A method for studying aging behavior of asphalt binder based on ultraviolet aging full cycle

Abstract

The present application relates to the technical field of road asphalt performance analysis, in particular to a kind of asphalt binder aging behavior research method based on ultraviolet aging full cycle, by 5 steps, finally the full cycle ultraviolet aging resistance ability M value of the asphalt binder to be measured is obtained.Compared with prior art, the beneficial effects of the present application are to construct a research method, based on the numerical value of index M, to realize the quantitative analysis of the ultraviolet aging behavior of asphalt binder, and the analysis result is accurate, the aging behavior and characteristics of asphalt binder can be evaluated and determined through quantitative result, which will provide relevant basis for improving the ultraviolet radiation shielding performance of asphalt binder.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of road asphalt performance analysis, and particularly relates to a method for researching aging behavior of asphalt binder based on ultraviolet aging full cycle. BACKGROUND

[0002] With the rapid development of China's economy and the implementation of the western development strategy, the construction of China's highways will shift to the western region with strong ultraviolet radiation. Asphalt pavement is widely used in highways and urban roads due to its smooth surface, comfortable driving, small vibration, low noise, wear resistance, short construction period, and easy maintenance. As a kind of high polymer material, asphalt will undergo ultraviolet aging under the participation of ultraviolet light and oxygen. Ultraviolet aging will cause changes in the rheological properties, chemical composition structure and other aspects of asphalt to different degrees, and asphalt pavement is prone to temperature shrinkage cracks, pavement potholes, peeling and other problems, which affect the road performance of asphalt pavement and reduce its service life.

[0003] The entire asphalt aging process can be referred to as full cycle aging, and the full cycle aging can be divided into primary aging stage and advanced aging stage according to the aging degree, and the two stages have different aging characteristics. In the primary aging stage, the aging phenomenon mainly occurs in the surface layer of asphalt, and the lower asphalt is not obvious; in the advanced aging stage, the intermigration of the surface layer of the aging asphalt and the lower layer of the unaged asphalt occurs, which causes the whole asphalt to move in the direction of uniformization.

[0004] At present, the research on the aging behavior of asphalt binder is limited to the primary aging stage, and most of them are qualitative evaluation according to the changes of three indicators, rheological properties and other macroscopic properties, and there is a lack of a method based on the full cycle of ultraviolet aging and capable of quantitatively studying the aging behavior of asphalt binder.

[0005] Therefore, in view of the deficiencies of the prior art, it is very necessary to provide a method for researching the aging behavior of asphalt binder based on the full cycle of ultraviolet aging to solve the deficiencies of the prior art. SUMMARY

[0006] The purpose of the present application is to provide a method for researching the aging behavior of asphalt binder based on the full cycle of ultraviolet aging to avoid the deficiencies of the prior art. The method for researching the aging behavior of asphalt binder based on the full cycle of ultraviolet aging realizes the quantitative analysis of the ultraviolet aging behavior of asphalt binder based on the value of index M, which provides relevant basis for improving the ultraviolet radiation shielding performance of asphalt binder.

[0007] The above-mentioned purpose of the present application is realized by the following technical measures:

[0008] A method for researching the aging behavior of asphalt binder based on the full cycle of ultraviolet aging is provided, which is carried out by the following steps:

[0009] S1, preparing a plurality of test pieces of the measured asphalt binder by corresponding bearing molds, and the test pieces are divided into a first test piece for simulating a primary aging stage and a plurality of second test pieces for simulating an advanced aging stage;

[0010] S2, respectively performing ultraviolet aging treatment on the second test pieces and their bearing molds, the second test pieces and their bearing molds, to obtain an aged first test piece and an aged second test piece;

[0011] S3, performing homogenization treatment on the aged second test piece to obtain a homogenized second test piece;

[0012] S4, performing tests on the homogenized second test piece and the aged first test piece to obtain test data;

[0013] S5, determining a linear regression equation of the primary aging stage and a linear regression equation corresponding to the advanced aging stage according to the test data, and then obtaining the full-cycle ultraviolet aging resistance M value of the measured asphalt binder according to the linear regression equation of the primary aging stage and the linear regression equation corresponding to the advanced aging stage.

[0014] In the S2, all the first test pieces and all the second test pieces are controlled to only receive ultraviolet radiation on the upper bottom surface, and the other sides are heat insulated, and each of the first test pieces and each of the second test pieces is the same distance from the ultraviolet lamp tube.

[0015] In the S4, all the homogenized second test pieces and the aged first test piece are respectively subjected to penetration test, ductility test, linear amplitude sweep test LAS and low temperature bending beam rheological test BBR, to obtain penetration data, ductility data, creep rate data and fatigue life data.

[0016] The first test pieces are defined as the first 1.1 test piece, the first 1.2 test piece, the first 1.3 test piece and the first 1.4 test piece.

[0017] Preferably, the S2 is specifically that the first 1.1 test piece and its bearing mold, the first 1.2 test piece and its bearing mold, the first 1.3 test piece and its bearing mold, the first 1.4 test piece and its bearing mold, and the second test piece and its bearing mold are respectively subjected to full-cycle ultraviolet aging treatment, wherein the time of the full-cycle ultraviolet aging treatment is 3h, 6h, 9h, 18h, 36h and 72h respectively, and when the corresponding time is reached, the first 1.1 test piece and its bearing mold, the first 1.2 test piece and its bearing mold, the first 1.3 test piece and its bearing mold, the first 1.4 test piece and its bearing mold, and the second test piece and its bearing mold are taken out as a whole, frozen at 0℃ for 1.5h, and then placed at room temperature for 15min.

[0018] Preferably, the above S3 specifically comprises:

[0019] S3.1, demoulding all the second test pieces after aging respectively, and placing them in homogenization glass dishes respectively, then adding carbon disulfide to dissolve the second test pieces after aging, to obtain carbon disulfide-pitch solutions;

[0020] S3.2, pouring each of the carbon disulfide-pitch solutions into a penetration sampling glass dish, a LAS sampling glass dish, an elongation sampling glass dish and a BBR sampling glass dish respectively, then placing the carbon disulfide-pitch solutions and the penetration sampling glass dish, the carbon disulfide-pitch solutions and the LAS sampling glass dish, the carbon disulfide-pitch solutions and the elongation sampling glass dish, and the carbon disulfide-pitch solutions and the BBR sampling glass dish in a temperature of 45℃ respectively, so that the carbon disulfide is completely evaporated, to obtain a penetration homogenization test piece, a LAS homogenization test piece, an elongation homogenization test piece and a BBR homogenization test piece.

[0021] In the above S3.1, the mass ratio of carbon disulfide to the second test piece after aging in each carbon disulfide-pitch solution is 3:1.

[0022] In the above S3.2, the mass of each of the carbon disulfide-pitch solutions and the penetration sampling glass dish, the carbon disulfide-pitch solutions and the LAS sampling glass dish, the carbon disulfide-pitch solutions and the elongation sampling glass dish, and the carbon disulfide-pitch solutions and the BBR sampling glass dish is measured every 15 minutes respectively, and when the mass of two adjacent measurements is the same, it is determined that the carbon disulfide is completely evaporated.

[0023] Preferably, the above S4 specifically comprises:

[0024] S4.1, demoulding the first test piece after aging to obtain a treatment, and defining the first test piece after aging as a first 1.1 test piece, a first 1.2 test piece, a first 1.3 test piece and a first 1.4 test piece respectively;

[0025] S4.2, cutting the homogenization second test piece to obtain a final penetration homogenization test piece, a final elongation homogenization test piece, a final LAS homogenization test piece and a final BBR homogenization test piece;

[0026] S4.3, performing a penetration test on the first 1.1 test piece after aging to obtain first penetration data, and performing a penetration test on the final penetration homogenization test piece to obtain second penetration data;

[0027] The first ductility data is obtained by carrying out a ductility test on the first 1.2 test piece after aging, and the second ductility data is obtained by carrying out a ductility test on the final ductility homogenization test piece;

[0028] The first creep rate data is obtained by carrying out a BBR test on the first 1.3 test piece after aging, and the second creep rate data is obtained by carrying out a BBR test on the final BBR homogenization test piece;

[0029] The first fatigue life data is obtained by carrying out a LAS test on the first 1.4 test piece after aging, and the second fatigue life data is obtained by carrying out a LAS test on the final LAS homogenization test piece.

[0030] In the S4.2, the cutting treatment of the penetration homogenization test piece is specifically cutting the penetration homogenization test piece by a first ring-shaped cutter, and finally obtaining a cut penetration homogenization test piece with an inner diameter of 5.5 cm and a height of 3.5 cm. Then the cut penetration homogenization test piece is placed at a temperature of 0℃ for 24h to obtain a final penetration homogenization test piece.

[0031] Preferably, the cutting treatment of the ductility homogenization test piece is specifically cutting the ductility homogenization test piece by an I-shaped cutter, and finally obtaining a cut ductility homogenization test piece with a height of 2.0 cm and a shape consistent with that of the I-shaped cutter. Then the cut ductility homogenization test piece is placed at a temperature of 0℃ for 24h to obtain a final ductility homogenization test piece;

[0032] Preferably, the cutting treatment of the LAS homogenization test piece is specifically cutting the LAS homogenization test piece by a second ring-shaped cutter, and finally obtaining a cut LAS homogenization test piece with an inner diameter of 0.8 cm and a height of 1 cm. Then the cut LAS homogenization test piece is placed at a temperature of 0℃ for 24h to obtain a final LAS homogenization test piece;

[0033] Preferably, the cutting treatment of the BBR homogenization test piece is specifically cutting the BBR homogenization test piece by a straight cutter, and finally obtaining a cut BBR homogenization test piece with a length of 12.7 cm, a width of 1.27 cm, and a height of 6.35 mm. Then the cut BBR homogenization test piece is placed at a temperature of 0℃ for 24h to obtain a final BBR homogenization test piece.

