Thermal regeneration old material heating temperature determination method and heating temperature determination system

Abstract

The invention provides a method and a system for determining the heating temperature of a thermal regeneration old material. The method for determining the heating temperature of the thermal regeneration old material comprises the following steps: heating more than one part of asphalt old material at different heating temperatures for preset time; recycling the heated old asphalt material to obtain old asphalt samples at different heating temperatures; carrying out multiple stress creep recovery tests on the old asphalt samples at different heating temperatures, and carrying out significance F test method analysis on test results to obtain an old asphalt material heating design temperature upper limit; preparing a standard Marshall test piece by using the heated old asphalt material, and performing high-temperature, low-temperature and fatigue performance tests on the standard Marshall test piece to obtain the lower limit of the heating design temperature of the old asphalt material; and calculating the average value of the upper limit of the heating design temperature of the old asphalt material and the lower limit of the heating design temperature of the old asphalt material, and taking the average value as the heating temperature of the thermal regeneration old material. The method can provide theoretical support for effective utilization of old materials.

Description

Technical Field

[0001] The present invention relates to the technical field of asphalt mixture recycling, and in particular to a method and a system for determining the heating temperature of hot recycled waste materials. Background Art

[0002] Central Plant Hot Recycling (CPHR) of waste asphalt pavement materials is an environmentally friendly and economical solution that aims to reduce resource consumption and environmental impact by reusing waste asphalt materials (RAP). However, this technology faces an obvious challenge - the limited proportion of old materials. In conventional operations, the blending ratio of RAP usually does not exceed 30%, mainly because the performance of high-mix recycled mixtures often cannot meet engineering requirements, especially in terms of low-temperature performance. The action plan advocates strengthening the large-scale, large-scale and high-value utilization of bulk solid waste to promote resource recycling and emission reduction. Therefore, there is an urgent need to develop innovative processes and design methods that can both ensure pavement performance and increase the blending ratio of old materials. Summary of the invention

[0003] The present invention provides a method and a system for determining the heating temperature of hot recycled waste materials, which are used to solve the problem of determining the heating temperature of hot recycled waste materials in the prior art, and to provide technical support for the application of plant-mixed hot recycled asphalt mixtures with high waste material content.

[0004] The present invention provides a method for determining the heating temperature of thermally regenerated waste materials, which comprises the following steps:

[0005] More than one portion of used asphalt material is placed at different heating temperatures and heated for a preset time;

[0006] The heated old asphalt material is recycled to obtain old asphalt samples at different heating temperatures;

[0007] Multiple stress creep recovery tests were conducted on old asphalt samples at different heating temperatures, and the test results were analyzed using the significance F test method to obtain the upper limit of the heating design temperature of old asphalt materials.

[0008] The heated old asphalt material is used to prepare standard Marshall specimens at different heating temperatures, and the standard Marshall specimens are tested for high temperature, low temperature and fatigue properties to obtain the lower limit of the heating design temperature of the old asphalt material;

[0009] Calculate the average value of the upper and lower design temperatures for heating of used asphalt materials, and use the average value as the heating temperature for hot recycled materials.

[0010] According to the method for determining the heating temperature of hot regenerated waste materials provided by the present invention, the process of recovering the heated waste asphalt materials to obtain waste asphalt samples at different heating temperatures is as follows:

[0011] A trichloroethylene extraction device is used to separate the old asphalt on the surface of the heated old asphalt material to obtain a mixed liquid of trichloroethylene and old asphalt;

[0012] The clean old asphalt samples were recovered from the mixture of trichloroethylene and old asphalt at different heating temperatures using the Absen asphalt recovery device.

[0013] Furthermore, the process of obtaining the upper limit of the design temperature for heating the asphalt waste material is as follows:

[0014] The dynamic shear rheometer DSR was used to conduct multiple stress creep recovery tests on old asphalt samples at different heating temperatures, and the irrecoverable creep compliance results of old asphalt at different heating temperatures were obtained.

