A method for preparing a regenerating agent for ultra-high-dosage fine separation asphalt mixture

Abstract

The invention discloses a method for preparing a regeneration agent for ultra-high-dosage fine separation asphalt mixture, firstly, petroleum asphalt, corn oil, epoxy soybean oil and liquid rubber are mixed, heated and stirred for reaction, a crosslinking agent is added for stirring, and then cooled to room temperature, and finally a curing agent and an accelerator are added for stirring to prepare the regeneration agent. When preparing the regeneration agent, liquid rubber and epoxy soybean oil are first reacted at high temperature to form a three-dimensional network structure, and the structure is evenly distributed in the asphalt mixture, and the crosslinking agent is evenly fixed in the mixture, so that the regeneration agent can avoid the sublimation of the crosslinking agent during use, so that the liquid rubber is fully vulcanized, the mechanical properties of the regeneration agent are improved, and the high and low temperature performance, water stability and durability of the asphalt mixture are improved.

Description

Technical Field

[0001] The invention belongs to the field of preparation of a regeneration agent for asphalt mixtures, and in particular relates to a method for preparing a regeneration agent for ultra-high-dosage fine separation asphalt mixtures. Background Art

[0002] With the increasing aging of my country's highways, a large number of asphalt pavements need to be repaired and maintained. According to the design life of asphalt pavements (15-20 years), 12% of asphalt pavements in the country need to be renovated every year, resulting in more than 10 million tons of old asphalt mixtures per year. The abandonment of a large amount of old asphalt mixtures not only occupies land and wastes resources, but is also more likely to cause environmental pollution. As the awareness of ecological environmental protection gradually increases, the mining of stone is becoming more and more difficult. Asphalt pavement regeneration technology has been vigorously promoted and applied because it can save raw materials such as asphalt and sand and gravel, and is conducive to the treatment of old asphalt mixtures and environmental protection, with obvious economic and social benefits.

[0003] Most of the current rap materials have the phenomenon of "false particle size". The old asphalt film left on the stone cannot be completely removed. The particle size of the old material will be inaccurate due to the existence of the asphalt film, which also leads to uneven heating during mixing with new materials and poor fusion with new asphalt. These will limit the amount of recycled asphalt mixture. Therefore, most rap material plants on the market generally add 20%-30% of hot recycled content. In addition, most existing rap materials have a high content of old asphalt and are not graded. The known regeneration agent is not targeted. When mixing, the mixing temperature needs to be increased and the mixing time needs to be extended to make the regeneration agent work and obtain a mixture with good performance.

[0004] Based on this situation, the applicant first developed a fine separation and regeneration asphalt mixture equipment (application number 2022115803816, name "A fine separation and regeneration system and separation method for recycled asphalt pavement materials"), which can divide the milling material into four grades of materials: 0-3mm, 3-5mm, 5-10mm, and 10-16mm. The old asphalt is basically concentrated in the 0-3mm grade material, and the old asphalt content can reach 10-12%, and the remaining grades of stone can be used directly. Therefore, in response to this situation, the applicant has specifically developed a regeneration agent suitable for 0-3mm grade materials, which is mixed with 0-3mm grade materials at room temperature, and then mixed with new aggregates and new asphalt, so that the rap material addition amount of 0-3mm grade materials can reach 80% or more while ensuring the performance of the asphalt mixture, achieving ultra-high admixture. Summary of the invention

[0005] Purpose of the invention: The technical problem to be solved by the present invention is to provide a method for preparing a regeneration agent for solving the problem of excessive old asphalt content in 0-3mm rap material. The regeneration agent prepared by the method is pre-mixed with the 0-3mm rap material at room temperature, and a regenerated asphalt mixture with good performance can be obtained without increasing the mixing temperature and prolonging the mixing time.

[0006] Technical solution: The method for preparing a regeneration agent for fine separation of asphalt mixture of the present invention comprises the following steps:

[0007] (1) Mix 2-5 parts of petroleum asphalt, 30-50 parts of corn oil, 10-30 parts of epoxidized soybean oil and 5-10 parts of liquid rubber, heat to 130-160° C., and stir for 10-20 minutes;

[0008] (2) adding 1-3 parts of a cross-linking agent, stirring for 5-15 minutes, and cooling to room temperature;

[0009] (3) Add 5-10 parts of curing agent and 1-3 parts of accelerator and stir for 10-20 minutes to prepare a regeneration agent.

[0010] The present invention combines corn oil, epoxidized soybean oil and liquid rubber, and during preparation, first cross-links the epoxidized soybean oil and liquid rubber at high temperature, and then adds a cross-linking agent, so that the linear rubber molecular chains form a three-dimensional network structure, and the cross-linking agent can be evenly fixed in the mixture, thereby preventing the sublimation of the cross-linking agent during the use of the regeneration agent, and effectively avoiding incomplete cross-linking of the liquid rubber from the root, thereby improving the high and low temperature performance and water stability of the regenerated asphalt mixture.