[0034] Preferably, the first ring-shaped cutter, the I-shaped cutter, the second ring-shaped cutter, and the straight cutter all need to be heated at 140℃ for 2h before cutting.

[0035] Preferably, the S5 specifically comprises:

[0036] S5.1, according to the full cycle UV aging treatment time as the abscissa, the penetration as the ordinate, according to the first penetration data to obtain the first penetration linear regression equation Y=k 针入度1 X+b 针入度1 , according to the second penetration data to obtain the second penetration linear regression equation Y=k 针入度2 X+b 针入度2 , the first penetration linear regression equation corresponding to the straight line is defined as L 针入度1 , and the second penetration linear regression equation corresponding to the straight line is L 针入度2 ;

[0037] According to the full cycle UV aging treatment time as the abscissa, the elongation as the ordinate, according to the first elongation data to obtain the first elongation linear regression equation Y=k 延度1 X+b 延度1 , according to the second elongation data to obtain the second elongation linear regression equation Y=k 延度2 X+b 延度2 , the first elongation linear regression equation corresponding to the straight line is defined as L 延度1 and the second elongation linear regression equation corresponding to the straight line is L 延度2 ;

[0038] According to the full cycle UV aging treatment time as the abscissa, the creep rate as the ordinate, according to the first creep rate data to obtain the first BBR linear regression equation Y=k BBR1 X+b BBR1 , according to the first creep rate data to obtain the second BBR second elongation linear regression equation Y=k BBR2 X+b BBR2 , the first BBR linear regression equation corresponding to the straight line is defined as L BBR1 and the second BBR linear regression equation corresponding to the straight line is L BBR2 ;

[0039] According to the full cycle UV aging treatment time as the abscissa, the fatigue life as the ordinate, according to the first fatigue life data to obtain the first LAS linear regression equation Y=k LAS1 X+b LAS1 , according to the second fatigue life data to obtain the second LAS second elongation linear regression equation Y=k LAS2 X+b LAS2 , the first LAS linear regression equation corresponding to the straight line is defined as L LAS1 and the second LAS linear regression equation corresponding to the straight line is L LAS2 ;

[0040] S5.2, obtain the trapezoidal area S 针入度 , the trapezoidal area S 延度 , the trapezoidal area S BBRand the area S of the trapezoid LAS Obtain the intersection point T 针入度 Intersection T 延度 Intersection T LAS Intersection point T BBR2 ;

[0041] The area S of the trapezoid 针入度 The method involves drawing a perpendicular line from the start time of the full-cycle UV aging process to obtain the first perpendicular line, and drawing a perpendicular line from the end time of the full-cycle UV aging process to obtain the second perpendicular line. The L value is then calculated using the Log function. 针入度1 and L 针入度2 Convert the ordinate to logarithmic values, and then according to L 针入度1 L 针入度2 The area of ​​the trapezoid formed by the four lines—the first perpendicular line, the second perpendicular line, and the third perpendicular line—is S. 针入度 ;

[0042] The area S of the trapezoid 延度 The method to obtain L is through the Log function. 延度1 and L 延度2 Convert the ordinate to logarithmic values, and then according to L 延度1 L 延度2 The area of ​​the trapezoid formed by the first perpendicular line, the second perpendicular line, and the other two perpendicular lines is S. 延度 ;

[0043] The area S of the trapezoid BBR The method to obtain L is through the Log function. BBR1 and L BBR2 Convert the ordinate to logarithmic values, and then according to L BBR1 L BBR2 The area of ​​the trapezoid formed by the first perpendicular line, the second perpendicular line, and the other two perpendicular lines is S. BBR ;

[0044] The area S of the trapezoid LAS The method to obtain L is through the Log function. LAS1 and L LAS2 Convert the ordinate to logarithmic values, and then according to L LAS1 L LAS2 The area of ​​the trapezoid formed by the first perpendicular line, the second perpendicular line, and the other two perpendicular lines is S. LAS ;

[0045] The intersection point T 针入度 The method to obtain is based on L 针入度1 and L 针入度2 The intersection of the two lines is T. 针入度 And the intersection point T 针入度 The corresponding coordinates are (X) 针入度 Y 针入度 );

[0046] The intersection point T 延度 The method to obtain is based on L 延度1 and L 延度2 The intersection of the two lines is T. 延度 And the intersection point T 延度 The corresponding coordinates are (X) 延度 Y 延度 );

[0047] The intersection point T BBR The method to obtain is based on L BBR1 and L BBR2 The intersection of the two lines is T. BBR And the intersection point T BBR The corresponding coordinates are (X) BBR Y BBR );

[0048] The intersection point T LAS The method to obtain is based on L LAS1 and L LAS2 The intersection of the two lines is T. LAS And the intersection point T LAS The corresponding coordinates are (X) LAS Y LAS );

[0049] S5.3 is obtained through the following steps:

[0050] S5.3.1, the area S of the trapezoid 针入度 Area S of the trapezoid 延度 Area S of the trapezoid LAS and the area S of the trapezoid BBR S is obtained by summing. 总和 Calculate the area S of the trapezoid. 针入度 In S 总和 The weight A of the penetration is obtained by the proportion. 针入度 Calculate the area S of the trapezoid. 延度 In S 总和 The weight A of the length is obtained by the proportion. 延度 Calculate the area S of the trapezoid. BBR In S 总和 The weight A of BBR is obtained by the proportion. BBR Calculate the area S of the trapezoid. LAS In S 总和 The weight A of LAS is obtained by the proportion. LAS ;

[0051] S5.3.2, using the formula M = X 针入度 A 针入度 +X 延度 A 延度

[0052] +X BBR A BBR +X LAS A LAS The UV aging resistance M value of the measured asphalt binder is calculated.

[0053] In S5.1, the change of the consistency of the measured asphalt binder in the primary aging stage and the advanced aging stage is obtained according to the relationship between |k 针入度1 | and |k 针入度2 | The change of the plasticity of the measured asphalt binder in the primary aging stage and the advanced aging stage is obtained according to the relationship between |k 延度2 | and |k 延度1 | The change of the fatigue performance of the measured asphalt binder in the primary aging stage and the advanced aging stage is obtained according to the relationship between |k BBR2 | and |k BBR1 | The change of the low temperature performance of the measured asphalt binder in the primary aging stage and the advanced aging stage is obtained according to the relationship between |k LAS2 | and |k LAS1 |.

[0054] Preferably, the first 1.1 test piece after aging is a cylindrical structure with a height of 3 cm and a diameter of 5.5 cm.

[0055] Preferably, the first 1.2 test piece after aging has a height of 2.0 cm, a length of 7.5 cm, a width of 3.2 cm at both ends, a narrowest width of 1.2 cm in the middle, and an included angle of 150° at the narrowest middle, and the first 1.2 test piece after aging is a left-right and top-bottom symmetrical structure.

[0056] Preferably, the I-shaped cutter has a height of 2.0 cm, a length of 7.5 cm, a width of 3.2 cm at both ends, a narrowest width of 1.2 cm in the middle, and an included angle of 150° at the narrowest middle, and the I-shaped cutter is a left-right and top-bottom symmetrical structure, and the shape of the first 1.2 test piece after aging matches the shape of the I-shaped cutter.

[0057] Preferably, the first 1.3 test piece after aging is a cylindrical structure with a height of 1 cm and a diameter of 0.8 cm.

[0058] Preferably, the first 1.4 test piece after aging is a long strip structure with a length of 12.7 cm, a width of 1.27 cm, and a height of 6.35 mm.

[0059] Preferably, the second test piece after aging is a cylindrical structure with a height of 5 mm and a diameter of 25 cm.

[0060] Preferably, the homogenization glass dish has a diameter of 25 cm and a height of 3 cm.

[0061] Preferably, the diameter of the penetration sampling glass dish is 7.9 cm, and the height is 15 cm.

[0062] Preferably, the diameter of the ductility sampling glass dish is 13.7 cm, and the height is 5 cm.

[0063] Preferably, the diameter of the BBR sampling glass dish is 17.2 cm, and the height is 3 cm.

[0064] Preferably, the diameter of the LAS sampling glass dish is 25 cm, and the height is 3 cm.

[0065] In the S4.3, the first ring-shaped cutter, the I-shaped cutter, the second ring-shaped cutter and the straight cutter all need to be heated at 140 DEG C for 2h before cutting.

[0066] Preferably, the penetration test is carried out according to T0604-2019 of JTG E20-2019 "Highway Engineering Asphalt and Asphalt Mixture Test Procedures".

[0067] Preferably, the ductility test is carried out according to T0605-2019 of JTG E20-2019 "Highway Engineering Asphalt and Asphalt Mixture Test Procedures".

[0068] Preferably, the BBR test is carried out according to AASHTO-T313 specification, and a 3-point load of 980 mN ± 50 mN is applied, and the loading time is 8 seconds, 15 seconds, 30 seconds, 60 seconds, 120 seconds and 240 seconds, respectively.

