Warm mix asphalt regenerant, preparation method thereof and asphalt regeneration method

Abstract

The invention discloses a warm mix asphalt regenerant, a preparation method thereof and an asphalt regeneration method, and belongs to the technical field of road building materials. The warm mix asphalt regenerant comprises the following raw materials in parts by weight: 15-25 parts of a viscosity reduction component, 50-70 parts of a regeneration component, 10-20 parts of a performance regulator and 3-8 parts of a composite additive. The invention provides a composite asphalt regenerant with warm mixing and regeneration dual functions, which is particularly suitable for low-temperature regeneration construction of high-proportion asphalt pavement recycled materials, realizes high-mixing-amount (70-100%) regeneration of the asphalt pavement recycled materials under the medium-temperature condition of 100-130 DEG C, keeps excellent balance of high-temperature and low-temperature performance of the regenerated asphalt, and has the advantages of high-temperature mixing performance, high-temperature mixing performance, high-temperature mixing performance, high-temperature mixing performance, low-temperature mixing performance, low-temperature mixing performance and the like. The regenerated asphalt keeps excellent performance balance of a softening point of 60-68 DEG C and ductility of 30-50 cm; the construction energy consumption is reduced by more than 40%; the construction process is simplified, and multiple effects are achieved by single agent.

Description

Technical Field

[0001] This invention relates to the field of road construction materials technology, specifically to a warm-mix asphalt recycling agent and its preparation method and asphalt recycling method. Background Technology

[0002] Asphalt pavement recycling technology is a complete process that involves excavating, recycling, heating, crushing, and screening old asphalt pavement using specialized pavement recycling equipment, then mixing it with recycling agents, new asphalt, and new aggregates in a certain proportion to form a mixture that meets specific road performance requirements and is then repaved onto the road surface.

[0003] Warm-mix asphalt is an asphalt mixture technology that uses certain technical measures to enable asphalt to be mixed and constructed at a relatively low temperature while maintaining its performance at a level no lower than that of hot-mix asphalt mixtures. The key to this technology is how to reduce the mixing viscosity of asphalt at a lower temperature without compromising the road performance of hot-mix asphalt mixtures.

[0004] Traditional asphalt recycling technology faces the following technical bottlenecks: High-temperature construction problems: Conventional hot recycling requires high temperatures of 160-180℃, leading to secondary aging of aged asphalt and high energy consumption (fuel consumption of 35-45L / t); Limitations on RAP (recycled asphalt pavement material) content: Ordinary recycling agents cannot solve the workability problem under high RAP content (>50%), and the actual RAP content in engineering projects is mostly limited to 30-40%; Performance imbalance: Commercially available warm mix additives often damage the high-temperature performance of recycled asphalt (dynamic stability reduced by 20-30%); Complex process: Existing technologies require the separate addition of recycling agents and warm mix additives, making metering control difficult.

[0005] Currently, existing technologies include the use of organic viscosity reducers to achieve warm mixing, but this results in a decrease in the softening point of recycled asphalt by 8-12℃; while existing technologies have developed composite recycling agents that can improve performance, they still require a construction temperature of over 150℃.

[0006] Therefore, how to develop a warm-mix asphalt recycling agent with both warm-mix and recycling functions, as well as its preparation method and asphalt recycling method, are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a warm-mix asphalt recycler, its preparation method, and an asphalt recycling method.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A warm-mix asphalt recycling agent comprises the following raw materials in parts by weight:

[0010] Viscosity reducing component 15-25 parts, regeneration component 50-70 parts, performance modifier 10-20 parts, composite additive 3-8 parts;

[0011] The viscosity-reducing component is a mixture of fatty amides and long-chain fatty acid esters;

[0012] The regenerated component is a mixture of tall oil and naphthenic oil;

[0013] The performance modifier is a mixture of nano-organic montmorillonite and styrene-isoprene-styrene block copolymer (SIS elastomer);

[0014] The composite additive is a mixture of antioxidants, ultraviolet absorbers, and compatibilizers.

[0015] The beneficial effects of this invention are as follows: The viscosity-reducing component fatty amide reduces the high-temperature viscosity of asphalt, with a viscosity reduction of 40-50% at 60℃; long-chain fatty acid esters improve low-temperature fluidity, with a viscosity of ≤0.25 Pa·s at 135℃; the recycled component tall oil is rich in carboxylic acid groups, replenishing the polar components missing in aged asphalt; naphthenic oil restores colloidal stability; nano-organic montmorillonite compensates for the high-temperature performance loss of warm mix additives; and styrene-isoprene-styrene block copolymer improves elasticity recovery by ≥75%.

