A kind of recycled asphalt concrete and a preparation method thereof

Abstract

A recycled asphalt concrete, a preparation method and an application thereof, wherein the raw materials of the recycled asphalt concrete contain SBS modified asphalt, recycled asphalt mixture, aggregate, modified microporous silica, waste mineral oil, guaiac wood oil, dioctyl phthalate, curing agent and anti-aging agent. The modified microporous silica, waste mineral oil, guaiac wood oil, dioctyl phthalate, curing agent and anti-aging agent in the present invention regenerate the aged asphalt in the recycled asphalt mixture, and with the assistance of aggregate and SBS modified asphalt, a recycled asphalt concrete is prepared. In this recycled asphalt concrete, the proportion of the recycled asphalt mixture is increased to more than 50%. This recycled asphalt concrete has good high-temperature rutting resistance and low-temperature cracking resistance, etc., and has a relatively high flexural tensile failure strength.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt, and particularly relates to a recycled asphalt concrete and a preparation method thereof. Background Art

[0002] After being used for a period of time, asphalt concrete pavements will slowly age under natural conditions, which easily causes the asphalt to harden and become brittle, losing its due physical properties, thus affecting the road performance. Coupled with the action of water and vehicle loads, it will further aggravate the pavement diseases. With the continuous increase in the number of pavement maintenance, reconstruction and expansion projects, the generation amount of waste asphalt will become larger and larger. Recycling and reusing the substandard asphalt pavements can make full use of the waste materials generated by the original asphalt pavements, save a large amount of asphalt, reduce construction costs, and at the same time reduce the occupation of land resources by waste materials and protect the environment.

[0003] At present, the mixing ratio of waste asphalt mixture in the hot recycling technology is generally not higher than 30%, and it is rarely used for the surface layer of expressways. The main reason is that the asphalt in the waste asphalt mixture ages, hardens and becomes brittle, and its viscoelastic properties deteriorate, making the hot recycled asphalt concrete prone to cracking problems, such as temperature cracking and fatigue cracking. Moreover, the higher the content of old materials, the more serious the cracking problem.

[0004] Therefore, aiming at the deficiencies of the existing technology, it is very necessary to provide a recycled asphalt concrete and a preparation method thereof to solve the deficiencies of the existing technology. Summary of the Invention

[0005] One of the purposes of the present invention is to provide a recycled asphalt concrete to avoid the deficiencies of the existing technology. This recycled asphalt concrete can improve the addition amount of recycled asphalt mixture while ensuring the quality, and increase the effect of waste utilization.

[0006] The above object of the present invention is achieved by the following technical measures:

[0007] Provide a recycled asphalt concrete, the raw materials of which include SBS modified asphalt, recycled asphalt mixture, aggregate, modified microporous silica, waste mineral oil, guaiac wood oil, dioctyl phthalate, curing agent and anti-aging agent.

[0008] The modified microporous silica is prepared by the following steps:

[0009] A1. Add 3,7-dimethyl-6-octen-1-ol to tetrahydrofuran, and add 4-cyclohexanone carboxylic acid and sodium hydroxide to obtain an intermediate;

[0010] A2. Add microporous silica to hydrochloric acid, stir and filter to obtain pretreated microporous silica;

[0011] A3. Add the intermediate to acetone, then add the pretreated microporous silica, and heat to obtain the modified microporous silica.

[0012] The recycled asphalt concrete of the present invention, by weight:

[0013] SBS modified asphalt: 10 parts;

[0014] Recycled asphalt mixture: 40 - 50 parts;

[0015] Aggregates: 10 - 25 parts;

[0016] Modified microporous silica: 3 - 5 parts;

[0017] Waste mineral oil: 0.5 - 2 parts;

[0018] Guaiacwood oil: 0.1 - 0.5 part;

[0019] Dioctyl phthalate: 0.05 - 0.1 part;

[0020] Curing agent: 0.05 - 0.1 part;

[0021] Anti - aging agent: 0.05 - 0.1 part.

[0022] Furthermore, the recycled asphalt concrete of the present invention, by weight:

[0023] SBS modified asphalt: 10 parts;

[0024] Recycled asphalt mixture: 44 parts;

[0025] Aggregates: 18 parts;

[0026] Modified microporous silica: 3.8 parts;

[0027] Waste mineral oil: 1.1 parts;

[0028] Guaiacwood oil: 0.3 part;

[0029] Dioctyl phthalate: 0.08 part;

[0030] Curing agent: 0.07 part;

[0031] Anti - aging agent: 0.06 part.

