Some standard content:
GB/T5304—2001
This standard is equivalent to the American Society for Testing and Materials standard ASTMD1754-1997 "Test Method for the Effect of Heat and Air on Asphalt Quality".
The main differences between this standard and GB/T5304—1985 are as follows: 1. This standard specifies the range of oven volume dimensions, adding "the maximum dimension of each side of the oven is 535mm". 2. The hanging position of the test thermometer in this standard has been changed from the original "the bottom of the thermometer mercury ball should be 6.4mm above the turntable" to "the bottom of the thermometer mercury ball should be 40mm above the turntable". 3. This standard specifies the diameter range of the turntable for placing sample III, from the original "the diameter is not less than 250mm" to "the diameter is 250~450mm". wwW.bzxz.Net
4. The installation position of the turntable for sample III in this standard has been changed from "as close to the center of the oven as possible" to "150mm above the bottom of the oven".
5. This standard adds the requirement of "mass reduction is reported as a negative value, and mass increase is reported as a positive value" in the report. 6. This standard adds the requirements for the 15℃ elongation, 60℃ viscosity, 135℃ viscosity and 60℃ viscosity ratio precision of asphalt before and after the film oven test.
7. This standard adds the requirement of "complete the determination of the properties of the heated sample within 72h". The main differences between this standard and ASTMD1754-1997: 1. ASTMD1754-1997 stipulates that the thickness of the metal plate for sample III is about 0.64mm. In combination with my country's actual situation, this standard stipulates that the thickness of the metal plate for the sample dish is 0.6~1.0mm. 2. This standard deletes "Appendix X1 recommended oven in ASTM D1754-1997" and adds "Appendix A Specifications of the thermometer used in the instrument".
3. This standard does not adopt the requirements of "standard deviation" and "coefficient of variation" in the precision requirements of test results in ASTM D1754-1997. Appendix A of this standard is the appendix of the standard.
This standard is proposed by the State Administration of Petroleum and Chemical Industry. This standard is technically managed by the Heavy Oil Research Institute of Petroleum University (East China). The drafting unit of this standard: Shengli Refinery of Qilu Petrochemical Company. The main drafters of this standard: Zhang Guangqing, Liu Huimin, Zhang Tianying. I
1 Scope
National Standard of the People's Republic of China
Asphalt thin-film oven test method
Asphalt thin-film oven test methodGB/T5304—2001
Replaces GB/T5304—1985
This standard is applicable to the determination of the effects of heat and air on petroleum asphalt films. This effect is determined by measuring the changes in certain properties of petroleum asphalt before and after the test.
This standard does not specify safety issues. If necessary, the user should formulate appropriate personal safety protection measures before use.
2 Referenced standards
The provisions contained in the following standards become part of this standard by reference. Unless Unless otherwise specified in the standard, the following referenced standards shall be the currently valid versions.
GB/T4509 Asphalt penetration test method
GB/T4508 Asphalt ductility test method
SH/T0557 Asphalt viscosity test method (vacuum capillary method)SH/T0654 Asphalt kinematic viscosity test method
3 Method overview
3.1 The petroleum asphalt film was heated in an oven at 163°C for 5 hours. The physical properties of the sample before and after the test were measured to determine the effects of heat and air on the properties of the petroleum asphalt. The change in mass of the specimen before and after the test. 3.2 This standard specifies the precision of viscosity, viscosity ratio, penetration ratio, mass change and ductility. 4 Significance and application
This standard can be used to predict the change in properties of petroleum asphalt during the normal hot mixing process (about 150°C), usually expressed in terms of viscosity, penetration and ductility. The properties of petroleum asphalt after the test are close to the quality of petroleum asphalt used in paving. If the hot mixing temperature is significantly different from 150°C, the effect on the quality of the petroleum asphalt will be greater or less than the measured data. 5 Instrumentation
5.1 Oven: It is an electric heating air natural convection oven. The working temperature can reach 180℃. The turntable axis should be aligned with the center of the oven, as described in 5.1.2, and should rotate well after installation.
5.1.1 Structure: The oven is rectangular, with a minimum dimension of 330mm and a maximum dimension of 535mm on each side (excluding the space occupied by the heating element). The front of the oven should be equipped with a tight hinged door, the size of which is roughly the same as the height and width of the oven interior. The door can be equipped with a window of at least 100mm×100mm, with two layers of glass with a gap in the middle. The reading of the thermometer in the oven can be read through the window without opening the door, and it is also allowed to set another glass door inside the oven door. In this way, the outer door can be opened at any time to measure the temperature inside the oven. Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on May 11, 2001, and implemented on December 1, 2001, the oven adopts natural convection ventilation. In order to make the ventilation in the oven uniform, air inlet and outlet are respectively provided at the bottom and top. The total area of the air inlet is more than 1.3cm2, and the total area of the top gas outlet is 1.3~12.9cm. 5.1.2 Turntable: The oven should have a metal circular plate with a diameter of 250~450mm. The structure of this plate should be a flat plate for placing the sample dish. When the sample dish is placed, it will not block the air circulation through the turntable. The turntable is installed on the suspended vertical axis and is located in the center of the horizontal dimension of the oven. The turntable is rotated by a special mechanical device at a speed of (5.5 ± 1.0) r/min. The turntable should be positioned vertically, and the best vertical position should be 150 mm above the bottom (excluding the space occupied by the heating element). 5.2 Thermometer: Comply with the provisions of Appendix A. The thermometer is hung on the bracket of the vertical axis of the turntable. The distance between the hanging point and the center and the outer edge of the turntable should be equal. The bottom of the mercury ball of the thermometer should be 40 mm above the turntable. 5.3 Sample III: Flat-bottomed cylindrical dish. The inner diameter is 140 mm and the depth is 9.5 mm. A 50g sample forms a film about 3.2 mm thick in the sample dish. The sample dish can be made of stainless steel or aluminum. The metal thickness is 0.6 to 1.0 mm and should not be deformed during use. 5.4 Analytical balance, used for precise weighing, accurate to 0.001 g. 6 Preparation
6.1 Place enough samples in a suitable container and heat them to a fluid state. Avoid local overheating of the samples during heating. The maximum heating temperature should not exceed 150°C. Stir the samples during heating, but avoid bubbles in the samples. Weigh (50±0.5)g of samples in sample dishes that meet the requirements of 5.3 and have known mass. 6.2 Pour the samples in 6.1 into the test mold of the analytical instrument that needs to measure the properties of petroleum asphalt before the test, and measure the viscosity, needle penetration, etc. of the samples before the test according to the reference standard. 6.3 If it is not necessary to measure the mass change, proceed according to 7.2. If it is necessary to measure the mass change, the weighed samples should be cooled to room temperature and weighed to 0.001g.
