Asphalt plant-mixed AC-13 thermal regeneration mixture with high mixing amount of asphalt milling material and preparation method of asphalt plant-mixed AC-13 thermal regeneration mixture

Abstract

The invention discloses an asphalt plant-mixed AC-13 thermal regeneration mixture highly doped with an asphalt milling material and a preparation method thereof, the asphalt plant-mixed AC-13 thermal regeneration mixture prepared by the invention has high mixing amount of the asphalt milling material, and keeps excellent performance, especially water stability and track dynamic stability; aging fatigue asphalt in the asphalt milling material can cause generation of a micro interlayer when the asphalt milling material is combined with new asphalt, and water in the asphalt is stably reduced after the asphalt milling material is used after water easily enters the micro interlayer, so that the asphalt milling material is heated at high temperature, the aging fatigue asphalt can be effectively stripped and reduced, and the service life of the asphalt milling material is prolonged. The surface of the asphalt milling material is obviously activated, the adhesive force of the surface of the asphalt milling material is increased, and the asphalt milling material is better combined with new asphalt, so that the mixing amount of the asphalt milling material can be increased, the recycling rate of the asphalt milling material can be increased, and the asphalt plant-mixed hot recycled mixture has high water stability and track dynamic stability.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt, and in particular to an asphalt plant-mixed AC-13 hot recycled mixture with a high amount of asphalt milling material. Background Art

[0002] The statements here only provide background technology related to the present invention and do not necessarily constitute prior art. In highway maintenance and repair, the original asphalt pavement needs to be milled, generating a large amount of asphalt milling material. The stockpiling of these waste materials not only occupies a large amount of land resources, but also causes serious ecological environmental pollution. At the same time, in the daily maintenance and repair of highways, a large amount of high-quality asphalt and stone will be used, which will not only consume a large amount of construction funds, but also bring serious waste of energy and resources. With the gradual enhancement of environmental awareness and the increasing depletion of non-renewable mineral resources, the supply of high-quality aggregates has dropped drastically, and the price has skyrocketed, bringing great cost pressure to highway construction and management departments.

[0003] Currently, asphalt milling materials are mixed into new asphalt to make factory-mixed hot recycled asphalt mixture for recycling, but the current dosage of asphalt milling materials is relatively low. If a high amount of asphalt milling materials is mixed into new asphalt, it will affect the performance of the factory-mixed AC-13 hot recycled mixture. In the prior art, for example, when the dosage of asphalt milling materials is 60%, as the dosage of asphalt milling materials increases, the water stability of the factory-mixed AC-13 hot recycled mixture will continue to decrease, so the utilization rate of the asphalt milling materials is limited. Summary of the invention

[0004] Therefore, based on the above background, the present invention provides an asphalt plant-mixed AC-13 hot recycled mixture with a high content of asphalt milling material. The asphalt milling material has a high content, which can be as high as 70% or more. The asphalt milling material has a high utilization rate and excellent performance, especially water stability.

[0005] The technical solution of the present invention is:

[0006] A factory-mixed AC-13 hot recycled mixture with a high content of asphalt milling material, which is made from the following raw materials:

[0007] 25-55wt% of medium-sized asphalt milling material, 15-60wt% of small-sized asphalt milling material, 0-20wt% of new aggregate 5-10mm crushed stone, 5-15wt% of fine aggregate machine-made sand, 0-3wt% of mineral powder, 0.2-1wt% of regeneration agent, and 1-3wt% of SBS modified asphalt;

[0008] The particle size of the medium-sized asphalt milling material is 9.5-16 mm;

[0009] The particle size of the small-size asphalt milling material is 0.01-9.5 mm.

[0010] Furthermore, the needle penetration of the SBS modified asphalt is required to be 60-80, the elongation (5°C) ≥30, and the softening point ≥55.

[0011] Specifically, the SBS modified asphalt has a needle penetration of 62, an elongation (5° C.) of 34, and a softening point of 76.0.

[0012] Furthermore, the new aggregate has a particle size of 5-10 mm and is made of at least one of basalt and amphibolite.

[0013] Furthermore, the particle size of the mineral powder is 0.1-0.6 mm. The fine aggregate machine-made sand 0-3 mm is made of limestone material.

[0014] The non-agglomerated hydrophilic coefficient of the mineral powder is less than 1, the plasticity index is less than 4%, the passing rate of less than 0.15 mm is 60-100, and the passing rate of less than 0.075 mm is 75-100.

