Recycled asphalt mixture as well as preparation device and preparation method thereof

Abstract

The invention discloses a recycled asphalt mixture as well as a manufacturing device and a manufacturing method thereof. The recycled asphalt mixture comprises 75-85 parts of an old asphalt mixture; 3-5 parts of new asphalt; 10-15 parts of a new aggregate; 2-4 parts of a filler; according to the present invention, a large amount of the old asphalt mixture which does not meet the original use standard after the long-term use or is discarded can be reutilized, such that the resource recycling is easily achieved, and the requirements of environmental protection and source opening are met.

Description

Technical Field

[0001] The present invention relates to the technical field of road resource recycling, and in particular to a recycled asphalt mixture and a production device and a production method thereof. Background Art

[0002] The original processing technology of factory-mixed hot recycled asphalt mixture is to add the recycled materials milled from the failed asphalt pavement into the agitator of the asphalt mixing station according to a certain ratio (currently, the proportion of old asphalt milling materials added does not exceed 30%) after crushing and screening, and then evenly mix them with new aggregates, asphalt, fillers, regeneration agents, etc. to produce recycled asphalt mixture.

[0003] The existing factory-mixed hot-recycled asphalt mixture is regenerated by heating the old asphalt milling material to 130°C in a hot regeneration drying drum and adding asphalt regeneration agent to regenerate the old asphalt mixture. The addition of regeneration agent will directly affect the oil-stone ratio of the regenerated asphalt mixture. The proportion of asphalt regeneration agent is usually 0.15%~0.25% of the asphalt mixture. It is difficult to fully blend with the old asphalt mixture in a limited time in the asphalt mixing cylinder, and the penetration and softening effect of the regeneration agent cannot be exerted. When a high proportion of old asphalt mixture is added, it will cause uneven regeneration, affecting the performance of the regenerated pavement. In addition, during the preparation process, the drying temperature of the old asphalt mixture is insufficient, resulting in the inability to completely remove moisture. When the aged asphalt mixture is mixed for a short time, the regeneration agent cannot be fully mixed and diffused with the aged asphalt, further reducing the cohesion and internal cohesion of the mixture, affecting the stability, durability and construction performance of the pavement.

[0004] In summary, the existing factory-mixed hot recycled asphalt mixture production process has problems such as insufficient regeneration of old asphalt mixture, high moisture content of old asphalt milling material resulting in difficulty in heating the drying drum, low dosage of old asphalt mixture, secondary aging of old asphalt, unsatisfactory regenerated pavement performance, and environmental pollution, resulting in the technology being unable to meet market demand well.

[0005] Therefore, it is necessary in this technical field to study a production process for recycled asphalt mixture that can achieve high-amount recycled material addition and effectively improve the performance of recycled pavement. Summary of the invention

[0006] The purpose of the present invention is to provide a recycled asphalt mixture and a production device and method thereof, which can reuse a large amount of old asphalt mixture that has failed to meet the original usage standards or has been discarded after long-term use, which is beneficial to the recycling of resources and meets the requirements of environmental protection and open source.

[0007] A regenerated asphalt mixture provided by the present invention comprises: 75-85 parts of old asphalt mixture; 0.1-1 part new asphalt; 10-15 parts new aggregate; 2-4 parts filler; 0.15-0.25 parts of asphalt regeneration agent.

[0008] The regenerated asphalt mixture provided by the present invention is mainly composed of a high-dosage old asphalt mixture, with a small amount of new asphalt, new aggregate, filler and asphalt regeneration agent, thereby realizing the recycling of waste resources and meeting the requirements of environmental protection and open source.

[0009] Furthermore, the old asphalt mixture includes old asphalt and old aggregate, and the old asphalt includes one or both of discarded road petroleum asphalt and SBS modified asphalt.

[0010] Furthermore, the old aggregate includes one or more of diabase, limestone and basalt.

[0011] Furthermore, the new asphalt is No. 70 base petroleum asphalt.

[0012] Furthermore, the new aggregate is one or both of limestone and basalt.

[0013] Furthermore, the filler is limestone powder.

[0014] The new aggregates, fillers, etc. used in the present invention are all materials that are widely available.

