CN115418081B

CN115418081B - Composite regenerant, warm mix regenerated asphalt mixture and preparation method

Info

Publication number: CN115418081B
Application number: CN202211173479.XA
Authority: CN
Inventors: 盛飞; 胡成生; 彭馨彦; 许龙; 洪晶; 蔡祥; 林勇文
Original assignee: Guangzhou Weixin Material Technology Co ltd; Guangzhou Municipal Engineering Maintenance Office Co ltd
Current assignee: Guangzhou Weixin Material Technology Co ltd; Guangzhou Municipal Engineering Maintenance Office Co ltd
Priority date: 2022-09-26
Filing date: 2022-09-26
Publication date: 2023-07-25
Anticipated expiration: 2042-09-26
Also published as: CN115418081A

Abstract

The invention relates to the technical field of road building materials and engineering, and provides a composite regenerant, a warm mix regenerated asphalt mixture and a preparation method thereof. The composite regenerant comprises an acid dispersant, a lubricant, a modified main agent, a curing agent, a diluent and a plasticizer, wherein the lubricant is cardanol; the modified main agent is epoxy bisphenol A resin. The composite regenerant provided by the invention has the functions of regeneration and warm mixing, can restore the low-temperature ductility of old asphalt, reduce the mixing temperature in the production process, prevent the aging of the old asphalt in the production process, and simultaneously can improve the fatigue resistance, the water stability and the low-temperature performance of the regenerated asphalt. The blending proportion of the recycled asphalt mixture (RAP) can be improved to 100% by adopting the composite regenerant to prepare the recycled asphalt mixture, and the obtained recycled asphalt mixture has excellent performances in all aspects and can be directly used for pavement surface layers.

Description

Composite regenerant, warm mix regenerated asphalt mixture and preparation method

Technical Field

The invention relates to the technical field of road building materials and engineering, in particular to a composite regenerant, a warm mix regenerated asphalt mixture and a preparation method thereof.

Background

By the end of 2020, the total road mileage reaches 519.81 thousands kilometers (where the expressway mileage is 16.10 thousands kilometers), the road maintenance mileage reaches 514.40 thousands kilometers, and the total road mileage is 99.0%. A large number of roads built in early stages in China enter the reconstruction, extension and major-minor repair and maintenance stages successively, a large number of asphalt mixture reclaimed materials (RAP) are generated, and the asphalt mixture reclaimed materials generated over time are more and more. If the asphalt mixture reclaimed materials are not processed correctly, the environment is not polluted, and the asphalt mixture reclaimed materials are a serious waste of resources. How to fully and reasonably apply the asphalt mixture reclaimed materials and exert the residual value to the greatest extent is a key problem facing us.

The asphalt pavement regeneration method can be roughly divided into four types of plant-mixed hot regeneration, in-situ hot regeneration, plant-mixed cold regeneration and in-situ cold regeneration according to the mixing temperature and mixing place of the regenerated pavement constituent materials. The plant-mixed heat regeneration is to uniformly heat and mix the waste materials with new aggregate, new asphalt and a regeneration additive according to a certain proportion after recycling, crushing and screening the waste materials; because asphalt is very sensitive to temperature change, old asphalt can be aged sharply or burnt when the temperature is too high; the traditional method for regenerating the old materials by hot-in-plant is realized by the contact heat transfer of the new aggregates, and the heating mode has strict requirements on the adding proportion of the asphalt mixture reclaimed materials in the aggregates, and is generally controlled to be about 30wt% (the rest 70wt% is the new aggregates). By introducing the warm mixing technology, the mixing temperature is reduced, and the mixing proportion of the asphalt mixture reclaimed materials can reach about 60 weight percent. The plant-mixing or on-site cold recycling is to utilize the existing recycled asphalt pavement material, and new aggregate is added or even not added in situ or in a production special site according to the design grading, so that the recycled asphalt mixture can be basically recycled up to 100%. However, the cold-recycled asphalt mixture has low performance, is generally used for a road base or an underlayment, and cannot be directly used as a surface layer, so that the recovery of the surface layer asphalt mixture by using the cold-recycling technology is similar to resource waste.