[0015] The irreversible creep compliance results were analyzed by the significance F test method to obtain the temperature corresponding to the significant decrease in the results at different heating temperatures. The heating temperature at the temperature inflection point was used as the upper limit of the design temperature for heating of used asphalt materials.

[0016] Furthermore, the process of obtaining the lower limit of the design temperature for heating the asphalt waste material is as follows:

[0017] The heated old asphalt material, new aggregate, new asphalt and regeneration agent are mixed in a preset proportion to obtain a recycled mixture;

[0018] The recycled mixture was molded by compaction method to obtain standard Marshall specimens at different heating temperatures.

[0019] High temperature, low temperature and fatigue performance tests were carried out on standard Marshall specimens at different heating temperatures, and the lower limit of the design temperature for heating of used asphalt materials was obtained by backcalculating based on the standard limits of high temperature performance, low temperature performance and fatigue performance.

[0020] Furthermore, the process of back-calculating the lower limit of the design temperature for heating of used asphalt materials according to the standard limit of high temperature performance, the standard limit of low temperature performance and the standard limit of fatigue performance is as follows:

[0021] Establish the road performance nomogram of standard Marshall specimens under the combination of heating temperature and blending ratio of asphalt waste material;

[0022] Based on the designed traffic volume, climate and environmental data and the designed structural layer information, the high temperature, low temperature and fatigue performance indicators required for the design are obtained;

[0023] The lower limit of the design temperature for heating old asphalt materials is obtained based on the high temperature, low temperature and fatigue performance indicators required by the design.

[0024] Furthermore, based on the road structure layer and the meteorological and traffic data, the high temperature, low temperature and fatigue performance indicators required for the design are obtained as follows:

[0025] In terms of high temperature performance, the dynamic stability of the standard Marshall specimen must be greater than 5000 times / mm; in terms of low temperature performance, the low temperature fracture energy of the standard Marshall specimen must be greater than 1075KJ / m 2 In terms of fatigue performance, the fatigue life of the standard Marshall specimen is greater than or equal to 107913 times.

[0026] Furthermore, the heating temperature of the hot recycled waste material is the average of the upper design temperature of the heating of the asphalt waste material and the lower design temperature of the heating of the asphalt waste material;

[0027] T mean =(T1+T2) / 2,

[0028] Where, T mean Represents the average value, T1 represents the upper limit of the design temperature for heating of used asphalt materials, and T2 represents the lower limit of the design temperature for heating of used asphalt materials.

[0029] The present invention also provides a system for determining the heating temperature of thermally regenerated waste materials using any of the above-mentioned methods for determining the heating temperature of thermally regenerated waste materials, which comprises a heating device, a recovery device, a test analysis device, a testing device and a calculation device;

[0030] The heating device is used to heat the asphalt waste material for a preset time at different heating temperatures;

[0031] The recycling device is used to recycle the heated old asphalt material to obtain old asphalt samples at different heating temperatures;

[0032] The test analysis device is used to perform multiple stress creep recovery tests on old asphalt samples at different heating temperatures, and analyze the test results using a significant F test method to obtain the upper limit of the heating design temperature of the old asphalt material;

[0033] The testing device is used to prepare standard Marshall specimens at different heating temperatures based on the heated old asphalt material, and to perform high temperature, low temperature and fatigue performance tests on the standard Marshall specimens to obtain the lower limit of the heating design temperature of the old asphalt material;

[0034] The calculation device is used to calculate the average value of the upper limit of the heating design temperature of the asphalt waste material and the lower limit of the heating design temperature of the asphalt waste material, and use the average value as the heating temperature of the hot recycled waste material.

