A method and device for evaluating storage stability of rubber asphalt

Abstract

The present invention discloses a method and device for evaluating the storage stability of rubber asphalt, and relates to the technical field of road engineering. The method disclosed in the present invention is to heat the rubber asphalt to be tested to a fully fluid state, stand it, and divide it into upper, middle and lower rubber asphalt samples; then add a normal temperature modifier and stir and mix it, cool it to room temperature, adjust it to the Brookfield rotation viscosity to reach the preset requirements, and obtain the original sample at room temperature, the upper sample at room temperature, the middle sample at room temperature and the lower sample at room temperature; then measure the particle size of the original sample at room temperature, the upper sample at room temperature, the middle sample at room temperature and the lower sample at room temperature, calculate the percentage of the particle size in the range of 0.1-1.1N, calculate the segregation index according to the proportion, and evaluate the storage stability. The present invention also provides a corresponding test device. Compared with the existing method, the method provided by the present invention is less disturbed by human factors and external factors, has higher test accuracy, and can more accurately and truly reflect the storage stability of rubber asphalt.

Description

Technical Field

[0001] The invention relates to the technical field of road engineering, and in particular to a method and a device for evaluating the storage stability of rubber asphalt. Background Art

[0002] Rubber asphalt is a modified asphalt binder material with excellent properties such as high temperature stability, low temperature flexibility, anti-aging, anti-fatigue, and water damage resistance. It is an ideal environmentally friendly pavement material and is widely used in actual road and bridge projects as the main material for the stress absorption layer and surface layer in road structures. During the processing of rubber asphalt, some rubber particles are not completely melted, which makes it easy for rubber asphalt to segregate during transportation and storage, and the performance of rubber asphalt after segregation is severely attenuated. Therefore, in order to ensure the performance of rubber asphalt and its mixture, it is necessary to evaluate the storage stability of rubber asphalt.

[0003] The current method for evaluating the storage stability of rubber asphalt is mainly to test macroscopic indicators such as softening point. Compared with the range of performance indicators after rubber asphalt separation, the test results of this type of test method have large human errors, which affects the accuracy of the evaluation. In order to further comprehensively and accurately evaluate the storage stability of rubber asphalt, it is necessary to develop a more accurate storage stability evaluation method for rubber asphalt. Summary of the invention

[0004] In view of the above shortcomings of the prior art, the present invention provides a method and device for evaluating the storage stability of rubber asphalt. The separation of rubber asphalt is mainly the separation of rubber powder modifier. The particle size composition of rubber asphalt before and after separation changes. Therefore, the present application evaluates the storage stability of rubber asphalt by analyzing the particle composition in rubber asphalt. It is specifically achieved by the following technology.

[0005] A method for evaluating the storage stability of rubber asphalt comprises the following steps:

[0006] Take the rubber asphalt to be tested, heat it to a completely fluid state, place it in a cylindrical container and keep it in a completely fluid state for standing, and divide the rubber asphalt after standing into upper, middle and lower rubber asphalt samples;

[0007] Take a rubber asphalt sample that is in a completely fluid state and has not been left to stand, add a room temperature modifier, stir and mix, and cool to room temperature until the Brookfield rotation viscosity reaches the preset requirement;

[0008] The upper, middle and lower rubber asphalt samples were treated in the same way to obtain the original sample at room temperature, the upper sample at room temperature, the middle sample at room temperature and the lower sample at room temperature respectively;

[0009] The particle sizes of the original sample at room temperature, the upper sample at room temperature, the middle sample at room temperature and the lower sample at room temperature were measured respectively, and the percentage of the particle size of each rubber asphalt sample in the range of 0.1-1.1N was calculated respectively, which were recorded as P0, P 上 , P 中 and P 下 ; Wherein, N is the particle size of the original rubber powder used to prepare rubber-modified asphalt;

[0010] The segregation index V is calculated according to the following formula, and the storage stability of the rubber asphalt to be tested is evaluated according to the segregation index:

[0011]

[0012] The smaller the segregation index, the smaller the storage stability grade of rubber asphalt, the better the storage stability, and the better the anti-segregation performance.