The asphalt aging is mainly characterized by thermal oxidation aging, the content of oxygen element is increased under the combined action of heat and oxygen, and meanwhile, because unsaturated functional groups in the asphalt are unstable in the aging process, oxidation, dehydrogenation, polycondensation, addition, crosslinking and other reactions occur to generate macromolecular polymers such as carbonyl groups, sulfoxide groups and the like. From a microscopic perspective, asphalt is mainly composed of aromatic components, saturated components, asphaltenes and colloid, and asphalt aging is represented by macromolecular polymers generated in the asphalt, and the saturated components and the aromatic components are converted into colloid and asphaltenes. The traditional regenerant generally adopts light oil containing aromatic components for adjusting the proportion of four components of old asphalt so as to reduce the old asphalt, but the blending proportion of asphalt mixture reclaimed materials in the regenerant is low, the highest blending amount is only about 60wt%, and the blending proportion of asphalt mixture reclaimed materials is too high, so that the performance of the regenerant asphalt mixture is adversely affected, and the regenerant is mainly characterized by reducing fatigue durability, low-temperature performance and water stability, especially fatigue durability.

Disclosure of Invention

In view of the above, the invention provides a compound regenerant, a warm mix regenerated asphalt mixture and a preparation method thereof. The composite regenerant provided by the invention has good regeneration effect on the asphalt mixture reclaimed materials, the blending ratio of the asphalt mixture reclaimed materials in the aggregate can reach 100% when the regenerated asphalt mixture is prepared, and the obtained regenerated asphalt mixture has excellent fatigue resistance and durability, water stability and low-temperature performance.

In order to achieve the above object, the present invention provides the following technical solutions:

the composite regenerant comprises the following components in percentage by mass: 30-50% of an acid dispersant, 35-50% of a lubricant, 10-20% of a modified main agent, 5-10% of a curing agent, 1-5% of a diluent and 1-2% of a plasticizer; the lubricant is cardanol; the modified main agent is epoxy bisphenol A resin.

Preferably, the acidic dispersant comprises one or more of polydiacid, octanoic acid, dicarboxylic acid and lauric acid.

Preferably, the curing agent is a tertiary amine-terminated epoxy curing agent; the diluent is one or more of propylene carbonate, vinylene carbonate and glycerol carbonate; the plasticizer is one or two of dioctyl phthalate and dibutyl phthalate.

The invention also provides a preparation method of the composite regenerant, which comprises the following steps:

(1) Stirring and mixing the modified main agent and the diluent, and then developing to obtain a first mixture;

(2) Stirring and mixing an acidic dispersing agent and a lubricating agent with the first mixture, and then developing to obtain a second mixture;

(3) And stirring and mixing the plasticizer and the curing agent with the second mixture to obtain the composite regenerant.

Preferably, the modified base, the acidic dispersant and the lubricant are subjected to a vacuum dehydration treatment prior to use.

Preferably, the temperature of stirring and mixing in the step (1) is 20-100 ℃, the time is 20-40 min, and the stirring speed is 3000-6000 r/min; the development temperature in the step (1) is 40-100 ℃ and the development time is 20-40 min;

the temperature of stirring and mixing in the step (2) is 20-60 ℃, the time is 10-30 min, and the stirring rotating speed is 1000-3000 r/min; the development temperature in the step (2) is 40-100 ℃ and the development time is 20-40 min;

the temperature of stirring and mixing in the step (3) is 20-60 ℃, the time is 20-40 min, and the stirring rotating speed is 1000r/min.

The invention also provides a warm mix reclaimed asphalt mixture, which comprises the following components in parts by weight: 100 parts of aggregate, 0.3 to 4 parts of composite regenerant and 0.3 to 3 parts of asphalt; the mass fraction of the asphalt mixture reclaimed materials in the aggregate is 60% -100%; the composite regenerant is the composite regenerant prepared by any one of claims 1 to 3 or the preparation method of any one of claims 4 to 6.

