Hot mix plant regenerant capable of being directly put into use by dry method and preparation method of hot mix plant regenerant

Abstract

The invention discloses a hot mix plant regenerant capable of being directly used by a dry method. The regenerant is prepared from the following components in parts by mass: 100 parts of base oil, 30-35 parts of R-PET powder, 1-2 parts of an anti-aging agent and 1-2 parts of an anti-ultraviolet agent, the R-PET powder is a PET depolymer prepared by carrying out surface activation on PET by adopting a physical crushing and chemical decomposition method; the prepared regenerant has excellent high-temperature stability, water stability and low-temperature crack resistance, can be directly used for plant mixing hot regeneration mixing, and is good in construction workability, the preparation method is simple and easy to operate, and meanwhile, the regenerant has the characteristics of environmental friendliness and resource conservation.

Description

Technical Field

[0001] The invention relates to the field of road engineering technical materials, and in particular to a factory-mixed hot regeneration agent that can be directly used by dry method and a preparation method thereof. Background Art

[0002] After the asphalt pavement is put into operation, under the influence of factors such as traffic load, ultraviolet radiation, wind and rain, and temperature, the chemical composition and structural composition of the asphalt change, causing the asphalt in the asphalt mixture to undergo irreversible aging. In engineering, it manifests as the decline of the road performance of the asphalt pavement, and the appearance of large-scale loose cracks, rutting and potholes and other diseases. At this time, the asphalt pavement has to enter the stage of milling and resurfacing, and a large amount of old asphalt mixture will be produced. The addition of regeneration agent can change the asphalt components and effectively reuse the old asphalt mixture, thereby realizing resource recycling and cost saving, with significant social, economic and environmental benefits. At present, the regeneration agent on the market is mainly made of waste motor oil, diesel, vegetable oil, etc., and there are problems such as unstable quality and poor regeneration effect. After the asphalt is regenerated, the low-temperature crack resistance of the asphalt is not significantly improved, while the high-temperature performance decreases rapidly, the performance improvement effect is uneven, and the product function is single.

[0003] Therefore, a new type of asphalt regeneration agent is needed to solve the technical problems of unstable quality of the regeneration agent and poor regeneration effect. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a factory-mixed hot regeneration agent that can be used directly by dry method and a preparation method thereof, which can improve the high and low temperature performance of the regenerated asphalt mixture, and the regeneration agent has good stability and has a good regeneration effect.

[0005] The factory-mixed hot regeneration agent that can be directly used by dry method of the present invention comprises the following components by mass: 100 parts of base oil, 30-35 parts of R-PET powder, 1-2 parts of anti-aging agent, and 1-2 parts of anti-ultraviolet agent; the R-PET powder is a PET depolymer obtained by surface activating PET by physical crushing and chemical decomposition;

[0006] Further, the preparation method of the R-PET powder comprises the following steps:

[0007] The recovered PET fragments were mixed with ethylene glycol and zinc acetate, and heated and stirred under nitrogen conditions until the PET fragments were completely dissolved, and then the adsorbent was added after cooling to room temperature, and then the mixed solution was filtered, and the filtrate was cooled until white flocculent crystals were precipitated, and the crystals were dried to obtain R-PET powder;

[0008] Further, the adsorbent is activated carbon;

[0009] Further, the filtrate is refrigerated at a temperature of 3-6°C until crystallization occurs, and the crystals are dried at a temperature of 55-65°C for 6-8h;

[0010] Further, the base oil is at least one of waste cooking oil, tire pyrolysis oil, and pig manure pyrolysis oil;

[0011] Further, the antioxidant is dimethylacetamide;

[0012] Furthermore, the anti-ultraviolet agent is light stabilizer 770.

[0013] The invention also discloses a method for preparing a factory-mixed hot regeneration agent that can be directly used by dry method, comprising the following steps: heating the base oil, adding R-PET powder and mixing evenly, and then adding an anti-aging agent and an anti-ultraviolet agent and mixing until the liquid is viscous.

[0014] Beneficial effects of the present invention: The factory-mixed hot regeneration agent that can be directly used by dry method and its preparation method, the prepared regeneration agent has excellent high temperature stability, water stability, and low temperature crack resistance, can be directly used for factory-mixed hot regeneration mixing, has good construction and workability, and the preparation method is simple and easy to operate, and is environmentally friendly and resource-saving. DETAILED DESCRIPTION

[0015] For a better understanding of the present invention, the following examples are provided to further illustrate the present invention, but the present invention is not limited to the following examples.