[0013] The existing methods for evaluating the storage stability of rubber asphalt are to first place the rubber asphalt in a static layer and then conduct a comprehensive evaluation on the rubber asphalt in different parts. However, some of these methods use the measured density difference as the evaluation basis, some use the particle size distribution range and asphalt frequency curve of the rubber asphalt in different parts as the evaluation basis based on image processing, some use the number of asphalt in different parts obtained by software simulation based on the particle size frequency distribution as the evaluation basis, and some combine the above evaluation methods to judge the storage stability. These methods all have their own problems to a greater or lesser extent. For example, the density difference between rubber powder and asphalt is not significant, and the density difference as the evaluation basis is not suitable for the stability evaluation of rubber asphalt; the particle size distribution range and asphalt frequency curve based on image processing are greatly affected by human factors and external factors such as image sample differences, image processing processes and methods, and the number of asphalt simulated by software is also affected by factors such as the initial sample and different software simulation processes and precision. In summary, the interference of human factors and external factors in the above existing methods will have a great impact on the test results and reduce the test accuracy.

[0014] Different from this, in the method for evaluating the storage stability of rubber asphalt provided by the present invention, the rubber asphalt is heated to a fully fluid state and then left to stand for a period of time to be divided into three layers of samples: upper, middle and lower; then the particle size distribution of the upper, middle and lower samples is measured respectively, and the percentage of particle size in the range of 0.1-1.1N is used as the evaluation standard to calculate the segregation index and obtain the storage stability of the rubber asphalt to be tested. This method can solve the problems existing in the above existing methods, such as sample differences, different software processing processes and precision, and other human factors and external factors that interfere greatly with the test results.

[0015] In rubber asphalt, the rubber powder is not fully melted with the matrix asphalt, and some of the rubber powder is in the form of particles in the rubber asphalt. The segregation of rubber asphalt is mainly manifested as the segregation of rubber powder particles. The more serious the segregation of rubber asphalt, the more agglomeration and sedimentation of rubber powder particles, and the greater the difference in particle size distribution of rubber asphalt in different layers.

[0016] Conventional rubber asphalt is in a solid state at room temperature. The rubber asphalt is prepared into a liquid state at room temperature. The particle size composition of the rubber asphalt can be analyzed at room temperature using particle size analysis equipment such as a laser particle size analyzer. Although the method provided by the present invention uses particle size as the source of evaluation data, the source and processing method of the particle size data are significantly different. This method uses a laser particle size analyzer to directly test the asphalt particle size composition in the rubber asphalt without too many intermediate processes, thus avoiding the accumulated errors and interferences of intermediate processes such as image recognition and software analysis in previous methods. In addition, the laser particle size analyzer is based on laser scattering technology, and the instrument itself has high test accuracy, and the particle size measurement results are more accurate. The present invention selects a particle size in a specific range of 0.1-1.1N as the evaluation basis, and uses a specific calculation formula to obtain the segregation index V. The method for obtaining particle size data and the data processing method are the technical key of the present invention. After measuring a large number of different types of rubber asphalt samples used for roads and bridges, it was found that the evaluation method of the present invention can more accurately evaluate the true storage stability of rubber asphalt samples. If more links are added to the particle size test process, or the selection range of the particle size ratio is expanded, reduced or changed during data processing, or other calculation formulas are used to calculate the segregation index V, the evaluation results obtained will have more or less errors from the true storage stability of rubber asphalt.

[0017] In the present invention, the role of adding the room temperature modifier is to prepare the rubber asphalt into a flowable state at room temperature.

[0018] Furthermore, the rubber asphalt to be tested is heated to a fully fluid state at 150-170° C. and allowed to stand for 1-12 hours.

[0019] Furthermore, the rubber asphalt to be tested was heated to a fully fluid state at 165°C and allowed to stand for 6 hours.

[0020] In the present invention, the rubber asphalt is heated to a fully fluid state under appropriate conditions and left to stand for an appropriate period of time, which can ensure that the data P0, P 上 , P 中 and P 下 Generally, it can be heated at 150-170℃ and left to stand for 1-12h.

[0021] Furthermore, the added mass of the room temperature modifier is 0.5-1.5 times of the rubber asphalt sample mixed therewith.

[0022] Furthermore, the added mass of the room temperature modifier is 1.0 times that of the rubber asphalt sample mixed therewith.

