A method for short-term aging test of asphalt

Abstract

The present application relates to a kind of asphalt short-term aging test method, which is based on T0609-2011 asphalt film heating test procedure in "Highway Engineering Asphalt and Asphalt Mixture Test Procedures" (JTG E20-2011), for road petroleum asphalt, the mass of asphalt sample in each sample pan is 24.5-25.5g, then placed in 162-164℃ thin film heating oven for 85 minutes;For polymer modified asphalt, the mass of asphalt sample in each sample pan is 12-13g, then placed in 162-164℃ thin film heating oven for 85 minutes;For high viscosity modified asphalt, the mass of asphalt sample in each sample pan is 12-13g, then placed in 162-164℃ thin film heating oven for 100 minutes.Compared with prior art, the present application is suitable for short-term aging test of different kinds of asphalt, makes up for the deficiency of existing asphalt short-term aging test method, and can accurately reflect the short-term aging of asphalt during mixing, transportation and paving process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of performance detection of highway asphalt pavement materials, and particularly relates to a short-term aging test method for asphalt. BACKGROUND

[0002] As an organic binder, asphalt is prone to aging under the conditions of temperature, oxygen, water, sunlight, etc., which leads to the degradation of asphalt pavement performance, pavement diseases such as peeling, potholes and cracking, and reduction of pavement service life. Generally, the short-term aging of asphalt occurs in the process of asphalt mixture mixing, transportation and paving. At present, the short-term aging test in the laboratory specified in the Highway Engineering Asphalt and Asphalt Mixture Test Specification (JTG E20-2011) uses the Thin Film Oven Test (TFOT) and the Rotating Thin Film Oven Test (RTFOT) to simulate the short-term aging process of asphalt. However, research has found that there are obvious differences in the aging performance indicators of asphalt obtained by the two aging methods. Since the viscosity of modified asphalt is larger, the asphalt cannot be fully rotated during the RTFOT test, is easy to overflow from the bottle opening, and the aging degree of the recovered asphalt by the two aging methods is lower, which does not match the actual engineering. Therefore, there is an urgent need to propose a short-term aging method that is simple to test, easy to clean and highly applicable for different types of asphalt, and to improve the accuracy of the evaluation of the short-term aging performance of asphalt. SUMMARY

[0003] The present application is to overcome the defects of the prior art and provide a short-term aging test method for asphalt. The method is based on the T0609-2011 asphalt thin film heating test specification in the Highway Engineering Asphalt and Asphalt Mixture Test Specification (JTG E20-2011), and is suitable for short-term aging tests of different types of asphalt. It makes up for the shortcomings of the current short-term aging test method for asphalt and can accurately reflect the short-term aging of asphalt in the mixing, transportation and paving process.

[0004] Applicant believes in the conception process: short-term aging of asphalt is to simulate the aging of mixture in the process of mixing, transportation, paving, etc., the current specification (Highway Engineering Asphalt and Asphalt Mixture Test Procedures (JTG E20-2011) T0609-2011 asphalt film heating test) short-term aging method can only reflect the short-term aging of general base asphalt, and is not suitable for commonly used modified asphalt, the two control factors of aging are aging time and aging temperature, but too high temperature can easily lead to uncontrollable aging process of asphalt, therefore, the thickness of the asphalt film is reduced, so that the aging time is reduced without changing the aging temperature, and the purpose of accurately evaluating the aging degree is achieved, and for different asphalts, the aging time and the thickness of the asphalt film are different, and need to be set accordingly, therefore, different asphalt film thicknesses and aging times are adopted for asphalts of different sources, so as to obtain an asphalt short-term aging test method suitable for different types of asphalts.

[0005] The object of the application can be achieved by the following technical solutions:

[0006] The object of the application is to provide a kind of asphalt short-term aging test method, the asphalt short-term aging test method is based on the method improved in T0609-2011 asphalt rotary film heating test procedure of Highway Engineering Asphalt and Asphalt Mixture Test Procedures (JTG E20-2011), the asphalt short-term aging test method is carried out in film heating oven, the asphalt short-term aging test method comprises the following steps:

[0007] S1, the clean, dried, cooled 4 sample dishes are numbered, and the mass m0 is weighed;

