Evaluation method and application of dissolution degree of rubber powder and asphalt in rubber powder modified asphalt

Abstract

The present invention discloses an evaluation method and application of the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt. The evaluation method comprises: separating rubber powder modified asphalt, collecting and obtaining undissolved rubber powder and asphalt containing dissolved rubber powder; evaluating the degree of solubility of rubber powder in rubber powder modified asphalt according to the dissolution rate of rubber powder particles; evaluating the dissolution of rubber powder in rubber powder modified asphalt according to the change of the area of ​​S=O functional group in Fourier infrared spectrum; calculating the change rate of asphalt rutting factor according to temperature scanning test parameters to evaluate the dissolution of rubber powder in rubber powder modified asphalt. The method can be applied to the evaluation of the degree of reaction between rubber powder and asphalt in rubber powder modified asphalt of different construction stages, different types of rubber powder particles and different amounts of rubber powder; combining the obtained evaluation results, it provides a better scientific theoretical basis for the application of rubber powder modified asphalt of various stages and types, thereby improving its application effect.

Description

Technical Field

[0001] The invention relates to the technical field of modified asphalt materials for road engineering, and in particular to an evaluation method and application of the dissolution degree of rubber powder and asphalt in rubber powder modified asphalt. Background Art

[0002] Rubber powder modified asphalt is a bonding material made by adding rubber powder particles made from waste tires to base asphalt, and then undergoing a series of processes such as high temperature, additives, and shear mixing. This process involves the rubber powder particles fully melting and swelling with the base asphalt under high temperature conditions to form a modified asphalt binder. Compared with traditional base asphalt, the performance of rubber powder modified asphalt has been significantly improved, which is mainly due to the interaction between rubber powder particles and asphalt. Therefore, the degree of solubility of rubber powder particles and asphalt in rubber powder modified asphalt usually directly affects the degree of performance improvement of the modified asphalt.

[0003] In the actual engineering field, rubber powder modified asphalt undergoes different construction procedures such as preparation, storage, transportation, construction process, paving, rolling, recycling and extraction. Rubber powder of different types, particle sizes and dosages reacts with asphalt to different degrees of dissolution, segregation and stratification under different environmental conditions. For these uncertain changes in rubber powder particles in modified asphalt, there is currently no simple, convenient, scientific and rigorous evaluation system for rubber powder modified asphalt at different construction stages, different rubber powder particle types and different rubber powder dosages, which brings uncertainty to the application effect to a certain extent, thereby limiting the application of rubber powder modified asphalt.

[0004] To evaluate and analyze the degree of solubility of rubber powder particles and asphalt in rubber powder modified asphalt, it is first necessary to separate the rubber powder particles and asphalt in the rubber powder modified asphalt. At present, the methods for phase separation of rubber powder modified asphalt include high-speed centrifugation, solvent precipitation, thermal analysis, high-performance liquid chromatography, etc. Among them: high-speed centrifugation has fast separation speed and good effect, but requires professional equipment and technicians to operate; although thermal analysis provides rich thermal performance information, it requires professional equipment and technicians to operate; high-performance liquid chromatography has high separation accuracy, but the separation process is cumbersome and requires professional equipment and technicians to operate.

[0005] The existing Chinese patent document CN116735522A discloses a method for evaluating the adsorption characteristics and reaction mechanism of rubber particles in rubber-modified asphalt. The method mainly extracts the components in the interaction area between asphalt and rubber particles by layer-by-layer separation, and then determines the molecular weight distribution of asphalt adsorbed by rubber particles and the absorption preference of asphalt functional groups by gel permeation chromatography and Fourier transform infrared spectroscopy, and performs thermogravimetric analysis on the original rubber particles and the rubber particles after the reaction with asphalt to determine the composition changes of the rubber particles before and after the reaction, so as to obtain the adsorption characteristics of rubber particles in rubber-modified asphalt and the mutual reaction mechanism between rubber particles and asphalt. However, this method cannot evaluate the solubility of rubber particles and asphalt, and the phase separation in this method is to pour the rubber-modified asphalt on the screen in a closed container, and then stand and separate to obtain the rubber particles and asphalt liquid phase. The surface of the rubber particles after simple separation is adsorbed with asphalt and its components or functional groups that interact with asphalt, which is not suitable for direct analysis and evaluation of the solubility of rubber powder particles and asphalt.