[0023] In the present invention, the added mass of the room temperature modifier also has an indirect impact on the evaluation results of the storage stability of rubber asphalt. If the added mass of the room temperature modifier is too much, the proportion of rubber asphalt in the room temperature rubber asphalt will be reduced, which will have an adverse effect on the test accuracy; if the added amount is too little, the viscosity of the rubber asphalt will be too high at room temperature, which is not conducive to the implementation of the test process.

[0024] Furthermore, the stirring and mixing method is to first stir at 100-300 rpm for 1-3 min, and then stir at 500-1000 rpm for 1-3 min.

[0025] Furthermore, the Brookfield rotational viscosity is preset to be no more than 200 mPa·s.

[0026] The above-mentioned preset requirement of Brookfield rotation viscosity provided by the present invention is obtained after a large number of experimental verifications. Compared with other specific viscosity values, the preset requirement is further determined to be no more than 200 mPa·s, which can ensure the reasonable viscosity range of rubber asphalt at room temperature and is conducive to determining the optimal dosage of the modifier at room temperature.

[0027] Furthermore, the method for achieving a preset viscosity requirement is as follows: after the room temperature modifier is initially added, mixed and stirred, and cooled to room temperature, if the Brookfield rotation viscosity is >200 mPa·s, the sample is heated again to 90-135°C, 10-50% of the mass of the room temperature modifier initially added is added thereto, stirred and mixed, and the Brookfield rotation viscosity is tested again; if the Brookfield rotation viscosity is still >200 mPa·s, the previous operation is repeated until the Brookfield rotation viscosity is ≤200 mPa·s.

[0028] Further, the method for evaluating the storage stability of the rubber asphalt to be tested according to the segregation index is:

[0029] When V≤1, storage stability is level I;

[0030] When 1<V≤2, storage stability is level II;

[0031] When 2<V≤3, storage stability is level III;

[0032] When 3<V, the storage stability is level IV.

[0033] The present invention further determines the above-mentioned method of grading the storage stability of rubber asphalt by segregation index, and the above-mentioned grading method can more accurately reflect the actual storage stability of rubber asphalt.

[0034] Furthermore, the room temperature modifier is at least one of methyl styrene block copolymers, tetrachloroethylene, carbon tetrachloride, petroleum ether, and toluene.

[0035] The present invention also provides a device for evaluating the storage stability of rubber asphalt, comprising a separation tube, wherein the separation tube is provided with an upper sampling port, a middle sampling port and a lower sampling port; the upper sampling port, the middle sampling port and the lower sampling port are respectively provided with valves.

[0036] Furthermore, the device also includes an overflow hole, and / or a base, and / or a handle.

[0037] The present invention also provides a device for evaluating the storage stability of rubber asphalt by combining the above method. The device is provided with an upper sampling port, a middle sampling port and a lower sampling port, and can obtain upper, middle and lower rubber asphalt samples after standing respectively.

[0038] Compared with the prior art, the present invention is beneficial in that: the method for evaluating the storage stability of rubber asphalt provided by the present invention has the advantages of less interference from human factors and external factors and high test accuracy compared with the prior art, and can more accurately and truly reflect the storage stability of rubber asphalt, providing more accurate technical guarantee for road and bridge construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the structure of the device for evaluating the storage stability of rubber asphalt;

[0040] In the figure: 1. separation tube; 2. upper sampling port; 3. middle sampling port; 4. lower sampling port; 5. valve; 6. overflow hole; 7. base; 8. handle. DETAILED DESCRIPTION

[0041] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0042] In the methods for evaluating the storage stability of rubber asphalt provided in the following examples and comparative examples, the room temperature modifier used is any one or more of methyl styrene block copolymers, tetrachloroethylene, carbon tetrachloride, petroleum ether, and toluene.

[0043] For the convenience of comparison, the following examples and comparative examples all use SMC room temperature asphalt modifier (the main component is methyl styrene block copolymer, purchased from Sichuan Guoxing Polymer Resin Co., Ltd., and a polymer solution prepared by mixing epoxy resin, epoxy resin curing agent and other additives in proportion) if necessary.

[0044] In the following examples and comparative examples, if necessary, the same device was used for evaluation. Figure 1 As shown, the device comprises an isolation tube 1, on which an upper sampling port 2, a middle sampling port 3 and a lower sampling port 4 are provided; the upper sampling port 2, the middle sampling port 3 and the lower sampling port 4 are respectively provided with valves 5.