[0069] Preferably, the LAS test is carried out according to AASHTO-T312 specification, and the test temperature is 18 DEG C, the plate size is 8 mm, the interval is 2 mm, and two sets of parallel tests are used.

[0070] The application provides a kind of based on the research method of asphalt binder aging behavior of ultraviolet aging full cycle, by following steps are carried out: S1, the asphalt binder to be measured is prepared into multiple test pieces by corresponding bearing mold, and the test piece is divided into the first test piece for simulating primary aging stage and multiple second test pieces for simulating advanced aging stage;S2, the second test piece and its bearing mold, the second test piece and its bearing mold are respectively subjected to ultraviolet aging treatment, to obtain the first test piece after aging and the second test piece after aging correspondingly;

[0071] S3, the second test piece after aging is homogenized to obtain a homogenized second test piece; S4, the homogenized second test piece and the first test piece after aging are tested to obtain corresponding test data; S5, a linear regression equation of the primary aging stage and a linear regression equation corresponding to the advanced aging stage are determined according to the test data, and then the full-cycle ultraviolet aging resistance M value of the measured asphalt binder is obtained according to the linear regression equation of the primary aging stage and the linear regression equation corresponding to the advanced aging stage. Compared with the prior art, the beneficial effects of the present application are that a research method is constructed, the ultraviolet aging behavior of the asphalt binder is quantitatively analyzed based on the numerical value of the index M, and the analysis result is accurate, the aging behavior and characteristics of the asphalt binder can be evaluated and determined through the quantitative result, which provides relevant basis for improving the ultraviolet radiation shielding performance of the asphalt binder. BRIEF DESCRIPTION OF DRAWINGS

[0072] The application is further described with reference to the accompanying drawings, but the content of the drawings does not constitute any limitation on the application.

[0073] Figure 1 It is a size marking diagram of the I-shaped ring knife.

[0074] Figure 2 It is a linear regression equation straight line diagram of each test.

[0075] Figure 3 It is an area calculation diagram of the primary aging stage and the advanced aging stage of each test.

[0076] Figure 4 It is a determination diagram of the intersection point of the linear regression equation of the primary aging stage and the advanced aging stage of each test.

[0077] Figure 5 It is a linear regression diagram of the penetration test of 70# base asphalt.

[0078] Figure 6 It is a linear regression diagram of the penetration test of T770 modified asphalt.

[0079] Figure 7 It is a linear regression diagram of the ductility test of 70# base asphalt.

[0080] Figure 8 It is a linear regression diagram of the ductility test of T770 modified asphalt.

[0081] Figure 9 It is a linear regression diagram of the LAS test of 70# base asphalt.

[0082] Figure 10 It is a linear regression diagram of the LAS test of T770 modified asphalt.

[0083] Figure 11Linear regression graph of BBR test of 70# base asphalt.

[0084] Figure 12 Linear regression graph of BBR test of T770 modified asphalt. DETAILED DESCRIPTION

[0085] The technical solutions of the present application are further described in combination with the following examples. The experimental methods in the following examples are all conventional methods unless otherwise specified. The raw materials, reagent materials, etc. used in the following examples can be purchased from conventional biochemical reagent stores or pharmaceutical business enterprises unless otherwise specified.

[0086] Example 1

[0087] A method for researching the aging behavior of asphalt binder based on the whole cycle of ultraviolet aging, which is carried out by the following steps:

[0088] S1, the measured asphalt binder is prepared into a plurality of test pieces through the corresponding bearing mold, and the test pieces are divided into a first test piece for simulating the primary aging stage and a plurality of second test pieces for simulating the advanced aging stage; wherein the first test piece is defined as the 1.1 test piece, the 1.2 test piece, the 1.3 test piece, and the 1.4 test piece, respectively;

[0089] S2, the second test piece and its bearing mold, and the second test piece and its bearing mold are respectively subjected to ultraviolet aging treatment, and the first test piece after aging and the second test piece after aging are correspondingly obtained;

[0090] S3, the second test piece after aging is subjected to homogenization treatment to obtain a homogenized second test piece;

[0091] S4, the homogenized second test piece and the first test piece after aging are subjected to testing to correspondingly obtain test data; wherein all the homogenized second test pieces and the first test pieces after aging are respectively subjected to penetration test, ductility test, linear amplitude sweep test LAS, and low-temperature bending beam rheological test BBR to correspondingly obtain penetration data, ductility data, creep rate data, and fatigue life data; the evaluation index of the penetration test of the present application is penetration, with the unit of cm; the evaluation index of the ductility test is ductility, with the unit of cm; the evaluation index of the BBR test is creep rate, with the unit of s / Mpa; and the evaluation index of the LAS test is fatigue life, with the unit of times;

[0092] S5, the linear regression equation of the primary aging stage and the linear regression equation corresponding to the advanced aging stage are determined according to the test data, and then the whole cycle ultraviolet aging resistance M value of the measured asphalt binder is obtained according to the linear regression equation of the primary aging stage and the linear regression equation corresponding to the advanced aging stage.

[0093] It should be noted that the soluble components in the asphalt in the primary aging stage volatilize under the action of ultraviolet radiation, and the asphalt is hardened and brittle, thereby affecting the performance of the asphalt, and the primary aging stage mainly occurs in the surface aging layer of the asphalt. The first test piece simulates the primary aging stage, and the first test piece is directly tested after being treated by ultraviolet aging and surface treatment. For the advanced aging stage, due to the long-term action of ultraviolet radiation, the asphalt in the surface aging layer interacts with the asphalt in the lower part which does not participate in aging, the surface asphalt gradually migrates downward, the lower asphalt migrates upward, and the aged asphalt and the unaged asphalt are fused with each other. The first test piece is directly tested after being treated by ultraviolet aging and surface treatment, and the phenomenon of interaction and fusion of the upper aging layer asphalt and the lower aging asphalt in the advanced aging stage is simulated by homogenization treatment.

[0094] Preparation of the first test piece in S1: place each bearing mold on a water platform, and use a level to ensure the levelness of the bearing mold; uniformly apply a release agent to the inner wall and bottom of the bearing mold, and the coating film thickness is 1 mm; heat the measured asphalt binder to a molten state, slowly and uniformly pour the measured asphalt binder from the center of the bearing mold, and ensure the flatness of the test piece. Since the height of the asphalt after ultraviolet aging may shrink, the pouring of the measured asphalt binder is stopped when the height of the measured asphalt binder is 1 mm higher than the top surface of the bearing mold, then the test piece is hardened after being placed at room temperature for 24 h, and then placed in a refrigerator at 0 ℃ for 48 h to ensure the stability of the asphalt state. Before ultraviolet aging treatment, the test mold is placed in a dry box at 25 ℃ for 48 h to remove the water in the bearing mold.

[0095] Preparation of the second test piece in S1: place a cylindrical bearing mold with a uniform size of a depth of 1 cm and an inner diameter of 25 cm on a water platform, and use a level to ensure the levelness of the bearing mold; uniformly apply a release agent to the inner wall and bottom of the bearing mold, and the coating film thickness is 1 mm; the pouring height of the second test piece is 5 mm, and a yellow marker is used to make a clear mark at a distance of 5 mm from the bottom of the inner wall of the bearing mold; heat the measured asphalt binder to a molten state (wherein the base asphalt is 120-140 ℃, and the modified asphalt is 130-150 ℃), slowly and uniformly pour the measured asphalt binder from the center of the bearing mold, and ensure the flatness of the test piece. At the same time, considering the height shrinkage of the asphalt after ultraviolet aging, the pouring of the measured asphalt binder is stopped when the height of the measured asphalt binder is slightly higher than the yellow mark line by 1 mm; the test piece is hardened after being placed at room temperature for 24 h, and then placed in a refrigerator at 0 ℃ for 48 h to ensure the stability of the asphalt state; before ultraviolet aging treatment, the bearing mold is placed in a dry box at 25 ℃ for 48 h to remove the water in the bearing mold.

[0096] In S2, all first test pieces and all second test pieces are controlled to only receive ultraviolet radiation on the upper bottom surface, other sides are heat insulated, and each first test piece and each second test piece is away from the ultraviolet lamp tube by the same distance, so that the ultraviolet radiation intensity received by all test pieces is consistent. The first 1.2 test piece, the first 1.3 test piece, the first 1.4 test piece and the second test piece are padded by using ceramic sheets of different heights, so that the height of the upper surface of the first 1.1 test piece, the first 1.2 test piece, the first 1.3 test piece, the first 1.4 test piece and the second test piece from the ultraviolet lamp tube is uniformly 60 cm. The ultraviolet aging equipment and aging parameter setting used in the present application are as follows: an enclosed ultraviolet weather resistance test box is used for aging; a xenon lamp or an ultraviolet aging lamp is used as the radiation light source to simulate the full sunlight spectrum; the aging temperature of the ultraviolet aging box is set to 60℃; the irradiation intensity of the ultraviolet aging box is set to 0.68W / m 2 .

[0097] S2 is specifically that the first 1.1 test piece and its bearing mold, the first 1.2 test piece and its bearing mold, the first 1.3 test piece and its bearing mold, the first 1.4 test piece and its bearing mold and the second test piece and its bearing mold are respectively subjected to whole-cycle ultraviolet aging treatment, and the time of the whole-cycle ultraviolet aging treatment is 3h, 6h, 9h, 18h, 36h and 72h respectively. When the corresponding time is reached, the corresponding first 1.1 test piece and its bearing mold, the first 1.2 test piece and its bearing mold, the first 1.3 test piece and its bearing mold, the first 1.4 test piece and its bearing mold and the second test piece and its bearing mold are taken out, frozen at 0℃ for 1.5h, and then placed at room temperature for 15min.