[0035] The method for determining the heating temperature of hot recycled materials provided by the present invention performs multiple stress creep recovery tests on old asphalt samples at different heating temperatures, and analyzes the test results by using the significance F test method to obtain the upper limit of the heating design temperature of the old asphalt materials; standard Marshall specimens at different heating temperatures are prepared using the heated old asphalt materials, and high temperature, low temperature and fatigue performance tests are performed on the standard Marshall specimens to obtain the lower limit of the heating design temperature of the old asphalt materials; the average value of the upper limit of the heating design temperature of the old asphalt materials and the lower limit of the heating design temperature of the old asphalt materials are calculated, and the average value is used as the heating temperature of the hot recycled materials; the present invention can scientifically and reasonably determine the heating temperature of the hot recycled materials, can effectively prevent the secondary aging problem of the old asphalt, and can also solve the technical problem that the road performance of the hot recycled asphalt mixture mixed in the factory with a high amount of old materials is difficult to meet the requirements of the specifications, and provide theoretical support for improving the effective utilization of old materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technical workers in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 It is a flow chart of the method for determining the heating temperature of thermally regenerated waste materials provided by the present invention;

[0038] Figure 2 It is the MSCR (Multiple Stress Creep and Recovery) test results of asphalt in RAP at different heating temperatures;

[0039] Figure 3 It is a nomogram of the influence of the heating temperature of the old material on the road performance of the prepared standard Marshall specimen under different old material contents; wherein, Figure (a) is a nomogram of the road performance of the Marshall specimen obtained by drawing the high temperature performance of the standard Marshall specimen under different old material contents; Figure (b) is a nomogram of the road performance of the standard Marshall specimen obtained by drawing the low temperature performance of the standard Marshall specimen under different old material contents; Figure (c) is a nomogram of the road performance of the standard Marshall specimen obtained by drawing the fatigue performance of the standard Marshall specimen under different old material contents;

[0040] Figure 4 This is a schematic diagram of the results of determining the lower limit of the heating temperature of the old material at different old material dosages based on performance;

[0041] Figure 5 It is a structural block diagram of the system for determining the heating temperature of thermally regenerated waste materials provided by the present invention.

[0042] Description of reference numerals:

[0043] 10. Heating device; 20. Recovery device; 30. Test and analysis device; 40. Testing device; 50. Calculation device. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] In the existing technology, one of the main reasons that limits the increase in the mixing rate of old materials is the insufficient preheating temperature of the old materials. According to the "Technical Specifications for Highway Asphalt Pavement Regeneration", the recommended heating temperature range for recycled materials in asphalt mixtures is 110℃~130℃, but in actual construction, affected by various factors such as equipment capacity, energy efficiency and operating conditions, the heating temperature of recycled materials is often difficult to reach the ideal level. The low preheating temperature affects the performance recovery of old asphalt materials, thereby restricting the use ratio of RAP in recycled mixtures.

[0046] In addition, the existing design method of recycled mixtures relies too much on volumetric indicators and lacks sufficient consideration of performance-oriented design. This method ignores the differences in the behavior of recycled mixtures under different temperature conditions, especially that high-temperature performance is usually excessive, while low-temperature performance is often insufficient, which poses a challenge to ensuring the long-term stability and durability of recycled pavement.

[0047] In order to solve these problems, future research and development will focus on optimizing preheating technology and design methods. On the one hand, the preheating temperature of RAP is increased to ensure that the asphalt in the old material can be effectively softened and restore its original adhesion and fluidity. On the other hand, a performance-based design method is developed, focusing on improving the overall performance of recycled mixtures under actual use conditions, especially crack resistance and durability under low temperature conditions. Through these improvement measures, not only can the blending rate of RAP be increased, but also the recycled pavement materials can be ensured to perform well under various climates and traffic loads, thereby promoting the development of green and low-carbon transportation infrastructure.

[0048] Combine the following Figure 1 The invention provides a method for determining the heating temperature of thermally regenerated waste materials, which is designed based on aging and performance balance.