[0045] Optionally, in some implementation cases, such as Figure 1 As shown, the device further comprises an overflow hole 6 , and / or a base 7 , and / or a handle 8 .

[0046] Optionally, in some implementation cases, an independent valve may also be provided on the overflow hole 6 .

[0047] Unless otherwise specified, the following methods were used to evaluate the storage stability of rubber asphalt in the following examples and comparative examples:

[0048] S1. Take the rubber asphalt to be tested, heat it to a fully fluid state, place it in a cylindrical container and keep it in a fully fluid state for standing, and divide the rubber asphalt after standing into upper, middle and lower rubber asphalt samples.

[0049] In some implementation cases, the rubber asphalt to be tested can be heated to a fully fluid state at 150-170° C., and the standing time can be selected to be 1-12 hours.

[0050] S2. Take a rubber asphalt sample that is in a completely fluid state and has not been left to stand, add a room temperature modifier, stir and mix, and cool to room temperature until the Brookfield rotational viscosity reaches the preset requirement; use the same method to treat the upper, middle and lower rubber asphalt samples to obtain the room temperature original sample, room temperature upper sample, room temperature middle sample and room temperature lower sample, respectively.

[0051] In some implementation cases, the mass of the room temperature modifier added can be selected to be 0.5-1.5 times that of the rubber asphalt sample used for mixing with it.

[0052] In some implementation cases, the method of adding the room temperature modifier and stirring and mixing can be selected as first stirring at 100-300 rpm for 1-3 min, and then stirring at 500-1000 rpm for 1-3 min.

[0053] In some implementation cases, the preset requirement of the Brookfield rotational viscosity is ≤200 mPa·s.

[0054] Furthermore, the method for achieving a preset viscosity requirement (i.e., ≤200mPa·s) is as follows: after the room temperature modifier is initially added, mixed and stirred, and cooled to room temperature, if the Brookfield rotational viscosity is >200mPa·s, the sample is heated to 90-135°C again, 10-50% of the mass of the room temperature modifier initially added is added thereto, stirred and mixed, and the Brookfield rotational viscosity is tested again; if the Brookfield rotational viscosity is still >200mPa·s, the previous operation is repeated until the Brookfield rotational viscosity is ≤200mPa·s.

[0055] S3, respectively measure the particle size of the original sample at room temperature, the upper sample at room temperature, the middle sample at room temperature and the lower sample at room temperature, and calculate the percentage of the particle size of each rubber asphalt sample in the range of 0.1-1.1N, which are recorded as P0, P1 and P2, respectively. 上 , P 中 and P 下 .

[0056] S4. Calculate the segregation index V according to the following formula, and evaluate the storage stability of the rubber asphalt to be tested according to the segregation index:

[0057]

[0058] Example 1

[0059] The rubber asphalt to be tested used in this embodiment is the first batch, the second batch and the third batch of commercially available finished rubber asphalt produced by the same manufacturer as the test object.

[0060] The method for evaluating the storage stability of rubber asphalt provided in this embodiment comprises the following steps:

[0061] (1) Close all valves on the device, take 1.5 times the volume of rubber asphalt from the separation tube of the device, heat it to 160°C, make the rubber asphalt fully fluid, and pour it into the separation tube; stop adding when the overflow hole of the separation tube begins to overflow with rubber asphalt.

[0062] (2) Preheat the oven to 160°C and maintain the temperature, place the separation tube in the oven and let it stand for 8 hours; open the valve of the upper sampling port and collect the outflowing sample; open the valve of the middle sampling port and collect the outflowing sample; open the valve of the lower sampling port and collect the outflowing sample; thereby dividing the rubber asphalt after standing into upper, middle and lower rubber asphalt samples; and take another portion of the original rubber asphalt in a fully fluid state for later use.

[0063] (3) Slowly add the room temperature modifier to the upper, middle and lower rubber asphalt samples respectively; in addition, slowly add the room temperature modifier to the original rubber asphalt; the mass of the room temperature modifier corresponds to 1 times that of the rubber asphalt sample.

[0064] The four mixed samples were stirred at 200 rpm for 2 min and then at 800 rpm for 2 min until uniformly stirred, and then allowed to stand at room temperature to obtain a room temperature original sample, a room temperature upper sample, a room temperature middle sample, and a room temperature lower sample.