[0032] Preferably, the above - mentioned modified microporous silica is prepared by the following steps:

[0033] A1. By weight, add 100 parts of 3,7-dimethyl-6-octen-1-ol to 200 to 300 parts of tetrahydrofuran, then add 60 to 80 parts of 4-cyclohexanonecarboxylic acid and 10 to 20 parts of sodium hydroxide, stir at 30°C to 40°C for 14 to 18 hours, and perform salting-out and drying to obtain an intermediate product;

[0034] A2. Add 10 parts of microporous silica to 10 to 20 parts of 0.5 mol / L to 2 mol / L hydrochloric acid solution, stir for 1 to 3 hours, and filter to obtain pretreated microporous silica;

[0035] A3. Add 3 to 5 parts of the intermediate product to 10 to 20 parts of acetone, then add 5 parts of the pretreated microporous silica, heat to 70°C to 90°C, stir for 1 to 3 hours, and then filter and dry to obtain modified microporous silica.

[0036] Preferably, the above-mentioned modified microporous silica is prepared by the following steps:

[0037] A1. By weight, add 100 parts of 3,7-dimethyl-6-octen-1-ol to 250 parts of tetrahydrofuran, add 66 parts of 4-cyclohexanonecarboxylic acid and 13.6 parts of sodium hydroxide, stir at 37°C for 16 hours, and perform salting-out and drying to obtain an intermediate product;

[0038] A2. Add 10 parts of microporous silica to 15.5 parts of 1.2 mol / L hydrochloric acid solution, stir for 2 hours, and filter to obtain pretreated microporous silica;

[0039] A3. Add 4 parts of the intermediate product to 17 parts of acetone, then add 5 parts of the pretreated microporous silica, heat to 82°C, stir for 2 hours, and then filter and dry to obtain modified microporous silica.

[0040] Preferably, the above-mentioned anti-aging agent is polyethylene naphthalate or phenyl-α-naphthylamine.

[0041] Preferably, the above-mentioned curing agent is polyetheramine or catechol.

[0042] The second object of the present invention is to provide a preparation method of recycled asphalt concrete to avoid the deficiencies of the prior art. The recycled asphalt concrete prepared by this preparation method of recycled asphalt concrete can increase the addition amount of recycled asphalt mixture while ensuring the quality, and improve the effect of waste utilization.

[0043] The above object of the present invention is achieved by the following technical measures:

[0044] Provide a preparation method of the above-mentioned recycled asphalt concrete, including the following steps:

[0045] S1. Mix and stir modified microporous silica, waste mineral oil, guaiacwood oil, dioctyl phthalate, curing agent and anti-aging agent to obtain a mixture;

[0046] S2. Crush the recycled asphalt mixture;

[0047] S3. Heat the SBS modified asphalt, then add the recycled asphalt mixture to the SBS modified asphalt, and then add the mixture to obtain a recycled asphalt mixture;

[0048] S4. Add aggregates to the recycled asphalt mixture to obtain recycled asphalt concrete.

[0049] Preferably, the above preparation method includes the following steps:

[0050] S1. Mix and stir modified microporous silica, waste mineral oil, guaiacwood oil, dioctyl phthalate, curing agent and anti-aging agent, and heat to 100°C - 120°C to obtain a mixture;

[0051] S2. Crush the recycled asphalt mixture to an average particle size less than 0.2 cm and heat to 100°C - 110°C;

[0052] S3. Heat the SBS modified asphalt to 100°C - 110°C, then add the recycled asphalt mixture to the SBS modified asphalt, and then add the mixture to obtain a recycled asphalt mixture;

[0053] S4. Add aggregates to the recycled asphalt mixture to obtain recycled asphalt concrete.