[0098] Regarding the number of test pieces, each first 1.1 test piece, first 1.2 test piece, first 1.3 test piece and first 1.4 test piece needs to be subjected to 3h, 6h, 9h, 18h, 36h and 72h aging treatment, and the first 1.1 test piece is subjected to penetration test, the first 1.2 test piece is subjected to ductility test, the first 1.3 test piece is subjected to linear amplitude scanning test LAS, and the first 1.3 test piece is subjected to low temperature bending beam rheological test BBR, so the number of first 1.1 test pieces, first 1.2 test pieces, first 1.3 test pieces and first 1.4 test pieces is at least 6. Each second test piece needs to be subjected to 3h, 6h, 9h, 18h, 36h and 72h aging treatment, and each second test piece needs to be subjected to penetration test, ductility test, linear amplitude scanning test LAS and low temperature bending beam rheological test BBR at each time, so the number of second test pieces is at least 24.

[0099] It also needs to be said that the mold selected for the first test piece simulating the primary aging stage should have thermal insulation properties, and the material is silica gel material. The mold shape and size are customized according to the corresponding test piece mold size requirements of the aging performance evaluation test 1:1, to ensure that the silica gel mold size is consistent with the specified size. It needs to be explained that the thermal insulation treatment of the four sides and the bottom of the test piece is required for S2, to avoid the heat conduction of the mold causing the asphalt bottom and the surrounding to be heated, which in turn causes the asphalt surface aging layer to be mixed with the lower unaged asphalt, affecting the test results.

[0100] The height of the first 1.2 test piece after aging is 2.0 cm, the length is 7.5 cm, the width of both ends is 3.2 cm, the narrowest width in the middle is 1.2 cm, the included angle of the narrowest part in the middle is 150°, and the first 1.2 test piece after aging is a left-right and up-down symmetric structure. The height of the H-shaped cutter is 2.0 cm, the length is 7.5 cm, the width of both ends is 3.2 cm, the narrowest width in the middle is 1.2 cm, the included angle of the narrowest part in the middle is 150°, and the H-shaped cutter is a left-right and up-down symmetric structure. The shape of the first 1.2 test piece after aging matches the H-shaped cutter. The shape and size of the H-shaped cutter and the first 1.2 test piece after aging of the present application are shown in Figure 1

[0101] The first 1.3 test piece after aging is a cylindrical structure with a height of 1 cm and a diameter of 0.8 cm; the first 1.4 test piece after aging is a long strip structure with a length of 12.7 cm, a width of 1.27 cm, and a height of 6.35 mm, and the second test piece after aging is a cylindrical structure with a height of 5 mm and a diameter of 25 cm. Based on the above reasons, the actual height of the first 1.1 test piece obtained in S1 is 3.1 cm, the height of the first 1.2 test piece is 2.1 cm, the height of the first 1.3 test piece is 1.1 cm, the height of the first 1.4 test piece is 7.35 mm, and the height of the second test piece is 6 mm. Moreover, the bearing mold corresponding to the first test piece in S1 corresponds to the above size one by one.

[0102] S3 specifically includes:

[0103] S3.1, demold all the second test pieces after aging, and respectively put them into homogenization glass dishes, then add carbon disulfide to the homogenization glass dishes to dissolve the second test pieces after aging, to obtain multiple carbon disulfide-asphalt solutions;

[0104] ​S3.2, pour each part of carbon disulfide-pitch solution into the penetration sampling glass dish, LAS sampling glass dish, ductility sampling glass dish and BBR sampling glass dish respectively, then place the carbon disulfide-pitch solution and the penetration sampling glass dish, the carbon disulfide-pitch solution and the LAS sampling glass dish, the carbon disulfide-pitch solution and the ductility sampling glass dish and the carbon disulfide-pitch solution and the BBR sampling glass dish in a temperature of 45℃ respectively to make the carbon disulfide completely evaporate, and correspondingly obtain the penetration homogenization sample, the LAS homogenization sample, the ductility homogenization sample and the BBR homogenization sample.

[0105] The diameter of the homogenization glass dish is 25 cm, and the height is 3 cm; the diameter of the penetration sampling glass dish is 7.9 cm, and the height is 15 cm. The diameter of the ductility sampling glass dish is 13.7 cm, and the height is 5 cm. The diameter of the BBR sampling glass dish is 17.2 cm, and the height is 3 cm. The diameter of the LAS sampling glass dish is 25 cm, and the height is 3 cm.

[0106] It needs to be explained that the reason why carbon disulfide is used in the present application is that the solubility of carbon disulfide to pitch is high, and when the pitch is hardened at 45℃, the carbon disulfide can be quickly volatilized and does not affect the chemical properties of the pitch. It also needs to be particularly emphasized that because the penetration test, the ductility test, the linear amplitude scanning test LAS and the low temperature bending beam rheological test BBR have requirements on the height and other sizes of the sample, and in order to ensure that the height and size of the first sample after aging correspond to the first 1.1 sample after aging, the first 1.2 sample after aging, the first 1.3 sample after aging and the first 1.4 sample after aging respectively, the other sizes of the second sample after aging can be achieved by cutting. The height is determined according to the height requirements of the penetration test, the ductility test, the linear amplitude scanning test LAS and the low temperature bending beam rheological test BBR on the sample, and because the volume of the second sample after aging is fixed, the height of the penetration homogenization sample, the LAS homogenization sample, the ductility homogenization sample and the BBR homogenization sample can be finally limited by adjusting the diameters of the penetration sampling glass dish, the LAS sampling glass dish, the ductility sampling glass dish and the BBR sampling glass dish.

[0107] S4 specifically includes:

[0108] S4.1, demolding the first sample after aging to obtain a processed sample, and defining the first sample after aging as the first 1.1 sample after aging, the first 1.2 sample after aging, the first 1.3 sample after aging and the first 1.4 sample after aging respectively;

[0109] S4.2, the homogenized second test piece is cut and treated, and the homogenized second test piece is defined as a penetration homogenized test piece, a LAS homogenized test piece, an elongation homogenized test piece and a BBR homogenized test piece, respectively, to obtain a final penetration homogenized test piece, a final elongation homogenized test piece, a final LAS homogenized test piece and a final BBR homogenized test piece;

[0110] S4.3, the first 1.1 test piece after aging is subjected to a penetration test to obtain first penetration data, and the final penetration homogenized test piece is subjected to a penetration test to obtain second penetration data;

[0111] The first 1.2 test piece after aging is subjected to an elongation test to obtain first elongation data, and the final elongation homogenized test piece is subjected to an elongation test to obtain second elongation data;

[0112] The first 1.3 test piece after aging is subjected to a BBR test to obtain first creep rate data, and the final BBR homogenized test piece is subjected to a BBR test to obtain second creep rate data;

[0113] The first 1.4 test piece after aging is subjected to a LAS test to obtain first fatigue life data, and the final LAS homogenized test piece is subjected to a LAS test to obtain second fatigue life data.

[0114] In S4.2, the cutting treatment of the penetration homogenized test piece is specifically cutting the penetration homogenized test piece by a first ring-shaped cutter, and finally obtaining a cut penetration homogenized test piece with an inner diameter of 5.5 cm and a height of 3.5 cm, and then the cut penetration homogenized test piece is placed at a temperature of 0℃ for 24h to obtain a final penetration homogenized test piece; the final penetration homogenized test piece is placed in a penetration metal sample dish after freezing, and the test mold is placed in a 25℃ drying box for 12h before testing;

[0115] In S4.2, the cutting treatment of the elongation homogenized test piece is specifically cutting the elongation homogenized test piece by an I-shaped cutter, and finally obtaining a cut elongation homogenized test piece with a height of 2.0 cm and a shape consistent with the shape of the I-shaped cutter, and then the cut elongation homogenized test piece is placed at a temperature of 0℃ for 24h to obtain a final elongation homogenized test piece; the final elongation homogenized test piece is loaded into an I-shaped test mold, the test mold is taken out after being stored in a refrigerator at 0℃ for 24h, and the test mold is placed in a 25℃ drying box for 12h before testing.

[0116] In S4.2, the cutting treatment of the LAS homogenization sample is specifically that the second annular cutter cuts the LAS homogenization sample, and finally a cut LAS homogenization sample with an inner diameter of 0.8 cm and a height of 1 cm is obtained. Then, the cut LAS homogenization sample is placed at a temperature of 0℃ for 24 hours to obtain a final LAS homogenization sample. The final LAS homogenization sample is placed on a glass plate coated with a release agent and is taken out after being stored in a refrigerator at 0℃ for 24 hours. Then, the test mold is placed in a dry box at 25℃ for 12 hours before the test is performed.

[0117] In S4.2, the cutting treatment of the BBR homogenization sample is specifically that the straight cutter cuts the BBR homogenization sample, and finally a cut BBR homogenization sample with a length of 12.7 cm, a width of 1.27 cm, and a height of 6.35 mm is obtained. Then, the cut BBR homogenization sample is placed at a temperature of 0℃ for 24 hours to obtain a final BBR homogenization sample. The final BBR homogenization sample is placed on a glass plate coated with a release agent and is taken out after being stored in a refrigerator at 0℃ for 24 hours. Then, the test mold is placed in a dry box at 25℃ for 12 hours before the test is performed.