[0065] (4) Use a Brookfield rotational viscometer to test the Brookfield rotational viscosity of the four room temperature samples in step (3).

[0066] Taking the room temperature lower sample of the first batch of finished rubber asphalt as an example, its rotational viscosity is measured to be 352 mPa·s, > 200 mPa·s; therefore, the room temperature lower sample is heated to 125°C again, 25% of the mass of the corresponding room temperature modifier in step (3) (i.e., 0.25 times the mass of the rubber asphalt sample) is added thereto, and the stirring method of step (3) is repeated. The rotational viscosity is again detected to be 162 mPa·s, ≤ 200 mPa·s, which meets the requirements, and the preparation of the room temperature lower sample is completed; if it still does not meet the requirements, the above processing method is repeated again until the rotational viscosity meets the requirement of ≤ 200 mPa·s; the same method is used to obtain the room temperature original sample, the room temperature upper sample and the room temperature middle sample.

[0067] (5) Use a particle size laser particle size analyzer to test the particle size distribution of the original sample at room temperature, the upper sample at room temperature, the middle sample at room temperature, and the lower sample at room temperature, and calculate the percentage of particles with a size between 0.1N and 1.1N, which are recorded as P0, P1, P2, P3, P4, P5, P6, P7, P8, P9, P10, P11, P12, P13, P14, P15, P16, P17, P18, P19, P20, P21, P22, P23, P24, P25, P26, P27, P28, P29, P30, P31, P32 上 , P 中 and P 下 Taking the original sample at room temperature as an example, the particle size of the original sample at room temperature is measured to be N = 0.45 mm, and the corresponding percentage of particle size between 0.1N-1.1N is P0 = 15.3%. Using the same method P 上 =6.2%, P 中 =16.5%, P 下 =22.1%.

[0068] (6) Calculate the segregation index V according to the following formula, and evaluate the storage stability of the rubber asphalt to be tested based on the segregation index:

[0069]

[0070] Finally, the segregation index V of the rubber asphalt to be tested was obtained to be 1.56.

[0071] Using the same method, the V values ​​of the second and third batches of finished rubber asphalt were calculated to be 0.63 and 2.51 respectively.

[0072] (7) Storage stability rating was performed according to the following method:

[0073] When V≤1, storage stability is level I;

[0074] When 1<V≤2, storage stability is level II;

[0075] When 2<V≤3, storage stability is level III;

[0076] When 3<V, the storage stability is level IV.

[0077] Comparative Example 1

[0078] The rubber asphalt to be tested in this comparative example is the same three batches of rubber asphalt as in Example 1. The method for evaluating the storage stability of rubber asphalt provided in this comparative example is different from that in Example 1 in that:

[0079] In step (4), the preset Brookfield rotation viscosity requirement is ≤300 mPa·s. Finally, the segregation index V of the three batches of rubber asphalt to be tested is 1.93, 1.12 and 3.36 respectively.

[0080] Comparative Example 2

[0081] The rubber asphalt to be tested in this comparative example is the same three batches of rubber asphalt as in Example 1. The method for evaluating the storage stability of rubber asphalt provided in this comparative example is different from that in Example 1 in that:

[0082] In step (4), the preset Brookfield rotation viscosity requirement is ≤100 mPa·s. Finally, the segregation index V of the three batches of rubber asphalt to be tested is 0.94, 0.41 and 1.85 respectively.

[0083] Comparative Example 3

[0084] The rubber asphalt to be tested in this comparative example is the same three batches of rubber asphalt as in Example 1. The method for evaluating the storage stability of rubber asphalt provided in this comparative example is different from that in Example 1 in that the storage stability rating is performed according to the following method:

[0085] When V≤1.5, storage stability is level I;

[0086] When 1.5<V≤3.0, storage stability is level II;

[0087] When 3.0<V≤4.5, storage stability is level III;

[0088] When 4.5<V, the storage stability is level IV.

[0089] Comparative Example 4

[0090] The rubber asphalt to be tested used in this comparative example is the same three batches of rubber asphalt as in Example 1. This comparative example is based on the requirements of JTG E20-2011 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" and JTG F40-2004 "Technical Specifications for Highway Asphalt Pavement Construction", and uses the standard method (T0661-2011 "Segregation Test for Polymer Modified Asphalt" to evaluate the storage stability of these rubber asphalts to be tested. The softening point differences of the three batches of rubber asphalt are 1.7°C, 0.9°C, and 3.0°C, respectively.