7 Test steps
7.1 Adjust the oven to a horizontal level. When the turntable rotates on the horizontal plane, the inclination angle between the turntable and the horizontal plane is not greater than 3°. 7.2 Place the empty sample III in the predetermined position of the turntable. When the oven is in equilibrium, adjust the temperature control switch to keep the temperature at (163 ± 1) °C. 7.3 After preheating and adjusting the oven according to 7.2, take out the empty sample container and quickly put the sample container on the turntable. Close the oven door and start rotating the turntable. After the sample is placed in the oven and the temperature in the oven rises to the required temperature again, keep it at (163 ± 1) °C for 5 hours. The starting time of 5 hours is from the temperature rising to 162 °C, but the sample should not be in the oven for more than 5.25 hours. After the test, remove the sample from the oven. If it is not necessary to measure the mass change of the sample, proceed according to 7.5. If it is necessary to measure the mass change of the sample, cool the sample to room temperature and weigh it to 0.001g. Note: It is not allowed to test different grades of asphalt in the same oven at the same time. 7.4 After the sample is weighed, place it on the turntable of a 163℃ oven, close the oven door, rotate the turntable for 15 minutes, take out the sample, and immediately proceed to the next step according to 7.5.
7.5 Scrape out the sample from each sample container with an appropriate spatula or putty force, and pour it into a 240m porcelain container or metal container. Stir and mix the sample thoroughly. If necessary, place the porcelain or metal container on a heating plate to heat it to keep the sample in a fluid state. Within 72 hours, use the test method specified in the reference standard to complete the determination of the viscosity, needle penetration and elongation of the sample after the test. 8 Report
8.1 Report according to 6.2 and 7.5 Measured viscosity and penetration of the sample. The viscosity ratio is expressed as the ratio of the viscosity of the petroleum asphalt after the test to the viscosity of the petroleum asphalt before the test. The penetration ratio is expressed as the percentage of the penetration of the petroleum asphalt after the test to the penetration of the petroleum asphalt before the test. 8.2 Report the ductility or other test results of the sample measured in accordance with 7.5. 8.3 When reporting the change in mass, the change in mass is expressed as the percentage of the mass change in all the sampled blood to the mass of the sample before the test. A decrease in mass is reported as a negative value, and an increase in mass is reported as a positive value. 2
9 Calculation
GB/T5304—2001
9.1 The penetration ratio P. (%) of the sample is calculated as follows: X100
Where: P--penetration of the sample after the test, 1/10mm; P
-penetration of the sample before the test, 1/10mm. 9.2 The mass change of the sample M. (%) is calculated as follows: mm×100
Wherein: m-
Total mass of the sample after the test, g;
Total mass of the sample before the test, 8.
9.3 The viscosity ratio V of the sample at 60℃ is calculated as follows: ms
Viscosity of the sample at 60℃ after the test, Pa·s;
Wherein:
-Viscosity of the sample at 60℃ before the test, Pa·s. 10 Precision
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Repeatability: The difference between two results of the same operator in the same laboratory should not exceed the value in Table 1. 10.1
Needle penetration ratio, %
Absolute value of mass change, %
Viscosity at 60°C
Viscosity at 135°C
Viscosity ratio at 60°C
Elongation (15°C), cm
Permissible difference between two test results
*000*-000(1)
（2）
.......(3)
Permissible range of two test results
(percentage of the average value), %
10.2 Reproducibility: The difference between two test results by different laboratories and different operators should not exceed the value shown in the table. 2 Values: Table 2
Needle penetration ratio, %
Absolute value of mass change, %
Viscosity at 60℃
Viscosity at 135℃
Viscosity ratio at 60℃
Elongation (15℃), cm
Permissible difference between two test results
Permissible range of two test results
(Percentage of the average value), %
GB/T5304—2001
Appendix A
(Appendix of the standard)
Specifications of the thermometer used in the instrument
This specification conforms to the specifications of ASTME113C.
This thermometer shall meet the following requirements.
Temperature range, ℃
Immersion depth
Minimum graduation, ℃
Each longer scale, ℃
Digit, ℃
Scale error, ℃
Expansion chamber is allowed to be heated to, ℃
Total length, mm
Rod diameter, mm
Length of mercury ball, mm
Diameter of mercury ball mm
Distance from ball bottom to 155℃ scale, mm
Length of scale part, mm
Bottom of ball to the top of shrink ball, mm
155~170
155,160,165,170
150~160
≥5.0 (not thicker than the rod)
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