[0015] The present invention also provides a device for producing the recycled asphalt mixture as described above, comprising a main mixing tank for mixing and stirring the old asphalt mixture, new asphalt, new aggregate, filler and asphalt regeneration agent, wherein the upstream of the main mixing tank is respectively connected to a recycled asphalt system, a new aggregate system, a new asphalt tank and a filler tank, and the downstream of the main mixing tank is connected to a finished product insulation bin.

[0016] The regenerated asphalt system includes a crushing and screening device, a first cold material bin, an electromagnetic preheating kiln, a countercurrent drying drum, a buffer bin, a first metering bin, a premixing cylinder and a miscible development and insulation bin, which are connected in sequence from upstream to downstream. A regeneration agent feed bin is also connected upstream of the premixing cylinder.

[0017] Furthermore, the new aggregate system includes a second cold material bin, a raw drying drum, a screening storage bin and a second metering bin which are sequentially connected from upstream to downstream, and the second metering bin is connected to the upstream of the main mixing tank.

[0018] The device for making recycled asphalt mixture provided by the present invention adds a premixing tank and a miscible development and insulation bin, that is, the old asphalt mixture is first fully premixed with the asphalt regeneration agent in the premixing tank, so that the asphalt regeneration agent can effectively reduce the viscosity of the old asphalt to achieve the required appropriate viscosity. The addition of the asphalt regeneration agent can also soften the brittle and hard old asphalt mixture, which is convenient for full dispersion under the action of machinery and heating, and convenient for subsequent uniform mixing with new asphalt and new aggregate. After the recycled asphalt mixture is stirred, it is heated and insulated in the miscible development and insulation bin for a period of time to restore the performance of the old asphalt mixture, and then it is stirred with the new asphalt, new aggregate and filler in the main mixing tank to promote diffusion and fusion between the old asphalt and the new asphalt, expand the contact area, and reduce the dosage of the asphalt regeneration agent, so as to improve the overall performance and reduce the phenomenon of oiling of the road surface after the construction of the recycled pavement is completed.

[0019] The present invention also provides a method for producing a regenerated asphalt mixture, using the production device as described above, the production method comprising the steps of: S1: collecting the discarded old asphalt mixture, crushing and screening the old asphalt mixture into different particle sizes in the crushing and screening device, and then entering the electromagnetic preheating kiln after transition in the first cold material bin; S2: Preliminary mixing of new aggregates with different gradations and then transitioning through the second cold material bin before entering the primary drying drum; S3: Determine the dosage of asphalt regeneration agent according to the dosage and aging degree of old asphalt; S4: Determine the amount of new asphalt and filler; S5: preheating the old asphalt mixtures of different particle sizes in the electromagnetic preheating kiln at a preheating temperature of 40° C., and then feeding them into a countercurrent drying drum after preheating, and setting the countercurrent drying drum to a temperature of 165° C.; S6: conveying the dried old asphalt mixture to a premixing tank, adding an asphalt regeneration agent and stirring in the premixing tank; S7: after stirring in step S6, the mixture is transported to a miscible development and insulation bin and heated and insulated at a temperature of 160° C. to form an old asphalt mixture with restored performance; S8: The old asphalt mixture with restored performance formed in step S7 is transported to the main mixing tank, and new asphalt, new aggregate and filler are added to the main mixing tank, mixed and stirred to form a recycled asphalt mixture.

[0020] Furthermore, after step S4 and before step S5, it is necessary to perform quality inspection on old asphalt mixtures, new aggregates, new asphalt, fillers and asphalt regeneration agents of different particle sizes, and determine whether they meet national standards.

[0021] In a method for making a recycled asphalt mixture provided by the invention, the old asphalt mixture is first fully pre-mixed with an asphalt regeneration agent in a pre-mixing tank, so that the asphalt regeneration agent can effectively reduce the viscosity of the old asphalt to achieve the desired appropriate viscosity. The addition of the asphalt regeneration agent can also soften the brittle old asphalt mixture, which is convenient for full dispersion, penetration and softening under the action of machinery and heating, and is convenient for subsequent uniform mixing with new asphalt and new aggregate. After the recycled asphalt mixture is stirred, it is heated and insulated in a miscible development and insulation bin for a period of time to restore the performance of the old asphalt mixture, and then it is stirred with new asphalt, new aggregate and filler in the main mixing tank to promote diffusion and fusion between the old asphalt and the new asphalt, expand the contact area, and reduce the dosage of the asphalt regeneration agent to improve the overall performance and reduce the phenomenon of oiling of the road surface after the construction of the recycled pavement is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of a device for producing a recycled asphalt mixture according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0024] The present invention provides a regenerated asphalt mixture, comprising: 75-85 parts of old asphalt mixture; 3-5 parts of new asphalt; 10-15 parts new aggregate; 2-4 parts filler; 0.15-0.25 parts of asphalt regeneration agent.