[0049] like Figure 1 As shown, the method for determining the heating temperature of hot recycled waste materials provided by the present invention comprises the following steps:

[0050] S1. Place more than one portion of used asphalt materials at different heating temperatures and heat for a preset time;

[0051] Specifically, the asphalt waste material can be obtained by recycling the waste asphalt material of the road surface, and the obtained asphalt waste material is dried. Then, more than one portion of the dried asphalt waste material is placed in an oven with different heating temperatures for heating, and the heating time can be 2 hours. It is understandable that the corresponding heating time can also be set according to the process requirements.

[0052] S2. Recovering the heated old asphalt material to obtain clean old asphalt samples at different heating temperatures;

[0053] Specifically, a trichloroethylene extraction device can be used to separate the old asphalt on the surface of the heated old asphalt material to obtain a mixture of trichloroethylene and old asphalt. Then, the Absen asphalt recovery device is used to recover clean old asphalt samples at different heating temperatures from the mixture of trichloroethylene and old asphalt.

[0054] S3. Conduct multiple stress creep recovery tests on clean old asphalt samples at different heating temperatures, and analyze the test results using the significance F test method to obtain the upper limit T1 of the heating design temperature of old asphalt materials;

[0055] Specifically, the DSR (Dynamic Shear Rheometer) was used to conduct multiple stress creep recovery tests on the old asphalt samples at different heating temperatures to obtain the irrecoverable creep compliance J of the old asphalt at different heating temperatures. nr result.

[0056] The irreversible creep compliance J nr The results were analyzed using the significance F test method to obtain the temperature corresponding to the significant decrease in the results at different heating temperatures (i.e., significant secondary aging of the old asphalt). The heating temperature that is less than this temperature and has the smallest difference with this temperature is taken as the upper limit T1 of the heating design temperature for the old asphalt.

[0057] S4. Using the heated old asphalt material to prepare standard Marshall specimens at different heating temperatures, and conducting high temperature, low temperature and fatigue performance tests on the standard Marshall specimens to obtain the lower limit T2 of the heating design temperature of the old asphalt material;

[0058] Specifically, the old asphalt material heated in step S1, new aggregate, new asphalt and regeneration agent are mixed according to a preset ratio to obtain a recycled mixture;

[0059] The recycled mixture was molded by compaction method to obtain standard Marshall specimens at different heating temperatures.

[0060] High temperature, low temperature and fatigue performance tests were carried out on standard Marshall specimens at different heating temperatures, and the lower limit T2 of the design temperature for heating of old asphalt materials was obtained by backcalculating based on the standard limit values ​​of high temperature performance (i.e. rutting dynamic stability index), low temperature performance (i.e. low temperature fracture energy index) and fatigue performance (i.e. splitting fatigue life index).

[0061] S5. Calculate the average value of the upper limit T1 of the heating design temperature of the asphalt waste material and the lower limit T2 of the heating design temperature of the asphalt waste material, and use the average value as the heating temperature of the hot recycled waste material.

[0062] Specifically, the average value of the upper limit T1 of the heating design temperature of the old asphalt material and the lower limit T2 of the heating design temperature of the old asphalt material is: mean =(T1+T2) / 2.

[0063] In the above step S4, the specific process of back-calculating the lower limit T2 of the heating design temperature of the old asphalt material according to the standard limit of high temperature performance, the standard limit of low temperature performance and the standard limit of fatigue performance is as follows:

[0064] S41. Establish a nomogram of the road performance of standard Marshall specimens at different combinations of heating temperature and blending ratio of old asphalt.

[0065] S42. Based on the design traffic volume, climate and environmental data and the design structural layer information, the high temperature, low temperature and fatigue performance indicators required for the design are obtained.

[0066] S43. Obtain the lower limit T2 of the design temperature for heating the old asphalt material based on the high temperature, low temperature and fatigue performance indicators required by the design.