[0015] Based on the same inventive concept, the present invention also provides a method for preparing a factory-mixed AC-13 hot recycled mixture with a high amount of asphalt milling material, comprising the following steps:

[0016] S1: crushing and screening the asphalt milling material, and screening the asphalt milling material with two particle sizes of 9.5-16mm and 0-9.5mm respectively;

[0017] S2: heating the asphalt milling materials of two particle sizes in step S1 at 130-160° C. respectively;

[0018] Specifically, the asphalt milling material enters the hot regeneration heating device and enters the mixing pot of the mixing equipment for mixing directly through the weighing system 4-5 minutes after discharge.

[0019] S3: Take the heated asphalt milling materials of two particle sizes in proportion, mix them, add the regeneration agent, and stir;

[0020] S4: Add new aggregates and SBS modified asphalt and mineral powder at room temperature that have been preheated respectively into the asphalt milling material, and after stirring, the factory-mixed AC-13 hot recycled mixture can be obtained.

[0021] Furthermore, after adding the regeneration agent in step S3, stirring is performed for 10 to 15 seconds.

[0022] Furthermore, in step S4, the new aggregate and SBS modified asphalt are preheated at 170-195°C respectively, wherein the new aggregate is preheated at 170-195°C, and the SBS modified asphalt is preheated at 165-170°C.

[0023] Furthermore, the stirring time in step S4 is 55 to 60 seconds.

[0024] Furthermore, the heating temperature of the asphalt milling material in step S2 is 160°C.

[0025] The beneficial effects achieved by the technical solution of the present invention are:

[0026] The asphalt milling material in the asphalt plant-mixed AC-13 hot recycled mixture prepared by the present invention has a high content of asphalt milling material, which can be as high as more than 70%, and maintains excellent performance, especially water stability and rutting dynamic stability;

[0027] Aged and fatigued asphalt in asphalt milling material will lead to the formation of micro-interlayers when the asphalt milling material is combined with new asphalt, which will cause water to easily enter the micro-interlayers, resulting in a decrease in the water stability of the asphalt after use, that is, a decrease in the residual Marshall stability. Therefore, the present invention heats the asphalt milling material at high temperature, which can effectively strip off and reduce the aged and fatigued asphalt, significantly activate the surface of the asphalt milling material, increase the adhesion of the surface of the asphalt milling material, and make the asphalt milling material better combined with the new asphalt, thereby not only increasing the dosage of the asphalt milling material and the recycling rate of the asphalt milling material, but also making the AC-13 hot recycled mixture mixed in the asphalt plant have high water stability and rutting dynamic stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Attached Figure 1 These are the Marshall test data of the AC-13 hot recycled mixture mixed in the asphalt plant of Example 1 (the upper part is the Marshall stability test data, and the lower part is the Marshall residual stability test data).

[0029] Attached Figure 2 The dynamic stability test results of the AC-13 hot recycled mixture mixed in the asphalt plant in Example 1 are shown.

[0030] Attached Figure 3 The dynamic stability test results of the AC-13 hot recycled mixture mixed in the asphalt plant in Example 3 are shown.

[0031] Attached Figure 4 These are the Marshall test data of the asphalt plant-mixed AC-13 hot recycled mixture of Example 3 (the upper part is the Marshall stability test data, and the lower part is the Marshall residual stability test data).

[0032] Attached Figure 5 These are the Marshall test data of the asphalt plant-mixed AC-13 hot recycled mixture of Example 4 (the upper part is the Marshall stability test data, and the lower part is the Marshall residual stability test data). DETAILED DESCRIPTION

[0033] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] Technical solution of the present invention:

[0035] A factory-mixed AC-13 hot recycled mixture with a high content of asphalt milling material, which is made from the following raw materials:

[0036] 25-55wt% of medium-sized asphalt milling material, 15-60wt% of small-sized asphalt milling material, 0-20wt% of new aggregate, 5-15wt% of fine aggregate machine-made sand, 0-3wt% of mineral powder, 0.2-1wt% of regeneration agent, and 1-3wt% of SBS modified asphalt;

[0037] The particle size of the medium-sized asphalt milling material is 9.5-16 mm;

[0038] The particle size of the small-size asphalt milling material is 0.01-9.5 mm.