[0006] Therefore, there is an urgent need for a method suitable for separating rubber powder particles from asphalt in rubber powder modified asphalt and evaluating the degree of solubility of rubber powder particles and asphalt. Summary of the invention

[0007] The technical problem to be solved by the present invention is: to provide a method for evaluating the solubility of rubber powder and asphalt in rubber powder modified asphalt and its application, the method can be applicable to the evaluation of the solubility of rubber powder and asphalt in rubber powder modified asphalt of different construction stages, different rubber powder particle types and different rubber powder dosages; through the evaluation and analysis of the solubility of rubber powder and asphalt in rubber powder modified asphalt, a better scientific theoretical basis is provided for the application of rubber powder modified asphalt of various stages and types, thereby improving its application effect.

[0008] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt. The method comprises the following steps:

[0010] S1. Separating the rubber powder modified asphalt, collecting and obtaining the undissolved rubber powder and the asphalt containing the dissolved rubber powder;

[0011] S2. Evaluate the dissolution degree of rubber powder in rubber powder modified asphalt based on the dissolution rate of rubber powder particles;

[0012] S3. Evaluate the dissolution of rubber powder in rubber powder modified asphalt according to the change of the area of ​​S=O functional group in Fourier infrared spectrum;

[0013] S4. Calculate the change rate of asphalt rutting factor based on the temperature scanning test parameters to evaluate the dissolution of rubber powder in rubber powder modified asphalt.

[0014] Furthermore, the rubber powder modified asphalt is obtained by adding rubber powder particles to base asphalt for modification, and the rubber powder particles used in the rubber powder modified asphalt for road engineering are usually made of waste tires.

[0015] Furthermore, the separation process in step S1 is specifically as follows:

[0016] S101, weighing the rubber powder modified asphalt to be separated in a container, and then heating and melting it to a flowable state;

[0017] S102, then pour the melted rubber powder modified asphalt into a filter screen, and set an asphalt collector under the filter screen to collect the filtered asphalt, which contains dissolved rubber powder particles; weigh the remaining rubber powder modified asphalt with a container again, and calculate the weight of the rubber powder modified asphalt used for separation;

[0018] The weight of the separated rubber powder modified asphalt = the weight of the rubber powder modified asphalt weighed with the container in step S101 - the weight of the remaining rubber powder modified asphalt weighed with the container in step S102;

[0019] S103, continue to heat the filter screen and the asphalt collector in step S102, and part of the rubber powder modified asphalt remaining on the filter screen will continue to flow through the filter screen to the asphalt collector under the action of gravity, and collect the asphalt in the asphalt collector to obtain the separated asphalt containing dissolved rubber powder;

[0020] S104, processing to obtain undissolved rubber powder:

[0021] First, the rubber powder-asphalt mixture on the filter screen treated in step S103 is circulated and flushed with trichloroethylene for 3 to 4 times to dissolve part of the asphalt, and then the scattered rubber powder particles are collected;

[0022] Then, the collected rubber powder particles are again cleaned 2-3 times by magnetic stirring using trichloroethylene as a solvent; the cleaning device is preferably a magnetic stirrer;

[0023] Finally, the cleaning solution after magnetic stirring cleaning is poured into the sieve together with the rubber powder particles, and trichloroethylene is used for circulation flushing again until the surface of the rubber powder particles is clean and free of asphalt. The rubber particles on the sieve are collected and dried to obtain the separated undissolved rubber powder.

[0024] In the present invention, trichloroethylene is a heterocyclic organic compound and a polar solvent. It has a high solubility in asphalt, but its influence on rubber powder particles is relatively small. In the phase separation process of the present invention, trichloroethylene is used as a solvent, which can better clean the asphalt wrapped on the surface of the undissolved rubber powder and reduce the influence on the undissolved rubber powder, thereby reducing the error generated in the separation process and improving the accuracy of the evaluation method.

[0025] Furthermore, the particle size of the rubber powder particles is generally 40-120 meshes, and the size of the filter screen selected for filtering and separating in step S1 is 150-200 meshes. The aperture of the sieve corresponding to 200 meshes is 0.075 mm.

[0026] Furthermore, the heating and melting conditions in step S101 are heating at 170°C±5°C for 1h±5min.

[0027] Furthermore, in step S103, the filter screen and the asphalt collector in step S102 are further heated to 195°C±5°C for 15min±3min.

[0028] Furthermore, the magnetic cleaning condition in step S104 is 800 r / min±50 r / min for 15 min±3 min. The separation effect is optimal at this time.

[0029] Further,

[0030] The dissolution rate of the rubber powder particles in step S2 is calculated by the following formula:

[0031]

[0032] The mass of the undissolved rubber powder is obtained by directly weighing the weight of the undissolved rubber powder separated in step S1; the amount of rubber powder particles added to the rubber powder modified asphalt is calculated based on the mass of the separated rubber powder modified asphalt and the mixing ratio of the rubber powder particles therein.

