GB/T 8928-2008 Standard Test Method for Density of Solid and Semi-Solid Petroleum Asphalt

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Card type: Test method

1. Method number / full title / English name / replacement relationship

• Standard number: GB/T 8928-2008
• Chinese title: Standard Test Method for Density of Solid and Semi-Solid Petroleum Asphalt
• English title: not provided in the available source
• Replacement relationship: not provided in the available source (the main text does not give replacement standard information)

2. Applicable scope and non-applicability

• Applicable scope: specifies the test method for determining the density of solid and semi-solid petroleum asphalt by the pycnometer method (Chapter 1).
• Not applicable: not applicable to the determination of solid petroleum asphalt with a relative density less than 1.000 (Chapter 1).
• Safety note: this standard does not address safety regulations related to use; users of the standard are responsible for establishing appropriate safety application procedures before use (Chapter 1).

3. Method principle

Using a pycnometer, at the specified temperature, separately determine the mass of the same volume of petroleum asphalt and water, and calculate the relative density and density of the petroleum asphalt according to the formula (Chapter 4).

4. Reagents and materials (purity / preparation)

• 6.8 Freshly boiled and cooled distilled water or deionized water.
• 6.9 Wetting agent: an aqueous solution of sodium alkylbenzenesulfonate with a mass fraction of 1% or a solution of other wetting agents may be used.
• Purity requirements for other reagents: not provided in the available source.

5. Apparatus and equipment

• 6.1 Pycnometer: glass material, the bottle mouth and stopper are carefully ground and fit tightly. The stopper diameter is 22 mm–26 mm, with its axis as the center, there is a small hole of diameter 1.0 mm–2.0 mm in the middle, the upper surface of the stopper is smooth and flat, and the lower surface is concave so that air can escape from the hole; the height at the center of the concave part is 4.0 mm–6.0 mm. After the stopper is put on, the pycnometer volume is 24 mL–30 mL, and the mass does not exceed 40 g. See Figure 1 for the schematic of the pycnometer.
• 6.2 Balance: sensitivity 0.0005 g.
• 6.3 Water bath: capable of maintaining the water temperature at the test temperature ±0.1 ℃.
• 6.4 Thermometer: glass thermometer, total immersion type, minimum scale 0.1 ℃, graduation value 1 ℃, measuring range 0 ℃~30 ℃. Other temperature measuring devices that meet the accuracy and sensitivity requirements may also be used.
• 6.5 Sieves: metal sieves with sieve openings of 0.3 mm~0.5 mm, 0.6 mm and 2.5 mm respectively.
• 6.6 Vacuum pump or water jet pump: capable of reaching a vacuum of 2.7 kPa.
• 6.7 Glass beaker: 600 mL~800 mL.
• Other apparatus: not provided in the available source.

6. Recommended operating conditions

• Test temperature: 25 ℃±0.1 ℃ (8.2, 10.1.5, 10.2.6).
• Water bath immersion depth: not less than 100 mm, with the beaker mouth higher than the water bath surface (8.2).
• The water surface in the beaker should exceed the top of the pycnometer by 40 mm (8.1).
• Heating of semi-solid sample: the heating temperature must not exceed its estimated softening point 110 ℃, and the heating time must not exceed 60 min (10.1.2).
• Oven holding of semi-solid sample: the oven temperature is higher than the estimated softening point of the sample by 100 ℃–110 ℃, and hold for 20 min–30 min (10.1.3).
• Residual pressure of vacuum desiccator: 2.7 kPa~3.3 kPa, for at least 15 min (10.2.4).
• Other operating conditions: not provided in the available source.