[0054] A recycled asphalt concrete of the present invention, its preparation method and application, wherein the raw materials of the recycled asphalt concrete contain SBS modified asphalt, recycled asphalt mixture, aggregates, modified microporous silica, waste mineral oil, guaiacwood oil, dioctyl phthalate, curing agent and anti-aging agent; the modified microporous silica is prepared by the following steps: A1. Add 3,7-dimethyl-6-octen-1-ol to tetrahydrofuran, and add 4-cyclohexanone carboxylic acid and sodium hydroxide to obtain an intermediate; A2. Add microporous silica to hydrochloric acid, stir and filter to obtain pretreated microporous silica; A3. Add the intermediate to acetone, and then add the pretreated microporous silica and heat to obtain modified microporous silica. The modified microporous silica, waste mineral oil, guaiacwood oil, dioctyl phthalate, curing agent and anti-aging agent of the present invention regenerate the aged asphalt in the recycled asphalt mixture, and together with aggregates and SBS modified asphalt, a recycled asphalt concrete is prepared. In this recycled asphalt concrete, the proportion of the recycled asphalt mixture is increased to more than 50%. This recycled asphalt concrete has good high-temperature rutting resistance and low-temperature cracking resistance, etc., and has a relatively high flexural tensile failure strength. Detailed implementation mode

[0055] The technical solution of the present invention will be further described in conjunction with the following embodiments. Unless otherwise specified in the following embodiments, the raw materials used in each embodiment are commercially available products. Aggregate refers to crushed stone, gravel, slag, natural sand, artificial sand, stone chips, cement, mineral powder, fly ash, etc. used in the mixture, which plays a role of skeleton and filling in the mixture. The waste mineral oil is selected from tar, petroleum residue oil, deasphalted oil, heavy distillate oil, waste lubricating oil, white oil, lubricating oil base oil, etc.

[0056] Example 1

[0057] A kind of recycled asphalt concrete, the raw materials of which contain SBS modified asphalt, recycled asphalt mixture, aggregate, modified microporous silica, waste mineral oil, guaiac oil, dioctyl phthalate, curing agent and anti-aging agent. Among them, the anti-aging agent is polyethylene naphthalate. The curing agent is polyetheramine. The waste mineral oil in this embodiment is a mixture of tar, petroleum residue oil and deasphalted oil, and the weight ratio of the three is 1:1:1. Moreover, the waste mineral oil is pre-filtered, settled, flash distilled, vacuum distilled and hydrorefined. The aggregate of the present invention is natural sand.

[0058] In this recycled asphalt concrete, by weight:

[0059] SBS modified asphalt: 10 parts;

[0060] Recycled asphalt mixture: 40 parts;

[0061] Aggregate: 25 parts;

[0062] Modified microporous silica: 5 parts;

[0063] Waste mineral oil: 2 parts;

[0064] Guaiac oil: 0.5 part;

[0065] Dioctyl phthalate: 0.1 part;

[0066] Curing agent: 0.1 part;

[0067] Anti-aging agent: 0.1 part.

[0068] The modified microporous silica is prepared by the following steps:

[0069] A1. By weight, add 100 parts of 3,7-dimethyl-6-octen-1-ol to 200 parts of tetrahydrofuran, add 80 parts of 4-cyclohexanone carboxylic acid and 10 parts of sodium hydroxide, stir at 30 °C for 14 h, and obtain an intermediate by salting out and drying;

[0070] A2. Add 10 parts of microporous silica into 10 parts of 2 mol / L hydrochloric acid solution, stir for 3 h, and filter to obtain pretreated microporous silica;

[0071] A3. Add 3 parts of the intermediate into 10 parts of acetone, then add 5 parts of pretreated microporous silica, heat to 70 °C, stir for 1 h, and filter and dry to obtain modified microporous silica.

[0072] The preparation method of the recycled asphalt concrete in this example includes the following steps:

[0073] S1. Mix and stir modified microporous silica, waste mineral oil, guaiac wood oil, dioctyl phthalate, curing agent and anti-aging agent, and heat to 100 °C to obtain a mixture;

[0074] S2. Crush the recycled asphalt mixture to an average particle size of less than 0.2 cm and heat to 100 °C;

[0075] S3. Heat the SBS modified asphalt to 100 °C, then add the recycled asphalt mixture to the SBS modified asphalt, and then add the mixture to obtain a recycled asphalt mixture;

[0076] S4. Add the aggregate to the recycled asphalt mixture to obtain recycled asphalt concrete.

[0077] Example 2

[0078] A kind of recycled asphalt concrete, the raw materials contain SBS modified asphalt, recycled asphalt mixture, aggregate, modified microporous silica, waste mineral oil, guaiac wood oil, dioctyl phthalate, curing agent and anti-aging agent. Among them, the anti-aging agent is phenyl-α-naphthylamine. The curing agent is catechol. The waste mineral oil in this example is a mixture of tar, petroleum residue and deasphalted oil, and the weight ratio of the three is 1:1:1, and the waste mineral oil is pre-filtered, settled, flash distilled, vacuum distilled and hydrorefined. The aggregate of the present invention is natural sand.