[0033] Further,

[0034] Step S3 evaluates the dissolution of rubber powder in the rubber powder modified asphalt according to the change in the area of ​​the S=O functional group in the Fourier transform infrared spectrum. The specific calculation process is as follows:

[0035] S301, performing Fourier infrared spectroscopy scanning on the undissolved rubber powder and the corresponding rubber powder particles separated from the rubber powder modified asphalt in step S1 to obtain an infrared spectrum;

[0036] In the infrared spectrum, the area change of sulfoxide (S=O) can reflect the dissolution of rubber powder in rubber powder modified asphalt. -1 The absorption peak at corresponds to the stretching vibration of the sulfoxide group (S=O);

[0037] S302, calculate the undissolved rubber powder and the corresponding rubber powder particles separated from the rubber powder modified asphalt according to the infrared spectrum at 1030cm -1 Functional group (i.e. sulfoxide) index:

[0038]

[0039] In the formula, Refers to 1030cm in the infrared spectrum -1 The area of ​​the absorption peak at Refers to 4000cm in the infrared spectrum -1 -650cm -1 The area of ​​the absorption peak at

[0040] S303. Calculate the dissolution of rubber powder in rubber powder modified asphalt:

[0041]

[0042] Where A is the absorption rate of rubber powder particles, unit %; I S＝Oa I is the functional group (i.e. sulfoxide) index of the separated undissolved rubber powder; S＝Ob It is the functional group (i.e. sulfoxide group) index of the corresponding rubber powder.

[0043] Further, step S4 calculates the asphalt rutting factor change rate according to the temperature scanning test parameters to evaluate the dissolution of the rubber powder in the rubber powder modified asphalt. The specific process is as follows:

[0044] S401, performing a temperature scanning test on the asphalt containing dissolved rubber powder separated in step S1 and the corresponding unmodified base asphalt, and obtaining the rutting factors G * / sinδ, referred to as G;

[0045] S402. Calculate the dissolution status of rubber powder in rubber powder modified asphalt:

[0046]

[0047] Where, B is the solubility of rubber powder in rubber powder modified asphalt, unit %; G a is the rutting factor of asphalt containing dissolved rubber powder after separation, unit kPa; G b It is the rutting factor of the corresponding base asphalt, unit is kPa.

[0048] In the second aspect, the present invention also provides the application of the evaluation method of the solubility of rubber powder and asphalt in the rubber powder modified asphalt in the preparation method of rubber powder modified asphalt or the construction application method of rubber powder modified asphalt. Specifically, the evaluation result of the solubility of rubber powder and asphalt in the rubber powder modified asphalt obtained by the evaluation method is used as a theoretical basis to optimize the preparation method or construction application conditions of the rubber powder modified asphalt to improve the application effect of the rubber powder modified asphalt.

[0049] The present invention has the following beneficial effects:

[0050] The evaluation method provided by the present invention comprises: collecting and obtaining the undissolved rubber powder and the dissolved rubber powder-containing asphalt by separating the rubber powder modified asphalt; analyzing and evaluating the degree of solubility of the rubber powder particles in the rubber powder modified asphalt by calculating the dissolution rate of the rubber powder particles; and evaluating the dissolution of the rubber powder in the rubber powder modified asphalt by analyzing the change in the area of ​​the corresponding functional groups of the Fourier infrared spectrum; and calculating the change rate of the asphalt rutting factor according to the temperature scanning test parameters to evaluate the dissolution of the rubber powder in the rubber powder modified asphalt.

[0051] The evaluation method provided by the present invention can separate rubber powder modified asphalts of different construction stages, different rubber powder particle types, and different rubber powder dosages, and can perform a simple, convenient, scientific and rigorous evaluation of the reaction degree between the separated undissolved rubber powder and the asphalt containing dissolved rubber powder. The method for separating the undissolved rubber powder from the asphalt containing dissolved rubber powder is simple to operate, and has high stability and accuracy. Therefore, the evaluation method provided by the present invention has a wide range of applications, strong practicality, simple operation, and can be evaluated more comprehensively, scientifically, and accurately.

[0052] The evaluation and analysis results of the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt obtained by the evaluation method provided by the present invention can provide a better scientific theoretical basis for the application of rubber powder modified asphalt of various stages and types, so as to further optimize the preparation method, formulation process, construction application conditions, etc. of the rubber powder modified asphalt, thereby improving its application effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic flow chart of a method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt provided by the present invention.

[0054] Figure 2 The present invention provides a phase separation flow chart of the rubber powder modified asphalt.