[0008] S2, the asphalt sample is injected into the four sample dishes with weighed mass respectively, and a uniform film of asphalt thickness is formed, and the mass m1 is weighed after cooling to room temperature in the dryer, and the penetration, viscosity, softening point, brittle point and ductility of the asphalt sample at this time are measured, wherein, for road petroleum asphalt, the mass of asphalt sample in each sample dish is 24.5-25.5g, for polymer modified asphalt, the mass of asphalt sample in each sample dish is 12-13g, and for high viscosity modified asphalt, the mass of asphalt sample in each sample dish is 12-13g;

[0009] S3, the thermometer is vertically hung on the rotating disc shaft of the film heating oven, located at the center of the rotating disc, the mercury ball of the thermometer is at 6mm above the top surface of the rotating disc, and the film heating oven is heated and kept at 162-164 DEG C, the film heating oven is adjusted to be horizontal, the rotating disc rotates on the horizontal plane, the inclination angle between the rotating disc and the horizontal plane is not greater than 3 DEG, and the position of the thermometer is equidistant from the center and the edge of the rotating disc;

[0010] S4, after the film heating oven reaches constant temperature 163℃, the sample container is quickly put on the rotating disc in the oven, and the oven door is closed and the rotating disc is started, so that the temperature in the film heating oven rises to 162℃, and then the temperature is kept at 162-164℃ for a period of time, wherein, for road petroleum asphalt, the temperature is kept for 85 minutes, for polymer modified asphalt, the temperature is kept for 85 minutes, and for high viscosity modified asphalt, the temperature is kept for 100 minutes;

[0011] S5, after heating, the sample container is taken out and placed in a desiccator to cool to room temperature, then the sample container is weighed to obtain the mass m2;

[0012] S6, after the sample is weighed, the sample container is put back into the film heating oven at 162-164℃ and rotated for 15min, then the sample is taken out, the sample is scraped out with a scraper or a spatula, heated and stirred to melt to a flowable state, and then corresponding tests of the residual material after various film heating tests are carried out.

[0013] Preferably, the sample container is a stainless steel disc with an inner diameter of 140mm and a depth of 9.5mm.

[0014] Preferably, the rotating disc in step S3 rotates at a speed of 4.5-6.5r / min on the horizontal plane.

[0015] Further, the road petroleum asphalt meets the technical requirements in Table 4.2.1-2 in "Technical Specification for Construction of Highway Asphalt Pavement" (JTG F40-2004).

[0016] Further preferably, the road petroleum asphalt is No. 70 or No. 90 road asphalt.

[0017] Further, the polymer modified asphalt meets the technical requirements in Table 4.6.2 in "Technical Specification for Construction of Highway Asphalt Pavement" (JTG F40-2004).

[0018] Further preferably, the polymer modified asphalt is I-D type SBS modified asphalt.

[0019] Further, the high viscosity modified asphalt meets the technical requirements in Table 5.2.2 in "Technical Specification for Design and Construction of Drainage Asphalt Pavement" (JTG / T3350-03-2020).

[0020] Further, the bottom and top of the film heating oven are respectively provided with air inlets and outlets for the escape of hot air and steam and the entry of air.

[0021] Further, the door of the film heating oven is a double-layer door with a gap between the two layers, wherein the inner door is made of glass, and as long as the outer door is opened, the reading of the thermometer in the oven can be read through the glass window.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The asphalt short-term aging test method provided by the present application is improved on the basis of the T0609-2011 asphalt rotary thin film heating test regulation in the Highway Engineering Asphalt and Asphalt Mixture Test Regulation (JTG E20-2011), is suitable for different types of asphalt, and is designed for targeted short-term aging test of different types of asphalt, so that the short-term aging process of different types of asphalt in the mixing, transportation and paving process can be more accurately reflected. The test is simple, easy to clean, shortens the aging time, saves resources, reduces costs, reduces carbon emissions, and responds to the strategic goal of low carbon and sustainable development of China. In addition, more solutions are provided for the long-term aging test method of asphalt. DETAILED DESCRIPTION

[0024] The present application will be described in detail below with specific embodiments. The following embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any form. It should be pointed out that, for those skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made. These all belong to the protection scope of the present application.

[0025] In the technical solution, if the preparation means, materials, structure or composition ratio and other features are not explicitly stated, they are considered as common technical features disclosed in the prior art.