[0079] In this recycled asphalt concrete, by weight:

[0080] SBS modified asphalt: 10 parts;

[0081] Recycled asphalt mixture: 50 parts;

[0082] Aggregate: 10 parts;

[0083] Modified microporous silica: 3 parts;

[0084] Waste mineral oil: 0.5 part;

[0085] Guaiac wood oil: 0.1 part;

[0086] Dioctyl phthalate: 0.05 parts;

[0087] Curing agent: 0.05 parts;

[0088] Anti-aging agent: 0.05 parts.

[0089] The modified microporous silica is prepared by the following steps:

[0090] A1. By weight, add 100 parts of 3,7-dimethyl-6-octen-1-ol to 300 parts of tetrahydrofuran, add 60 parts of 4-cyclohexanone carboxylic acid and 20 parts of sodium hydroxide, stir at 40 °C for 18 h, and obtain an intermediate by salting out and drying;

[0091] A2. Add 10 parts of microporous silica to 20 parts of 0.5 mol / L hydrochloric acid solution, stir for 1 h, filter to obtain pretreated microporous silica;

[0092] A3. Add 5 parts of the intermediate to 20 parts of acetone, then add 5 parts of pretreated microporous silica, heat to 90 °C, stir for 3 h, and filter and dry to obtain modified microporous silica.

[0093] The preparation method of the recycled asphalt concrete in this example includes the following steps:

[0094] S1. Mix and stir the modified microporous silica, waste mineral oil, guaiac oil, dioctyl phthalate, curing agent and anti-aging agent, and heat to 110 °C to obtain a mixture;

[0095] S2. Crush the recycled asphalt mixture to an average particle size of less than 0.2 cm and heat to 110 °C;

[0096] S3. Heat the SBS modified asphalt to 110 °C, then add the recycled asphalt mixture to the SBS modified asphalt, and then add the mixture to obtain a recycled asphalt mixture;

[0097] S4. Add the aggregate to the recycled asphalt mixture to obtain recycled asphalt concrete.

[0098] Example 3

[0099] A kind of recycled asphalt concrete, the raw materials contain SBS modified asphalt, recycled asphalt mixture, aggregate, modified microporous silica, waste mineral oil, guaiac oil, dioctyl phthalate, curing agent and anti-aging agent. The anti-aging agent is polyethylene naphthalate. The curing agent is polyetheramine. The waste mineral oil in this example is a mixture of tar, petroleum residue and deasphalted oil, and the weight ratio of the three is 1:1:1, and the waste mineral oil is pre-filtered, settled, flash distilled, vacuum distilled and hydrorefined. The aggregate of the present invention is natural sand.

[0100] In this recycled asphalt concrete, by weight,

[0101] SBS modified asphalt: 10 parts;

[0102] Recycled asphalt mixture: 44 parts;

[0103] Aggregates: 18 parts;

[0104] Modified microporous silica: 3.8 parts;

[0105] Waste mineral oil: 1.1 parts;

[0106] Guaiacwood oil: 0.3 parts;

[0107] Dioctyl phthalate: 0.08 parts;

[0108] Curing agent: 0.07 parts;

[0109] Anti-aging agent: 0.06 parts.

[0110] The modified microporous silica is prepared by the following steps:

[0111] A1. By weight, add 100 parts of 3,7-dimethyl-6-octen-1-ol to 250 parts of tetrahydrofuran, add 66 parts of 4-cyclohexanonecarboxylic acid and 13.6 parts of sodium hydroxide, stir at 37 °C for 16 h, and obtain an intermediate by salting out and drying;

[0112] A2. Add 10 parts of microporous silica to 15.5 parts of 1.5 mol / L hydrochloric acid solution, stir for 2 h, and filter to obtain pretreated microporous silica;

[0113] A3. Add 4 parts of the intermediate to 17 parts of acetone, then add 5 parts of pretreated microporous silica, heat to 82 °C, stir for 2 h, and filter and dry to obtain modified microporous silica.