[0067] In order to facilitate a clearer and more intuitive understanding of the method for determining the heating temperature of thermally regenerated waste materials provided by the present invention, a specific embodiment is used to illustrate it below.

[0068] Taking a first-class highway in Shanxi Province as an example, the application of the method for determining the heating temperature of hot recycled waste materials provided by the present invention is specifically introduced.

[0069] In this application case, recycled highway asphalt pavement (RAP) materials that have been in service for more than 10 years are used, combined with new high-performance SBS modified asphalt and new aggregates to improve the durability of the road surface. Among them, the new aggregates are divided into four grades according to different particle sizes, and the material selection of each grade takes into account its unique mechanical properties:

[0070] The new aggregate with a particle size of 0 to 3 mm is limestone. This type of fine particles is suitable for filling gaps and enhancing the density of the mixture.

[0071] Limestone was also selected as the new aggregate with a particle size of 3 to 5 mm. This range of particles can provide additional structural stability while maintaining good gradation.

[0072] The new aggregate with a particle size of 5 to 10 mm is made of basalt with a higher hardness. This medium-sized particle size can significantly increase the compressive strength and wear resistance of the mixture.

[0073] Basalt is also used as new aggregate with a particle size of 10 to 15 mm. Large particles of basalt can act as a skeleton in the mixture, enhancing the stability and bearing capacity of the overall structure.

[0074] The following method is used to prepare the high-dosage factory-mixed hot standard Marshall specimen, and the specific process is as follows:

[0075] S11, recycling waste asphalt materials from road surfaces to obtain old asphalt materials, drying the obtained old asphalt materials, placing the dried old asphalt materials in ovens with different heating temperatures for heating, and the heating time can be set to 2 hours.

[0076] S22. Use a trichloroethylene extraction device to separate the old asphalt on the surface of the heated old asphalt material to obtain a mixture of trichloroethylene and old asphalt; then use the Absen asphalt recovery device to recover clean old asphalt samples at different heating temperatures from the mixture of trichloroethylene and old asphalt.

[0077] S33, DSR was used to conduct multiple stress creep recovery tests on old asphalt samples at different heating temperatures to obtain the irrecoverable creep compliance J of old asphalt at different heating temperatures. nr Results: The test temperatures for the multiple stress creep recovery tests were set at 58°C, 64°C, 70°C and 76°C.

[0078] The irreversible creep compliance J nr The results were analyzed by the significant F test method. Figure 2 And as shown in Table 1.

[0079] Depend on Figure 2 It can be seen that at the four test temperatures of 58°C, 64°C, 70°C and 76°C, when the heating temperature is less than or equal to 160°C, the irrecoverable creep compliance J of the recovered asphalt in RAP under 0.1 kPa and 3.2 kPa stress is nr However, when the heating temperature was 160℃~180℃, the J of the recovered asphalt in RAP nr0.1 and J nr3.2 Taking the test temperature of 58℃ as an example, compared with the unheated RAP material, the J of the recovered asphalt in the RAP after heating at 180℃ is nr0.1 and J nr3.2Relevant studies have shown that the irreversible creep compliance J of asphalt after aging nr Therefore, it is reasonable to believe that when the heating temperature of RAP material is less than or equal to 160℃, increasing the heating temperature of RAP will not cause secondary aging of old asphalt, but when the heating temperature reaches 180℃, the old asphalt will experience a certain degree of secondary aging.

[0080] Table 1 Calculation results of test statistics for F test

[0081]

[0082]

[0083] In Table 1, J nr0.1 represents the irreversible creep compliance J obtained during 10 creep recovery cycles under a stress level of 0.1 kPa nr The average value of J nr3.2 represents the irreversible creep compliance J obtained during 10 creep recovery cycles under a stress level of 3.2 kPa nr The average value of R 0.1 It represents the average value of the creep recovery rate R obtained from 10 creep recovery cycles under the stress level of 0.1 kPa. 3.2 It represents the average value of the creep recovery rate R obtained from 10 creep recovery cycles under a stress level of 3.2 kPa.