[0026] Example 1

[0027] The present embodiment provides a kind of asphalt short-term aging test method, the asphalt sample used is road petroleum asphalt, which meets the technical requirements of No. 70 asphalt in Table 4.2.1-2 in Highway Asphalt Pavement Construction Technical Specification (JTG F40-2004), the asphalt short-term aging test method is carried out in thin film heating oven, and the asphalt short-term aging test method comprises the following steps:

[0028] S1, number the clean, dried and cooled 4 sample pans, and weigh their mass m0;

[0029] S2, the asphalt sample is injected into the 4 sample pans with weighed mass respectively, the mass of asphalt sample in each sample pan is 25g, and a thin film with uniform asphalt thickness is formed, then it is placed into a desiccator and cooled to room temperature, and then the mass m1 is weighed, and the penetration, viscosity, softening point, brittle point and ductility of the asphalt sample at this time are measured;

[0030] S3, vertically suspending a thermometer on a rotary disc shaft of the film heating oven at the center of the rotary disc, with the mercury ball of the thermometer being 6mm above the top surface of the rotary disc, and heating and keeping the film heating oven at 162-164℃, adjusting the film heating oven to be horizontal so that the rotary disc rotates on the horizontal plane, and the angle between the rotary disc and the horizontal plane is not more than 3°, and the distance between the thermometer and the center and the edge of the rotary disc is equal;

[0031] S4, after the film heating oven reaches the constant temperature of 163℃, quickly placing the sample container into the rotary disc in the film heating oven, closing the door of the film heating oven and starting the rotary disc frame, and keeping the temperature in the film heating oven at 162℃ after the temperature rises again, and keeping the temperature at 162-164℃ for 85 minutes;

[0032] S5, taking out the sample container after heating, placing it into a desiccator to cool to room temperature, and then taking the sample container to weigh its mass m2;

[0033] S6, after weighing the sample, placing the sample container back into the film heating oven at 162-164℃ and rotating for 15 minutes, taking out the sample, scraping the sample out with a scraper or a spatula, heating and stirring to melt the sample to a flowable state, and then performing corresponding tests on the residual sample after various film heating tests.

[0034] The sample container used in the embodiment is a stainless steel disc with an inner diameter of 140mm and a depth of 9.5mm, the bottom and the top of the film heating oven are respectively provided with air inlets and outlets, the door of the film heating oven is a double-layer door, and a gap is left between the two layers, and the inner layer is made of glass.

[0035] Example 2

[0036] The embodiment provides a short-term aging test method for asphalt, the asphalt sample used is SBS polymer modified asphalt, the SBS polymer modified asphalt meets the technical requirements of I-D type SBS modified asphalt in Table 4.6.2 in Road Petroleum Asphalt Technical Specification for Highway Asphalt Pavement Construction (JTG F40-2004), the short-term aging test method for asphalt is performed in a film heating oven, and the short-term aging test method for asphalt comprises the following steps:

[0037] S1, numbering four sample containers after cleaning, drying and cooling, and weighing the mass m0 of the four sample containers;

[0038] S2, injecting the asphalt sample into the four sample containers with weighed masses, respectively, with the mass of the asphalt sample in each sample container being 12.5g, and forming an asphalt film with uniform thickness, placing the sample containers into a desiccator to cool to room temperature, weighing the mass m1, and simultaneously measuring the penetration, viscosity, softening point, brittle point and ductility of the asphalt sample at this time;

[0039] S3, vertically suspending a thermometer on the rotary disc shaft of the film heating oven at the center of the rotary disc, with the mercury ball of the thermometer being 6 mm above the top surface of the rotary disc, and heating and maintaining the film heating oven to 162-164℃, adjusting the film heating oven to be horizontal so that the rotary disc rotates on the horizontal plane, and the inclination angle between the rotary disc and the horizontal plane is not greater than 3°, and the distance between the thermometer and the center and the edge of the rotary disc is equal;

[0040] S4, after the film heating oven reaches a constant temperature of 163℃, quickly placing the sample container into the rotary disc in the oven, closing the oven door and starting the rotary disc frame, and after the temperature in the film heating oven rises to 162℃, maintaining the temperature at 162-164℃ for 85 minutes;

[0041] S5, after heating, taking out the sample container, placing it in a desiccator to cool to room temperature, and then taking the sample container to weigh its mass m2;

[0042] S6, after weighing the sample, placing the sample container back into the film heating oven at 162-164℃ and rotating for 15 minutes, taking out the sample, scraping it out with a scraper or spatula, heating and stirring to melt it to a flowable state, and then performing corresponding tests on the residue after various film heating tests.

[0043] The sample container used in this embodiment is a stainless steel disc with an inner diameter of 140 mm and a depth of 9.5 mm. The bottom and top of the film heating oven are respectively provided with air inlets and outlets. The door of the film heating oven is a double-layer door with a gap between the two layers. The inner layer door is made of glass.