[0039] The SBS modified asphalt has a needle penetration requirement of 60-80, an elongation (5°C) ≥30, and a softening point ≥55.

[0040] Specifically, the SBS modified asphalt has a needle penetration of 62, an elongation (5° C.) of 34, and a softening point of 76.0.

[0041] The new aggregate has a particle size of 5-10 mm and is made of at least one of basalt and amphibolite. The fine aggregate machine-made sand has a particle size of 0-3 mm and is made of limestone.

[0042] The particle size of the mineral powder is 0.1-0.6 mm.

[0043] The non-agglomerated hydrophilic coefficient of the mineral powder is less than 1, the plasticity index is less than 4%, the passing rate of less than 0.15 mm is 60-100, and the passing rate of less than 0.075 mm is 75-100.

[0044] The regeneration agent added to the AC-13 hot recycled mixture mixed in the factory can reduce the viscosity of aged asphalt. Through penetration and diffusion, the ductility of the old asphalt in the recycled asphalt milling material is reduced to the asphalt ductility required by the mixture, so that it regains good fluidity and workability, and is easy to mix evenly with the new asphalt mixture; and increase the needle penetration, making the asphalt softer, thereby improving the flexibility and crack resistance of the asphalt after use.

[0045] The present invention also provides a method for preparing a factory-mixed AC-13 hot-regenerated mixture with a high amount of asphalt milling material, comprising the following steps:

[0046] S1: crushing and screening the asphalt milling materials, and screening the asphalt milling materials with two particle sizes of 9.5-16mm and 0.01-9.5mm respectively;

[0047] S2: The asphalt milling materials of the two particle sizes in step S1 are heated at 160° C. respectively (the asphalt milling materials enter the mixing pot of the mixing equipment directly through the weighing system for mixing 4-5 minutes after entering the hot regeneration heating device and discharging);

[0048] S3: Take the heated asphalt milling materials of two particle sizes in proportion, mix them, add the regeneration agent, and stir for 10 to 15 seconds;

[0049] S4: Add new aggregate and SBS modified asphalt and mineral powder at room temperature that have been preheated to the asphalt milling material, and stir for 55 to 60 seconds to obtain the factory-mixed AC-13 hot recycled mixture with a temperature of 175-180°C.

[0050] In this step, the new aggregate and SBS modified asphalt are preheated at 170-195°C respectively, wherein the new aggregate is preheated at 170-195°C and the SBS modified asphalt is preheated at 165-170°C.

[0051] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0052] Unless otherwise specified, the materials, reagents, etc. used in the following examples can be obtained from commercial channels in accordance with industry standards.

[0053] Example 1: A factory-mixed AC-13 hot recycled mixture with a high amount of asphalt milling material, which is made from the following raw materials:

[0054] 38wt% of medium-sized asphalt milling material, 32wt% of small-sized asphalt milling material, 0.5wt% of regeneration agent, 20wt% of new aggregate 5-10mm crushed stone, 9wt% of fine aggregate machine-made sand, 1wt% of mineral powder, and 2.6wt% of SBS modified asphalt.

[0055] The particle size of the medium-sized asphalt milling material is 9.5-16 mm;

[0056] The particle size of the small-size asphalt milling material is 0.01-9.5 mm.

[0057] The preparation method of the asphalt plant-mixed AC-13 hot recycled mixture of this embodiment comprises the following steps:

[0058] S1: crushing and screening the asphalt milling materials, and screening the asphalt milling materials with two particle sizes of 9.5-16mm and 0.01-9.5mm respectively;

[0059] S2: The asphalt milling materials of the two particle sizes in step S1 are heated at 160° C. respectively (the asphalt milling materials enter the mixing pot of the mixing equipment directly through the weighing system for mixing 4-5 minutes after entering the hot regeneration heating device and discharging);

[0060] S3: Take the heated asphalt milling materials of two particle sizes in proportion, mix them, add the regeneration agent, and stir for 10 to 15 seconds;

[0061] S4: Add new aggregates and SBS modified asphalt and room temperature mineral powder that have been preheated to the asphalt milling material, and stir for 55 to 60 seconds to obtain the asphalt plant-mixed AC-13 hot recycled mixture.

[0062] In this step, the new aggregate and SBS modified asphalt are preheated at 170-195°C, respectively, wherein the new aggregate is preheated at 170-195°C, and the SBS modified asphalt is preheated at 165-170°C.

