Method for rapidly detecting and evaluating thermal storage stability of sbs modified asphalt

Abstract

This invention relates to the field of asphalt testing and evaluation, and provides a rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt. This method includes sample preparation, using a dynamic shear rheometer to measure the composite modulus G* and phase angle δ of the sample at a series of test temperatures, calculating the viscoelastic coefficient Vc under the corresponding test temperature conditions, and obtaining the logarithmic viscoelastic coefficient lg(Vc) through linear regression. c The slope K with respect to the test temperature lg(Vc) According to the slope K lg(Vc) Obtain the stability factor S f According to the stability factor S f The thermal storage stability evaluation level of the test sample is determined. The technical solution of this invention can accurately reflect the sensitivity of SBS modified asphalt to test temperature, accurately characterize the dispersion state of SBS polymer in the matrix asphalt, and thus rapidly evaluate the thermal storage stability of SBS modified asphalt. The operation steps are simple, the accuracy is high, and it is suitable for widespread application.

Description

Technical Field

[0001] This invention relates to the field of modified asphalt stability testing technology, and is a rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt. Background Technology

[0002] Modifying road asphalt with thermoplastic polymers can effectively improve its high-temperature rutting resistance, low-temperature cracking resistance, and fatigue resistance. Currently, the most widely used asphalt modifiers in China include SBS, SBR, PE, and EVA, with SBS being the most widely used. Due to the low polarity of SBS, its molecular weight, density, and solubility parameters differ significantly from those of the base asphalt, resulting in only partial adsorption and compatibility between the SBS polymer and the base asphalt, rather than complete melting. This physically dispersed system is thermodynamically unstable and prone to phase separation, leading to segregation and severely impacting its production and use. Testing the thermal storage stability of SBS-modified asphalt can evaluate the dispersion state of SBS polymers in the base asphalt, determine the thermal storage stability of SBS-modified asphalt, and provide a basis for SBS-modified asphalt quality testing, formulation research, production processing, and engineering applications.

[0003] Currently, the industry uses the polymer-modified asphalt segregation test (T0661-2011) and the polymer-modified asphalt segregation test method (SHT0740-2003) to evaluate the thermal storage stability of SBS modified asphalt. First, the sample is sieved through a 0.3mm sieve, and approximately 50g of the sample is poured into an aluminum tube with a diameter of approximately 25mm and a length of 140mm. After cooling to room temperature, the open end is sealed. Then, the sample tube is placed vertically on a test tube rack and placed in an oven at 163℃±5℃ for 48h±1h. Finally, the sample tube, along with the test tube rack, is removed and placed in a refrigerator, where it is placed vertically for at least 4 hours to allow for rapid cooling and solidification. The sample is then divided into upper, middle, and lower parts, and the upper and lower samples are obtained separately. The difference in softening points (ΔTR&B) using the ring and ball method is used to determine whether the sample is qualified. This test method has low equipment costs and can effectively control the product quality of SBS modified asphalt to a certain extent, therefore it is widely used in countries around the world. However, this method still has some problems: (1) The test takes too long. The current method is complicated and takes at least 53 hours for one test. It cannot evaluate the product properties in time, cannot monitor and adjust the production process in time, and cannot quickly test and accept the product quality, which greatly reduces the production efficiency and delays the construction progress; (2) The diameter of the sample tube (25mm) used to store SBS modified asphalt is too small, which is disproportionate to the size of the industrial storage tank. Moreover, it does not have a stirrer and cannot accurately simulate the actual factory storage conditions. The thermal storage stability of SBS modified asphalt often increases due to the extended thermal storage time and stirring, which leads to a large deviation in the test results, which is inconsistent with the actual situation. (3) The error is large. In the process of segregation value detection, due to the lengthy steps, human factors and instrument errors, it is often difficult to accurately measure its segregation value. (4) For some SBS modified asphalts on the market (such as high asphalt content or modified asphalt with some fillers), the high density material settles to the lower layer during thermal storage, which increases the viscosity and softening point of the lower layer of modified asphalt. The polymer modifier with lower density floats to the top, which enhances the elasticity and toughness of the upper layer of SBS modified asphalt rich in polymers. This also manifests as an increase in the softening point, thereby reducing the difference in softening points between the upper and lower samples, ultimately leading to the erroneous conclusion that the segregation is "qualified". Summary of the Invention

[0004] This invention provides a rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt, which overcomes the shortcomings of the prior art and effectively solves the problems of excessively long test time and inaccurate test results in existing stability evaluation methods.