The invention also provides a preparation method of the warm mix reclaimed asphalt mixture, which comprises the following steps:

and heating the aggregate to 80-130 ℃, and then sequentially adding the composite regenerant and asphalt to stir and mix to obtain the warm mix regenerated asphalt mixture.

Preferably, the stirring and mixing process is as follows: adding the compound regenerant, stirring for 45-100 s, and then adding asphalt and continuously stirring for 30-60 s.

The invention provides a composite regenerant, which comprises the following components in percentage by mass: 30-50% of an acid dispersant, 35-50% of a lubricant, 10-20% of a modified main agent, 5-10% of a curing agent, 1-5% of a diluent and 1-2% of a plasticizer; the lubricant is cardanol; the modified main agent is epoxy bisphenol A resin. The invention adds acid dispersant into the compound regenerant, which can break up the black material in the waste asphalt mixture, dissolve the old asphalt, reduce the viscosity of the old asphalt, ensure the even distribution of the old asphalt in the production process, thereby mixing the new asphalt and the old asphalt evenly.

According to the invention, cardanol is used as a lubricant, four components of old asphalt can be regulated, and meanwhile, an aged macromolecular polymer of the asphalt is reduced into small molecules, for example, carbonyl compounds are reduced into olefin compounds, so that the low-temperature ductility of the old asphalt is further recovered; meanwhile, the mixing temperature in the production process is further reduced, the problem of old material temperature control in the production process is solved, ageing in the old material production process can be prevented, more importantly, the mixing proportion of the asphalt mixture reclaimed material (RAP) in the aggregate is improved to 60% -100%, and when the mixing proportion is 100%, new aggregate is not required to be added in the preparation of the regenerated asphalt mixture. Therefore, the composite regenerant provided by the invention has the functions of regeneration and warm mixing.

The invention selects the epoxy bisphenol A resin as the modified main agent, the new asphalt, the old asphalt, the epoxy resin and the curing agent thereof are subjected to cross-linking polymerization reaction under certain conditions, the epoxy resin after the curing reaction is a disperse phase, the epoxy resin can only be dispersed in the asphalt in the form of small colloidal particles, and the epoxy resin plays a good role in toughening in the asphalt due to the formation of the structure, so that the fatigue resistance, the water stability, the low-temperature performance and the like of the regenerated asphalt mixture can be improved.

In addition, the invention develops the compound regenerant pertinently, adopts a single-component design, can avoid inaccurate proportioning and calculating errors of double-component proportioning, and simultaneously avoids performance influence caused by metering errors and uneven mixing, thereby being more beneficial to stable and efficient production.

The invention also provides a warm mix reclaimed asphalt mixture, which comprises the following components in parts by weight: 100 parts of aggregate, 0.3-4 parts of composite regenerant and 0.3-3 parts of asphalt, wherein the mass fraction of asphalt mixture reclaimed materials (RAP) in the aggregate is 60% -100%. The mixing proportion of RAP in the aggregate can reach 60% -100%, when the RAP in the aggregate is 100%, new aggregate is not needed to be added, and the recycled asphalt mixture is adopted, so that the mixing amount of the RAP in the aggregate in the conventional warm mix recycled asphalt mixture in the field is less than 60%, the mixing amount of the RAP in the aggregate can be greatly improved and can reach 100%, the residual value of the RAP can be utilized to the maximum extent, the pollution of the RAP which cannot be treated to the environment is avoided, and the purpose of protecting the environment is achieved; the regenerated asphalt mixture provided by the invention has good fatigue performance, low temperature resistance and water damage resistance, and can be directly used for pavement surface layers.

The invention also provides a preparation method of the warm mix regenerated asphalt mixture, which adopts the composite regenerant to prepare the warm mix regenerated asphalt mixture, has low mixing production temperature, can reduce the emission of harmful gases and other substances, and is more environment-friendly.

Detailed Description

The invention provides a composite regenerant, which comprises the following components in percentage by mass: 30-50% of an acid dispersant, 35-50% of a lubricant, 10-20% of a modified main agent, 5-10% of a curing agent, 1-5% of a diluent and 1-2% of a plasticizer; the lubricant is cardanol; the modified main agent is epoxy bisphenol A resin.