[0084] It can be concluded from Table 1 that at the 0.05 significance level, it can be considered that the irreversible creep compliance J of the recovered asphalt in RAP at the six heating temperatures under 0.1 kPa and 3.2 kPa stress is nr At the 0.05 significance level, it can be considered that when the heating temperature is less than or equal to 160°C, the recovery rate and irrecoverable creep compliance J of the recovered asphalt in RAP under 0.1 kPa and 3.2 kPa stress after heating at different heating temperatures are different. nr That is, when the RAP heating temperature is less than or equal to 160°C, increasing the RAP heating temperature will not cause secondary aging of the old asphalt, but when the heating temperature exceeds the 160°C threshold and reaches 180°C, it will cause secondary aging of the old asphalt at this heating temperature.

[0085] Therefore, in this embodiment, 160°C is used as the upper limit T1 of the design temperature for heating the scrap material.

[0086] S44. Obtain standard Marshall specimens at different heating temperatures based on the heated old asphalt material; test the high temperature performance, low temperature performance and fatigue performance of the standard Marshall specimens at different old material dosages, such as Figure 3As shown in the figure, the road performance nomogram of the standard Marshall specimen is drawn; based on the designed traffic volume, climate and environmental data and the designed structural layer information, the performance design target requirements of the standard Marshall specimen are obtained.

[0087] Among them, based on the road structure layer and meteorological and traffic data, the indoor performance target value required for the design is:

[0088] In terms of high temperature performance, the dynamic stability of the standard Marshall specimen must be greater than 5000 times / mm; in terms of low temperature performance, the low temperature fracture energy of the standard Marshall specimen must be greater than 1075KJ / m 2 In terms of fatigue performance, the fatigue life of the standard Marshall specimen is greater than or equal to 107913 times.

[0089] The final design combination should meet the design target requirements of high temperature performance, low temperature performance and fatigue performance at the same time, according to the performance design target requirements of the standard Marshall specimen, such as Figure 3 As shown, find out the lower limit T2 of the design temperature for heating of old materials corresponding to different old material dosages in the nomogram.

[0090] like Figure 4 As shown, the performance nomogram of high temperature performance, low temperature performance and fatigue performance is integrated. It can be seen that the combination with better high temperature performance is mainly distributed in the upper right part of the old material heating temperature image under different old material dosages; the combination with better low temperature performance is mainly distributed in the lower left area and upper right corner area of ​​the old material heating temperature image under different old material dosages; the combination with better fatigue performance is mainly distributed in the upper right corner area of ​​the old material heating temperature image under different old material dosages. Among them, the horizontal axis of the old material heating temperature image under different old material dosages represents the old material dosage, and the vertical axis represents the old material heating temperature.

[0091] It is not difficult to see that it is entirely possible to Figure 4 In the image of the heating temperature of the old material under different old material dosages, a region with the best comprehensive performance is selected, and the way to achieve this is to regenerate the old material by high-temperature heating. In this region, the heating temperature of the old material reaches 150-160°C, the old material mixing rate can reach 70%-80%, and the high temperature performance, low temperature performance, and fatigue performance all reach a good level, achieving the improvement of the performance of the standard Marshall specimen and the balance of performance and old material dosage.

[0092] Therefore, in this embodiment, the lower limit T2 of the design temperature for heating the old material corresponding to 80% of the old material content is 150°C.

[0093] S55. Calculate the average value T of the upper and lower limits of the design temperature for heating the old material mean :

[0094] T mean=(T1+T2) / 2,

[0095] And the average value T mean As the heating temperature of thermally recycled waste materials.