[0055] Figure 3 This is a graph showing the infrared spectrum test results of ordinary rubber powder modified asphalt in Example 1 of the present invention.

[0056] Figure 4 This is a diagram of the rutting factor of ordinary rubber powder modified asphalt in Example 1 of the present invention.

[0057] Figure 5 This is a graph showing the infrared spectrum test results of the activated rubber powder modified asphalt of Example 2 of the present invention.

[0058] Figure 6 This is the rutting factor diagram of the activated rubber powder modified asphalt in Example 2 of the present invention. DETAILED DESCRIPTION

[0059] As used herein:

[0060] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0061] When a parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges of "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0062] In these examples, parts and percentages are by mass unless otherwise indicated.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing the specific embodiments and are not intended to limit the present invention. In the embodiments, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0064] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Preferred embodiments of the present invention are provided in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0065] The rubber powder modified asphalt involved in the present invention is prepared by adding rubber powder particles to base asphalt, specifically through a series of processes such as high temperature, shear mixing, etc., and additives can be added during the preparation process for activation to further optimize the performance of the rubber powder modified asphalt. The rubber powder particles usually used in the rubber powder modified asphalt for road engineering are made of waste tires, which can be waste tire rubber powder particles directly purchased on the market. The following is an example of a common rubber powder modified asphalt and an activated rubber powder modified asphalt.

[0066] Example 1 (Evaluation of the degree of solubility of rubber powder and asphalt in ordinary rubber powder modified asphalt)

[0067] The present invention provides a method for evaluating the degree of solubility of rubber powder and asphalt in common rubber powder modified asphalt. The common rubber powder modified asphalt is prepared by the following method:

[0068] The first stage: first heat the base asphalt in a 150°C oven until it is melted, then place it in a constant temperature electric heating jacket and heat it to 185°C, and use a mixer to add ordinary rubber powder particles (30% external addition) while stirring, the stirring time is 20 minutes, and the stirring rate is 4000r / min.

[0069] The base asphalt in this embodiment adopts 70# petroleum asphalt produced by Maoming Petrochemical Co., Ltd., and its basic properties are shown in Table 1 below:

[0070] Table 1 Basic properties of Mao Petrochemical 70# base asphalt

[0071]

[0072] The ordinary rubber powder particles added in this embodiment are rubber powder particles (rubber powder) provided by Guangxi Jiaoke New Materials Technology Co., Ltd., and their performance index parameters are shown in Table 2 and Table 3 below:

[0073] Table 2 Physical indexes of rubber powder particles

[0074]

[0075] Table 3 Chemical indexes of rubber powder particles

[0076]

[0077] The second stage: Based on the first stage, use a high-speed shearing machine to shear at 4500r / min for 10min.

[0078] The third stage: Based on the second stage, use a mixer to stir and develop for 30 minutes at 185°C.

[0079] The evaluation method for the common rubber powder modified asphalt specifically includes the following steps:

[0080] S1. Separate the common rubber powder modified asphalt, collect and obtain the asphalt containing undissolved rubber powder and dissolved rubber powder.

[0081] like Figure 2 As shown, the phase separation process of the undissolved rubber powder in the rubber powder modified asphalt and the asphalt containing dissolved rubber powder in this embodiment is specifically as follows:

[0082] S101. Weigh 500 g of the rubber powder modified asphalt to be separated with a cup, and then heat and melt it until it becomes flowable. The heating and melting condition is preferably heated at 170° C. for 1 hour.

[0083] S102, then pour the melted rubber powder modified asphalt into a new impurity-free filter screen with a mesh size of 200 (aperture size of 0.075 mm), and set an asphalt collector under the filter screen to collect the filtered asphalt, which contains dissolved rubber powder particles. Weigh the remaining rubber powder modified asphalt with a cup again, a total of 400g, and calculate the mass of the rubber powder modified asphalt used for separation.

[0084] The mass of the separated rubber powder modified asphalt = the mass of the rubber powder modified asphalt weighed with a cup in step S101, 500g - the mass of the remaining rubber powder modified asphalt weighed with a cup in step S102, 400g = 100g.

[0085] S103, continue to heat the filter screen and asphalt collector in step S102 to 195°C for 15 minutes. Some of the rubber powder-modified asphalt remaining on the filter screen will continue to flow through the filter screen to the asphalt collector under the action of gravity. The asphalt in the asphalt collector is collected to obtain the separated asphalt containing dissolved rubber powder.

[0086] S104, further processing to obtain undissolved rubber powder:

[0087] First, the rubber powder-asphalt mixture on the filter screen treated in step S103 is cyclically flushed with trichloroethylene for three times to dissolve part of the asphalt, and then the scattered rubber powder particles are collected.