[0063] Example 2: A factory-mixed AC-13 hot recycled mixture with a high amount of asphalt milling material, which is made from the following raw materials:

[0064] 38wt% of medium-sized asphalt milling material, 32wt% of small-sized asphalt milling material, 0.5wt% of regeneration agent, 20wt% of new aggregate 5-10mm crushed stone, 9wt% of fine aggregate machine-made sand, 1wt% of mineral powder, and 2.6wt% of SBS modified asphalt.

[0065] The particle size of the medium-sized asphalt milling material is 9.5-16 mm;

[0066] The particle size of the small-size asphalt milling material is 0.01-9.5 mm.

[0067] The preparation method of the asphalt plant-mixed AC-13 hot recycled mixture of this embodiment comprises the following steps:

[0068] S1: crushing and screening the asphalt milling materials, and screening the asphalt milling materials with two particle sizes of 9.5-16mm and 0.01-9.5mm respectively;

[0069] S2: The asphalt milling materials of the two particle sizes in step S1 are heated at 130° C. respectively (the asphalt milling materials enter the mixing pot of the mixing equipment directly through the weighing system for mixing 4-5 minutes after entering the hot regeneration heating device and discharging);

[0070] S3: Take the heated asphalt milling materials of two particle sizes in proportion, mix them, add the regeneration agent, and stir for 10 to 15 seconds;

[0071] S4: Add new aggregates and SBS modified asphalt and room temperature mineral powder that have been preheated to the asphalt milling material, and stir for 55 to 60 seconds to obtain the factory-mixed AC-13 hot recycled mixture.

[0072] In this step, the new aggregate and SBS modified asphalt are preheated at 170-195°C respectively, wherein the new aggregate is preheated at 170-195°C and the SBS modified asphalt is preheated at 165-170°C.

[0073] Example 3: A factory-mixed AC-13 hot recycled mixture with a high amount of asphalt milling material, which is made from the following raw materials:

[0074] An asphalt plant mixed AC-13 hot recycled mixture with a high content of asphalt milling material, which is made from the following raw materials:

[0075] 38wt% of medium-sized asphalt milling material, 32wt% of small-sized asphalt milling material, 0.5wt% of regeneration agent, 20wt% of new aggregate 5-10mm crushed stone, 9wt% of fine aggregate machine-made sand, 1wt% of mineral powder, and 2.6wt% of SBS modified asphalt.

[0076] The particle size of the medium-sized asphalt milling material is 9.5-16 mm;

[0077] The particle size of the small-size asphalt milling material is 0.01-9.5 mm.

[0078] The preparation method of the asphalt plant-mixed AC-13 hot recycled mixture of this embodiment comprises the following steps:

[0079] S1: crushing and screening the asphalt milling materials, and screening the asphalt milling materials with two particle sizes of 9.5-16mm and 0.01-9.5mm respectively;

[0080] S2: The asphalt milling materials of the two particle sizes in step S1 are heated at 140° C. respectively (the asphalt milling materials enter the mixing pot of the mixing equipment directly through the weighing system for mixing 4-5 minutes after entering the hot regeneration heating device and discharging);

[0081] S3: Take the heated asphalt milling materials of two particle sizes in proportion, mix them, add the regeneration agent, and stir for 10 to 15 seconds;

[0082] S4: Add new aggregates and SBS modified asphalt and room temperature mineral powder that have been preheated to the asphalt milling material, and stir for 55 to 60 seconds to obtain the factory-mixed AC-13 hot recycled mixture.

[0083] In this step, the new aggregate and SBS modified asphalt are preheated at 170-195°C respectively, wherein the new aggregate is preheated at 170-195°C and the SBS modified asphalt is preheated at 165-170°C.

[0084] Example 4: A factory-mixed AC-13 hot recycled mixture with a high amount of asphalt milling material, which is made from the following raw materials:

[0085] An asphalt plant mixed AC-13 hot recycled mixture with a high content of asphalt milling material, which is made from the following raw materials:

[0086] 38wt% of medium-sized asphalt milling material, 32wt% of small-sized asphalt milling material, 0.5wt% of regeneration agent, 20wt% of new aggregate 5-10mm crushed stone, 9wt% of fine aggregate machine-made sand, 1wt% of mineral powder, and 2.6wt% of SBS modified asphalt.