[0005] The technical solution of this invention is achieved through the following measures: a rapid detection and evaluation method for the thermal storage stability of SBS modified asphalt, comprising the following steps:

[0006] Step 1: Sample preparation. Heat the SBS modified asphalt sample to a constant temperature of 160℃ to 165℃, stir gently, and after the sample is homogeneous and air bubbles are removed, pour it into a 25mm parallel plate mold and cool it to room temperature to prepare the sample for later use.

[0007] Step 2: Parameter determination. Using a dynamic shear rheometer, the composite modulus G* and phase angle δ of the above-mentioned sample were measured at a series of test temperatures. The viscoelastic coefficient V under the corresponding test temperature conditions was calculated using the following equations (1), (2), and (3). c and logarithmic viscoelastic coefficient lg(V c );

[0008] V c (X)=G * ×f(x)×g(x)…………………………………………Equation (1)

[0009] f(x) = |Cos m x|…………………………………………………..Equation (2)

[0010] g(x) = |Sin n x|..…………………………………………….…...Formula (3)

[0011] Where: V c (X) is the viscoelastic coefficient function of the sample to be tested; G* is the composite modulus of the sample to be tested measured by dynamic shear rheology test, in kPa, x is a multiple of the phase angle δ, and m and n cannot be zero at the same time.

[0012] Step 3: Calculate the stability factor: Obtain the logarithmic viscoelastic coefficient lg(V) through linear regression. c The slope K with respect to the test temperature lg(Vc) The stability factor S of the test sample is calculated according to the following formula (4). f ;

[0013]

[0014] Step 4: Stability level evaluation, based on stability factor S f Determine the thermal storage stability rating of the sample to be tested.

[0015] The following are further optimizations and / or improvements to the above-mentioned technical solution:

[0016] In the first step of the above method, the sample preparation process, from the start of heating to the completion of casting the 25mm parallel plate mold, takes no more than 2 hours; the same sample is heated no more than 3 times.

[0017] In the second step of the above method, the parameter determination of the dynamic shear rheological test is controlled by either stress control or strain control. In stress control mode, the stress range is 100 Pa to 1000 Pa; in strain control mode, the strain range is 5% to 50%, and the angular frequency is 5 rad / s to 50 rad / s.

[0018] In the second step of the above method, the parameter determination includes at least four test temperature points, with the test temperature points ranging from 40℃ to 94℃. The values ​​of two adjacent test temperature points in the series are 3℃ or 6℃ apart.

[0019] In the second step of the above method, the parameter determination of the dynamic shear rheology test is controlled by either stress control or strain control. In stress control mode, the stress range is 100 Pa to 500 Pa; in strain control mode, the strain range is 10% to 20%, and the angular frequency is 10 rad / s to 20 rad / s.

[0020] In the second step of the above method, the parameter determination of the series of test temperatures shall include at least four test temperature points, with the test temperature points ranging from 40℃ to 94℃. The series of test temperatures shall include at least the temperature point corresponding to the high temperature PG grade of the sample to be tested, and the values ​​of two adjacent temperature points in the series of test temperatures shall be 3℃ apart.

[0021] In the second step of the above method, the parameter determination is performed using a strain control mode for the dynamic shear rheological test, with a strain magnitude of 12% and an angular frequency of 10 rad / s.

[0022] In the second step of the above method, the parameter determination includes at least four test temperature points, with the test temperature points ranging from 64℃ to 85℃, and the values ​​of two adjacent test temperature points in the series of test temperatures are 3℃ apart.

[0023] In the second step of the above method for parameter determination, in equations (1), (2), and (3): x = 2δ, δ, m = 0, ±1, ±2, ±3, ±4, n = 0, ±1, ±2, ±3, ±4; m and n are not both zero.

[0024] In the second step of the above method for parameter determination, in equations (1), (2), and (3): m=1, 2, 3, 4, n=-1, -2, -3, -4;

[0025] In the second step of the above method, the viscoelastic coefficient V is determined. c Calculate using the following formula (5):

[0026]

[0027] Where: Vc (δ) is the viscoelastic coefficient function, with the value retained to two decimal places; G* is the composite modulus of the test sample measured by dynamic shear rheology test, in kPa, with the value retained to two decimal places; δ is the phase angle of the test sample measured by dynamic shear rheology test, with the value retained to one decimal place.

[0028] The fourth step of the above method involves using the stability factor S. f Determine the thermal storage stability rating of the sample to be tested, where:

[0029] Stability factor S of the sample to be tested f When the value is greater than or equal to 23.5, its thermal storage stability evaluation level is Level 1.