[0088] Then, the collected rubber powder particles are again cleaned twice by magnetic stirring using trichloroethylene as a solvent; the cleaning device is preferably a magnetic stirrer; the magnetic cleaning condition is cleaning at a speed of 800r / min for 15min, at which the separation effect is best.

[0089] Finally, the cleaning solution after magnetic stirring cleaning is poured into the screen together with the rubber powder particles, and trichloroethylene is used for cyclic washing again until the surface of the rubber powder particles is clean and free of asphalt, and the rubber particles on the screen are collected and dried to obtain the separated undissolved rubber powder. After weighing, 12.4g of undissolved rubber powder (insoluble matter) is obtained in this embodiment.

[0090] S2. Evaluate the dissolution degree of the rubber powder particles in the rubber powder modified asphalt according to the dissolution rate of the rubber powder particles. The dissolution rate of the rubber powder particles of the present invention is calculated by the following formula:

[0091]

[0092] The weight of the undissolved rubber powder is obtained by directly weighing the weight of the undissolved rubber powder separated in step S1, which is 12.4 g; the amount of rubber powder particles added to the rubber powder modified asphalt is calculated based on the weight of the separated rubber powder modified asphalt and the mixing ratio of the rubber powder particles therein: 100 g*30%=30 g. Therefore, in this embodiment,

[0093]

[0094] S3. According to the change of the area of ​​the S=O functional group in Fourier infrared spectrum, the dissolution of rubber powder in rubber powder modified asphalt is evaluated. The specific process is as follows:

[0095] S301, the embodiment of the present invention uses a NICOLET is10 Fourier transform infrared spectrometer to perform Fourier transform infrared spectroscopy scanning on the undissolved ordinary rubber powder particles and the corresponding ordinary rubber powder particles separated from the rubber powder modified asphalt in step S1 to obtain an infrared spectrum; the resolution is selected to be 4cm -1 , mid-infrared spectral wavenumber range is 400cm -1 ~4000cm -1 The test was performed with 32 scans. The results are as follows: Figure 3 shown.

[0096] In the infrared spectrum, the area change of sulfoxide (S=O) can reflect the dissolution of rubber powder in rubber powder modified asphalt. -1 The absorption peak at corresponds to the stretching vibration of the sulfoxide group (S=O).

[0097] S302, according to the infrared spectrum, the undissolved ordinary rubber powder particles and the corresponding ordinary rubber powder particles are separated to obtain the -1 Functional group (i.e. sulfoxide) index:

[0098]

[0099] In the formula, Refers to 1030cm in the infrared spectrum -1 The area of ​​the absorption peak at Refers to 4000cm in the infrared spectrum -1 -650cm -1 The area of ​​the absorption peak.

[0100] The functional group index calculation refers to the ratio of the area under a certain scanning frequency to the total area. The functional group index is used to quantitatively analyze the changes in functional groups. Figure 2 And the above calculation formula, we get 1030cm -1 The functional group index is shown in Table 4 below:

[0101] Table 4 Undissolved ordinary rubber powder and corresponding ordinary rubber powder particles of Example 1 at 1030 cm -1 Functional Group Index

[0102]

[0103] S303. Calculate the dissolution of rubber powder in ordinary rubber powder modified asphalt according to the functional group index using the following formula:

[0104]

[0105] Wherein, A is the dissolution of rubber powder particles in the common rubber powder asphalt of this embodiment, unit %; S＝0a I is the functional group (i.e. sulfoxide) index of the separated undissolved ordinary rubber powder particles; S＝Ob It is the functional group (i.e. sulfoxide group) index corresponding to ordinary rubber powder.

[0106] According to Table 4, the dissolution of rubber powder particles in the common rubber powder modified asphalt of this embodiment is calculated:

[0107]

[0108] S4. Calculate the change rate of the asphalt rutting factor according to the temperature scanning test parameters to evaluate the dissolution status of the rubber powder particles in the separated asphalt containing dissolved rubber powder. The specific process is as follows:

[0109] S401, perform a temperature scanning test on the asphalt containing dissolved rubber powder separated in step S1 and the corresponding unmodified base asphalt. The results are as follows: Figure 4 As shown, the rutting factor G is obtained * / sinδ, referred to as G. In this embodiment, the MCR 302e rheometer produced by Anton Paar of the United States was used. First, the rubber powder was put into a rheological mold with a thickness of 1 mm and a diameter of 25 mm to prepare a disc, and then the disc sample was put into the rotational rheometer for testing, and the scanning frequency was 10H. Z , the temperature range is 46℃~88℃, and the temperature scan is performed every 6℃.