[0016] In the examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0017] Embodiment 1

[0018] The factory-mixed hot regeneration agent that can be used by dry method direct investment of the present invention comprises the following components by mass: 100 parts of base oil, 30-35 parts of R-PET powder, 1-2 parts of anti-aging agent, and 1-2 parts of anti-ultraviolet agent; the R-PET powder is a PET depolymer obtained by surface activation of PET by physical crushing and chemical decomposition; the surface activation of PET by physical crushing and chemical decomposition improves the activity, so that the compatibility of PET and asphalt is improved, and some new light components can be introduced to effectively restore the low-temperature performance of aged asphalt. R-PET powder uses waste mineral water bottles as raw materials, has good economic benefits and achieves the purpose of saving resources. The use of anti-aging agent can decompose the agglomerated asphaltene groups, improve the penetration effect of the regeneration agent in the aged asphalt, and the addition of anti-ultraviolet agent can improve the anti-aging ability and stability of the regenerated asphalt mixture.

[0019] In this embodiment, the preparation method of the R-PET powder comprises the following steps:

[0020] The recovered PET fragments are mixed with ethylene glycol and zinc acetate, and heated and stirred under nitrogen conditions until the PET fragments are completely dissolved, and then the adsorbent is added after cooling to room temperature, and then the mixed solution is filtered, and the filtrate is cooled until white flocculent crystals are precipitated, and the crystals are dried to obtain R-PET powder; the specific steps are:

[0021] Step 1: Remove the outer packaging and bottle cap of the mineral water bottle, break it into small pieces of 5mm×5mm, rinse the broken small pieces with clean water and dry them in an oven at 60℃ for 3-4h;

[0022] Step 2: Weigh 1000-1100 parts by weight of dried PET chips, and add the PET chips, 6000-7000 parts by weight of ethylene glycol, and 2-3 parts of zinc acetate to a three-necked round-bottom flask in sequence. Place the round-bottom flask in an electric heating mantle that integrates temperature control, magnetic stirring, and heating, and install a condenser on the three-necked flask. Pass nitrogen into the flask for 25-30 minutes to expel the air in the flask;

[0023] Step 3: Stir the mixture in step 2 at a speed of 300-400 r / min and a heating temperature of 180° C. until the PET fragments are completely dissolved, stop introducing nitrogen and stirring, and cool to room temperature at room temperature;

[0024] Step 4: Add activated carbon to the mixed solution cooled to room temperature in step 3, let it stand for 1 hour for adsorption and impurity removal, and then filter to remove the activated carbon.

[0025] Step 5: The mixed solution of step 4 is filtered with boiling water, and the filtrate is placed in a refrigerator at 5°C for 6-8 hours, and a large amount of white flocculent crystals are precipitated from the filtrate, which is then filtered. The obtained target crystals are dried in a vacuum drying oven at 60°C for 6-8 hours to obtain the depolymerization product R-PET of PET.

[0026] In this embodiment, the filtrate is refrigerated at a temperature of 3-6°C until crystallization occurs, and the crystals are dried at a temperature of 55-65°C for 6-8h;

[0027] In this embodiment, preferably, the base oil is at least one of waste cooking oil, tire pyrolysis oil, and pig manure pyrolysis oil; the antioxidant is dimethylacetamide; and the anti-ultraviolet agent is light stabilizer 770.

[0028] The invention also discloses a method for preparing a factory-mixed hot regeneration agent that can be directly used by dry method, comprising the following steps: heating the base oil, adding R-PET powder and mixing evenly, and then adding an anti-aging agent and an anti-ultraviolet agent and mixing until the liquid is viscous.

[0029] Embodiment 1

[0030] The factory-mixed hot regeneration agent of this embodiment that can be used by dry direct injection, the regeneration agent raw materials include the following components by mass: 100 parts of base oil, 30 parts of R-PET powder, 1 part of anti-aging agent, and 1 part of anti-ultraviolet agent.

[0031] Preparation of R-PET:

[0032] Step 1: Remove the outer packaging and bottle cap of the mineral water bottle, break it into small pieces of 5mm×5mm, rinse the broken small pieces with clean water and dry them in an oven at 60℃ for 3h.