[0030] Stability factor S of the sample to be tested f When the value is greater than 22.0 and less than 23.5, its thermal storage stability evaluation level is Level II;

[0031] Stability factor S of the sample to be tested f When the value is less than or equal to 22.0, its thermal storage stability evaluation level is level three.

[0032] The SBS modified bitumen samples to be tested were prepared in the laboratory or obtained from storage tanks in industrial plants.

[0033] The technical solution of this invention can accurately reflect the sensitivity of SBS modified asphalt to test temperature and accurately characterize the dispersion state of SBS polymer in the matrix asphalt, thereby rapidly evaluating the thermal storage stability of SBS modified asphalt. This invention features simple operation steps, high instrument accuracy, and reliable testing, making it suitable for widespread application. Detailed Implementation

[0034] This invention is not limited to the following embodiments; specific implementation methods can be determined according to the technical solution of this invention and actual conditions. Unless otherwise specified, all chemical reagents and chemical products mentioned in this invention are well-known and commonly used chemical reagents and chemical products in the prior art; room temperature in this invention generally refers to a temperature between 15°C and 25°C, and is generally defined as 25°C.

[0035] The present invention will be further described below with reference to embodiments:

[0036] Example 1:

[0037] The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt of the present invention includes the following steps:

[0038] Step 1: Sample preparation. Heat the SBS modified asphalt sample to a constant temperature of 160℃ to 165℃, stir gently, and after the sample is homogeneous and air bubbles are removed, pour it into a 25mm parallel plate mold and cool it to room temperature to prepare the sample for later use.

[0039] Step 2: Parameter determination. Using a dynamic shear rheometer, the composite modulus G* of the above-mentioned sample was measured at a series of test temperatures, with units of kPa and phase angle δ. The viscoelastic coefficient V under the corresponding test temperature conditions was calculated using the following equations (1), (2), and (3). c and logarithmic viscoelastic coefficient lg(V c );

[0040] V c (X)=G * ×f(x)×g(x)…………………………………………Equation (1)

[0041] f(x) = |Cos m x|…………………………………………………..Equation (2)

[0042] g(x) = |Sin n x|..…………………………………………….…...Formula (3)

[0043] Where: V c (X) is the viscoelastic coefficient function of the sample to be tested; G* is the composite modulus of the sample to be tested measured by dynamic shear rheology test, in kPa; x is a multiple of the phase angle δ; m and n cannot be zero at the same time.

[0044] Step 3: Calculate the stability factor: Obtain the logarithmic viscoelastic coefficient lg(V) through linear regression. c The slope K with respect to the test temperature lg(Vc) The stability factor S of the test sample is calculated according to the following formula (4). f ;

[0045]

[0046] Step 4: Stability level evaluation, based on stability factor S f Determine the thermal storage stability rating of the sample to be tested.

[0047] As needed, the third step is to calculate the stability factor S in the stability factor. f The value is rounded to two decimal places; slope K lg(Vc) The values ​​are rounded to four decimal places, and the linear regression coefficient R0 is... 2 It should be greater than 0.995. If the linear regression coefficient R... 2If the coefficient is less than 0.995, the highest test temperature should be removed step by step from high to low until the linear regression coefficient is greater than or equal to 0.995. Moreover, the test temperature should include at least four or more test temperature points from low to high. Otherwise, the test should be repeated.

[0048] The parallel plate mold used for preparing the test sample is 25mm thick, and the clamps for the dynamic shear rheometer mold are 25mm thick parallel plates, which are matched together.

[0049] Example 2:

[0050] As an optimization of the above embodiment, in the first step of sample preparation, the entire operation process from the start of heating to the completion of casting the 25mm parallel plate mold takes no more than 2 hours, and the number of heating times for the same sample does not exceed 3.

[0051] Example 3: An optimization of the above examples

[0052] In the second step of parameter determination, the dynamic shear rheological test is controlled by either stress control or strain control. In stress control mode, the stress range is 100 Pa to 1000 Pa; in strain control mode, the strain range is 5% to 50%, and the angular frequency is 5 rad / s to 50 rad / s.

[0053] The series of test temperatures includes at least four test temperature points, with the test temperature points ranging from 40℃ to 94℃. The values ​​of two adjacent test temperature points in the series of test temperatures are separated by 3℃ or 6℃.