[0011] Furthermore, in step (1) of the preparation method, the liquid rubber includes liquid isoprene rubber, liquid butadiene rubber or polysulfide liquid rubber.

[0012] Furthermore, in step (2) of the preparation method, the cross-linking agent is sulfur.

[0013] Furthermore, in step (3) of the preparation method, the curing agent is an aromatic amine curing agent or an acid anhydride curing agent. Among them, the aromatic amine curing agent preferably includes diaminodiphenylmethane, diaminodiphenyl sulfone-4-diaminodiphenylmethane or diethyltoluenediamine. The acid anhydride curing agent preferably includes phthalic anhydride, tetrahydrophthalic anhydride or polyazelaic anhydride.

[0014] Furthermore, in step (3) of the preparation method, the promoter is 2,4,6-tris(dimethylaminomethyl)phenol.

[0015] Furthermore, when the regeneration agent prepared by the preparation method of the present invention is used, it can be evenly mixed with the stone in the finely separated asphalt mixture, wherein the addition amount of the regeneration agent is 1-3% of the stone in the finely separated asphalt mixture.

[0016] Beneficial effect: Compared with the prior art, the significant advantages of the present invention are: when the regeneration agent is prepared, liquid rubber and epoxidized soybean oil are first reacted at high temperature to form a three-dimensional network structure, which is evenly distributed in the asphalt mixture, and the cross-linking agent is evenly fixed in the mixture, thereby enabling the regeneration agent to avoid sublimation of the cross-linking agent during use, allowing the liquid rubber to be fully vulcanized, thereby improving the mechanical properties of the regeneration agent, and improving the high and low temperature performance, water stability and durability of the asphalt mixture. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described in detail below in conjunction with the embodiments. It should be noted that the raw materials involved in the present invention can all be purchased from the market.

[0018] Example 1

[0019] The raw material components of the regeneration agent of this Example 1 are shown in Table 1 below.

[0020] Table 1 Raw material components of the regeneration agent of Example 1

[0021] Serial number raw material Content / portion 1 70# Petroleum Asphalt 2 2 Corn Oil 30 3 Epoxidized soybean oil 30 4 Liquid isoprene rubber 10 5 S 3 6 Methylenedianiline 10 7 DMP30 3

[0022] The preparation method of the regeneration agent of this embodiment 1 comprises the following steps:

[0023] (1) petroleum asphalt, corn oil, epoxidized soybean oil and liquid rubber were mixed, heated to 140°C, and stirred at a speed of 200 r / min for 15 min;

[0024] (2) Add the crosslinking agent and stir for 10 minutes, then stop stirring and wait for the liquid to cool to room temperature;

[0025] (3) Add curing agent and accelerator, stir at a speed of 300 r / min for 15 minutes to obtain a regeneration agent.

[0026] Comparative Example 1

[0027] The raw material components of the regeneration agent in Comparative Example 1 are the same as those in Example 1, but the preparation method is different, specifically:

[0028] (1) 70# petroleum asphalt, corn oil and epoxidized soybean oil were heated to 140°C and stirred at 200 r / min for 15 min;

[0029] (2) Add liquid rubber and stir for 10 minutes. Stop stirring and wait for the liquid to cool to room temperature.

[0030] (3) Slowly pour the curing agent, accelerator and cross-linking agent into a beaker and stir at a speed of 300 r / min for 15 minutes to obtain a regeneration agent.

[0031] Example 2

[0032] The raw material components of the regeneration agent of Example 2 are shown in Table 2 below.

[0033] Table 2 Raw material components of the regeneration agent of Example 2

[0034] Serial number raw material Content / portion 1 70# Petroleum Asphalt 3 2 Corn Oil 40 3 Epoxidized soybean oil 20 4 Liquid isoprene rubber 7 5 S 1 6 Phthalic anhydride 6 7 DMP30 2

[0035] The preparation method of the regeneration agent of this embodiment 2 comprises the following steps:

[0036] (1) petroleum asphalt, corn oil, epoxidized soybean oil and liquid rubber were mixed, heated to 140°C, and stirred at a speed of 200 r / min for 15 min;

[0037] (2) Add the crosslinking agent and stir for 10 minutes, then stop stirring and wait for the liquid to cool to room temperature;

[0038] (3) Add curing agent and accelerator, stir at a speed of 300 r / min for 15 minutes to obtain a regeneration agent.

[0039] Example 3

[0040] The raw material components of the regeneration agent of Example 3 are shown in Table 3 below.