All the raw materials used in the present invention are commercially available unless otherwise specified.

The composite regenerant provided by the invention comprises 30-50% of an acidic dispersant, preferably 35-45% by mass. In the present invention, the acidic dispersant preferably includes one or more of polydiacid, octanoic acid, dicarboxylic acid and lauric acid. The invention adopts the acid dispersant, and can break up the black materials in the waste asphalt mixture, thereby uniformly mixing the new asphalt and the old asphalt.

The composite regenerant provided by the invention comprises 35-50% of lubricant, preferably 40-45% of lubricant by mass fraction. In the invention, the lubricant is cardanol; the cardanol can regulate four components of old asphalt, simultaneously reduce asphalt aged macromolecular polymers into small molecules, for example, reduce carbonyl compounds into olefin compounds, and further restore the low-temperature ductility of the old asphalt.

The composite regenerant provided by the invention comprises 10-20% of a modified main agent, preferably 13-16% of the modified main agent. In the present invention, the modifying main agent is an epoxy bisphenol a type resin. The invention adopts the epoxy bisphenol A resin as the modified main agent, can play the role of a toughening agent, and further improves the fatigue resistance and durability, the water stability, the low-temperature performance and the like of the regenerated asphalt mixture.

The composite regenerant provided by the invention comprises 5-10% of a curing agent, preferably 6-8% of the curing agent by mass fraction. In the invention, the curing agent is preferably a tertiary amine terminated epoxy curing agent; the invention has no special requirements on the specific type of the tertiary amine-terminated epoxy curing agent, and the curing agent known by the person skilled in the art can be adopted; in a specific embodiment of the present invention, the tertiary amine terminated epoxy curing agent is preferably a tertiary amine terminated hyperbranched polymer, specifically a commercially available QNP type 1 low temperature latent epoxy resin curing agent. In the invention, the terminal tertiary amino epoxy hardener belongs to a latent epoxy hardener, ensures the realization of a single-component composite regenerant, can promote the solidification reaction by heating in the production process, and has better storage stability.

The composite regenerant provided by the invention comprises 1-5% of a diluent, preferably 2-4% of the diluent. In the present invention, the diluent is preferably one or more of propylene carbonate, vinylene carbonate and glycerol carbonate. In the invention, the main function of the diluent is to dilute the modified main agent, ensure the uniform mixing of the modified main agent and the curing agent, and simultaneously have little adverse effect on the physical properties of the cured product, or can improve the physical properties of the cured product, when the temperature exceeds 60 ℃, the reaction between carbonic ester and amine can be triggered to produce methyl amino acid ester, and the reaction product contains hydroxyl groups, so that a tough bridging point is provided for the formation of hydrogen bonds, and the mechanical properties of the cured resin are improved.

The composite regenerant provided by the invention comprises 1-2% of plasticizer, preferably 1.2-1.5% of plasticizer. In the present invention, the plasticizer is preferably one or both of dioctyl phthalate and dibutyl phthalate. The plasticizer adopted by the invention has good softening effect and good compatibility with asphalt, so that the product has good softness, and has softening and plasticizing effects in an asphalt modification system.

The invention mixes the modified main agent and the diluent (marked as first mixing) and then develops (marked as first development) to obtain a first mixture. In the invention, the modified main agent is preferably subjected to vacuum dehydration treatment before use; the temperature of the first stirring and mixing is preferably 20-100 ℃, more preferably 40-60 ℃, the time of the first stirring and mixing is preferably 20-40 min, more preferably 30min, and the stirring rotating speed of the first stirring and mixing is preferably 3000-6000 r/min, more preferably 4000-5000 r/min; the temperature of the first development is preferably 40 to 100 ℃, more preferably 50 to 60 ℃, and the time of the first development is preferably 20 to 40min, more preferably 30min.