[0016] This invention provides a composite asphalt recycling agent that combines warm-mix and recycling functions. It is particularly suitable for low-temperature recycling of high-proportion asphalt pavement recycled materials, achieving high-volume (70-100%) recycling of asphalt pavement recycled materials under medium-temperature conditions of 100-130℃. This maintains an excellent balance of high and low temperature performance in the recycled asphalt, ensuring a good balance between a softening point of 60-68℃ and a ductility of 30-50cm. It reduces construction energy consumption by more than 40%, simplifies the construction process, and achieves multiple effects with a single agent. This recycling agent integrates warm-mix and recycling functions, solving the problems of high-temperature construction and separate agent addition required by traditional technologies. It is particularly suitable for environmentally friendly recycling projects on high-grade highways.

[0017] Furthermore, the tall oil has an acid value ≥150mg KOH / g, a rosin acid content of 45-55%, and an aromatic content of ≥35% in the naphthenic oil;

[0018] The nano-organomontmorillonite has a layer spacing of ≥3.5nm, and the styrene content in the styrene-isoprene-styrene block copolymer is 10-30%.

[0019] Furthermore, the fatty amide is erucamide, and the long-chain fatty acid ester is butyl stearate;

[0020] The tall oil mentioned is refined tall oil;

[0021] The antioxidant is a mixture of hindered phenolic antioxidants and phosphites, with a mass ratio of hindered phenolic antioxidants to phosphites of 1:1.

[0022] The ultraviolet absorber is a benzotriazole ultraviolet absorber;

[0023] The compatibilizer is a maleic anhydride graft polymer.

[0024] Furthermore, the maleic anhydride grafted polymer is a maleic anhydride-grafted ethylene-vinyl acetate copolymer with a grafting rate of 1-5%.

[0025] Furthermore, the mass ratio of the fatty amide to the long-chain fatty acid ester is 1:(0.5-2);

[0026] The mass ratio of tall oil to naphthenic oil is 1:1;

[0027] The mass ratio of the nano-organo-montmorillonite and the styrene-isoprene block copolymer is 1:1;

[0028] The mass ratio of the antioxidant, ultraviolet absorber and compatibilizer is 1:1.

[0029] This invention also provides a method for preparing a warm-mix asphalt recycling agent, comprising the following steps:

[0030] (1) Weigh out each raw material according to the warm mix asphalt recycling agent described above;

[0031] (2) The recycled component is heated, and then the viscosity-reducing component, performance regulator and composite additive are added in sequence. Finally, the mixture is homogenized and cooled to obtain the warm-mix asphalt recycling agent.

[0032] Further, in step (2), the regenerated components are heated to 80-100°C, the homogenization speed is 2800-2900 r / min, the homogenization time is 5 hours, and then cooled to below 50°C.

[0033] The present invention also provides a method for asphalt recycling, comprising the following steps:

[0034] The asphalt pavement recycled material is heated, and then the warm mix asphalt recycling agent is added to the heated asphalt pavement recycled material and mixed.

[0035] Furthermore, the amount of warm-mix asphalt recycling agent added is 3-8% of the mass of the recycled asphalt pavement material.

[0036] Furthermore, the recycled asphalt pavement material is heated to 100-130℃, the mixing speed is 100-200 rpm, and the mixing time is 20-30 minutes. Detailed Implementation

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In this embodiment of the invention, the hindered phenolic antioxidant is BASF Irganox 1010, and the benzotriazole UV absorber is BASF Tinuvin 328.

[0039] Naphthenic oil quality specifications: softening point ≥100℃; pour point ≤-30℃; CA% ≥50%; flash point >200℃.

[0040] Example 1

[0041] The asphalt recycling method includes the following steps:

[0042] The asphalt pavement recycled material is heated, and then warm mix asphalt recycling agent is added to the asphalt pavement recycled material heated to 120°C. The amount of warm mix asphalt recycling agent added is 5% of the mass of the asphalt pavement recycled material. Mix for 25 minutes at a mixing speed of 200 rpm.

[0043] The preparation method of warm-mix asphalt recycling agent includes the following steps:

[0044] (1) Weigh out each raw material:

[0045] Viscosity-reducing component 20kg: a mixture of erucamide and butyl stearate;

[0046] 60 kg of regenerated components: a mixture of refined tall oil and naphthenic oil;

[0047] Performance modifier 15kg: a mixture of nano-organic montmorillonite and SIS elastomer;

[0048] 5kg of compound additive: Antioxidant: a mixture of Irganox 1010 and phosphite; UV absorber: Tinuvin 328; Compatibilizer: maleic anhydride graft polymer;

[0049] The mass ratio of Irganox 1010 to phosphite is 1:1.

[0050] The mass ratio of erucamide to butyl stearate is 1:1;

[0051] The mass ratio of refined tall oil to naphthenic oil is 1:1;

[0052] The mass ratio of nano-organic montmorillonite to SIS elastomer is 1:1;

[0053] The mass ratio of antioxidant, UV absorber and compatibilizer is 1:1.