[0054] Example 4: An optimization of the above examples

[0055] In the second step of parameter determination, the dynamic shear rheological test is controlled by either stress control or strain control. In stress control mode, the stress range is 100 Pa to 500 Pa; in strain control mode, the strain range is 10% to 20%, and the angular frequency is 10 rad / s to 20 rad / s.

[0056] The series of test temperatures includes at least four test temperature points, with the test temperature points ranging from 40℃ to 94℃. The series of test temperatures includes at least the temperature point corresponding to the high-temperature PG grade of the sample to be tested, and the values ​​of two adjacent temperature points in the series of test temperatures are 3℃ apart.

[0057] Example 5: An optimization of the above examples

[0058] In the second step of parameter determination, the dynamic shear rheological test control mode is strain control mode, with a strain magnitude of 12% and an angular frequency of 10 rad / s.

[0059] The series of test temperatures includes at least four test temperature points, with the test temperature points ranging from 64℃ to 85℃, and the values ​​of two adjacent test temperature points in the series of test temperatures are 3℃ apart.

[0060] Example 6: An optimization of the above examples

[0061] In the second step of parameter determination, in equations (1), (2), and (3):

[0062] x = 2δ, δ, m = 0, ±1, ±2, ±3, ±4, n = 0, ±1, ±2, ±3, ±4; m and n are not both zero.

[0063] Example 7: An optimization of the above examples

[0064] In the second step of parameter determination, in equations (1), (2), and (3):

[0065] m=1, 2, 3, 4, n=-1, -2, -3, -4;

[0066] Example 8: An optimization of the above examples

[0067] In the second step of parameter determination, the viscoelastic coefficient V c Calculate using the following formula (5):

[0068]

[0069] Where: V c (δ) is the viscoelastic coefficient function, with the value retained to two decimal places; G* is the composite modulus of the test sample measured by dynamic shear rheology test, in kPa, with the value retained to two decimal places; δ is the phase angle of the test sample measured by dynamic shear rheology test, with the value retained to one decimal place.

[0070] Example 9: An optimization of the above examples

[0071] In the fourth step of stability level evaluation, based on the stability factor S f Determine the thermal storage stability rating of the sample to be tested:

[0072] Stability factor S of the sample to be tested f When the value is greater than or equal to 23.5, its thermal storage stability evaluation level is Level 1.

[0073] Stability factor S of the sample to be tested f When the value is greater than 22.0 and less than 23.5, its thermal storage stability evaluation level is Level II;

[0074] Stability factor S of the sample to be tested fWhen the value is less than or equal to 22.0, its thermal storage stability evaluation level is level three.

[0075] Example 10: An optimization of the above examples

[0076] In the above method, the SBS modified bitumen sample to be tested is prepared in the laboratory or obtained from the storage tank of an industrial plant.

[0077] The technical solution of this invention can be applied to SBS modified asphalt prepared in the laboratory and SBS modified asphalt obtained from storage tanks in industrial plants. In specific applications, the logarithmic viscoelastic coefficient lg(V) can be obtained through linear regression as needed. c The slope K with respect to the test temperature lg(Vc) Furthermore, the stability factor S was obtained. f At that time, the composite modulus G* and phase angle δ obtained from the dynamic shear rheological test can be used to determine the value of V. c (δ) The viscoelastic coefficient V is calculated. c The viscoelastic coefficient V under each test temperature condition was determined. c Taking the logarithm to base 10, we obtain the logarithmic viscoelastic coefficient lg(V). c The numerical value is rounded to two decimal places.

[0078] Based on the logarithmic viscoelastic coefficient lg(V) c The logarithmic viscoelastic coefficient lg(V) is calculated with the test temperature as the abscissa and the corresponding test temperature as the x-axis. c Plot the logarithmic viscoelastic coefficient lg(V) on the ordinate. c For the curve of the test temperature, the slope K of the regression line is obtained by linear regression. lg(Vc) Among them, the slope K of the regression line lg(Vc) The numerical values ​​should be retained to four decimal places. The linear regression coefficient should be greater than or equal to 0.995. If the linear regression coefficient is less than 0.995, the highest test temperature in the series of test temperatures should be removed step by step from high to low until the linear regression coefficient reaches 0.995. In addition, it should be ensured that the test temperature includes at least four test temperature points from low to high. Otherwise, the test should be repeated.