[0025] The regenerated asphalt mixture provided by the present invention is mainly composed of a high-dosage old asphalt mixture, with a small amount of new asphalt, new aggregate, filler and asphalt regeneration agent, thereby realizing the recycling of waste resources and meeting the requirements of environmental protection and open source.

[0026] It is worth noting that the main component of the asphalt regeneration agent used in the present invention is base oil, which is usually derived from waste mineral oil, such as extracted oil, lubricating oil, engine oil and heavy oil during the refining of lubricating oil.

[0027] The old asphalt mixture includes old asphalt and old aggregate, and the old asphalt includes abandoned road petroleum asphalt and one or two of SBS modified asphalt.

[0028] The old aggregate includes one or more of diabase, limestone and basalt.

[0029] The new asphalt is No. 70 base petroleum asphalt.

[0030] The new aggregate is one or both of limestone and basalt.

[0031] The filler is limestone powder.

[0032] The new aggregates, fillers, etc. used in the present invention are all materials that are widely available.

[0033] Combination Figure 1 The present invention also provides a device for making the above-mentioned recycled asphalt mixture, including a main mixing tank for mixing and stirring old asphalt mixture, new asphalt, new aggregate, filler and asphalt regeneration agent, the upstream of the main mixing tank is respectively connected to a recycled asphalt system, a new aggregate system, a new asphalt tank and a filler tank, and the downstream of the main mixing tank is connected to a finished product insulation bin.

[0034] The recycled asphalt system includes a crushing and screening device, a first cold material bin, an electromagnetic preheating kiln, a countercurrent drying drum, a buffer bin, a first metering bin, a premixing tank and a miscible development and insulation bin, which are connected in sequence from upstream to downstream. A regeneration agent feed bin is also connected upstream of the premixing tank.

[0035] The new aggregate system includes a second cold material bin, a raw drying drum, a screening storage bin and a second metering bin which are connected in sequence from upstream to downstream. The second metering bin is connected to the upstream of the main mixing tank.

[0036] The device for making recycled asphalt mixture provided by the present invention includes a variety of specific equipment. It is worth noting that there are many ways to connect the upstream and downstream of each equipment, such as through a conveyor belt, etc. In order to simplify the description, no further details will be given.

[0037] The device for making recycled asphalt mixture provided by the present invention adds a preheating kiln, a premixing tank and a miscible development and insulation bin, that is, the old asphalt mixture is first fully premixed with the asphalt regeneration agent in the premixing tank, so that the asphalt regeneration agent can effectively reduce the viscosity of the old asphalt to achieve the required appropriate viscosity. The addition of the asphalt regeneration agent can also soften the brittle old asphalt mixture, which is convenient for full dispersion, penetration and softening under the action of machinery and heating, and is convenient for subsequent uniform mixing with new asphalt and new aggregate. After the recycled asphalt mixture is stirred, it is heated and insulated in the miscible development and insulation bin for a period of time to restore the performance of the old asphalt mixture, and then it is stirred with the new asphalt, new aggregate and filler in the main mixing tank to promote diffusion and fusion between the old asphalt and the new asphalt, expand the contact area, and reduce the dosage of the asphalt regeneration agent, so as to improve the overall performance and reduce the phenomenon of oiling of the road surface after the construction of the recycled pavement is completed.

[0038] The use of two mixing tanks, a premixing tank and a main mixing tank, can greatly improve the mixing uniformity of the recycled asphalt mixture and reduce the possibility of segregation of the recycled asphalt mixture. At the same time, it can enable the regeneration agent, old asphalt and new asphalt to diffuse, penetrate and fuse with each other.