[0118] It should be further noted that, in order to facilitate cutting, the first annular cutter, the I-shaped cutter, the second annular cutter, and the straight cutter in S4.2 all need to be heated at 140℃ for 2 hours before cutting. The above cutters are all steel cutters with a blade thickness of not more than 0.3 mm and a cutter material of high-carbon stainless steel. The first annular cutter is a circular closed cutter with an inner diameter of 5.5 cm and a depth of 5 cm. The second annular cutter is a circular closed cutter with an inner diameter of 0.8 mm and a corresponding depth of 1 cm. The size of the I-shaped cutter is customized according to the I-shaped test mold 1:1, and specific dimensions are shown in the attached drawings. Figure 1 .

[0119] The S5 of the present application specifically includes:

[0120] S5.1, according to the full cycle ultraviolet aging treatment time as the horizontal coordinate, the penetration as the vertical coordinate, according to the first penetration data, the first penetration linear regression equation Y=k 针入度1 X+b 针入度1 , according to the second penetration data, the second penetration linear regression equation Y=k 针入度2 X+b 针入度2 , the first penetration linear regression equation corresponding to the straight line is defined as L 针入度1 , and the second penetration linear regression equation corresponding to the straight line is L 针入度2 ;

[0121] According to the full cycle ultraviolet aging treatment time as the horizontal coordinate, the elongation as the vertical coordinate, according to the first elongation data, the first elongation linear regression equation Y=k 延度1 X+b延度1 , the second elongation linear regression equation Y=k 延度2 X+b 延度2 , the straight line corresponding to the first elongation linear regression equation is defined as L 延度1 and the straight line corresponding to the second elongation linear regression equation is defined as L 延度2 ;

[0122] According to the full cycle UV aging treatment time as the horizontal coordinate, the creep rate as the vertical coordinate, according to the first creep rate data, the first BBR linear regression equation Y=k BBR1 X+b BBR1 , according to the first creep rate data, the second BBR second elongation linear regression equation Y=k BBR2 X+b BBR2 , the straight line corresponding to the first BBR linear regression equation is defined as L BBR1 and the straight line corresponding to the second BBR linear regression equation is defined as L BBR2 ;

[0123] According to the full cycle UV aging treatment time as the horizontal coordinate, the fatigue life as the vertical coordinate, according to the first fatigue life data, the first LAS linear regression equation Y=k LAS1 X+b LAS1 , according to the second fatigue life data, the second LAS second elongation linear regression equation Y=k LAS2 X+b LAS2 , the straight line corresponding to the first LAS linear regression equation is defined as L LAS1 and the straight line corresponding to the second LAS linear regression equation is defined as L LAS2 ;

[0124] S5.2, the trapezoidal area S 针入度 , the trapezoidal area S 延度 , the trapezoidal area S BBR and the trapezoidal area S LAS ; the intersection T 针入度 , the intersection T 延度 , the intersection T LAS and the intersection T BBR2 ;

[0125] The method for obtaining the trapezoidal area S 针入度 is to obtain the first vertical line by taking the starting time point of the full cycle UV aging treatment time as the vertical line, and the second vertical line by taking the end time point of the full cycle UV aging treatment time as the vertical line, and then converting the vertical coordinates of L 针入度1 and L 针入度2 into logarithmic values by the Log function, and then the trapezoidal area surrounded by the four straight lines of L 针入度1 , L 针入度2 , the first vertical line and the second vertical line is S针入度 ;

[0126] trapezoidal area S 延度 The method obtains the trapezoidal area S 延度1 by converting the longitudinal coordinates of L 延度2 and L 延度1 into logarithmic values through a Log function, and then according to the trapezoidal area surrounded by the four straight lines of L 延度2 , L 延度 , the first vertical line and the second vertical line.

[0127] trapezoidal area S BBR The method obtains the trapezoidal area S BBR1 by converting the longitudinal coordinates of L BBR2 and L BBR1 into logarithmic values through a Log function, and then according to the trapezoidal area surrounded by the four straight lines of L BBR2 , L BBR , the first vertical line and the second vertical line.

[0128] trapezoidal area S LAS The method obtains the trapezoidal area S LAS1 by converting the longitudinal coordinates of L LAS2 and L LAS1 into logarithmic values through a Log function, and then according to the trapezoidal area surrounded by the four straight lines of L LAS2 , L LAS , the first vertical line and the second vertical line.

[0129] intersection point T 针入度 The method obtains the intersection point T 针入度1 of the two straight lines according to L 针入度2 and L 针入度 , and the corresponding coordinates of the intersection point T 针入度 are (X 针入度 , Y 针入度 ).

[0130] intersection point T 延度 The method obtains the intersection point T 延度1 of the two straight lines according to L 延度2 and L 延度 , and the corresponding coordinates of the intersection point T 延度 are (X 延度 , Y 延度 ).

[0131] intersection point T BBR The method obtains the intersection point T BBR1 of the two straight lines according to L BBR2 and L BBR , and the corresponding coordinates of the intersection point T BBR are (X BBR , Y BBR ).

[0132] Intersection T LAS The method to obtain is based on L LAS1 and L LAS2 The intersection of the two lines is T. LAS And the intersection point T LAS The corresponding coordinates are (X) LAS Y LAS );

[0133] S5.3 is obtained through the following steps:

[0134] S5.3.1, the area S of the trapezoid 针入度 Area S of the trapezoid 延度 Area S of the trapezoid LAS and the area S of the trapezoid BBR S is obtained by summing. 总和 Calculate the area S of the trapezoid. 针入度 In S 总和 The weight A of the penetration is obtained by the proportion. 针入度 Calculate the area S of the trapezoid. 延度 In S 总和 The weight A of the length is obtained by the proportion. 延度 Calculate the area S of the trapezoid. BBR In S 总和 The weight A of BBR is obtained by the proportion. BBR Calculate the area S of the trapezoid. LAS In S 总和 The weight A of LAS is obtained by the proportion. LAS ;

[0135] S5.3.2, using the formula M = X 针入度 A 针入度 +X 延度 A 延度

[0136] +X BBR A BBR +X LAS A LAS The UV aging resistance M value of the tested asphalt binder was calculated.

[0137] It should be noted that in each linear regression equation of S5.1, the UV aging time (h) is used as the independent variable X, with the x-axis values ​​being X1 = 3h, X2 = 6h, X3 = 9h, X4 = 18h, X5 = 36h, and X6 = 72h; then, the penetration, ductility, creep rate, and fatigue life results are used as the dependent variable Y, with the y-axis values ​​being Y1, Y2, Y3, Y4, Y5, and Y6, respectively; and the coordinate point (X... i Plot a scatter plot using Yi (i = 1-6), perform linear regression to obtain the relevant linear regression equation and corresponding line, as shown below. Figure 2The general formula of different linear regression equations. Figure 3 The general determination diagram of the trapezoidal area S between the different first linear regression equations, the corresponding second linear regression equations, the first vertical line and the second vertical line.

[0138] Figure 4 The determination diagram of the intersection of the different first linear regression equations and the second linear regression equations.

[0139] In S5.1, according to the relationship between |k 针入度1 | and |k 针入度2 , the consistency of the measured asphalt cement changes in the primary aging stage and the advanced aging stage; according to the relationship between |k 延度2 | and |k 延度1 , the plasticity of the measured asphalt cement changes in the primary aging stage and the advanced aging stage; according to the relationship between |k BBR2 | and |k BBR1 , the fatigue performance of the measured asphalt cement changes in the primary aging stage and the advanced aging stage; according to the relationship between |k LAS2 | and |k LAS1 , the low-temperature performance of the measured asphalt cement changes in the primary aging stage and the advanced aging stage.

[0140] It should be noted that the penetration test will be carried out according to T0604-2019 of JTG E20-2019 “Highway Engineering Asphalt and Asphalt Mixture Test Procedures”. The ductility test is carried out according to T0605-2019 of JTG E20-2019 “Highway Engineering Asphalt and Asphalt Mixture Test Procedures”. The BBR test is carried out according to the AASHTO-T313 specification, and a 3-point load of 980mN±50mN is applied, and the loading time is 8 seconds, 15 seconds, 30 seconds, 60 seconds, 120 seconds and 240 seconds respectively. The LAS test is carried out according to the AASHTO-T312 specification, and the test temperature is 18℃, the flat plate size is 8mm, the interval is 2mm, and two sets of parallel tests are used.

[0141] Compared with the prior art, the beneficial effects of the present application are to construct a research method, to realize the quantitative analysis of the ultraviolet aging behavior of asphalt cement based on the numerical value of the index M, and the analysis result is accurate, and the aging behavior and characteristics of the asphalt cement can be evaluated and determined through the quantitative result, which will provide relevant basis for improving the ultraviolet radiation shielding performance of the asphalt cement.

[0142] Example 2

[0143] Application of the method for studying the aging behavior of asphalt binders based on the full cycle of ultraviolet aging according to Example 1. In this example, 70# base asphalt and T770 modified asphalt were used as the measured asphalt binders. In S1, the 70# base asphalt was heated to 130°C, and the T770 modified asphalt was heated to 140°C.

[0144] In this example, for the 70# base asphalt, the first penetration data and the second penetration data were obtained according to Figure 5 Then, the first penetration linear regression equation Y = -0.0098X + 6.1752 was obtained according to the first penetration data, and R 2 was 0.9487. The second penetration linear regression equation Y = -0.0078X + 5.444 was obtained according to the second penetration data, and R 2 was 0.9652.