[0079] According to the viscoelastic coefficient function V c The stability factor S determined by the expression (δ) f The thermal storage stability evaluation level of SBS modified asphalt was determined by comparing its correlation with the segregation softening point difference ΔTR&B. The viscoelastic coefficient function V... c Taking (δ) equation (5) as an example, the thermal storage stability evaluation level of SBS modified asphalt is:

[0080] If the stability factor S of the test sample fIf the value is greater than or equal to 23.5, the thermal storage stability evaluation level of the test sample is Level 1, that is, the thermal storage and thermal transportation stability of SBS modified asphalt is excellent, the SBS polymer particles do not aggregate, and it can be used directly and can be stored and transported for a long time.

[0081] If the stability factor S of the test sample f If the value is greater than 22.0 and less than 23.5, the thermal storage stability evaluation level of the test sample is Level II, that is, the thermal storage and thermal transportation stability of SBS modified asphalt is good, but the SBS polymer particles have a tendency to aggregate, and long-term thermal storage and thermal transportation should be avoided.

[0082] If the stability factor S of the test sample f If the value is less than or equal to 22.0, the thermal storage stability evaluation level of the test sample is level three, that is, the thermal storage and thermal transportation stability of SBS modified asphalt is poor, and the SBS polymer particles exhibit obvious aggregation and stratification during thermal storage, making it impossible to perform long-term thermal storage and thermal transportation.

[0083] The technical solution of this invention can accurately reflect the sensitivity of SBS modified asphalt to test temperature and accurately characterize the dispersion state of SBS polymer in the matrix asphalt, thereby rapidly evaluating the thermal storage stability of SBS modified asphalt. This invention features simple operation steps, high instrument accuracy, and reliable testing, making it suitable for widespread application.

[0084] Example 11: Preparation or sampling of the test sample

[0085] Sample 1:

[0086] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-A. The No. 70 road asphalt, co-solvent, and stabilizer KSH-A were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0087] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 230°C, and the stabilizer is added. The mixture is reacted for 3 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0088] Sample 2

[0089] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-A. The No. 70 road asphalt, co-solvent, and stabilizer KSH-A were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0090] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 230°C, and the stabilizer is added. The mixture is reacted for 4 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0091] Sample 3

[0092] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-A. The No. 70 road asphalt, co-solvent, and stabilizer KSH-A were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0093] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 230°C, and the stabilizer is added. The mixture is reacted for 5 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0094] Sample 4

[0095] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 2.0g of stabilizer KSH-B. The No. 70 road asphalt, co-solvent, and stabilizer KSH-B were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0096] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 3 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0097] Sample 5

[0098] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 2.0g of stabilizer KSH-B. The No. 70 road asphalt, co-solvent, and stabilizer KSH-B were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0099] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 4 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0100] Sample 6

[0101] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 2.0g of stabilizer KSH-B. The No. 70 road asphalt, co-solvent, and stabilizer KSH-B were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0102] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 5 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0103] Sample 7

[0104] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 2.0g of stabilizer KSH-B. The No. 70 road asphalt, co-solvent, and stabilizer KSH-B were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0105] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using an FM300 high-shear dispersion emulsifier manufactured by FLUKE. The temperature is raised to 200°C, the stabilizer is added, and the mixture is reacted for 6 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0106] Sample 8

[0107] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 2.0g of stabilizer KSH-B. The No. 70 road asphalt, co-solvent, and stabilizer KSH-B were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0108] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 7 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0109] Sample 9

[0110] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-C. The No. 70 road asphalt, co-solvent, and stabilizer KSH-C were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0111] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 7 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0112] Sample 10

[0113] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-D. The No. 70 road asphalt, co-solvent, and stabilizer KSH-D were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0114] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 7 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0115] Sample 11

[0116] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-E. The No. 70 road asphalt, co-solvent, and stabilizer KSH-E were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0117] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 7 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0118] Sample 12

[0119] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-F. The No. 70 road asphalt, co-solvent, and stabilizer KSH-F were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0120] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 7 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0121] Sample 13

[0122] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-G. The No. 70 road asphalt, co-solvent, and stabilizer KSH-G were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0123] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 7 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0124] Sample 14

[0125] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-H. The No. 70 road asphalt, co-solvent, and stabilizer KSH-H were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0126] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 7 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0127] Sample 15

[0128] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1425g of No. 70 road asphalt, 75g of co-solvent, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-M. The No. 70 road asphalt, co-solvent, and stabilizer KSH-M were all produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0129] The specific operation is as follows: the pre-weighed No. 70 road asphalt is placed in a forced-air drying oven and preheated to 180°C. The pre-weighed co-solvent and SBS polymer are added. The mixture is sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier. The temperature is then raised to 200°C, and the stabilizer is added. The mixture is reacted for 7 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0130] Sample 16

[0131] The sample was obtained from the sampling port of the finished product storage tank in the SBS modified bitumen production workshop of Company A.