[0039] It is worth mentioning that the buffer bin used in the present invention serves as a buffer zone in the material transmission process, and can temporarily store the old asphalt mixture in the countercurrent drying drum from the upstream process, which helps to balance the production rates of the previous and subsequent processes and avoid material accumulation or insufficient supply problems caused by mismatched production rates. The old asphalt mixture needs to maintain a certain temperature during the transmission process to ensure its performance and processability. The buffer bin can adjust the temperature of the material to a certain extent to keep it within the appropriate processing temperature range. At the same time, during the transmission and storage of the old asphalt mixture, the buffer bin can reduce the stress concentration inside the old asphalt mixture and avoid the material from being broken or performance degradation due to uneven force.

[0040] The first metering bin can accurately measure the amount of old asphalt mixture entering the next process, which is crucial for controlling the proportion of the overall recycled asphalt mixture and ensuring the quality of the recycled pavement. Through precise metering, it can ensure that various materials are mixed according to the design requirements, thereby obtaining a recycled asphalt mixture with excellent performance.

[0041] The role of the second metering bin is similar to that of the first metering bin in the overall process.

[0042] It is worth mentioning that the insulation temperature in the finished product insulation bin is set between 150℃-160℃ for use in engineering construction, and it can also promote the fusion of recycled asphalt mixture during high-temperature insulation.

[0043] As a preferred embodiment of the present invention, a device for producing a recycled asphalt mixture provided by the present invention also includes a flue gas treatment system. The flue gas treatment system can be a plurality of dust removal bags or other devices, such as an activated carbon adsorber, etc. The dust removal bags are generally installed in the original drying drum.

[0044] The present invention also provides a method for preparing a recycled asphalt mixture, the brief steps of which are: S1: collecting the discarded old asphalt mixture, crushing and screening the old asphalt mixture into different particle sizes in the crushing and screening device, and then entering the electromagnetic preheating kiln after transition in the first cold material bin; S2: Preliminary mixing of new aggregates with different gradations and then transitioning through the second cold material bin before entering the primary drying drum; S3: Determine the dosage of asphalt regeneration agent according to the dosage and aging degree of old asphalt; S4: Determine the amount of new asphalt and filler; S5: preheating the old asphalt mixtures of different particle sizes in the electromagnetic preheating kiln at a preheating temperature of 40° C., and then feeding them into a countercurrent drying drum after preheating, and setting the countercurrent drying drum to a temperature of 165° C.; S6: conveying the dried old asphalt mixture to a premixing tank, adding an asphalt regeneration agent and stirring in the premixing tank; S7: after stirring in step S6, the mixture is transported to a miscible development and insulation bin and heated and insulated at a temperature of 160° C. to form an old asphalt mixture with restored performance; S8: The old asphalt mixture with restored performance formed in step S7 is transported to the main mixing tank, and new asphalt, new aggregate and filler are added to the main mixing tank, mixed and stirred to form a recycled asphalt mixture.

[0045] After step S4 and before step S5, it is necessary to perform quality inspection on old asphalt mixtures, new aggregates, new asphalt, fillers and asphalt regeneration agents of different particle sizes, and determine whether they meet national standards.

[0046] It is worth noting that the above national standard refers to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTGE20-2011), and the reference indicators include softening point, 5°C elongation, etc.

[0047] It is worth noting that in step S8, the mixed development is kept warm in the heat preservation chamber for a period of time, and the specific time varies according to the amount.

[0048] It is worth mentioning that when adding the regeneration agent in step S6, the regeneration agent needs to be metered, that is, a metering bin identical to the first metering bin needs to be configured, and the regeneration agent and the old asphalt mixture need to be metered and transported to the premixing tank at the same time. Similarly, when adding new asphalt, new aggregate and filler in step S8, the new asphalt, new aggregate and filler need to be metered separately, that is, a metering bin identical to the second metering bin needs to be configured, and the old asphalt mixture with restored performance, new asphalt, new aggregate and filler need to be metered and transported to the premixing tank at the same time.

[0049] It should be noted that the miscible development insulation chamber described in the present invention can accommodate a variety of substances or materials for mixing and reaction under specific conditions, and maintain a suitable temperature throughout the process to promote their development or changes. It is equipped with a high-precision temperature control device, which can monitor and adjust the temperature in the insulation chamber in real time to meet the needs of different processes. Its internal specific structure and form can be various, which are not specifically explained here.