[0044] Example 3

[0045] The present embodiment provides a short-term aging test method for asphalt. The asphalt sample used is a high-viscosity modified asphalt that meets the technical requirements in Table 5.2.2 of “Drainage Asphalt Pavement Design and Construction Technical Specification” (JTG / T 3350-03—2020). The short-term aging test method for asphalt is performed in a film heating oven. The short-term aging test method for asphalt comprises the following steps:

[0046] S1, numbering, weighing the mass m0 of the four clean, dried and cooled sample containers;

[0047] S2, injecting the asphalt sample into the four sample containers with known masses, with the mass of the asphalt sample in each sample container being 12.5 g, and forming a uniform asphalt film, placing it in a desiccator to cool to room temperature, weighing the mass m1, and simultaneously measuring the penetration, viscosity, softening point, brittle point and ductility of the asphalt sample at this time;

[0048] S3, vertically suspending the thermometer on the rotary disc shaft of the film heating oven at the center of the rotary disc, with the mercury ball of the thermometer being 6mm above the top surface of the rotary disc, and heating and keeping the film heating oven to 162-164℃, adjusting the film heating oven to be horizontal, and rotating the rotary disc on the horizontal plane, with the inclination angle between the rotary disc and the horizontal plane being no more than 3°, and the distance between the thermometer and the center and the edge of the rotary disc being equal;

[0049] S4, after the film heating oven reaches the constant temperature of 163℃, quickly placing the sample container into the rotary disc in the film heating oven, closing the door of the film heating oven, and starting the rotary disc frame, and keeping the temperature in the film heating oven to be 162℃, and keeping the temperature at 162-164℃ for 100 minutes;

[0050] S5, after heating, taking out the sample container, placing it into a dryer to cool to room temperature, and then taking the sample container to weigh the mass m2;

[0051] S6, after weighing the sample, placing the sample container back into the film heating oven at 162-164℃ to rotate for 15 minutes, taking out the sample, scraping the sample out with a scraper or a spatula, heating and stirring to melt the sample to a flowable state, and then performing corresponding tests on the residual sample after various film heating tests.

[0052] The sample container used in the embodiment is a stainless steel disc with an inner diameter of 140mm and a depth of 9.5mm, the bottom and the top of the film heating oven are respectively provided with air inlets and outlets, the door of the film heating oven is a double-layer door, and a gap is left between the double-layer door, and the inner door is made of glass.

[0053] Comparative Example

[0054] In order to determine the accuracy of the short-term aging method proposed in the present application, the three kinds of asphalt in Examples 1, 2 and 3 were respectively subjected to short-term aging according to T0609-2011 asphalt film heating test (TFOT) and T0610-2011 rotary heating film test (RTFOT) in Highway Engineering Asphalt and Asphalt Mixture Test Regulations (JTG E20-2011); in addition, the three kinds of asphalt in Examples 1, 2 and 3 were applied to actual engineering, and were subjected to the short-term aging process of mixing, transportation and paving in actual engineering, and then the three kinds of asphalt mixtures after the short-term aging in actual engineering were collected as a standard control group.

[0055] The aged asphalt obtained by the short-term aging test method proposed in the present application, the standard TFOT and FTFOT aging method and the short-term aging method in actual engineering was tested by a dynamic shear rheometer to obtain the rut factor, and the rut factor of the asphalt mixture in the standard control group was compared. The comparison results are shown in Tables 1, 2 and 3 respectively.

[0056] The results show that the bitumen used in Example 1, Example 2 and Example 3 has certain differences in the results of conventional short-term aging methods TFOT and RTFOT and the corresponding engineering actual short-term aging, especially the modified bitumen and its corresponding engineering actual short-term aging has obvious difference, after aging by the short-term aging test method of the application, Example 1, Example 2 and Example 3 have less difference with the corresponding engineering actual short-term aging, and can more accurately reflect the short-term aging condition of different kinds of bitumen in the process of mixing, transportation and paving in engineering practice.

[0057] Table 1: Test results of Example 1 and comparison with comparative examples.

[0058]

[0059]

[0060] Table 2: Test results of Example 2 and comparison with comparative examples.

[0061] Aging Method Track Factor / kPa Difference from Short Term Aging in Engineering Practice / % Example 2 3.77 3.25 RTFOT 3.50 10.28 TFOT 3.09 20.84 Short Term Aging in Engineering Practice 3.90 0.00

[0062] Table 3: Test results of Example 3 and comparison with comparative examples.