[0132] Sample 17

[0133] The sample was taken from the finished product storage tank in the SBS modified bitumen production workshop of Company B.

[0134] Sample 18

[0135] The sample was taken from the finished product storage tank in the SBS modified asphalt production workshop of Company C.

[0136] Sample 19

[0137] The sample was taken from the finished product storage tank in the SBS modified asphalt production workshop of Company D.

[0138] Sample 20

[0139] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1500g of No. 90 road asphalt, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-A. The No. 90 road asphalt was West Pacific No. 90 road asphalt, the stabilizer KSH-A was produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0140] The specific operation is as follows: the pre-weighed No. 90 road asphalt is placed in a blower drying oven and preheated to 180°C. It is then sheared for 15 minutes using a FLUKE FM300 high shear dispersion emulsifier, kept at a constant temperature of 180°C, and stabilizer is added. The mixture is then reacted for 0.5 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0141] Sample 21

[0142] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1500g of No. 90 road asphalt, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-A. The No. 90 road asphalt was West Pacific No. 90 road asphalt, the stabilizer KSH-A was produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0143] The specific operation is as follows: the pre-weighed No. 90 road asphalt is placed in a blower drying oven and preheated to 180°C. It is then sheared for 15 minutes using a FLUKE FM300 high shear dispersion emulsifier, kept at a constant temperature of 180°C, and stabilizer is added. The mixture is then reacted for 1.0 hour under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0144] Sample 22

[0145] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1500g of No. 90 road asphalt, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-A. The No. 90 road asphalt was West Pacific No. 90 road asphalt, the stabilizer KSH-A was produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0146] The specific operation is as follows: the pre-weighed No. 90 road asphalt is placed in a blower drying oven and preheated to 180°C. It is then sheared for 15 minutes using a FLUKE FM300 high shear dispersion emulsifier, kept at a constant temperature of 180°C, and stabilizer is added. The mixture is then reacted for 1.5 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0147] Sample 23

[0148] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1500g of No. 90 road asphalt, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-A. The No. 90 road asphalt was West Pacific No. 90 road asphalt, the stabilizer KSH-A was produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0149] The specific operation is as follows: the pre-weighed No. 90 road asphalt is placed in a blower drying oven and preheated to 180°C. It is then sheared for 15 minutes using a FLUKE FM300 high shear dispersion emulsifier, kept at a constant temperature of 180°C, and stabilizer is added. The mixture is then reacted for 2.0 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0150] Sample 24

[0151] The SBS-modified asphalt sample to be tested was prepared from the following materials: 1500g of No. 90 road asphalt, 75g of 6302L type SBS, and 1.5g of stabilizer KSH-A. The No. 90 road asphalt was West Pacific No. 90 road asphalt, the stabilizer KSH-A was produced by PetroChina Karamay Petrochemical Co., Ltd., and the 6302L type SBS was produced by PetroChina Dushanzi Petrochemical Co., Ltd.

[0152] The specific operation is as follows: the pre-weighed No. 90 road asphalt is placed in a forced-air drying oven and preheated to 180°C. It is then sheared for 15 minutes using a FLUKE FM300 high-shear dispersion emulsifier, kept at a constant temperature of 180°C, and stabilizer is added. The mixture is then reacted for 2.5 hours under stirring conditions of 140 rpm to obtain the SBS modified asphalt sample to be tested.

[0153] Example 12:

[0154] Dynamic shear rheological tests and stability factor calculation

[0155] Dynamic shear rheology tests were conducted on SBS modified asphalt samples 1 to 24 at temperatures ranging from 64℃ to 85℃ using a dynamic shear rheometer. The composite modulus G* and phase angle δ of the samples were obtained at 64℃, 67℃, 70℃, 73℃, 76℃, 79℃, 82℃, and 82℃. The viscoelastic coefficient V was calculated based on the obtained composite modulus G* and phase angle δ. c and logarithmic viscoelastic coefficient lg(V c ), where the viscoelastic coefficient V c The results were obtained by calculation using the above formula (5), and the experimental results are shown in Table 1.