[0145] In this example, for the T770 modified asphalt, the first penetration data and the second penetration data were obtained according to Figure 6 Then, the first penetration linear regression equation Y = -0.0088X + 6.0285 was obtained according to the first penetration data, and R 2 was 0.9095. The second penetration linear regression equation Y = -0.008X + 5.2423 was obtained according to the second penetration data, and R 2 was R2 = 0.947.

[0146] In this example, for the 70# base asphalt, the first ductility data and the second ductility data were obtained according to Figure 7 Then, the first ductility linear regression equation Y = -0.0298X + 10.948 was obtained according to the first ductility data, and R 2 was 0.9363. The second ductility linear regression equation Y = -0.0612X + 16.286 was obtained according to the second ductility data, and R 2 was 0.9179.

[0147] In this example, for the T770 modified asphalt, the first ductility data and the second ductility data were obtained according to Figure 8 Then, the first ductility linear regression equation Y = -0.0344X + 11.675 was obtained according to the first ductility data, and R 2 was 0.9009. The second ductility linear regression equation Y = -0.0595X + 24.628 was obtained according to the second ductility data, and R 2 was 0.9164.

[0148] In this example, for the 70# base asphalt, the first fatigue life data and the second fatigue life data were obtained according to Figure 9Then, based on the first fatigue life data, the first LAS linear regression equation was obtained: Y = -35.549X + 2565.8, and R0... 2 The value is 0.9227. Based on the second fatigue life data, the second LAS linear regression equation is Y = -47.264X + 3915.2, and R0... 2 It is 0.9942.

[0149] In this embodiment, the T770 modified asphalt was obtained based on the first fatigue life data and the second fatigue life data. Figure 10 Then, based on the first fatigue life data, the first LAS linear regression equation was obtained: Y = y = -38.47X + 5943.4, and R0... 2 The value is 0.9499. Based on the second fatigue life data, the second LAS linear regression equation is Y = y = -45.529X + 8325.5, and R0... 2 It is 0.9388.

[0150] In this embodiment, the 70# base asphalt is obtained based on the first creep rate data and the second creep rate data. Figure 11 Then, based on the first creep rate data, the first BBR linear regression equation was obtained: Y = -0.0009X + 0.429, and R0... 2 The value is 0.9684. Based on the second creep rate data, the second BBR linear regression equation is Y = -0.0013X + 0.4682, and R0... 2 It is 0.9822.

[0151] In this embodiment, the T770 modified asphalt is obtained based on the first creep rate data and the second creep rate data. Figure 12 Then, based on the first creep rate data, the first BBR linear regression equation was obtained: Y = -0.0009X + 0.4469, and R... 2 The value is 0.9264. Based on the second creep rate data, the second BBR linear regression equation is Y = -0.0012X + 0.5005, and R0... 2 It is 0.9486.

[0152] Table 1. Primary and Advanced Aging Stages of 70# Base Asphalt | k 基质 |

[0153]

[0154] Table 2. Primary and Advanced Aging Stages of T770 Modified Asphalt | k 改性 |

[0155]

[0156] According to Table 1 and Table 2, the primary aging stage slope of different tests can be expressed by the general formula k1, and the advanced aging stage slope of different tests can be expressed by the general formula k2. For the penetration slope of the primary aging stage, it is k 针入度1 For the penetration slope of the advanced aging stage, it is k 针入度2 For the ductility slope of the primary aging stage, it is k 延度1 For the ductility slope of the advanced aging stage, it is k 延度2 For the fatigue life slope of the primary aging stage, it is k LAS1 For the fatigue life slope of the advanced aging stage, it is k LAS2 For the creep rate slope of the primary aging stage, it is k BBR1 For the creep rate slope of the advanced aging stage, it is k BBR2 .

[0157] The penetration, ductility, fatigue life and creep rate of 70# base asphalt can be expressed by k 基质 , and the penetration, ductility, fatigue life and creep rate of T770 modified asphalt can be expressed by k 改性 .

[0158] In Table 1 and Table 2, by comparing the absolute values of the primary aging stage slope k1 and the advanced aging stage slope k2 of the four evaluation indexes of penetration, ductility, fatigue life and creep rate, the performance change speed of the primary aging stage and the advanced aging stage under the influence of ultraviolet aging is respectively represented; there are two cases for the comparison of the slopes:

[0159] Case one: |k1|>|k2|, which indicates that for the performance represented by the evaluation index, the primary aging stage changes faster than the advanced aging stage under the influence of ultraviolet aging;

[0160] Case two: |k1|<|k2|, which indicates that for the performance represented by the evaluation index, the advanced aging stage changes faster than the primary aging stage under the influence of ultraviolet aging;

[0161] The penetration data in Table 1 and Table 2 show that:

[0162] (1) |k 针入度1 |>|k 针入度2 |, which indicates that for the consistency of asphalt, the primary aging stage changes faster than the advanced aging stage under the influence of ultraviolet aging;

[0163] (2) In the advanced aging stage, for T770 modified asphalt and 70# base asphalt, |k 改性 |>|k 基质 | is shown, which indicates that due to the effect of the modifier in T770 modified asphalt, the change of the consistency of asphalt under the action of ultraviolet aging is promoted.

[0164] The ductility, fatigue life, and creep rate of Tables 1 and 2 show that:

[0165] (1) |k2| > |k1|, which indicates that the plasticity, fatigue performance, and low-temperature performance of the asphalt change more rapidly in the advanced aging stage than in the primary aging stage under the influence of ultraviolet aging;

[0166] (2) In the advanced aging stage, |k2| < |k1| for the T770 modified asphalt and the 70# base asphalt, which indicates that the plasticity, fatigue performance, and low-temperature performance of the asphalt change more slowly in the advanced aging stage than in the primary aging stage under the influence of ultraviolet aging. 改性 | < |k 基质 |, which indicates that the plasticity, fatigue performance, and low-temperature performance of the asphalt are inhibited from changing under the influence of ultraviolet aging due to the effect of the modifier in the T770 modified asphalt.

[0167] The specific calculation method of the trapezoidal area S in S5.2 is as follows:

[0168] For different indicators of the Y axis, the ordinate of L 针入度1 and L 针入度2 is a unit, the ordinate of L LAS1 and L LAS2 is ten thousand or even ten thousand, and the ordinate of L BBR1 and L BBR2 is a decimal point. To eliminate the influence of the dimension of each indicator, the ordinate values of each indicator should be standardized, that is, L 针入度1 , L 针入度2 , L 延度1 , L 延度2 , L BBR1 , L BBR2 , L LAS1 , and L LAS2 The values of the ordinate are processed by logarithm. The values of the ordinate of the above straight line are calculated by the Log function, and the last logarithmic result is taken as the ordinate value. Then, the trapezoidal area S value is calculated, and two vertical lines perpendicular to the X axis are marked as the first vertical line L3 and the second vertical line L4, which pass through the two points (3, 0) and (72, 0), respectively. In this embodiment, L 针入度1 and L 针入度2 , L 延度1 and L 延度2 , L BBR1 and L BBR2 , or L LAS1 and L LAS2 are represented by L1 and L2; the area of the trapezoid surrounded by L1, the first vertical line L3, the second vertical line L4, and the X axis is S 1-3-4-X , the area of the trapezoid surrounded by L2, the first vertical line L3, the second vertical line L4, and the X axis is S 2-3-4-X , and the area S = |S 1-3-4-X | - |S2-3-4-X | See appendix for details Figure 3 .

[0169] So, for 70# base asphalt and T770 modified asphalt S 针入度 S 延度 S BBR S LAS The results are obtained using the method described above and the corresponding straight line, as shown in Table 3.

[0170] Table 3. Area S of 70# base asphalt and T770 modified asphalt

[0171] [SA 针入度 ]]> [SA 延度 ]]> [SA LAS ]]> [SA BBR ]]> 70# base asphalt 7.41 21.60 49.50 3.75 T770 modified asphalt 8.69 45.65 23.58 6.34

[0172] According to L 针入度1 and L 针入度2 Find the intersection point T of the two lines. 针入度 Intersection T 针入度 The corresponding coordinates are (X) 针入度 Y 针入度 According to L 延度1 and L 延度2 Find the intersection point T of the two lines. 延度 Intersection T 延度 The corresponding coordinates are (X) 延度 Y 延度 According to L BBR1 and L BBR2 Obtain the intersection point TB of the two lines. BR Intersection T BBR The corresponding coordinates are (X) BBR Y BBR According to L LAS1 and L LAS2 Find the intersection point T of the two lines. LAS Intersection T LAS The corresponding coordinates are (X) LAS Y LAS These intersections represent the same performance index results after UV aging in the primary aging stage and the advanced aging stage. The horizontal axis X represents the aging time corresponding to the degree of UV aging, specifically reflecting the difference in UV aging resistance between asphalt in the primary aging stage and asphalt in the advanced aging stage.