After the first mixture is obtained, the acid dispersant and the lubricant are stirred and mixed with the first mixture (marked as second stirring and mixing), and then development is carried out (marked as second development), so that the second mixture is obtained. In the present invention, the acidic dispersant and the lubricant are preferably subjected to a vacuum dehydration treatment before use; the temperature of the second stirring and mixing is preferably 20-60 ℃, more preferably 25-35 ℃, the time of the second stirring and mixing is preferably 10-30 min, more preferably 15-25 min, and the stirring rotating speed of the second stirring and mixing is preferably 1000-3000 r/min, more preferably 2000r/min; the temperature of the second development is preferably 40 to 100 ℃, more preferably 50 to 60 ℃, and the time of the second development is preferably 20 to 40min, more preferably 30min.

After the second mixture is obtained, the plasticizer and the curing agent are stirred and mixed with the second mixture (marked as third stirring and mixing) to obtain the composite regenerant. In the invention, the temperature of the third stirring and mixing is preferably 20-60 ℃, more preferably 20-30 ℃, the time of the third stirring is preferably 20-40 min, more preferably 30min, and the stirring rotating speed of the third stirring is preferably 1000r/min; the invention preferably adds the plasticizer and the curing agent after the second mixture has cooled.

The invention also provides a warm mix reclaimed asphalt mixture, which comprises the following components in parts by weight: 100 parts of aggregate, 0.3 to 4 parts of composite regenerant and 0.3 to 3 parts of asphalt; the mass fraction of asphalt mixture reclaimed materials (RAP) in the aggregate is 60-100%.

The warm mix regenerated asphalt mixture provided by the invention comprises 100 parts of aggregate, wherein the mass fraction of asphalt mixture reclaimed materials (RAP) in the aggregate is 60-100%, preferably more than 60% and less than or equal to 100%, more preferably 80-100%, and most preferably 100%. In the invention, the RAP is subjected to crushing and screening pretreatment before use, and meets the requirements of the highway asphalt pavement regeneration technical specification (JTG/T5521-2019), the grading curve meets the requirements of the asphalt pavement construction technical specification (JTG F40-2004), and in the specific embodiment of the invention, the AC-13 graded RAP, the AC-20 graded RAP or the SMA-13 graded RAP can be adopted. Table 5.8.2 of Highway asphalt pavement regeneration specification (JTG/T5521-2019) makes technical requirements for asphalt mixture Recovery (RAP), wherein the penetration of asphalt in the RAP at 25 ℃ is required to be not less than 10 (0.1 mm). When the compound regenerant is used for preparing the regenerated asphalt mixture, the penetration degree of asphalt in the RAP at 25 ℃ is not required, in the specific embodiment of the invention, the penetration degree of asphalt in the RAP at 25 ℃ can be 8-24, and can be 8, 18, 20, 24 and the like, namely, the invention can adopt RAP with various ageing degrees, and the recycling property of the RAP is very good. The mass fraction of RAP in the aggregate adopted by the invention is 60-100%, when the mass fraction of RAP is 100%, RAP is adopted completely, and when the mass fraction of RAP is more than or equal to 60% and less than 100%, the balance is new aggregate, and the invention has no special requirement on the new aggregate and can meet the asphalt pavement construction technical specification (JTG F40-2004).

Based on the mass parts of aggregate, the warm mix reclaimed asphalt mixture provided by the invention comprises 0.3-4 parts of composite regenerant, preferably 0.5-3 parts; the composite regenerant is the composite regenerant described in the scheme or the composite regenerant prepared by the preparation method described in the scheme, and is not described in detail herein.

The warm mix reclaimed asphalt mixture provided by the invention comprises 0.3-3 parts of asphalt, preferably 0.5-1.5 parts of asphalt by taking the mass parts of aggregate as a reference. The invention has no special requirements on the types of asphalt, and asphalt well known to those skilled in the art is adopted, wherein the asphalt refers to new asphalt, can be common asphalt or modified asphalt, and can be selected according to actual needs; in a specific embodiment of the present invention, the asphalt is preferably 70# A asphalt or SBS (I-D) modified asphalt.

The invention preferably heats the aggregate to 90-120 ℃, and then adds the compound regenerant and asphalt; in the invention, the stirring and mixing process is as follows: adding the compound regenerant, stirring for 45-100 s, preferably 50-80 s, adding asphalt, continuously stirring for 30-60 s, preferably 40-50 s, and obtaining the warm mix regenerated asphalt mixture.