[0041] Table 3 Raw material components of the regeneration agent of Example 3

[0042] Serial number raw material Content / portion 1 70# Petroleum Asphalt 5 2 Corn Oil 50 3 Epoxidized soybean oil 10 4 Liquid isoprene rubber 5 5 S 1 6 Diaminodiphenyl sulfone-4-diaminodiphenylmethane 5 7 DMP30 1

[0043] The preparation method of the regeneration agent of this embodiment 3 comprises the following steps:

[0044] (1) petroleum asphalt, corn oil, epoxidized soybean oil and liquid rubber were mixed, heated to 130°C, and stirred at a speed of 200 r / min for 20 min;

[0045] (2) Add the crosslinking agent and stir for 5 minutes, then stop stirring and wait for the liquid to cool to room temperature;

[0046] (3) Add curing agent and accelerator, stir at 300 r / min for 10 min to obtain a regeneration agent.

[0047] Example 4

[0048] The raw material components of the regeneration agent of Example 4 are shown in Table 4 below.

[0049] Table 4 Raw material components of the regeneration agent of Example 4

[0050] Serial number raw material Content / portion 1 70# Petroleum Asphalt 3 2 Corn Oil 50 3 Epoxidized soybean oil 30 4 Liquid isoprene rubber 5 5 S 3 6 Tetrahydrophthalic anhydride 8 7 DMP30 3

[0051] The preparation method of the regeneration agent of this embodiment 4 comprises the following steps:

[0052] (1) petroleum asphalt, corn oil, epoxidized soybean oil and liquid rubber were mixed, heated to 160°C, and stirred at a speed of 200 r / min for 10 min;

[0053] (2) Add the crosslinking agent and stir for 15 minutes, then stop stirring and wait for the liquid to cool to room temperature;

[0054] (3) Add curing agent and accelerator, stir at 300 r / min for 20 min to obtain a regeneration agent.

[0055] Performance test 1

[0056] The regeneration agent prepared in the above embodiment was tested according to the "Technical Specifications for Highway Asphalt Pavement Regeneration" JTG / T5521-2019 of the Ministry of Transport, and the results are shown in Table 5.

[0057] Table 5 Performance test data of regeneration agent

[0058]

[0059]

[0060] Performance test 2

[0061] According to the gradation of SMA-13, 0-3mm rap material was used to replace part of the new material to prepare Marshall, rutting plate and small beam specimens, and the test results of the specimens prepared with new materials were compared. The rap material content was 80%. First, 0-3mm rabbet material and regeneration agent were mixed evenly, and the regeneration agent addition amount was 1%, 2% and 3%. Then, aggregates, new asphalt, etc. were mixed together to make test specimens and tested. The test results are shown in Table 6.

[0062] Table 6 Performance test data of recycled asphalt mixture

[0063]

[0064]

[0065] In summary, it can be seen from Table 5 and Table 6 that the present invention is suitable for a regenerated additive for finely separated asphalt mixtures. The various components in the additive are cross-linked under high temperature conditions to form a stable structure in the asphalt mixture, so that the high and low temperature performance and water stability of the regenerated asphalt mixture are restored. When the addition amount is 3%, the high and low temperature performance and water stability of the new material can be fully achieved or even exceeded.

[0066] In addition to the above embodiments, the aromatic amine curing agent used in the present invention may also be diethyltoluenediamine, and the acid anhydride curing agent may also be polyazelaic anhydride.

Claims

1. A method for preparing a regeneration agent for ultra-high-dosage fine separation asphalt mixture, characterized in that The steps include: (1) mixing 2-5 parts of petroleum asphalt, 30-50 parts of corn oil, 10-30 parts of epoxidized soybean oil and 5-10 parts of liquid rubber, heating to 130-160° C., and stirring for 10-20 minutes; the liquid rubber includes liquid isoprene rubber, liquid butadiene rubber or polysulfide liquid rubber; (2) adding 1-3 parts of a cross-linking agent, stirring for 5-15 minutes, and cooling to room temperature; (3) Add 5-10 parts of curing agent and 1-3 parts of accelerator and stir for 10-20 minutes to prepare a regeneration agent; When the regeneration agent is prepared by the preparation method and used, the regeneration agent is evenly mixed with the stone in the finely separated asphalt mixture, wherein the addition amount of the regeneration agent is 1-3% of the stone in the finely separated asphalt mixture.

2. The method for preparing the regeneration agent according to claim 1, characterized in that: In step (2), the cross-linking agent is sulfur.

3. The method for preparing the regeneration agent according to claim 1, characterized in that: In step (3), the curing agent is an aromatic amine curing agent or an acid anhydride curing agent.

4. The method for preparing the regeneration agent according to claim 3, characterized in that: The aromatic amine curing agent includes diaminodiphenylmethane, diaminodiphenyl sulfone-4-diaminodiphenylmethane or diethyltoluenediamine.

5. The method for preparing the regeneration agent according to claim 3, characterized in that: The acid anhydride curing agent includes phthalic anhydride, tetrahydrophthalic anhydride or polyazelaic anhydride.

6. The method for preparing the regeneration agent according to claim 1, characterized in that: In step (3), the promoter is 2,4,6-tris(dimethylaminomethyl)phenol.

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