[0114] The preparation method of the recycled asphalt concrete in this example includes the following steps:

[0115] S1. Mix and stir the modified microporous silica, waste mineral oil, guaiacwood oil, dioctyl phthalate, curing agent and anti-aging agent, and heat to 105 °C to obtain a mixture;

[0116] S2. Crush the recycled asphalt mixture to an average particle size of less than 0.2 cm and heat to 105 °C;

[0117] S3. Heat the SBS modified asphalt to 105 °C, then add the recycled asphalt mixture to the SBS modified asphalt, and then add the mixture to obtain a recycled asphalt mixture;

[0118] S4. Add the aggregate to the recycled asphalt mixture to obtain recycled asphalt concrete.

[0119] Comparative Example 1

[0120] A recycled asphalt concrete, having the same other features as in Example 3, except that in this recycled asphalt concrete, by weight:

[0121] SBS modified asphalt: 10 parts;

[0122] Recycled asphalt mixture: 44 parts;

[0123] Aggregate: 18 parts;

[0124] Modified microporous silica: 2 parts;

[0125] Waste mineral oil: 3 parts;

[0126] Guaiacwood oil: 0.05 part;

[0127] Dioctyl phthalate: 0.08 part;

[0128] Curing agent: 0.07 part;

[0129] Antioxidant: 0.06 part.

[0130] Comparative Example 2

[0131] A recycled asphalt concrete, having the same other features as in Example 3, except that in this recycled asphalt concrete, by weight:

[0132] SBS modified asphalt: 10 parts;

[0133] Recycled asphalt mixture: 44 parts;

[0134] Aggregate: 18 parts;

[0135] Modified microporous silica: 7 parts;

[0136] Waste mineral oil: 0.3 part;

[0137] Guaiacwood oil: 1 part;

[0138] Dioctyl phthalate: 0.08 part;

[0139] Curing agent: 0.07 part;

[0140] Antioxidant: 0.06 part.

[0141] Comparative Example 3

[0142] A recycled asphalt concrete, with other features being the same as those in Example 3, except that modified microporous silica is not added to the raw materials of the recycled asphalt concrete, and in this recycled asphalt concrete, by weight,

[0143] SBS modified asphalt: 10 parts;

[0144] Recycled asphalt mixture: 44 parts;

[0145] Aggregates: 18 parts;

[0146] Waste mineral oil: 4.9 parts;

[0147] Guaiac wood oil: 0.3 part;

[0148] Dioctyl phthalate: 0.08 part;

[0149] Curing agent: 0.07 part;

[0150] Anti-aging agent: 0.06 part.

[0151] The preparation method of the recycled asphalt concrete in this example includes the following steps:

[0152] S1. Mix and stir waste mineral oil, guaiac wood oil, dioctyl phthalate, curing agent and anti-aging agent, and heat to 105 °C to obtain a mixture;

[0153] S2. Crush the recycled asphalt mixture to an average particle size of less than 0.2 cm and heat to 105 °C;

[0154] S3. Heat the SBS modified asphalt to 105 °C, then add the recycled asphalt mixture to the SBS modified asphalt, and then add the mixture to obtain a recycled asphalt mixture;

[0155] S4. Add aggregates to the recycled asphalt mixture to obtain recycled asphalt concrete.

[0156] Comparative Example 4

[0157] A recycled asphalt concrete, with other features being the same as those in Example 3, except that waste mineral oil is not added to the raw materials of the recycled asphalt concrete, and in this recycled asphalt concrete, by weight,

[0158] SBS modified asphalt: 10 parts;

[0159] Recycled asphalt mixture: 44 parts;

[0160] Aggregates: 18 parts;

[0161] Modified microporous silica: 3.8 parts;

[0162] Guaiac wood oil: 1.4 parts;

[0163] Dioctyl phthalate: 0.08 parts;

[0164] Curing agent: 0.07 parts;

[0165] Anti-aging agent: 0.06 parts.

[0166] The preparation method of the recycled asphalt concrete of this embodiment includes the following steps:

[0167] S1. Mix and stir modified microporous silica, guaiac oil, dioctyl phthalate, curing agent and anti-aging agent, and heat to 105 °C to obtain a mixture;

[0168] S2. Crush the recycled asphalt mixture to an average particle size less than 0.2 cm and heat to 105 °C;

[0169] S3. Heat the SBS modified asphalt to 105 °C, then add the recycled asphalt mixture to the SBS modified asphalt, and then add the mixture to obtain a recycled asphalt mixture;

[0170] S4. Add the aggregate to the recycled asphalt mixture to obtain recycled asphalt concrete.