7. Sampling and sample preparation

• Sampling: sample according to GB/T 11147 (Chapter 7).
• Preparation of semi-solid petroleum asphalt sample (10.1.1~10.1.3):
  • If the sample contains water, the sample should be carefully heated or other suitable methods should be used to remove the water; if the sample contains mechanical impurities, a sieve with openings of 0.3 mm~0.5 mm should be used to filter out the impurities.
  • Carefully heat the sample, stirring to prevent local overheating, until the sample has sufficient fluidity to be poured into the pycnometer. The heating temperature must not exceed its estimated softening point 110 ℃, and the heating time must not exceed 60 min, and avoid mixing air bubbles into the sample.
  • Pour a sufficient amount of sample into a clean, dry, preheated and constant-weight pycnometer; the amount poured is about 3/4 of the pycnometer capacity. Do not allow the sample to adhere to the bottle mouth or the bottle wall above the liquid surface, and prevent entrapment of air bubbles.
• Preparation of solid petroleum asphalt sample (10.2.1~10.2.2):
  • If the sample surface is moist, the sample needs to be dried before testing. It may be blown dry with clean dry air, or the sample may be placed in a forced-air oven at 50 ℃ to dry.
  • Crush 50 g–100 g of dry sample, taking care not to grind. Sieve out a sample with a particle size of 0.6 mm–2.5 mm. Place not less than 5 g of the sample into a dry, clean and constant-weight pycnometer.

8. Analytical procedure

8.1 Apparatus preparation (Chapter 8)

• 8.1 Pour freshly boiled and cooled distilled water or deionized water into a beaker of 600 mL~800 mL; the water level should exceed the top of the pycnometer by 40 mm.
• 8.2 Place the beaker into a water bath maintained at 25 ℃±0.1 ℃, with an immersion depth of not less than 100 mm, and the beaker mouth higher than the water bath surface. The beaker should be able to be conveniently fixed and removed in the water bath.

8.2 Pycnometer calibration (Chapter 9)

• 9.1 Weigh a clean, dry pycnometer. When determining semi-solid asphalt, weigh to the nearest 0.001 g; when determining solid asphalt, weigh to the nearest 0.0005 g. Record this mass as m1.
• 9.2 Remove the beaker from the water bath, fill the pycnometer with water from the beaker, insert the stopper, place the pycnometer into the beaker, tighten the stopper, and return the beaker to the water bath.
  • Note: The pycnometer should be calibrated at the test temperature; data for a pycnometer calibrated at one temperature cannot be used at a different temperature.
• 9.3 Keep the pycnometer in water for more than 30 min, remove the pycnometer, immediately wipe the top of the stopper once with a dry soft cloth or filter paper, then quickly wipe dry the outer periphery of the pycnometer, and immediately weigh. When the sample is semi-solid asphalt, weigh to the nearest 0.001 g; when the sample is solid asphalt, weigh to the nearest 0.0005 g. Record this mass as m2.
  • Note: Even if small water droplets form due to expansion, do not wipe the top of the stopper dry again. If moisture condenses on the pycnometer during weighing, quickly wipe the outside of the pycnometer dry again (excluding the top) before recording the mass.

8.3 Determination of relative density of semi-solid petroleum asphalt (10.1)

• 10.1.1 If the sample contains water, the sample should be carefully heated or other suitable methods should be used to remove the water; if the sample contains mechanical impurities, a sieve with openings of 0.3 mm~0.5 mm should be used to filter out the impurities.
• 10.1.2 Carefully heat the sample, stirring to prevent local overheating, until the sample has sufficient fluidity to be poured into the pycnometer. The heating temperature must not exceed its estimated softening point 110 ℃, and the heating time must not exceed 60 min, and avoid mixing air bubbles into the sample.
• 10.1.3 Pour a sufficient amount of sample into a clean, dry, preheated and constant-weight pycnometer; the amount poured is about 3/4 of the pycnometer capacity. Do not allow the sample to adhere to the bottle mouth or the bottle wall above the liquid surface, and prevent entrapment of air bubbles. Immediately transfer the pycnometer containing the sample into an oven at a temperature higher than the estimated softening point of the sample by 100 ℃–110 ℃, and hold for 20 min–30 min.
• 10.1.4 Remove the pycnometer containing the sample from the oven, cool at room temperature for more than 40 min, then weigh together with the stopper, to the nearest 0.001 g, and record the mass of the pycnometer and sample as m3.
• 10.1.5 Remove from the water bath the beaker maintained at 25 ℃±0.1 ℃, fill the pycnometer containing the sample with water from the beaker, taking care that no air bubbles are allowed in the pycnometer, and insert the stopper. Place the pycnometer into the beaker, tighten the stopper, and return the beaker to the water bath.
• 10.1.6 Keep the pycnometer in the beaker for more than 30 min. Remove the pycnometer, wipe it dry as described in 9.3 and immediately weigh, to the nearest 0.001 g, and record the total mass of water, sample and pycnometer as m4.