[0050] In a method for preparing a recycled asphalt mixture provided by the invention, the old asphalt mixture is first fully pre-mixed with the asphalt regeneration agent in a pre-mixing tank, so that the asphalt regeneration agent can effectively reduce the viscosity of the old asphalt to achieve the desired appropriate viscosity. Preheating can reduce the moisture content. The addition of the asphalt regeneration agent can also soften the brittle old asphalt mixture, which is convenient for full dispersion under the action of machinery and heating, and for subsequent uniform mixing with new asphalt and new aggregate. After the recycled asphalt mixture is stirred, it is heated and insulated in a miscible development and insulation bin for a period of time to promote diffusion and fusion between the old asphalt and the new asphalt, expand the contact area, and reduce the dosage of the asphalt regeneration agent to improve the overall performance and reduce the phenomenon of oiling of the road surface after the construction of the recycled pavement is completed.

[0051] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A recycled asphalt mixture, characterized in that: include: 75-85 parts of old asphalt mix; 0.5-1 part new asphalt; 10-15 parts new aggregate; 2-4 servings of stuffing; 0.15-0.25 parts of asphalt rejuvenator.

2. The regenerated asphalt mixture according to claim 1, characterized in that: The old asphalt mixture comprises old asphalt and old aggregate, and the old asphalt comprises one or both of abandoned road petroleum asphalt and SBS modified asphalt.

3. The recycled asphalt mixture according to claim 1, characterized in that: The old aggregate includes one or more of diabase, limestone and basalt.

4. The regenerated asphalt mixture according to claim 1, 2 or 3, characterized in that: The new asphalt is No. 70 base petroleum asphalt.

5. The regenerated asphalt mixture according to claim 4, characterized in that: The new aggregate is one or both of limestone and basalt.

6. The regenerated asphalt mixture according to claim 5, characterized in that: The filler is limestone powder.

7. A device for producing recycled asphalt mixture as claimed in claim 6, characterized in that: It includes a main mixing tank for mixing and stirring the old asphalt mixture, new asphalt, new aggregate, filler and asphalt regeneration agent, wherein the upstream of the main mixing tank is respectively connected to a regenerated asphalt system, a new aggregate system, a new asphalt tank and a filler tank, and the downstream of the main mixing tank is connected to a finished product insulation bin; The regenerated asphalt system includes a crushing and screening device, a first cold material bin, an electromagnetic preheating kiln, a countercurrent drying drum, a buffer bin, a first metering bin, a premixing cylinder and a miscible development and insulation bin, which are connected in sequence from upstream to downstream. A regeneration agent feed bin is also connected upstream of the premixing cylinder.

8. The device for producing recycled asphalt mixture according to claim 7, characterized in that: The new aggregate system includes a second cold material bin, a raw drying drum, a screening storage bin and a second metering bin which are connected in sequence from upstream to downstream, and the second metering bin is connected to the upstream of the main mixing tank.

9. A method for preparing a recycled asphalt mixture, characterized in that: Using the production device according to any one of claims 7-8, the production method comprises the steps of: S1: collecting the discarded old asphalt mixture, crushing and screening the old asphalt mixture into different particle sizes in the crushing and screening device, and then entering the electromagnetic preheating kiln after transition in the first cold material bin; S2: Preliminary mixing of new aggregates with different gradations and then transitioning through the second cold material bin before entering the primary drying drum; S3: Determine the amount of asphalt regeneration agent according to the amount and aging degree of old asphalt; S4: Determine the amount of new asphalt and filler; S5: preheating the old asphalt mixture of different particle sizes in the electromagnetic preheating kiln at a preheating temperature of 40°C, and then feeding it into a countercurrent drying drum after preheating, and the countercurrent drying drum is set at a temperature of 165°C; S6: conveying the dried old asphalt mixture to a premixing tank, adding an asphalt regeneration agent and stirring in the premixing tank; S7: after stirring in step S6, the mixture is transported to a miscible development and heat preservation bin and heated at a temperature of 160°C to form an old asphalt mixture with restored performance; S8: The old asphalt mixture with restored performance formed in step S7 is transported to the main mixing tank, and new asphalt, new aggregate and filler are added to the main mixing tank, mixed and stirred to form a recycled asphalt mixture.

10. The method for producing recycled asphalt mixture according to claim 9, characterized in that: After step S4 and before step S5, it is necessary to perform quality inspection on old asphalt mixtures, new aggregates, new asphalt, fillers and asphalt regeneration agents of different particle sizes, and determine whether they meet national standards.

Images