[0096] In this embodiment, at a content of 80% of old materials, the upper limit T1 of the design heating temperature of the old materials to ensure that no secondary aging of the old asphalt is caused is 160°C, and the lower limit T2 of the design heating temperature of the old materials to meet the high temperature performance, low temperature performance and fatigue performance is 150°C. Therefore, in this embodiment, the optimal heating temperature of the thermally regenerated old materials is (150+160) / 2=155°C.

[0097] It can be seen from the above embodiments that the method for determining the heating temperature of hot recycled materials based on aging and performance balance proposed by the present invention can effectively prevent the secondary aging problem of old asphalt, and at the same time solve the technical problem that the road performance of hot recycled asphalt mixture mixed with a high amount of old materials is difficult to meet the regulatory requirements, providing theoretical support for improving the effective utilization of old materials.

[0098] In an exemplary embodiment, if Figure 5 As shown, based on the method for determining the heating temperature of thermally recycled waste materials provided by the present invention, the present invention also provides a system for determining the heating temperature of thermally recycled waste materials, which includes a heating device 10, a recovery device 20, a test analysis device 30, a testing device 40 and a computing device 50.

[0099] A heating device 10 is used to heat the asphalt waste material at different heating temperatures for a preset time;

[0100] The recovery device 20 is used to recover the heated old asphalt material to obtain clean old asphalt samples at different heating temperatures;

[0101] The test analysis device 30 is used to perform multiple stress creep recovery tests on clean old asphalt samples at different heating temperatures, and analyze the test results using the significance F test method to obtain the upper limit T1 of the heating design temperature of the old asphalt material;

[0102] The testing device 40 is used to obtain standard Marshall specimens at different heating temperatures according to the heated old asphalt material, and to perform high temperature, low temperature and fatigue performance tests on the standard Marshall specimens to obtain the lower limit T2 of the heating design temperature of the old asphalt material;

[0103] The calculation device 50 is used to calculate the average value of the upper limit T1 of the heating design temperature of the asphalt waste material and the lower limit T2 of the heating design temperature of the asphalt waste material, and use the average value as the heating temperature of the hot recycled waste material.

[0104] It should be noted that the system for determining the heating temperature of thermally recycled waste materials provided in the above-mentioned embodiment and the method for determining the heating temperature of thermally recycled waste materials provided in the above-mentioned embodiment belong to the same concept, and the specific implementation process is detailed in the method embodiment, which will not be repeated here.

[0105] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technical workers in this field can understand and implement it without paying creative labor.

[0106] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, ordinary technical workers in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for determining the heating temperature of thermally regenerated waste materials, characterized in that: The following steps are involved: More than one portion of used asphalt material is placed at different heating temperatures and heated for a preset time; The heated old asphalt material is recycled to obtain old asphalt samples at different heating temperatures; Multiple stress creep recovery tests were conducted on old asphalt samples at different heating temperatures, and the test results were analyzed using the significance F test method to obtain the upper limit of the heating design temperature of old asphalt materials. The heated old asphalt material is used to prepare standard Marshall specimens at different heating temperatures, and the standard Marshall specimens are tested for high temperature, low temperature and fatigue properties to obtain the lower limit of the heating design temperature of the old asphalt material; Calculate the average value of the upper and lower design temperatures for heating of used asphalt materials, and use the average value as the heating temperature for hot recycled materials.

2. The method for determining the heating temperature of thermally regenerated waste materials according to claim 1, characterized in that: The process of recycling the heated old asphalt material to obtain old asphalt samples at different heating temperatures is as follows: A trichloroethylene extraction device is used to separate the old asphalt on the surface of the heated old asphalt material to obtain a mixed liquid of trichloroethylene and old asphalt; The clean old asphalt samples were recovered from the mixture of trichloroethylene and old asphalt at different heating temperatures using the Absen asphalt recovery device.

