recycled asphalt according to claim 1, characterized in that: The auxiliary viscosity reducing agent is one or more of solvent oil, ethylene glycol diglycidyl ether, and trimethylolpropane triglycidyl ether.

4. The viscosity-reducing and life-extending warm mix recycled asphalt according to claim 1, characterized in that: The reaction regeneration agent is one or more of polymethylene polyphenyl isocyanate, toluene diisocyanate, and hexamethylene diisocyanate.

5. The viscosity-reducing and life-extending warm mix recycled asphalt according to claim 1, characterized in that: The antioxidant is at least one of 2,2,4-trimethyl-1,2-dihydroquinoline and 4-[(4,6-dioctylthio-1,3,5-triazine-2-yl)amino]-2,6-di(1,1-methylethyl)phenol (hindered phenol type antioxidant 565).

6. The method for preparing a viscosity-reducing and life-extending warm-mix recycled asphalt according to any one of claims 1 to 5, characterized in that: The invention includes the preparation of a viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent and the preparation of a viscosity-reducing and life-extending warm-mix regenerated asphalt.

7. The method for preparing a viscosity-reducing and life-extending warm-mix recycled asphalt according to claim 6, characterized in that: The following steps are involved: S1: weigh the raw materials of the common asphalt regeneration agent, auxiliary viscosity reducer, reaction regeneration agent and anti-aging agent and mix the regeneration agent at the same temperature according to the mass ratio and set aside; S2: The raw materials weighed in S1 are mixed at a stirring speed of 300-600 rpm at 25-100° C. for 10-30 min to obtain a viscosity-reducing and life-extending composite warm-mix asphalt regeneration agent, which is sealed and stored at room temperature; S3: First, the new asphalt is aged at 163°C for 85 minutes, and then placed in an aging box at 100°C and 2.1MPa pressure for 20 hours to prepare aged asphalt; S4: heating the aged asphalt to 125-150°C to make it have a certain fluidity after melting; S5: Weigh 5-10% of the warm mix regeneration agent involved in step S2, add it to the aged asphalt at a stirring speed of 300-600 rpm, and stir for 5-15 minutes to prepare a viscosity-reducing and life-extending warm mix regenerated asphalt.

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