[0054] The refined tall oil has an acid value ≥150mg KOH / g and a rosin acid content of 50%.

[0055] The nano-organic montmorillonite interlayer spacing is ≥3.5nm, and the styrene content in the SIS elastomer is 30%.

[0056] The maleic anhydride-grafted polymer is a maleic anhydride-grafted ethylene-vinyl acetate copolymer with a grafting rate of 5%.

[0057] (2) Heat the recycled component to 90°C, then add the viscosity reducing component, performance regulator and composite additive in sequence, and finally homogenize at a speed of 2800 r / min for 5 hours, and cool to below 50°C to obtain warm-mix asphalt recycling agent.

[0058] Example 2

[0059] The asphalt recycling method includes the following steps:

[0060] The asphalt pavement recycled material is heated, and then warm mix asphalt recycling agent is added to the asphalt pavement recycled material heated to 100°C. The amount of warm mix asphalt recycling agent added is 3% of the mass of the asphalt pavement recycled material. Mix for 20 minutes at a mixing speed of 200 rpm.

[0061] The preparation method of warm-mix asphalt recycling agent includes the following steps:

[0062] (1) Weigh out each raw material:

[0063] Viscosity-reducing component 15kg: a mixture of erucamide and butyl stearate;

[0064] 50 kg of regenerated components: a mixture of refined tall oil and naphthenic oil;

[0065] Performance modifier 10kg: a mixture of nano-organic montmorillonite and SIS elastomer;

[0066] 3kg of compound additives: Antioxidant: a mixture of Irganox 1010 and phosphite; UV absorber: Tinuvin 328; Compatibilizer: maleic anhydride graft polymer;

[0067] The mass ratio of Irganox 1010 to phosphite is 1:1.

[0068] The mass ratio of erucamide to butyl stearate is 1:0.5;

[0069] The mass ratio of refined tall oil to naphthenic oil is 1:1;

[0070] The mass ratio of nano-organic montmorillonite to SIS elastomer is 1:1;

[0071] The mass ratio of antioxidant, UV absorber and compatibilizer is 1:1.

[0072] The refined tall oil has an acid value ≥150mg KOH / g and a rosin acid content of 50%.

[0073] The nano-organic montmorillonite interlayer spacing is ≥3.5nm, and the styrene content in the SIS elastomer is 30%.

[0074] The maleic anhydride-grafted polymer is a maleic anhydride-grafted ethylene-vinyl acetate copolymer with a grafting rate of 5%.

[0075] (2) Heat the recycled component to 80°C, then add the viscosity reducing component, performance regulator and composite additive in sequence, and finally homogenize at a speed of 2800 r / min for 5 hours, and cool to below 50°C to obtain warm-mix asphalt recycling agent.

[0076] Example 3

[0077] The asphalt recycling method includes the following steps:

[0078] The asphalt pavement recycled material is heated, and then warm mix asphalt recycling agent is added to the asphalt pavement recycled material heated to 130°C. The amount of warm mix asphalt recycling agent added is 8% of the mass of the asphalt pavement recycled material. Mix for 30 minutes at a mixing speed of 200 rpm.

[0079] The preparation method of warm-mix asphalt recycling agent includes the following steps:

[0080] (1) Weigh out each raw material:

[0081] Viscosity-reducing component 25kg: a mixture of erucamide and butyl stearate;

[0082] 70 kg of regenerated components: a mixture of refined tall oil and naphthenic oil;

[0083] Performance modifier 20kg: a mixture of nano-organic montmorillonite and SIS elastomer;

[0084] 8kg of compound additives: Antioxidant: a mixture of Irganox 1010 and phosphite; UV absorber: Tinuvin 328; Compatibilizer: maleic anhydride graft polymer;

[0085] The mass ratio of Irganox 1010 to phosphite is 1:1.

[0086] The mass ratio of erucamide to butyl stearate is 1:2;

[0087] The mass ratio of refined tall oil to naphthenic oil is 1:1;

[0088] The mass ratio of nano-organic montmorillonite to SIS elastomer is 1:1;

[0089] The mass ratio of antioxidant, UV absorber and compatibilizer is 1:1.

[0090] The refined tall oil has an acid value ≥150mg KOH / g and a rosin acid content of 50%.

[0091] The nano-organic montmorillonite interlayer spacing is ≥3.5nm, and the styrene content in the SIS elastomer is 30%.

[0092] The maleic anhydride-grafted polymer is a maleic anhydride-grafted ethylene-vinyl acetate copolymer with a grafting rate of 5%.

[0093] (2) Heat the recycled component to 100°C, then add the viscosity reducing component, performance regulator and composite additive in sequence, and finally homogenize at a speed of 2800 r / min for 5 hours, and cool to below 50°C to obtain warm-mix asphalt recycling agent.