[0173] Table 4. Intersection point T, x-axis of 70# base asphalt and T770 modified asphalt

[0174]

[0175] The specific method for determining the aging behavior and characteristics of asphalt binder throughout the entire UV aging cycle is as follows:

[0176] This invention will use the trapezoidal area S 针入度 Area S of the trapezoid延度 , trapezoidal area S LAS and trapezoidal area S BBR are added to obtain S 总和 , the trapezoidal area S 针入度 is calculated 总和 The weight A of penetration is obtained by the ratio of S 针入度 ; the trapezoidal area S 延度 is calculated 总和 The weight A of ductility is obtained by the ratio of S 延度 ; the trapezoidal area S BBR is calculated 总和 The weight A of BBR is obtained by the ratio of S BBR ; the trapezoidal area S LAS is calculated 总和 The weight A of LAS is obtained by the ratio of S LAS , as shown in Table 5:

[0177] Table 5. Weight of each test of 70# base asphalt and T770 modified asphalt

[0178] A 针入度 ]]> A 延度 ]]> A LAS ]]> A BBR ]]> 70# base asphalt 0.090 0.263 0.602 0.046 T770 modified asphalt 0.103 0.542 0.280 0.075

[0179] The weight range of the performance index of the full cycle UV aging of the asphalt binder can be determined by Table 5, and Table 6 is obtained:

[0180] Table 6. Weight range of performance index of full cycle UV aging of asphalt binder

[0181] Performance Index Weight Range Institutional (A 针入度 )]]> 0.090-0.103 plastic (A 延度 )]]> 0.263-0.542 Fatigue performance (A LAS )]]> 0.280-0.602 Low temperature performance (A BBR )]]> 0.046-0.075

[0182] In the above table, for consistency, plasticity and low temperature performance, the weight of the base asphalt is taken as the lower endpoint, and the weight of the T770 modified asphalt is taken as the upper endpoint; for the fatigue performance index, the weight of the base asphalt is taken as the upper endpoint, and the weight of the T770 modified asphalt is taken as the lower endpoint.

[0183] The anti-UV aging ability M value of the measured asphalt binder is then calculated by the formula M=X 针入度 A 针入度 +X 延度 A 延度 +X BBR A BBR +X LAS A LAS The M value represents the ability of the asphalt to resist UV aging after any UV aging time, and reflects the overall aging performance of the asphalt; for the full cycle UV aging asphalt test piece, the anti-UV aging ability M is equal to the abscissa X t and A 针入度 , A 延度 , A BBR and ALAS Algebraic sum, as shown in Table 7.

[0184] Table 7. M value summary of 70# base asphalt and T770 modified asphalt anti-UV aging ability

[0185] M 70# base asphalt 151 T770 modified asphalt 489

[0186] The M value of the present application reflects the aging resistance ability of the asphalt in the whole UV aging cycle by combining the aging time of the same effect of the aging performance of the primary aging stage and the advanced aging stage of the asphalt after UV aging and the weight of different performances; the increase of the M value reflects the improvement of the anti-aging ability of the asphalt in the whole UV aging cycle; on the contrary, the decrease of the M value reflects the decrease of the anti-aging ability of the asphalt in the whole UV aging cycle. According to the results in Table 7, the M value of the T770 modified asphalt is larger than that of the 70# base asphalt, which indicates that the effect of the modifier improves the anti-aging ability of the asphalt cement in the whole UV aging cycle, and the overall aging degree of the asphalt in the whole UV aging cycle is smaller.

[0187] According to Tables 1-7, the method for studying the aging behavior of the asphalt cement based on the whole UV aging cycle according to the present application has relevant reference basis and foundation for evaluating and analyzing the UV aging performance of different asphalt materials. In the practical asphalt performance research and analysis, the quantitative analysis of the UV aging behavior of the asphalt cement is realized based on the index M, the analysis result is accurate, the aging behavior and characteristics of the asphalt cement can be evaluated and determined through the quantitative result, which provides relevant basis for improving the UV radiation shielding performance of the asphalt cement.

[0188] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A method for studying the aging behavior of asphalt binders based on the entire ultraviolet aging cycle, characterized in that, This can be done through the following steps: S1. The asphalt binder to be tested is prepared into multiple test specimens using corresponding bearing molds, and the test specimens are divided into a first specimen for simulating the primary aging stage and multiple second specimens for simulating the advanced aging stage. S2. The first specimen and its supporting mold, and the second specimen and its supporting mold are subjected to ultraviolet aging treatment respectively to obtain the first specimen and the second specimen after aging. S3. The aged second specimen is homogenized to obtain a homogenized second specimen; S4. Test the homogenized second specimen and the aged first specimen to obtain corresponding test data; S5. Based on the test data, determine the linear regression equation for the primary aging stage and the corresponding linear regression equation for the advanced aging stage. Then, based on the linear regression equation for the primary aging stage and the corresponding linear regression equation for the advanced aging stage, obtain the M value of the full-cycle UV aging resistance of the tested asphalt binder. S3 specifically includes: S3.1 Demold all the aged second specimens separately and place them in homogenization glass dishes. Then add carbon disulfide to the homogenization glass dishes to dissolve the aged second specimens, thereby obtaining multiple portions of carbon disulfide-asphalt solution. S3.

2. Pour each portion of carbon disulfide-asphalt solution into a corresponding penetration sampling glass, LAS sampling glass, ductility sampling glass, and BBR sampling glass. Then, place the carbon disulfide-asphalt solution and the penetration sampling glass, the carbon disulfide-asphalt solution and the LAS sampling glass, the carbon disulfide-asphalt solution and the ductility sampling glass, and the carbon disulfide-asphalt solution and the BBR sampling glass at a temperature of 45℃ to allow the carbon disulfide to evaporate completely, thereby obtaining penetration homogenization specimens, LAS homogenization specimens, ductility homogenization specimens, and BBR homogenization specimens. S4 specifically includes: S4.

1. The first specimen after aging is demolded and the first specimen after aging is defined as specimen 1.1 after aging, specimen 1.2 after aging, specimen 1.3 after aging and specimen 1.4 after aging. S4.2 Cut the homogenized second specimen and define the homogenized second specimen as a penetration homogenization specimen, a LAS homogenization specimen, a ductility homogenization specimen and a BBR homogenization specimen, respectively, to obtain the final penetration homogenization specimen, the final ductility homogenization specimen, the final LAS homogenization specimen and the final BBR homogenization specimen. S4.

3. The first needle penetration data is obtained by performing a needle penetration test on the aged 1.1 specimen, and the second needle penetration data is obtained by performing a needle penetration test on the final needle penetration homogenized specimen. The first ductility data is obtained by performing a ductility test on the aged 1.2 specimens, and the second ductility data is obtained by performing a ductility test on the final ductility homogenized specimens. The first creep rate data was obtained by performing a BBR test on the aged 1.3 specimen, and the second creep rate data was obtained by performing a BBR test on the final BBR homogenized specimen. The first fatigue life data was obtained by conducting an extended LAS test on the aged specimen 1.4, and the second fatigue life data was obtained by conducting an extended LAS test on the final LAS homogenized specimen. S5 specifically includes: S5.

1. Using the total UV aging treatment time as the x-axis and penetration as the y-axis, the linear regression equation for the first penetration, Y=k, is obtained based on the first penetration data. 针入度1 X+b 针入度1 Based on the second needle penetration data, the linear regression equation for the second needle penetration, Y=k, was obtained. 针入度2 X+b 针入度2 Let L be the straight line corresponding to the first needle depth linear regression equation. 针入度1 The straight line corresponding to the second needle depth linear regression equation is L. 针入度2 ; Using the total UV aging treatment time as the x-axis and ductility as the y-axis, the first ductility linear regression equation Y=k is obtained based on the first ductility data. 延度1 X+b 延度1 Based on the second degree of extension data, the second degree of extension linear regression equation Y=k is obtained. 延度2 X+b 延度2 Let L be the straight line corresponding to the first-degree linear regression equation. 延度1 The straight line corresponding to the second-length linear regression equation is L 延度2 ; Using the total UV aging treatment time as the x-axis and creep rate as the y-axis, the first BBR linear regression equation Y=k was obtained based on the first creep rate data. BBR1 X+b BBR1 Based on the second creep rate data, the second BBR second ductility linear regression equation Y=k was obtained. BBR2 X+b BBR2 Let L be the straight line corresponding to the first BBR linear regression equation. BBR1 The straight line corresponding to the second BBR linear regression equation is L BBR2 ; Using the full-cycle UV aging treatment time as the x-axis and fatigue life as the y-axis, the first LAS linear regression equation Y=k was obtained based on the first fatigue life data. LAS1 X+b LAS1 Based on the second fatigue life data, the second LAS second ductility linear regression equation Y=k was obtained. LAS2 X+b LAS2 Let L be the straight line corresponding to the first LAS linear regression equation. LAS1 The straight line corresponding to the second LAS linear regression equation is L LAS2 ; S5.2, Obtain the area S of the trapezoid 针入度 Area S of the trapezoid 延度 Area S of the trapezoid BBR and the area S of the trapezoid LAS Obtain the intersection point T 针入度 Intersection T 延度 Intersection T LAS and intersection point T BBR ; The area S of the trapezoid 针入度 The method involves drawing a perpendicular line from the start time of the full-cycle UV aging process to obtain the first perpendicular line, and drawing a perpendicular line from the end time of the full-cycle UV aging process to obtain the second perpendicular line. The L value is then calculated using the Log function. 针入度1 and L 针入度2 Convert the ordinate to logarithmic values, and then according to L 针入度1 L 针入度2 The area of ​​the trapezoid formed by the four lines—the first perpendicular line, the second perpendicular line, and the third perpendicular line—is S. 针入度 ; The area S of the trapezoid 延度 The method to obtain L is through the Log function. 延度1 and L 延度2 Convert the ordinate to logarithmic values, and then according to L 延度1 L 延度2 The area of ​​the trapezoid formed by the first perpendicular line, the second perpendicular line, and the other two perpendicular lines is S. 延度 ; The area S of the trapezoid BBR The method to obtain L is through the Log function. BBR1 and L BBR2 Convert the ordinate to logarithmic values, and then according to L BBR1 L BBR2 The area of ​​the trapezoid formed by the first perpendicular line, the second perpendicular line, and the other two perpendicular lines is S. BBR ; The area S of the trapezoid LAS The method to obtain L is through the Log function. LAS1 and L LAS2 Convert the ordinate to logarithmic values, and then according to L LAS1 L LAS2 The area of ​​the trapezoid formed by the first perpendicular line, the second perpendicular line, and the other two perpendicular lines is S. LAS ; The intersection point T 针入度 The method to obtain is based on L 针入度1 and L 针入度2 The intersection of the two lines is T. 针入度 And the intersection point T 针入度 The corresponding coordinates are (X) 针入度 Y 针入度 ); The intersection point T 延度 The method to obtain is based on L 延度1 and L 延度2 The intersection of the two lines is T. 延度 And the intersection point T 延度 The corresponding coordinates are (X) 延度 Y 延度 ); The intersection point T BBR The method to obtain is based on L BBR1 and L BBR2 The intersection of the two lines is T. BBR And the intersection point T BBR The corresponding coordinates are (X) BBR Y BBR ); The intersection point T LAS The method to obtain is based on L LAS1 and L LAS2 The intersection of the two lines is T. LAS And the intersection point T LAS The corresponding coordinates are (X) LAS Y LAS ); S5.3 is obtained through the following steps: S5.3.1, the area S of the trapezoid 针入度 Area S of the trapezoid 延度 Area S of the trapezoid LAS and the area S of the trapezoid BBR S is obtained by summing. 总和 Calculate the area S of the trapezoid. 针入度 In S 总和 The weight A of the penetration is obtained by the proportion. 针入度 Calculate the area S of the trapezoid. 延度 In S 总和 The weight A of the length is obtained by the proportion. 延度 Calculate the area S of the trapezoid. BBR In S 总和 The weight A of BBR is obtained by the proportion. BBR Calculate the area S of the trapezoid. LAS In S 总和 The weight A of LAS is obtained by the proportion. LAS ; S5.3.2, using the formula M=X 针入度 A 针入度 +X 延度 A 延度 +X BBR A BBR +X LAS A LAS The UV aging resistance M value of the tested asphalt binder was calculated.