The following description of the embodiments of the present invention will clearly and fully describe the technical solutions of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The tertiary amine-terminated hyperbranched polymers employed in the following examples are all QNP type 1 low temperature latent epoxy curing agents.

Example 1

(1) Preparation of composite regenerant

The composite regenerant comprises the following components: 35% of polydiacid, 40% of cardanol, 15% of epoxy bisphenol A resin, 7% of tertiary amine-terminated hyperbranched polymer, 2% of propylene carbonate and 1% of dioctyl phthalate.

The preparation method of the composite regenerant comprises the following steps: firstly, carrying out vacuum pretreatment on epoxy bisphenol A resin, then carrying out high-speed dispersion stirring on the epoxy bisphenol A resin and propylene carbonate at 60 ℃, wherein the stirring speed is 4000r/min, stirring for 30min, and then developing for 30min in a 60 ℃ oven to obtain a mixture a; vacuum dehydrating the polydiacid and cardanol for 30min, adding the polydiacid and cardanol into the mixture a, dispersing and stirring at a high speed, wherein the stirring temperature is 25 ℃, the stirring speed is 2000min, stirring for 20min, then, developing for 30min in a 60 ℃ oven to obtain a mixture b, cooling, adding dioctyl phthalate and tertiary amine-terminated hyperbranched polymer into the mixture b, and stirring for 30min at a 20 ℃ with a stirring speed of 1000r/min to obtain the composite regenerant.

(2) Preparation of warm mix reclaimed asphalt mixture

An AC-13 graded asphalt mix Recovery (RAP) was selected in which the asphalt to stone ratio of old asphalt was 3.5% and the penetration at 25℃was 8 (0.1 mm). The warm mix recycled asphalt mixture comprises the following components in parts by mass: 1.2 parts of composite regenerant, 1.6 parts of 70# A grade asphalt and 100 parts of RAP.

The preparation method of the warm mix reclaimed asphalt mixture comprises the following steps: heating RAP at 120 ℃, adding the composite regenerant into the RAP, stirring for 60s, adding 70# A grade asphalt into the RAP, and stirring for 45s to obtain the warm mix regenerated asphalt mixture.

Example 2

(1) Preparation of composite regenerant

The composite regenerant comprises the following components: 32% of polydiacid, 50% of cardanol, 10% of epoxy bisphenol A resin, 5% of tertiary amine-terminated hyperbranched polymer, 1.5% of propylene carbonate and 1.5% of dioctyl phthalate.

The preparation method of the composite regenerant was the same as in example 1.

(2) Preparation of warm mix reclaimed asphalt mixture

An AC-13 graded asphalt mix Recovery (RAP) was selected in which the asphalt to stone ratio of the old asphalt was 3.8% and the penetration at 25℃was 20 (0.1 mm). The warm mix recycled asphalt mixture comprises the following components in parts by mass: 0.8 part of compound regenerant, 1.3 parts of 70# A grade asphalt and 100 parts of RAP.

The method for preparing the warm mix reclaimed asphalt mixture is the same as in example 1.

Example 3

(1) Preparation of composite regenerant

The composite regenerant comprises the following components: 42% of polydiacid, 40% of cardanol, 10% of epoxy bisphenol A resin, 5% of tertiary amine-terminated hyperbranched polymer, 2% of propylene carbonate and 1% of dioctyl phthalate.

(2) Preparation of warm mix reclaimed asphalt mixture

An AC-20 graded asphalt mix Recovery (RAP) was selected in which the asphalt to stone ratio of old asphalt was 3.2% and the penetration at 25℃was 18.0 (0.1 mm). The warm mix recycled asphalt mixture comprises the following components in parts by mass: 0.7 part of compound regenerant, 1.4 parts of 70# A grade asphalt and 100 parts of RAP.

Example 4

(1) Preparation of composite regenerant

The composite regenerant comprises the following components: 35% of polydiacid, 35% of cardanol, 18% of epoxy bisphenol A resin, 9% of tertiary amine-terminated hyperbranched polymer, 2% of propylene carbonate and 1% of dioctyl phthalate.