[0063] Aging Method Track Factor / kPa Difference from Short Term Aging in Engineering Practice / % Example 3 5.52 2.36 RTFOT 4.54 19.71 TFOT 4.15 26.68 Short Term Aging in Engineering Practice 5.66 0.00

[0064] The above description of the examples is for the purpose of facilitating the understanding and use of the application by those of ordinary skill in the art. Those skilled in the art can obviously make various modifications to these examples, and apply the general principles described herein to other examples without having to go through creative labor. Therefore, the application is not limited to the above examples, and the improvements and modifications made by those skilled in the art according to the disclosure of the application without departing from the scope of the application should be within the protection scope of the application.

Claims

1. A method for short-term aging of bitumen, characterized in that, The asphalt short-term aging test method is carried out in a film heating oven, and the asphalt short-term aging test method comprises the following steps: S1, number the four sample pans after cleaning, drying and cooling, and weigh their mass m0; S2, inject the asphalt sample into the four sample pans with weighed mass respectively, and form a thin film with uniform asphalt thickness, then place them in a desiccator to cool to room temperature, and weigh the mass m1 at this time, and measure the penetration, viscosity, softening point, brittle point and ductility of the asphalt sample at this time, wherein the mass of the asphalt sample in each sample pan is 24.5-25.5g for road petroleum asphalt, 12-13g for polymer modified asphalt, and 12-13g for high viscosity modified asphalt; S3, vertically hang the thermometer on the rotating disc shaft of the film heating oven, at the center of the rotating disc, and the mercury ball of the thermometer is 6mm above the top surface of the rotating disc, and heat and maintain the film heating oven to 162-164℃, adjust the film heating oven to be horizontal, so that the rotating disc rotates on the horizontal plane, and the inclination angle between the rotating disc and the horizontal plane is not greater than 3°, and the position of the thermometer is equidistant from the center and the edge of the rotating disc; S4, after the film heating oven reaches a constant temperature of 163℃, quickly place the sample pans on the rotating disc in the oven, close the oven door and start the rotating disc frame, and after the temperature in the film heating oven rises to 162℃, maintain the temperature at 162-164℃ for a period of time, wherein for road petroleum asphalt, maintain for 85 minutes, for polymer modified asphalt, maintain for 85 minutes, and for high viscosity modified asphalt, maintain for 100 minutes; S5, after heating, take out the sample pan, place it in a desiccator to cool to room temperature, and then weigh the mass m2 of the sample pan; S6, after weighing the sample, place the sample pan back in the film heating oven at 162-164℃ and rotate for 15 minutes, take out the sample, scrape it out with a scraper or spatula, heat and stir to melt it to a flowable state, and then perform the corresponding tests on the residues after the various film heating tests.

2. The short-term aging test method for bitumen according to claim 1, characterized in that, The sample pan is a stainless steel disc with an inner diameter of 140mm and a depth of 9.5mm.

3. The method of claim 1, wherein the asphalt is aged for 1 to 3 hours. The rotating disc in step S3 rotates on the horizontal plane at a speed of 4.5-6.5r / min.

4. The short-term aging test method for bitumen according to claim 1, characterized in that, The road petroleum asphalt meets the technical requirements in Table 4.2.1-2 in the Technical Specification for Highway Asphalt Pavement Construction (JTG F40-2004).

5. The method of claim 4, wherein the asphalt is aged for 1 hour. The road petroleum asphalt is No. 70 or No. 90 road asphalt.

6. The short-term aging test method for asphalt according to claim 1, characterized in that, The polymer modified asphalt meets the technical requirements in Table 4.6.2 in the Technical Specification for Highway Asphalt Pavement Construction (JTG F40-2004).

7. The method of claim 6, wherein the asphalt is aged for 1 hour. The polymer modified asphalt is I-D type SBS modified asphalt.

8. The short-term aging test method for bitumen according to claim 1, characterized in that, The high viscosity modified asphalt meets the technical requirements in Table 5.2.2 in the Technical Specification for Drainage Asphalt Pavement Design and Construction (JTG / T 3350-03-2020). The bottom and top of the film heating oven are respectively provided with air inlets and outlets.

9. The method of claim 1, wherein the asphalt is aged for a period of time of about 1 hour to about 24 hours. The door of the film heating oven is a double-layer door, and the inner door is made of glass.

10. The method of claim 1, wherein the asphalt is aged for a period of time of about 1 hour to about 24 hours. ​

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