[0110] S402, according to Figure 4 Based on the results, taking the rutting factor at 58°C as an example, the dissolution status of rubber powder in rubber powder modified asphalt after the temperature scanning test is calculated:

[0111]

[0112] Where, B is the dissolution status of rubber powder in rubber powder modified asphalt, unit: %; G a is the rutting factor of asphalt containing dissolved rubber powder after separation, unit kPa; G b It is the rutting factor of the corresponding base asphalt, unit is kPa.

[0113] In this embodiment, the dissolution of rubber powder in rubber powder modified asphalt under the rutting factor at 58°C is:

[0114]

[0115] The above evaluation results are analyzed as follows:

[0116] 1. In step S2, the mass of undissolved rubber powder (insoluble matter) in common rubber powder modified asphalt is converted with the mass of known common rubber powder particles added to obtain the dissolution of rubber in asphalt in terms of physical mass of the finished product of laboratory common rubber modified asphalt. In this embodiment, the dissolution rate of common rubber powder particles in asphalt is 58.67%, and the dissolution rate of rubber powder particles is relatively high. The above results show that the dissolution rate of rubber powder can be effectively improved by optimizing the shearing process, adjusting the amount of rubber powder, and selecting the appropriate type of rubber powder. This result not only provides a scientific basis for the preparation process of rubber modified asphalt, but also points out the direction for the optimization of its subsequent storage, transportation and construction links, ensuring that each step of operation has data to rely on.

[0117] 2. The functional group absorption peak change rate is obtained by calculating the intermediate parameter S=0 functional group index in step S3 of the evaluation method, which can reflect the dissolution of rubber powder particles in asphalt at the microscopic chemical level. In this embodiment, the dissolution rate of ordinary rubber powder in asphalt is 45.70%, and the dissolution rate of rubber powder particles is relatively high. The result shows that the rubber powder absorption rate can be adjusted from the perspectives of shearing process, rubber powder dosage, rubber powder type, etc. to make the rubber powder absorption rate higher. The calculation result can also provide a reference basis for the preparation, storage, transportation, and construction of rubber powder modified asphalt, and provide data support for adjustment and optimization.

[0118] 3. The temperature of the asphalt phase containing the dissolved rubber powder is scanned by the evaluation method step S4, and the change rate of the rutting factor is calculated to obtain the dissolution of the rubber powder particles in the asphalt at the macro-rheological level. In this embodiment, the absorption rate of ordinary rubber powder in asphalt is 183.06%, and its value is greater than 1 because the rutting factor result is of a large order of magnitude, but it has no effect on the evaluation of the dissolution degree of rubber particles.

[0119] Example 2 (Evaluation of the degree of solubility of rubber powder and asphalt in rubber powder-modified asphalt)

[0120] This embodiment provides a method for evaluating the degree of solubility of rubber powder and asphalt in activated rubber powder modified asphalt, and the activated rubber powder modified asphalt is prepared by the following method:

[0121] The first stage: firstly heat the matrix asphalt in a 150°C oven until it is melted, then place it on a constant temperature electric heating jacket and heat it to 170°C, then add 30% activated rubber powder while stirring for 20 minutes, and the stirring rate is 4000r / min. The matrix asphalt in this embodiment is the same as that in Example 1, and the activated rubber powder is obtained by electromagnetic activation on the basis of the rubber powder particles in Example 1, specifically, firstly put the unactivated ordinary rubber powder particles in Example 1 into the activation tank, and the rubber powder is raised to the activation temperature of 260°C to 270°C by electromagnetic instantaneous heating, and the activation is completed for 5min to 6min.

[0122] The second stage: Based on the first stage, use a high-speed shearing machine to shear at 4500r / min for 10min.

[0123] The third stage: Based on the second stage, the preparation of activated rubber powder modified asphalt is completed by using a mixer at 170°C for 30 minutes.

[0124] The activated rubber powder modified asphalt prepared in this example was separated and evaluated by referring to the method of Example 1, and the results are as follows:

[0125] S2. Solubility of activated rubber powder particles in activated rubber powder modified asphalt:

[0126]

[0127] S3, according to the method of Example 1, the Fourier transform infrared spectroscopy test is carried out to evaluate the dissolution of the undissolved activated rubber powder particles after separation. The Fourier transform infrared spectrum of this example is as follows Figure 5 As shown, referring to the calculation method of Example 1, first calculate 1030cm -1 The changes of functional group index are shown in Table 5:

[0128] Table 5 Activated rubber powder modified asphalt 1030cm of Example 2 -1 Functional Group Index

[0129]