[0171] Comparative Example 5

[0172] A kind of recycled asphalt concrete, other features are the same as those of Example 3, the difference is that guaiac oil is not added to the raw materials of the recycled asphalt concrete, and in this recycled asphalt concrete, by weight,

[0173] SBS modified asphalt: 10 parts;

[0174] Recycled asphalt mixture: 44 parts;

[0175] Aggregate: 18 parts;

[0176] Modified microporous silica: 3.8 parts;

[0177] Waste mineral oil: 1.4 parts;

[0178] Dioctyl phthalate: 0.08 parts;

[0179] Curing agent: 0.07 parts;

[0180] Anti-aging agent: 0.06 parts.

[0181] The preparation method of the recycled asphalt concrete of this embodiment includes the following steps:

[0182] S1. Mix and stir modified microporous silica, waste mineral oil, dioctyl phthalate, curing agent and anti-aging agent, and heat to 105 °C to obtain a mixture;

[0183] S2. Crush the recycled asphalt mixture to an average particle size of less than 0.2 cm and heat it to 105°C.

[0184] S3. Heat the SBS modified asphalt to 105°C, then add the recycled asphalt mixture to the SBS modified asphalt, and then add the mixture to obtain the recycled asphalt mixture.

[0185] S4. Add the aggregate to the recycled asphalt mixture to obtain the recycled asphalt concrete.

[0186] Comparative Example 6

[0187] A kind of recycled asphalt concrete, with other characteristics being the same as those in Example 3, except that the modified microporous silica is replaced with microporous silica in the raw materials of the recycled asphalt concrete.

[0188] Effect Example

[0189] Perform performance tests on the recycled asphalt concrete prepared in Examples 1 - 3 and Comparative Examples 1 - 6. Among them, the penetration is tested in accordance with GB / T4509 - 2010 "Determination Method of Asphalt Penetration". The ductility is determined in accordance with GB / T4508 - 2010 "Determination Method of Asphalt Ductility". The dynamic stability is determined in accordance with T0719 - 2011 in JTGE20 - 2011 "Test Regulations for Asphalt and Asphalt Mixtures in Highway Engineering", where the test size is a plate specimen of 300mm * 300mm * 50mm, the test temperature is 60°C, the wheel load is 0.7MPa, and the repeated wheel load time is 60min. The low-temperature crack resistance experiment is carried out using the asphalt mixture bending test regulations in JTGE20 - 2011 "Test Regulations for Asphalt and Asphalt Mixtures in Highway Engineering"; the specimen size is a length of 250mm ± 2mm, a width of 30mm ± 2mm, a height of 35mm ± 2mm, a span of 200mm ± 0.5mm, the test temperature is -10°C ± 0.5°C, and the loading rate is 50mm / min. The flexural tensile failure strength test is carried out using the asphalt mixture flexural tensile failure strength regulations in JTGE20 - 2011 "Test Regulations for Asphalt and Asphalt Mixtures in Highway Engineering", where the flexural tensile failure strength is tested on a rutting plate specimen with a height of 35mm, a length of 250mm, and a width of 30mm at a temperature of -10°C and a loading rate of 500mm / min.

[0190] Obtain Table 1 and Table 2 correspondingly.

[0191] Table 1. Performance test results of the recycled asphalt concrete in Examples 1 - 3

[0192]

[0193] Table 2. Performance test results of recycled asphalt concrete for Comparative Examples 1 - 6

[0194]

[0195] As can be seen from the above table, the penetration of the recycled concrete prepared in Examples 1 to 3 of the present invention is between 26 and 27, and its viscosity is better. The dynamic stability of the recycled concrete of the present invention is in the range of 6334 times / mm to 6456 times / mm, and it can meet the usage requirements in summer-heat regions in terms of high-temperature rutting resistance. The maximum flexural tensile strain of this recycled concrete is ≥3000 με, and its low-temperature anti-cracking performance also meets the usage requirements in winter-cold regions. The flexural tensile failure strength of the present invention is greater than 23.3 MPa, and its strength is relatively large. From Example 3 of the present invention and Comparative Examples 3 to 6 of the recycled concrete, it can be seen that when modified microporous silica, waste mineral oil, and guaiacwood oil exist simultaneously, the high-temperature rutting resistance, low-temperature anti-cracking performance, and flexural tensile failure strength can be significantly improved. At the same time, the above data show that the present invention can further improve the above performances through the reasonable ratio of each component and appropriate preparation conditions.

[0196] It can be seen that the recycled concrete of the present invention still has good high-temperature rutting resistance and low-temperature anti-cracking performance, etc., and has a relatively high flexural tensile failure strength when the proportion of recycled asphalt mixture is more than 50%.