[0033] Step 2: Weigh 1000 parts by mass of the dried PET chips, add the PET chips, 6000 parts by mass of ethylene glycol and 2 parts by mass of zinc acetate into a three-necked round-bottom flask. Place the round-bottom flask in an electric heating mantle that integrates temperature control, magnetic stirring and heating, and install a condenser on the three-necked flask. Pass nitrogen into the flask for 30 minutes to expel the air in the flask.

[0034] Step 3: Stir the mixture in step 2 at a speed of 300 r / min and a heating temperature of 180° C. until the PET fragments are completely dissolved, stop introducing nitrogen and stirring, and cool to room temperature.

[0035] Step 4: Add activated carbon to the mixed solution cooled to room temperature in step 3, let it stand for 1 hour for adsorption and impurity removal, and then filter to remove the activated carbon.

[0036] Step 5: The mixed solution of step 4 is filtered with boiling water, and the filtrate is placed in a refrigerator at 5°C for 6 hours, and a large amount of white flocculent crystals are precipitated from the filtrate, which is then filtered. The obtained target crystals are dried in a vacuum drying oven at 60°C for 6 hours to obtain the depolymerization product R-PET of PET.

[0037] Preparation of regeneration agent:

[0038] Step 1: Weigh the base oil (pig manure cracking oil) according to the mass fraction, place it in an oven at 130°C for 1 hour to preheat and dry.

[0039] Step 2: Weigh the R-PET powder according to the mass fraction, place it in the preheated base oil, and stir it in a constant temperature oil bath until the R-PET powder is completely dissolved in the base oil. The oil bath temperature is 130°C and the stirring speed is 300r / min.

[0040] Step 3: Add anti-aging agent and anti-ultraviolet agent to the mixture prepared in step 2, and stir until it completely turns into a uniform viscous liquid at a stirring speed of 300 r / min.

[0041] Embodiment 2

[0042] The factory-mixed hot regeneration agent that can be used by dry direct injection in this embodiment comprises the following components in parts by mass: 100 parts of base oil, 35 parts of R-PET powder, 2 parts of anti-aging agent, and 2 parts of anti-ultraviolet agent.

[0043] Preparation of R-PET:

[0044] Step 1: Remove the outer packaging and bottle cap of the mineral water bottle, break it into small pieces of 5mm×5mm, rinse the broken small pieces with clean water and dry them in an oven at 60℃ for 3h.

[0045] Step 2: Weigh 1000 parts by mass of the dried PET chips, add the PET chips, 7000 parts by mass of ethylene glycol and 2 parts by mass of zinc acetate into a three-necked round-bottom flask. Place the round-bottom flask in an electric heating mantle that integrates temperature control, magnetic stirring and heating, and install a condenser on the three-necked flask. Pass nitrogen into the flask for 30 minutes to expel the air in the flask.

[0046] Step 3: Stir the mixture in step 2 at a speed of 400 r / min and a heating temperature of 180° C. until the PET fragments are completely dissolved, stop introducing nitrogen and stirring, and cool to room temperature.

[0047] Step 4: Add activated carbon to the mixed solution cooled to room temperature in step 3, let it stand for 1 hour for adsorption and impurity removal, and then filter to remove the activated carbon.

[0048] Step 5: The mixed solution of step 4 is filtered with boiling water, and the filtrate is placed in a refrigerator at 5°C for 6 hours, and a large amount of white flocculent crystals are precipitated from the filtrate, which is then filtered. The obtained target crystals are dried in a vacuum drying oven at 60°C for 6 hours to obtain the depolymerization product R-PET of PET.

[0049] Preparation of regeneration agent:

[0050] Step 1: Weigh the base oil (tire pyrolysis oil) according to the mass fraction, place it in an oven at 130°C for 1 hour to preheat and dry.

[0051] Step 2: Weigh the R-PET powder according to the mass fraction, place it in the preheated base oil, and stir it in a constant temperature oil bath until the R-PET powder is completely dissolved in the base oil. The oil bath temperature is 130°C and the stirring speed is 400r / min.

[0052] Step 3: Add anti-aging agent and anti-ultraviolet agent to the mixture prepared in step 2, and stir until it completely turns into a uniform viscous liquid at a stirring speed of 400 r / min.