[0130] Then, according to the data in Table 5, the dissolution rate of rubber powder particles in the activated rubber powder asphalt in this embodiment is calculated:

[0131]

[0132] S4. Evaluate the dissolution of rubber powder in the activated rubber powder modified asphalt according to the temperature scanning test. The temperature scanning test results of this embodiment are as follows: Figure 6 As shown, according to Figure 6 And referring to the above calculation formula, the dissolution of rubber powder in the activated rubber powder modified asphalt of this embodiment is calculated under the rutting factor at 58°C:

[0133]

[0134] The above evaluation results of this embodiment are analyzed by comparing them with the evaluation results of embodiment 1, and the analysis is as follows:

[0135] 1. By converting the mass of undissolved rubber powder (insoluble matter) with the known mass of activated rubber powder added in step S2, the dissolution of rubber powder particles in asphalt in the laboratory finished product activated rubber powder modified asphalt in terms of physical mass can be obtained. In this embodiment, the solubility rate of activated rubber powder in asphalt is 66%, and the solubility rate of rubber powder particles is relatively high. The solubility rate of activated rubber powder particles in this embodiment is improved compared with the solubility rate of ordinary rubber powder in Example 1, indicating that electromagnetic heat activation of rubber powder can effectively improve the dissolution of rubber powder particles in asphalt. The above results show that improving the rubber powder preparation process can effectively improve the dissolution rate of rubber powder. This result not only provides a scientific basis for the preparation process of rubber modified asphalt, but also points out the direction for the optimization of its subsequent storage, transportation and construction links, ensuring that each step of the operation has data to rely on.

[0136] 2. The dissolution rate of the activated rubber powder in asphalt in this embodiment is calculated to be 60.48% by the evaluation method step S3, and the dissolution rate of the rubber powder particles is relatively high. This result also shows that the dissolution rate of the rubber powder particles can be made higher by adjusting the shearing process, the amount of rubber powder, the type of rubber powder, etc. At the same time, compared with the ordinary rubber powder in Example 1, the dissolution rate of the activated rubber powder in asphalt in this embodiment is improved, indicating that activating the ordinary rubber powder can increase the S=O absorption peak area in the functional group and thus increase the dissolution rate of the rubber powder particles. This calculation result can also provide a reference basis for the preparation, storage, transportation, and construction of rubber powder modified asphalt and provide data support for adjustment and optimization.

[0137] 3. The dissolution of rubber powder in the activated rubber powder modified asphalt in this embodiment is calculated by the evaluation method step S4 to be 258.11%. Compared with Example 1, this result shows that activating the rubber powder can improve the dissolution of asphalt in it and also reflects that the process improves the high temperature performance of the rutting factor. This result not only provides a scientific basis for the preparation process of rubber modified asphalt, but also points out the direction for the optimization of its subsequent storage, transportation and construction links, ensuring that each step of the operation has data to rely on.

[0138] In summary, the evaluation method provided by the present invention has a wide range of applications, strong practicality, simple operation, and can be evaluated more comprehensively, scientifically, and accurately. The evaluation and analysis results of the degree of dissolution of rubber powder and asphalt in rubber powder modified asphalt obtained by the evaluation method provided by the present invention can provide a better scientific theoretical basis for the application of various stages and types of rubber powder modified asphalt, so as to further optimize the preparation method, formulation process, construction application conditions, etc. of the rubber powder modified asphalt, thereby improving its application effect.

[0139] The above descriptions are only some preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt, characterized in that: The steps include: S1, separating the rubber powder modified asphalt, collecting and obtaining the undissolved rubber powder and the asphalt containing the dissolved rubber powder; S2. Evaluate the dissolution degree of rubber powder in rubber powder modified asphalt based on the dissolution rate of rubber powder particles; S3. Evaluate the dissolution of rubber powder in rubber powder modified asphalt according to the change of S=O functional group area in Fourier infrared spectrum. The specific process is as follows: S301, performing Fourier infrared spectroscopy scanning on the undissolved rubber powder and the corresponding rubber powder particles separated from the rubber powder modified asphalt in step S1 to obtain an infrared spectrum; In the infrared spectrum, the area change of sulfoxide S=O can reflect the dissolution of rubber powder in rubber powder modified asphalt. -1 The absorption peak at corresponds to the stretching vibration of the sulfoxide group; S302, calculate the undissolved rubber powder and the corresponding rubber powder particles separated from the rubber powder modified asphalt according to the infrared spectrum at 1030cm -1 Functional group index: ； In the formula, Refers to 1030cm in the infrared spectrum -1 The area of ​​the absorption peak at Refers to 4000cm in the infrared spectrum -1 -650cm -1 The area of ​​the absorption peak at S303. Calculate the dissolution of rubber powder in rubber powder modified asphalt: A= ； Where A is the absorption rate of rubber powder particles, unit: % I S=Oa is the functional group index of the separated undissolved rubber powder; I S=Ob is the functional group index of the corresponding rubber powder; S4. Calculate the change rate of asphalt rutting factor based on the temperature scanning test parameters to evaluate the dissolution of rubber powder in rubber powder modified asphalt.