3. The method for determining the heating temperature of thermally regenerated waste materials according to claim 2, characterized in that: The process of obtaining the upper limit of the design temperature for heating the old asphalt material is as follows: The dynamic shear rheometer DSR was used to conduct multiple stress creep recovery tests on old asphalt samples at different heating temperatures, and the irrecoverable creep compliance results of old asphalt at different heating temperatures were obtained. The irreversible creep compliance results were analyzed by the significance F test method to obtain the temperature corresponding to the significant decrease in the results at different heating temperatures. The heating temperature at the temperature inflection point was used as the upper limit of the design temperature for heating of used asphalt materials.

4. The method for determining the heating temperature of thermally regenerated waste materials according to claim 3, characterized in that: The process of obtaining the lower limit of the design temperature for heating the old asphalt material is as follows: The heated old asphalt material, new aggregate, new asphalt and regeneration agent are mixed in a preset proportion to obtain a recycled mixture; The recycled mixture was molded by compaction method to obtain standard Marshall specimens at different heating temperatures. High temperature, low temperature and fatigue performance tests were carried out on standard Marshall specimens at different heating temperatures, and the lower limit of the design temperature for heating of used asphalt materials was obtained by backcalculating based on the standard limits of high temperature performance, low temperature performance and fatigue performance.

5. The method for determining the heating temperature of thermally regenerated waste materials according to claim 4, characterized in that: The process of back-calculating the lower limit of the design temperature for heating of used asphalt materials based on the standard limit of high temperature performance, the standard limit of low temperature performance and the standard limit of fatigue performance is as follows: Establish the road performance nomogram of standard Marshall specimens under the combination of heating temperature and blending ratio of asphalt waste material; Based on the designed traffic volume, climate and environmental data and the designed structural layer information, the high temperature, low temperature and fatigue performance indicators required for the design are obtained; The lower limit of the design temperature for heating old asphalt materials is obtained based on the high temperature, low temperature and fatigue performance indicators required by the design.

6. The method for determining the heating temperature of thermally regenerated waste materials according to claim 5, characterized in that: Based on the road structure layer and meteorological and traffic data, the high temperature, low temperature and fatigue performance indicators required for the design are obtained as follows: In terms of high temperature performance, the dynamic stability of the standard Marshall specimen must be greater than 5000 times / mm; in terms of low temperature performance, the low temperature fracture energy of the standard Marshall specimen must be greater than 1075KJ / m 2 In terms of fatigue performance, the fatigue life of the standard Marshall specimen is greater than or equal to 107913 times.

7. The method for determining the heating temperature of thermally regenerated waste materials according to claim 4, characterized in that: The heating temperature of the hot recycled waste material is the average of the upper design temperature of the asphalt waste material heating and the lower design temperature of the asphalt waste material heating; T mean =(T1+T2) / 2, Where, T mean Represents the average value, T1 represents the upper limit of the design temperature for heating of used asphalt materials, and T1 represents the lower limit of the design temperature for heating of used asphalt materials.

8. A system for determining the heating temperature of hot recycled waste material using the method for determining the heating temperature of hot recycled waste material according to any one of claims 1 to 7, characterized in that: It includes heating device, recovery device, test and analysis device, testing device and calculation device; The heating device is used to heat the asphalt waste material for a preset time at different heating temperatures; The recycling device is used to recycle the heated old asphalt material to obtain old asphalt samples at different heating temperatures; The test analysis device is used to perform multiple stress creep recovery tests on old asphalt samples at different heating temperatures, and analyze the test results using a significant F test method to obtain the upper limit of the heating design temperature of the old asphalt material; The testing device is used to prepare standard Marshall specimens at different heating temperatures based on the heated old asphalt material, and to perform high temperature, low temperature and fatigue performance tests on the standard Marshall specimens to obtain the lower limit of the heating design temperature of the old asphalt material; The calculation device is used to calculate the average value of the upper limit of the heating design temperature of the asphalt waste material and the lower limit of the heating design temperature of the asphalt waste material, and use the average value as the heating temperature of the hot recycled waste material.

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