[0053] Embodiment 3

[0054] The factory-mixed hot regeneration agent that can be used by dry direct injection in this embodiment comprises the following components in parts by mass: 100 parts of base oil, 31 parts of R-PET powder, 2 parts of anti-aging agent, and 1 part of anti-ultraviolet agent.

[0055] Preparation of R-PET:

[0056] Step 1: Remove the outer packaging and bottle cap of the mineral water bottle, break it into small pieces of 5mm×5mm, rinse the broken small pieces with clean water and dry them in an oven at 60℃ for 3h.

[0057] Step 2: Weigh 1000 parts by mass of the dried PET chips, add the PET chips, 6500 parts by mass of ethylene glycol and 2 parts by mass of zinc acetate into a three-necked round-bottom flask. Place the round-bottom flask in an electric heating mantle that integrates temperature control, magnetic stirring and heating, and install a condenser on the three-necked flask. Pass nitrogen into the flask for 30 minutes to expel the air in the flask.

[0058] Step 3: Stir the mixture in step 2 at a speed of 400 r / min and a heating temperature of 180° C. until the PET fragments are completely dissolved, stop introducing nitrogen and stirring, and cool to room temperature.

[0059] Step 4: Add activated carbon to the mixed solution cooled to room temperature in step 3, let it stand for 1 hour for adsorption and impurity removal, and then filter to remove the activated carbon.

[0060] Step 5: The mixed solution of step 4 is filtered with boiling water, and the filtrate is placed in a refrigerator at 5°C for 8 hours, and a large amount of white flocculent crystals are precipitated from the filtrate, which is then filtered. The obtained target crystals are dried in a vacuum drying oven at 60°C for 6 hours to obtain the depolymerization product R-PET of PET.

[0061] Preparation of regeneration agent:

[0062] Step 1: Weigh 100 parts of base oil (waste cooking oil) by mass fraction, place it in an oven at 130°C for 1 hour to preheat and dry.

[0063] Step 2: Weigh the R-PET powder according to the mass fraction, place it in the preheated base oil, and stir it in a constant temperature oil bath until the R-PET powder is completely dissolved in the base oil. The oil bath temperature is 130°C and the stirring speed is 400r / min.

[0064] Step 3: Add anti-aging agent and anti-ultraviolet agent to the mixture prepared in step 2, and stir until it completely turns into a uniform viscous liquid at a stirring speed of 400 r / min.

[0065] Embodiment 4

[0066] The factory-mixed hot regeneration agent of this embodiment that can be used by dry direct injection, the regeneration agent raw materials include the following components by mass: 100 parts of base oil (waste cooking oil), 35 parts of R-PET powder, 1 part of anti-aging agent, and 2 parts of anti-ultraviolet agent.

[0067] The preparation method of S-PET powder is the same as that of Example 1;

[0068] The preparation method of the regeneration agent is the same as that of Example 1.

[0069] Embodiment 5

[0070] The factory-mixed hot regeneration agent of this embodiment that can be used by dry direct injection, the regeneration agent raw materials include the following components by mass: 100 parts of base oil (tire pyrolysis oil), 33 parts of R-PET powder, 1.2 parts of anti-aging agent, and 1.8 parts of anti-ultraviolet agent.

[0071] The preparation method of S-PET powder is the same as that of Example 2;

[0072] The preparation method of the regeneration agent is the same as that of Example 2.

[0073] Embodiment 6

[0074] The factory-mixed hot regeneration agent of this embodiment that can be used by dry direct injection, the regeneration agent raw materials include the following components by mass: 100 parts of base oil (tire pyrolysis oil), 32 parts of R-PET powder, 1.5 parts of anti-aging agent, and 1.5 parts of anti-ultraviolet agent.

[0075] The preparation method of S-PET powder is the same as that of Example 3;

[0076] The preparation method of the regeneration agent is the same as that of Example 3.

[0077] In the above embodiment, the antioxidant is dimethylacetamide; the anti-ultraviolet agent is light stabilizer 770.

[0078] The regeneration agent prepared above is used to prepare factory-mixed hot-regenerated asphalt mixture.

[0079] Comparative Example 1: Factory-mixed hot recycled asphalt mixture without adding regeneration agent.

[0080] Comparative Example 2: Asphalt mixture was prepared using a commercially available asphalt regeneration agent for factory-mixed hot recycling.