2. The method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt according to claim 1, characterized in that: Rubber powder modified asphalt is made by adding rubber powder particles to base asphalt for modification. The rubber powder particles used in rubber powder modified asphalt for road engineering are made from waste tires.

3. The method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt according to claim 1 or 2, characterized in that: The separation process in step S1 is as follows: S101, weighing the rubber powder modified asphalt to be separated in a container, and then heating and melting it to a flowable state; S102, then pour the melted rubber powder modified asphalt into a filter screen, and set an asphalt collector under the filter screen to collect the filtered asphalt, which contains dissolved rubber powder particles; weigh the remaining rubber powder modified asphalt with a container again, and calculate the weight of the rubber powder modified asphalt used for separation; S103, continue to heat the filter screen and the asphalt collector in step S102, and part of the rubber powder modified asphalt remaining on the filter screen will continue to flow through the filter screen to the asphalt collector under the action of gravity, and collect the asphalt in the asphalt collector to obtain the separated asphalt containing dissolved rubber powder; S104, processing to obtain undissolved rubber powder: First, the rubber powder-asphalt mixture on the filter screen treated in step S103 is circulated and flushed with trichloroethylene for 3 to 4 times to dissolve part of the asphalt, and then the scattered rubber powder particles are collected; Then, the collected rubber powder particles were washed again 2 to 3 times by magnetic stirring using trichloroethylene as solvent; Finally, pour the cleaning solution after magnetic stirring cleaning into the sieve together with the rubber powder particles, and rinse again with trichloroethylene until the surface of the rubber powder particles is clean and free of asphalt. Collect the rubber particles on the sieve and dry them to obtain the separated undissolved rubber powder.

4. The method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt according to claim 3, characterized in that: The particle size of the rubber powder particles is 40-120 meshes, and accordingly, the size of the filter screen selected for filtering and separating in step S1 is 150-200 meshes.

5. The method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt according to claim 3, characterized in that: The heating and melting conditions in step S101 are 170±5°C for 1h±5min; Step S103: Continue heating the filter screen and the asphalt collector in step S102 to 195°C±5°C for 15min±3min.

6. The method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt according to claim 3, characterized in that: The magnetic cleaning condition in step S104 is cleaning at a rotation speed of 800 r / min±50 r / min for 15 min±3 min.

7. The method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt according to claim 3, characterized in that: The dissolution rate of the rubber powder particles in step S2 is calculated by the following formula: Dissolution rate of rubber powder particles = 1- 100%; The mass of the undissolved rubber powder is obtained by directly weighing the mass of the undissolved rubber powder separated in step S1; the amount of rubber powder particles added to the rubber powder modified asphalt is calculated based on the mass of the separated rubber powder modified asphalt and the mixing ratio of the rubber powder particles therein.

8. The method for evaluating the degree of solubility of rubber powder and asphalt in rubber powder modified asphalt according to claim 3, characterized in that: Step S4 calculates the asphalt rutting factor change rate according to the temperature scanning test parameters to evaluate the dissolution of the rubber powder in the rubber powder modified asphalt. The specific process is as follows: S401, performing a temperature scanning test on the asphalt containing dissolved rubber powder separated in step S1 and the corresponding unmodified base asphalt, and obtaining the rutting factors G * / sinδ, referred to as G; S402. Calculate the solubility of rubber powder in rubber powder modified asphalt: B= ； Wherein, B is the solubility of rubber powder in rubber powder modified asphalt, unit: % is the rutting factor of asphalt containing dissolved rubber powder after separation, in kPa; It is the rutting factor of the corresponding base asphalt, unit is kPa.

9. Application of the method for evaluating the degree of solubility of rubber powder and asphalt in the rubber powder modified asphalt as described in any one of claims 1 to 8 in a method for preparing rubber powder modified asphalt or a method for construction and application of rubber powder modified asphalt, specifically, using the evaluation result of the degree of solubility of rubber powder and asphalt in the rubber powder modified asphalt obtained by the evaluation method as a theoretical basis to optimize the preparation method or construction and application conditions of the rubber powder modified asphalt, so as to improve the application effect of the rubber powder modified asphalt.

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