2. The method for studying the aging behavior of asphalt binder based on the entire UV aging cycle as described in claim 1, characterized in that: In S2, all the first specimens and all the second specimens are controlled to be exposed to ultraviolet radiation only on their top surface, while the other sides are heat-insulated, and each of the first specimens and each of the second specimens is at the same distance from the ultraviolet lamp. In S4, all homogenized second specimens and aged first specimens are subjected to penetration test, ductility test, linear amplitude scanning test (LAS), and low-temperature bending beam rheological test (BBR) to obtain corresponding penetration data, ductility data, creep rate data, and fatigue life data.

3. The method for studying the aging behavior of asphalt binder based on the entire UV aging cycle as described in claim 2, characterized in that: The first test specimens are respectively defined as test specimen 1.1, test specimen 1.2, test specimen 1.3, and test specimen 1.4; Specifically, S2 involves subjecting the first 1.1 specimen and its supporting mold, the first 1.2 specimen and its supporting mold, the first 1.3 specimen and its supporting mold, the first 1.4 specimen and its supporting mold, and the second specimen and its supporting mold to full-cycle UV aging treatment. The full-cycle UV aging treatment times are 3h, 6h, 9h, 18h, 36h, and 72h, respectively. After reaching the corresponding time, the first 1.1 specimen and its supporting mold, the first 1.2 specimen and its supporting mold, the first 1.3 specimen and its supporting mold, the first 1.4 specimen and its supporting mold, and the second specimen and its supporting mold are taken out as a whole, frozen at 0℃ for 1.5h, and then placed at room temperature for 15min.

4. The method for studying the aging behavior of asphalt binder based on the entire UV aging cycle as described in claim 3, characterized in that: In S3.1, the mass ratio of carbon disulfide to the aged second specimen in each part of carbon disulfide-asphalt solution is 3:1; In S3.2, the mass of carbon disulfide-asphalt solution and penetration sampling glass, carbon disulfide-asphalt solution and LAS sampling glass, carbon disulfide-asphalt solution and ductility sampling glass, and carbon disulfide-asphalt solution and BBR sampling glass are measured every 15 minutes. When the mass of two consecutive measurements is the same, it is determined that the carbon disulfide has been completely evaporated.

5. The method for studying the aging behavior of asphalt binder based on the entire UV aging cycle as described in claim 4, characterized in that: In S4.2, the cutting process of the needle penetration uniformity specimen is specifically carried out by cutting the needle penetration uniformity specimen with a first annular cutter, and finally obtaining the cut needle penetration uniformity specimen with an inner diameter of 5.5 cm and a height of 3.5 cm. Then, the cut needle penetration uniformity specimen is placed at a temperature of 0℃ for 24 h to obtain the final needle penetration uniformity specimen. The cutting process of the ductility homogenization specimen is specifically carried out by cutting the ductility homogenization specimen with an I-shaped cutter, and finally obtaining the cut ductility homogenization specimen with a height of 2.0 cm and a shape consistent with the shape of the I-shaped cutter. Then, the cut ductility homogenization specimen is placed at a temperature of 0℃ for 24 hours to obtain the final ductility homogenization specimen. The LAS homogenization specimen is cut by cutting the LAS homogenization specimen with a second ring cutter, and finally the cut LAS homogenization specimen with an inner diameter of 0.8 cm and a height of 1 cm is obtained. Then the cut LAS homogenization specimen is placed at a temperature of 0℃ for 24 h to obtain the final LAS homogenization specimen. The BBR homogenization specimen is cut by cutting it with a straight cutter to obtain a BBR homogenization specimen with a length of 12.7cm, a width of 1.27cm, and a height of 6.35mm. The cut BBR homogenization specimen is then placed at 0℃ for 24h to obtain the final BBR homogenization specimen. The first annular cutter, the I-shaped cutter, the second annular cutter, and the straight cutter all need to be heated at 140°C for 2 hours before cutting.

6. The method for studying the aging behavior of asphalt binder based on the entire UV aging cycle as described in claim 5, characterized in that: In S5.1, according to |k 针入度1 | and |k 针入度2 The relationship |k| indicates the change in consistency of the tested asphalt binder during the primary and advanced aging stages; based on |k| 延度2 | and |k 延度1 The relationship between |k| and |k| indicates the change in plasticity of the tested asphalt binder during the primary and advanced aging stages; based on |k| BBR2 | and |k BBR1 The relationship between |k| and |k| indicates the changes in the fatigue properties of the tested asphalt binder during the primary and advanced aging stages; based on |k| LAS2 | and |k LAS1 The relationship between | indicates the changes in the low-temperature performance of the tested asphalt binder during the primary and advanced aging stages.

7. The method for studying the aging behavior of asphalt binder based on the entire UV aging cycle as described in claim 6, characterized in that: The first specimen after aging was a cylindrical structure with a height of 3 cm and a diameter of 5.5 cm. The first and second specimens after aging have a height of 2.0 cm, a length of 7.5 cm, a width of 3.2 cm at both ends, a minimum width of 1.2 cm in the middle, and a minimum included angle of 150° in the middle. The first and second specimens after aging have a symmetrical structure from left to right and top to bottom. The I-shaped cutter has a height of 2.0 cm, a length of 7.5 cm, a width of 3.2 cm at both ends, a minimum width of 1.2 cm in the middle, and a minimum included angle of 150°. The I-shaped cutter has a symmetrical structure from left to right and top to bottom, and the shape of the aged 1st and 2nd specimens matches that of the I-shaped cutter. The aged specimen 1.3 was a cylindrical structure with a height of 1 cm and a diameter of 0.8 cm; The aging specimen 1.4 is a long strip structure with a length of 12.7cm, a width of 1.27cm, and a height of 6.35mm; The second specimen after aging is a cylindrical structure with a height of 5 mm and a diameter of 25 cm; The homogenizing glass dish has a diameter of 25cm and a height of 3cm; The diameter of the sampling glass dish is 7.9 cm and the height is 15 cm. The diameter of the ductility sampling glass dish is 13.7 cm and the height is 5 cm; The BBR sampling glass dish has a diameter of 17.2 cm and a height of 3 cm; The LAS sampling glass dish has a diameter of 25cm and a height of 3cm; In step S4.3, the first annular cutter, the I-shaped cutter, the second annular cutter, and the straight cutter all need to be heated at 140°C for 2 hours before cutting; The penetration test will be conducted in accordance with T0604-2019 of JTG E20-2019 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering"; The ductility test was conducted in accordance with T0605-2019 of JTG E20-2019 "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering"; The BBR test was conducted according to the AASHTO-T313 standard, and a three-point load of 980mN±50mN was applied for loading times of 8 seconds, 15 seconds, 30 seconds, 60 seconds, 120 seconds and 240 seconds respectively. The LAS test was conducted in accordance with the AASHTO-T312 standard, with a test temperature of 18℃, a plate size of 8mm, a spacing of 2mm, and two sets of parallel tests.

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