[0081] The above asphalt mixture is mixed by the following method:

[0082] The waste asphalt mixture with required gradation was heated at 160°C for 3h and then put into a mixing pot for dry mixing for 30s. The regeneration agent suitable for factory-mixed hot regeneration (prepared in Examples 1-3) and the regeneration agent with high market sales volume (Comparative Example 2) were added respectively, added to the preheated mixing pot and stirred for 30s (temperature 160°C), and then new aggregate and fiber were added and stirred for 30s. Finally, new asphalt was added and mixed to form a regenerated asphalt mixture, and various test pieces for testing road performance were immediately prepared. The gradation of asphalt mixture is taken as AC-20 as an example. The amount of regeneration agent is 6% of the mass of waste asphalt. The regenerated asphalt mixture prepared by Examples 1-3 is compared with the regenerated asphalt mixture prepared by using the commonly used asphalt regeneration agent on the market. The test results are shown in the table below.

[0083] Road performance of recycled asphalt mixture

[0084] project Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Regeneration agent dosage (%) 6 6 6 0 6 RAP material content (%) 30 30 30 30 30 Dynamic stability (times / min) 1458.5 1335.2 1377.6 1659.4 1056.8 Low temperature bending strain (με) 2479 2381 2416 2011 2296 Residual stability (%) 96.9 94.9 95.3 69.1 81.2

[0085] The above test items are carried out in accordance with the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), and the performance indicators are in accordance with the requirements of the "Technical Specifications for Highway Asphalt Pavement Construction" (JTG F40-2004).

[0086] The road performance of the regenerated asphalt mixture was analyzed. The regeneration agent for factory-mixed hot regeneration prepared in the embodiment of the present invention makes the regenerated asphalt mixture have excellent high-temperature stability, water stability, and low-temperature crack resistance. The road performance fully meets the requirements of the specifications and is better than the regenerated asphalt mixture prepared with the commercially available regeneration agent as a comparison example. In addition, the regeneration agent prepared in the present invention can reduce the mixing temperature of the waste asphalt mixture. At the same time, the raw materials used are mainly waste materials, and the economic and environmental benefits are more significant.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A factory-mixed hot regeneration agent that can be used directly by dry method, characterized in that: The regeneration agent raw material comprises the following components by mass: 100 parts of base oil, 30-35 parts of R-PET powder, 1-2 parts of anti-aging agent, and 1-2 parts of anti-ultraviolet agent; the R-PET powder is a PET depolymer obtained by surface activating PET by physical crushing and chemical decomposition.

2. The plant-mixed hot regeneration agent that can be used by dry direct injection according to claim 1 is characterized in that: The preparation method of the R-PET powder comprises the following steps: The recovered PET fragments are mixed with ethylene glycol and zinc acetate, and heated and stirred under nitrogen conditions until the PET fragments are completely dissolved. After cooling to room temperature, an adsorbent is added, and then the mixed solution is filtered. The filtrate is cooled until white flocculent crystals are precipitated, and the crystals are dried to obtain R-PET powder.

3. The plant-mixed hot regeneration agent that can be used by dry direct injection according to claim 2 is characterized in that: The adsorbent is activated carbon.

4. The plant-mixed hot regeneration agent that can be used by dry direct injection according to claim 2 is characterized in that: The filtrate is refrigerated at a temperature of 3-6°C until crystallization occurs, and the crystals are dried at a temperature of 55-65°C for 6-8 hours.

5. The plant-mixed hot regeneration agent that can be used by dry direct injection according to claim 1 is characterized in that: The base oil is at least one of waste cooking oil, tire pyrolysis oil, and pig manure pyrolysis oil.

6. The plant-mixed hot regeneration agent that can be used by dry direct injection according to claim 1 is characterized in that: The antioxidant is dimethylacetamide.

7. The plant-mixed hot regeneration agent that can be used by dry direct injection according to claim 1 is characterized in that: The anti-ultraviolet agent is light stabilizer 770.

8. The method for preparing a factory-mixed hot regeneration agent that can be directly used by dry process according to claim 1, characterized in that: The method comprises the following steps: heating the base oil, adding the R-PET powder and mixing evenly, and then adding the anti-aging agent and the anti-ultraviolet agent and mixing until the liquid becomes viscous.