[0156] Then, based on the logarithmic viscoelastic coefficient lg(V) cThe logarithmic viscoelastic coefficient lg(V) is calculated with the test temperature as the abscissa and the corresponding test temperature as the x-axis. c Plot the logarithmic viscoelastic coefficient lg(V) on the ordinate. c For the curve of the test temperature, the slope K of the regression line is obtained by linear regression. lg(Vc) Numerical values ​​are rounded to four decimal places; among them, the linear regression coefficient R0 2 The linear regression coefficient R0 should be greater than or equal to 0.995. 2 If the coefficient is less than 0.995, the highest test temperature in the series of test temperatures must be removed step by step from high to low until the linear regression coefficient reaches 0.995. Furthermore, the test temperature must include at least four test temperature points from low to high; otherwise, the test must be repeated. The stability factor S of the sample to be tested is calculated according to the above formula (4). f The values ​​are rounded to two decimal places. The experimental results are shown in Table 2.

[0157] Example 13:

[0158] Separation test

[0159] To further illustrate the testing effectiveness of the technical solution disclosed in this invention, segregation tests were conducted on SBS modified asphalt samples 1 to 24 according to method T0661-2011 in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTGE20-2011 to determine the thermal storage stability of the SBS modified asphalt. The test results are shown in Table 3.

[0160] The test results show that the evaluation results obtained by using the technical solution of this invention and the method T0661-2011 in the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" JTGE20-2011 for the 23 SBS modified asphalt samples (excluding sample 18) are highly consistent. For samples with more severe segregation and stratification during thermal storage, their rheological properties, i.e., viscoelastic coefficient V, are higher during dynamic shear rheological testing. c The greater the sensitivity to changes in test temperature, the larger the absolute value of the slope of the regression line, and ultimately the smaller the stability factor value. Conversely, for samples that are less prone to segregation and stratification during thermal storage, their rheological properties, i.e., the viscoelastic coefficient V, will be higher during dynamic shear rheological tests. c The less sensitive the value is to changes in the test temperature, the smaller the absolute value of the slope of the regression line, and the larger its stability factor value.

[0161] In terms of instrument precision, the dynamic shear rheometer used in this invention achieves a temperature control accuracy of 0.1℃, a test frequency accuracy of 0.1 rad / s, a strain amplitude accuracy of 0.1%, and an applied stress accuracy of 0.01 N, demonstrating high precision. In terms of the test process, this invention involves fewer test steps, with only the mold handling process being affected by human factors; therefore, the reliability of the test is higher. In terms of test results, the SBS polymer exhibits high sensitivity to changes in test temperature, accurately characterizing the dispersion state of the SBS polymer in the base asphalt, thus enabling rapid assessment of the thermal storage stability of SBS-modified asphalt. Furthermore, it can accurately determine the thermal storage stability of SBS-modified asphalt similar to sample 18, which is difficult to identify through the polymer-modified asphalt segregation test (T 0661-2011). Conversely, the thermal storage stability of samples 1 to 24 was evaluated using the polymer-modified bitumen segregation test (T0661-2011). However, the softening point determination process is susceptible to human factors, such as the sample preparation process, including pouring temperature, isothermal time, isothermal temperature, and scraping process, all of which significantly affect the test results. Furthermore, the instrument's heating rate and sensor accuracy also have a considerable impact on the results during the softening point determination process.

[0162] Most notably, SBS modified asphalt samples similar to Sample 18, when tested using current methods, meet the technical requirement in the "Technical Specification for Construction of Highway Asphalt Pavement" JTGF40-2004 that the segregation index of SBS modified asphalt should not exceed 2.5℃. However, this sample exhibited significant stratification during hot storage. The denser material deposited at the bottom, increasing the viscosity and softening point of the lower layer of SBS modified asphalt. Conversely, the less dense SBS modifier floated to the top, enhancing the elasticity and toughness of the upper layer of SBS modified asphalt rich in polymers, which also resulted in an increased softening point. Ultimately, this reduced the difference in segregation softening points between the upper and lower layers, leading to the erroneous conclusion that the difference was "qualified." Furthermore, the difference in viscosity and ductility between the upper and lower layers also demonstrates that Sample 18 underwent severe segregation stratification during hot storage. Therefore, the difference in segregation softening points cannot accurately reflect these inherent property changes in the SBS modified asphalt material. Conversely, the rapid detection and evaluation method for the thermal storage stability of SBS modified asphalt provided by this invention can accurately and quickly identify that sample 18 has poor thermal storage stability.

[0163] In summary, the above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the requirements of different situations.