[0094] Comparative Example 1

[0095] In embodiments 1-3 of this invention, the asphalt pavement recycled material is SBS modified asphalt pavement recycled material.

[0096] Comparative Example 1 is the SBS modified asphalt raw material used in Examples 1-3 before paving the SBS modified asphalt pavement recycled material.

[0097] SBS modified asphalt raw material: 4.2% SBS modifier is added to No. 70 heavy-duty asphalt.

[0098] Table 1 Performance determination of recycled asphalt in Examples 1-3 and Comparative Example 1

[0099] performance Comparative Example 1 Example 1 Example 2 Example 3 Construction temperature (°C) 113 115 112 116 RAP content (%) 74 79 75 88 Softening point of recycled asphalt (°C) 62 66 60 68 Ductility at 15℃ (cm) 42 38 45 52 Marshall stability (kN) 12.6 12.5 12.1 12.4 Freeze-thaw splitting strength ratio 88％ 88％ 85％ 89％ Construction energy consumption (L fuel oil / t) 21 22 18 21 Elastic recovery rate (%) 8％ 82％ 83％ 85％ Fatigue life (15℃) (cycles) <![CDATA[2.1×10 5 ]]> <![CDATA[2.1×10 5 ]]> <![CDATA[2.0×10 5 ]]> <![CDATA[2.1×10 5 ]]>

[0100] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A warm-mix asphalt recycling agent, characterized in that, Including the following parts by weight of raw materials: Viscosity reducing component 15-25 parts, regeneration component 50-70 parts, performance modifier 10-20 parts, composite additive 3-8 parts; The viscosity-reducing component is a mixture of fatty amides and long-chain fatty acid esters; The regenerated component is a mixture of tall oil and naphthenic oil; The performance modifier is a mixture of nano-organo-montmorillonite and styrene-isoprene-styrene block copolymer; The composite additive is a mixture of antioxidants, ultraviolet absorbers, and compatibilizers.

2. The warm-mix asphalt recycling agent according to claim 1, characterized in that, The tall oil has an acid value ≥150mgKOH / g, a rosin acid content of 45-55%, and an aromatic content of ≥35% in the naphthenic oil. The nano-organomontmorillonite has a layer spacing of ≥3.5nm, and the styrene content in the styrene-isoprene-styrene block copolymer is 10-30%.

3. The warm-mix asphalt recycling agent according to claim 1, characterized in that, The fatty amide is erucamide, and the long-chain fatty acid ester is butyl stearate; The tall oil mentioned is refined tall oil; The antioxidant is a mixture of hindered phenolic antioxidants and phosphites, with a mass ratio of hindered phenolic antioxidants to phosphites of 1:

1. The ultraviolet absorber is a benzotriazole ultraviolet absorber; The compatibilizer is a maleic anhydride graft polymer.

4. The warm-mix asphalt recycling agent according to claim 3, characterized in that, The maleic anhydride grafted polymer is a maleic anhydride-grafted ethylene-vinyl acetate copolymer with a grafting rate of 1-5%.

5. The warm-mix asphalt recycling agent according to claim 1, characterized in that, The mass ratio of the fatty amide to the long-chain fatty acid ester is 1:(0.5-2); The mass ratio of tall oil to naphthenic oil is 1:1; The mass ratio of the nano-organo-montmorillonite and the styrene-isoprene block copolymer is 1:1; The mass ratio of the antioxidant, ultraviolet absorber and compatibilizer is 1:

1.

6. A method for preparing a warm-mix asphalt recycling agent, characterized in that, Includes the following steps: (1) Weigh each raw material according to any one of claims 1-5 for the warm-mix asphalt recycling agent; (2) The recycled component is heated, and then the viscosity-reducing component, performance regulator and composite additive are added in sequence. Finally, the mixture is homogenized and cooled to obtain the warm-mix asphalt recycling agent.

7. The method for preparing a warm-mix asphalt recycling agent according to claim 6, characterized in that, In step (2), the regenerated components are heated to 80-100℃, the homogenization speed is 2800-2900r / min, the homogenization time is 5 hours, and then cooled to below 50℃.

8. A method for asphalt recycling, characterized in that, Includes the following steps: The asphalt pavement recycled material is heated, and then the warm-mix asphalt recycling agent according to any one of claims 1-5 is added to the heated asphalt pavement recycled material and mixed.

9. The asphalt recycling method according to claim 8, characterized in that, The amount of warm-mix asphalt recycling agent added is 3-8% of the mass of the recycled asphalt pavement material.

10. The asphalt recycling method according to claim 8, characterized in that, Heat the recycled asphalt pavement material to 100-130℃, mix at 100-200 rpm, and mix for 20-30 minutes.