[0087] The particle size of the medium-sized asphalt milling material is 9.5-16 mm;

[0088] The particle size of the small-size asphalt milling material is 0.01-9.5 mm.

[0089] The preparation method of the asphalt plant-mixed AC-13 hot recycled mixture of this embodiment comprises the following steps:

[0090] S1: crushing and screening the asphalt milling materials, and screening the asphalt milling materials with two particle sizes of 9.5-16mm and 0.01-9.5mm respectively;

[0091] S2: The asphalt milling materials of the two particle sizes in step S1 are heated at 170° C. respectively (the asphalt milling materials enter the mixing pot of the mixing equipment directly through the weighing system for mixing 4-5 minutes after entering the hot regeneration heating device and discharging);

[0092] S3: Take the heated asphalt milling materials of two particle sizes in proportion, mix them, add the regeneration agent, and stir for 10 to 15 seconds;

[0093] S4: Add new aggregates and SBS modified asphalt and room temperature mineral powder that have been preheated to the asphalt milling material, and stir for 55 to 60 seconds to obtain the factory-mixed AC-13 hot recycled mixture.

[0094] In this step, the new aggregate and SBS modified asphalt are preheated at 170-195°C respectively, wherein the new aggregate is preheated at 170-195°C and the SBS modified asphalt is preheated at 165-170°C.

[0095] The water stability and rutting dynamic stability of Examples 1 to 4 were tested, and the results are shown in the attached figures.

[0096] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An asphalt plant mixed AC-13 hot recycled mixture with a high amount of asphalt milling material, characterized in that: It is made from the following raw materials: 25-55wt% of medium-sized asphalt milling material, 15-60wt% of small-sized asphalt milling material, 0-20wt% of new aggregate, 5-15wt% of fine aggregate machine-made sand, 0-3wt% of mineral powder, 0.2-1wt% of regeneration agent, and 1-3wt% of SBS modified asphalt; The particle size of the medium-sized asphalt milling material is 9.5-16 mm; The particle size of the small-size asphalt milling material is 0.01-9.5 mm.

2. The asphalt plant-mixed AC-13 hot recycled mixture with high asphalt milling material according to claim 1 is characterized in that: The SBS modified asphalt has a needle penetration of 60-80, an elongation (5°C) ≥30, and a softening point ≥55.

3. The asphalt plant-mixed AC-13 hot recycled mixture with high asphalt milling material according to claim 2 is characterized in that: The particle size of the fine aggregate machine-made sand is 0.01-3 mm.

4. The asphalt plant-mixed AC-13 hot recycled mixture with high asphalt milling material according to claim 1 is characterized in that: The particle size of the mineral powder is 0.1-0.6 mm.

5. The method for preparing the asphalt plant-mixed AC-13 hot recycled mixture with high asphalt milling material according to any one of claims 1 to 4, characterized in that: The steps include: S1: crushing and screening the asphalt milling material, and screening the asphalt milling material with two particle sizes of 9.5-16mm and 0.01-9.5mm respectively; S2: heating the asphalt milling materials of two particle sizes in step S1 at 130-170° C. respectively; S3: Take the heated asphalt milling materials of two particle sizes in proportion, mix them, add the regeneration agent, and stir; S4: Add new aggregates and SBS modified asphalt and room temperature mineral powder that have been preheated to the asphalt milling material, and stir to obtain a factory-mixed hot recycled asphalt mixture.

6. The method for preparing the asphalt plant-mixed AC-13 hot recycled mixture with high asphalt milling material according to claim 5, characterized in that: After adding the regeneration agent in step S3, stirring is performed for 10 to 15 seconds.

7. The method for preparing the asphalt plant-mixed AC-13 hot recycled mixture with high asphalt milling material according to claim 5, characterized in that: In step S4, the new aggregate and SBS modified asphalt are preheated at 170-195°C respectively, wherein the new aggregate is preheated at 170-195°C and the SBS modified asphalt is preheated at 165-170°C.

8. The method for preparing a hot recycled mixture of asphalt plant with high asphalt milling material according to claim 5, characterized in that: The stirring time in step S4 is 55 to 60 seconds.

9. The method for preparing a hot recycled mixture of asphalt plant with high asphalt milling material according to claim 5, characterized in that: The heating temperature of the asphalt milling material in step S2 is 160°C.

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