[0197] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention and not to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A regenerated asphalt concrete, characterized in that: In parts by weight, SBS modified asphalt: 10 parts; Recycled asphalt mixture: 40 to 50 parts; Aggregate: 10 to 25 parts; Modified microporous silica: 3 to 5 parts; Waste mineral oil: 0.5 to 2 parts; Guaiac wood oil: 0.1 to 0.5 parts; Dioctyl phthalate: 0.05 to 0.1 parts; Curing agent: 0.05 to 0.1 parts; Anti-aging agent: 0.05 to 0.1 parts; The modified microporous silica is prepared by the following steps: A1. In parts by weight, add 100 parts of 3,7-dimethyl-6-octen-1-ol to 200-300 parts of tetrahydrofuran, and add 60-80 parts of 4-cyclohexanonecarboxylic acid and 10-20 parts of sodium hydroxide, stir at 30° C. to 40° C. for 14 h to 18 h, and salt out and dry to obtain an intermediate; A2, adding 10 parts of microporous silica to 10 to 20 parts of 0.5 mol / L to 2 mol / L hydrochloric acid solution, stirring for 1 h to 3 h, filtering, and obtaining pretreated microporous silica; A3. Add 3 to 5 parts of the intermediate to 10 to 20 parts of acetone, then add 5 parts of pretreated microporous silica, heat to 70°C to 90°C, stir for 1 to 3 hours, filter and dry to obtain modified microporous silica.

2. The regenerated asphalt concrete according to claim 1, characterized in that: In parts by weight, SBS modified asphalt: 10 parts; Recycled asphalt mixture: 44 parts; Aggregate: 18 parts; Modified microporous silica: 3.8 parts; Waste mineral oil: 1.1 parts; Guaiac wood oil: 0.3 parts; Dioctyl phthalate: 0.08 parts; Curing agent: 0.07 parts; Anti-aging agent: 0.06 parts.

3. The regenerated asphalt concrete according to claim 2, characterized in that: The modified microporous silica is prepared by the following steps: A1. In parts by weight, 100 parts of 3,7-dimethyl-6-octen-1-ol were added to 250 parts of tetrahydrofuran, and 66 parts of 4-cyclohexanonecarboxylic acid and 13.6 parts of sodium hydroxide were added, and the mixture was stirred at 37° C. for 16 hours, and then salted out and dried to obtain an intermediate; A2, adding 10 parts of microporous silica to 15.5 parts of 1.2 mol / L hydrochloric acid solution, stirring for 2 hours, filtering, and obtaining pretreated microporous silica; A3. Add 4 parts of the intermediate to 17 parts of acetone, then add 5 parts of pretreated microporous silica, heat to 82°C, stir for 2 hours, filter and dry to obtain modified microporous silica.

4. The regenerated asphalt concrete according to claim 3, characterized in that: The anti-aging agent is polyethylene naphthalate or phenyl-α-naphthylamine.

5. The regenerated asphalt concrete according to claim 4, characterized in that: The curing agent is polyetheramine or catechol.

6. A method for preparing regenerated asphalt concrete according to any one of claims 1 to 5, characterized in that: The steps include: S1, modified microporous silica, waste mineral oil, guaiac wood oil, dioctyl phthalate, a curing agent and an anti-aging agent are mixed and stirred to obtain a mixture; S2, crushing the recycled asphalt mixture; S3, heating the SBS modified asphalt, then adding the recycled asphalt mixture to the SBS modified asphalt, and then adding the mixture to obtain a recycled asphalt mixture; S4. Adding the aggregate to the recycled asphalt mixture to obtain recycled asphalt concrete.

7. The preparation method according to claim 6, characterized in that: The steps include: S1, modified microporous silica, waste mineral oil, guaiac wood oil, dioctyl phthalate, a curing agent and an anti-aging agent are mixed and stirred, and heated to 100° C. to 120° C. to obtain a mixture; S2, crushing the recycled asphalt mixture to an average particle size of less than 0.2 cm, and heating to 100°C to 110°C; S3, heating the SBS modified asphalt to 100°C to 110°C, then adding the recycled asphalt mixture to the SBS modified asphalt, and then adding the mixture to obtain a recycled asphalt mixture; S4. Adding the aggregate to the recycled asphalt mixture to obtain recycled asphalt concrete.

Images