[0164] Table 1

[0165]

[0166]

[0167]

[0168] Table 2

[0169]

[0170]

[0171] Table 3

[0172]

[0173]

Claims

1. A rapid method for testing and evaluating the thermal storage stability of SBS modified asphalt, characterized in that... Includes the following steps: Step 1: Sample preparation. Heat the SBS modified asphalt sample to a constant temperature of 160℃ to 165℃, stir gently, and after the sample is homogeneous and air bubbles are removed, pour it into a parallel plate mold and cool it to room temperature to prepare the sample for later use. Step 2: Parameter determination. Using a dynamic shear rheometer, the composite modulus G* and phase angle δ of the above-mentioned sample were measured at a series of test temperatures. The viscoelastic coefficient V under the corresponding test temperature conditions was calculated according to Equations (1), (2), and (3). c and logarithmic viscoelastic coefficient lg(V c ); Where: V c (X) is the viscoelastic coefficient function of the sample under test; G* is the composite modulus of the sample under test measured by dynamic shear rheology test, in kPa; and x is a multiple of the phase angle δ. m = 0, ±1, ±2, ±3, ±4, n = 0, ±1, ±2, ±3, ±4; m and n cannot be zero at the same time; Step 3: Calculate the stability factor: Obtain the logarithmic viscoelastic coefficient lg(V) through linear regression. c The slope K with respect to the test temperature lg(Vc) The stability factor S of the test sample is calculated according to the following formula (4). f ; Step 4: Stability level evaluation, based on stability factor S f Determine the thermal storage stability rating of the sample to be tested.

2. The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt according to claim 1, characterized in that... In the first step of sample preparation, the entire process from the start of heating to the completion of casting a 25mm parallel plate mold takes no more than 2 hours, and the same sample is heated no more than 3 times.

3. The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt according to claim 1 or 2, characterized in that... In the second step of parameter determination, the dynamic shear rheology test control mode is either stress control mode or strain control mode. The stress range in the stress control mode is 100 Pa to 1000 Pa; the strain range in the strain control mode is 5% to 50%, and the angular frequency is 5 rad / s to 50 rad / s; or / and, the series of test temperatures includes at least four test temperature points, the test temperature points range from 40℃ to 94℃, and the values ​​of two adjacent temperature points in the series of test temperatures are separated by 3℃ or 6℃.

4. The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt according to claim 3, characterized in that... In the second step of parameter determination, the dynamic shear rheology test control mode is either stress control mode or strain control mode. The stress range in the stress control mode is 100 Pa to 500 Pa; the strain range in the strain control mode is 10% to 20%, and the angular frequency is 10 rad / s to 20 rad / s; or / and, the series of test temperatures includes at least four test temperature points, the test temperature points range from 40℃ to 94℃, the series of test temperatures includes at least the temperature point corresponding to the high temperature PG level of the sample to be tested, and the two adjacent temperature points in the series of test temperatures are 3℃ apart.

5. The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt according to claim 4, characterized in that... In the second step of parameter determination, the dynamic shear rheology test control mode is strain control mode, the strain magnitude is 12%, and the angular frequency is 10 rad / s; or / and, the series of test temperatures includes at least four test temperature points, the test temperature points range from 64℃ to 85℃, and the values ​​of two adjacent temperature points in the series of test temperatures are 3℃ apart.

6. The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt according to claim 1, characterized in that... In the second step of parameter determination, in equations (1), (2), and (3): m=1, 2, 3, 4, n=-1, -2, -3, -4.

7. The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt according to claim 6, characterized in that... In the second step of parameter determination, the viscoelastic coefficient V c Calculate using the following formula (5): in: G* is the viscoelastic coefficient function, with values ​​rounded to two decimal places; G* is the composite modulus of the sample under test as measured by dynamic shear rheology test, in kPa, with values ​​rounded to two decimal places; δ is the phase angle of the sample under test as measured by dynamic shear rheology test, with values ​​rounded to one decimal place.

8. The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt according to claim 7, characterized in that... Fourth step, based on the stability factor S f Determine the thermal storage stability rating of the sample to be tested, where: Stability factor S of the sample to be tested f When the value is greater than or equal to 23.5, its thermal storage stability evaluation level is Level 1; Stability factor S of the sample to be tested f When the value is greater than 22.0 and less than 23.5, its thermal storage stability evaluation level is Level II; Stability factor S of the sample to be tested f When the value is less than or equal to 22.0, its thermal storage stability evaluation level is level three.

9. The rapid testing and evaluation method for the thermal storage stability of SBS modified asphalt according to claim 1, characterized in that... The SBS modified bitumen samples to be tested were prepared in the laboratory or obtained from storage tanks in industrial plants.

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