[0091] Three batches of rubber asphalt to be tested were evaluated by using the methods of Examples 1-3 and Comparative Examples 1-4, and the results are shown in Table 1 below.

[0092] Table 1 Evaluation results of storage stability of rubber asphalt to be tested

[0093]

[0094] According to the evaluation results in Table 1 above, it can be seen that if the preset requirements of the Brookfield rotational viscosity are changed, there will be a great impact on the segregation index test results; if the storage stability rating standard is changed, it will have a great impact on the rubber asphalt evaluation results, which will cause the rating results of the present invention to be less consistent with the evaluation standards in the current specifications.

[0095] The determination of the test parameters in the test method of the present invention is accurate and reasonable, the test results are highly consistent with the evaluation results obtained by the existing standard method, and the test method of the present invention can classify the storage stability of rubber asphalt and more accurately compare and evaluate the storage stability of different rubber asphalts, which shows that the method of the present invention can more accurately reflect the storage stability of rubber asphalt.

[0096] The above specific embodiments describe the implementation of the present invention in detail, but the present invention is not limited to the specific details in the above embodiments. Within the scope of the claims and technical concept of the present invention, the technical solution of the present invention can be modified and changed in many simple ways, and these simple modifications all belong to the protection scope of the present invention.

Claims

1. A method for evaluating the storage stability of rubber asphalt, characterized in that: The following steps are involved: Take the rubber asphalt to be tested, heat it to a completely fluid state, place it in a cylindrical container and keep it in a completely fluid state for standing, and divide the rubber asphalt after standing into upper, middle and lower rubber asphalt samples; Take a rubber asphalt sample that is in a completely fluid state and has not been left to stand, add a room temperature modifier, stir and mix, and cool to room temperature until the Brookfield rotation viscosity reaches the preset requirement; use the same method to treat the upper, middle and lower rubber asphalt samples to obtain a room temperature original sample, a room temperature upper sample, a room temperature middle sample and a room temperature lower sample, respectively; The particle sizes of the original sample at room temperature, the upper sample at room temperature, the middle sample at room temperature and the lower sample at room temperature were measured respectively, and the percentage of the particle size of each rubber asphalt sample in the range of 0.1-1.1N was calculated respectively, which were recorded as P0, P 上 , P 中 and P 下 ; Wherein, N is the particle size of the original rubber powder used to prepare rubber-modified asphalt; The segregation index V is calculated according to the following formula, and the storage stability of the rubber asphalt to be tested is evaluated according to the segregation index: ； The preset requirement of Brookfield rotational viscosity is ≤200mPa·s; The method for achieving the preset viscosity requirement is as follows: after the room temperature modifier is initially added, mixed and stirred, and cooled to room temperature, if the Brookfield rotation viscosity is greater than 200 mPa·s, the sample is heated to 90-135°C again, 10-50% of the mass of the room temperature modifier initially added is added thereto, stirred and mixed, and the Brookfield rotation viscosity is tested again; if the Brookfield rotation viscosity is still greater than 200 mPa·s, the previous operation is continued to be repeated until the Brookfield rotation viscosity is ≤200 mPa·s; The method for evaluating the storage stability of the rubber asphalt to be tested according to the segregation index is: When V≤1, storage stability is level I; When 1<V≤2, storage stability is level II; When 2<V≤3, storage stability is level III; When 3<V, the storage stability is level IV.

2. The method for evaluating the storage stability of rubber asphalt according to claim 1, characterized in that: Heat the rubber asphalt to be tested at 150-170℃ until it is fully fluid and let it stand for 1-12 hours.

3. The method for evaluating the storage stability of rubber asphalt according to claim 1, characterized in that: The added mass of the room temperature modifier is 0.5-1.5 times of the rubber asphalt sample stirred and mixed with it.

4. The method for evaluating the storage stability of rubber asphalt according to claim 3, characterized in that: The added mass of the room temperature modifier is 1.0 times the mass of the rubber asphalt sample mixed with it.

5. The method for evaluating the storage stability of rubber asphalt according to any one of claims 1 to 4, characterized in that: The room temperature modifier is at least one of methyl styrene block copolymer, tetrachloroethylene, carbon tetrachloride, petroleum ether and toluene.

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