(2) Preparation of warm mix reclaimed asphalt mixture

An SMA-13 graded asphalt mix Recovery (RAP) was selected in which the asphalt to stone ratio of the old asphalt was 4.4% and the penetration at 25℃was 24 (0.1 mm). The warm mix recycled asphalt mixture comprises the following components in parts by mass: 0.8 part of compound regenerant, 1.8 parts of SBS (I-D) modified asphalt and 100 parts of RAP.

Comparative example 1

Reference to highway asphalt pavement construction technical Specification (JTG F40-2004), standard SBS modified asphalt AC-13 was selected as comparative example 1.

Comparative example 2

Other conditions were the same as in example 2 except that the amount of the compound regenerant was changed to 0.2 parts.

Comparative example 3

Other conditions were the same as in example 2 except that the amount of the 70# A grade asphalt was changed to 3.5 parts.

Performance test:

the asphalt mixtures of examples 1 to 4 and comparative examples 1 to 3 were subjected to dynamic stability test, immersion Marshall test residual stability test, freeze-thaw cleavage test residual strength ratio test, four-point bending fatigue test, and trabecular bending test (-10 ℃) and the relevant standards for each test reference are shown in Table 1, and the test results are shown in Table 1.

Table 1 summary of test results for examples 1 to 4 and comparative examples 1 to 3

As can be seen from Table 1, the regenerated asphalt mixture provided by the invention has excellent fatigue resistance and durability, high dynamic stability, good water stability and better low-temperature performance, and the performances of the regenerated asphalt mixture are similar to those of the modified asphalt SBS mixture (comparative example 1); as is clear from comparative example 2, the reduction of the composite regenerant resulted in a reduction of the effective asphalt, unsatisfactory performance against fly-away and water stability; as is clear from comparative example 3, the increase of asphalt cement leads to the destruction of the compact structure of the skeleton, and the high-temperature stability is not satisfactory. Meanwhile, asphalt mixture reclaimed materials (RAP) with different aging degrees are respectively used in examples 1-4, and the obtained reclaimed asphalt mixtures have excellent performances, so that the composite regenerant disclosed by the invention is suitable for asphalt mixture reclaimed materials (RAP) with various aging degrees.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims

1. The composite regenerant is characterized by comprising the following components in parts by mass: 30-50% of an acid dispersant, 35-50% of a lubricant, 10-20% of a modified main agent, 5-10% of a curing agent, 1-5% of a diluent and 1-2% of a plasticizer; the lubricant is cardanol; the modified main agent is epoxy bisphenol A resin; the acid dispersant is polydiacid; the plasticizer is one or two of dioctyl phthalate and dibutyl phthalate; the curing agent is a tertiary amine epoxy curing agent.

2. The composite regenerant according to claim 1, wherein said diluent is one or more of propylene carbonate, vinylene carbonate and glycerol carbonate.

3. The method for preparing the composite regenerant according to any one of claims 1 to 2, comprising the steps of:

4. A method of preparing according to claim 3, wherein the modified host, the acidic dispersant and the lubricant are subjected to a vacuum dehydration treatment prior to use.

5. The method according to claim 3, wherein the temperature of the stirring and mixing in the step (1) is 20-100 ℃, the time is 20-40 min, and the stirring speed is 3000-6000 r/min; the development temperature in the step (1) is 40-100 ℃ and the development time is 20-40 min;

6. The warm mix regenerated asphalt mixture is characterized by comprising the following components in parts by weight: 100 parts of aggregate, 0.3 to 4 parts of composite regenerant and 0.3 to 3 parts of asphalt; the mass fraction of the asphalt mixture reclaimed materials in the aggregate is 60% -100%; the composite regenerant is the composite regenerant prepared by any one of claims 1-2 or the preparation method of any one of claims 3-5.

7. The method for preparing the warm mix reclaimed asphalt mixture of claim 6, comprising the steps of:

8. The method according to claim 7, wherein the stirring and mixing process is as follows: adding the compound regenerant, stirring for 45-100 s, and then adding asphalt and continuously stirring for 30-60 s.