8.4 Determination of relative density of solid petroleum asphalt (10.2)

• 10.2.1 If the sample surface is moist, the sample needs to be dried before testing. It may be blown dry with clean dry air, or the sample may be placed in a forced-air oven at 50 ℃ to dry.
• 10.2.2 Crush 50 g–100 g of dry sample, taking care not to grind. Sieve out a sample with a particle size of 0.6 mm–2.5 mm. Place not less than 5 g of the sample into a dry, clean and constant-weight pycnometer, weigh together with the stopper, to the nearest 0.0005 g, and record this mass as m3.
• 10.2.3 Remove the stopper, take the beaker out of the water bath, pour water from the beaker into the pycnometer so that the water level is about 10 mm above the sample, and at the same time add a few drops of wetting agent, shake the pycnometer to make the sample sink and allow air adsorbed on the sample surface to escape. Take care not to shake the sample out of the bottle during shaking.
• 10.2.4 Place the pycnometer without the stopper into a vacuum desiccator, start the vacuum device, evacuate at a rate that does not cause bumping or violent boiling, maintain the residual pressure in the vacuum desiccator at 2.7 kPa~3.3 kPa for at least 15 min to remove air bubbles. If bubbles still remain, repeat the above operation until no visible bubbles are present, and then continue evacuating for 15 min.
• 10.2.5 Remove the beaker from the water bath, fill the pycnometer with water from the beaker, gently insert the stopper, taking care that no air bubbles are allowed in the pycnometer, place the pycnometer into the beaker, insert the stopper tightly, and return the beaker to the water bath.
• 10.2.6 Keep the pycnometer in the beaker at a temperature of 25 ℃±0.1 ℃ for not less than 30 min, then remove the pycnometer, dry it by the method described in 9.3, and weigh it immediately to the nearest 0.0005 g, recording this mass as m4.

9. Qualitative and Quantitative Determination and Calculation Formulas

• 11.1 The relative density of the test sample is calculated according to formula (1):
  • Formula: the original formula (1) source-text extraction is shown as "m3mi •..•••… (1)"; the numerator, denominator, and complete expression require confirmation against the source standard (source-text extraction).
  • Symbols in the formula:
    • m1— the numerical value of the mass of the pycnometer, in grams (g);
    • m2— the numerical value of the mass of the pycnometer and water, in grams (g);
    • m3— the numerical value of the mass of the pycnometer and test sample, in grams (g);
    • m4— the numerical value of the mass of the pycnometer, water, and test sample, in grams (g).
• 11.2 Density ρ25 is calculated according to formula (2):
  • ρ25 = 0.9971 × D25 (the original source-text extraction is shown as "pP25 = 0.9971XD2"; the symbols require confirmation against the source standard (source-text extraction))
  • Where:
    • ρ25— the numerical value of the density of the test sample at 25 ℃, in grams per cubic centimeter (g/cm³);
    • 0.9971— the numerical value of the density of water at 25 ℃, in grams per cubic centimeter (g/cm³).
• Terms and definitions (Chapter 3):
  • 3.1 Density density: mass divided by volume at the standard test temperature, denoted as ρ (the original source-text extraction is shown as "p"; requires confirmation against the source standard (source-text extraction)).
  • 3.2 Relative density relative density: the ratio of the mass of a given volume of material at the standard test temperature to the mass of the same volume of water, denoted as D. Note: relative density is specific gravity.

10. Precision

• 12.1 Precision of relative density:
  • The repeatability of the relative density of semi-solid asphalt is 0.002, and the reproducibility is 0.005.
  • The repeatability of the relative density of solid petroleum asphalt is 0.007, and the reproducibility is 0.011.
• 12.2 Precision of density:
  • For semi-solid asphalt at 25 ℃, the repeatability of density is 0.002 g/cm³, and the reproducibility is 0.005 g/cm³.
  • For solid petroleum asphalt at 25 ℃, the repeatability of density is 0.007 g/cm³, and the reproducibility is 0.011 g/cm³.

11. Report

• Relative density and density may be reported together as needed, or either one may be reported separately (Chapter 13).
• 13.1 Report of relative density: take the arithmetic mean of the results of two parallel determinations (accurate to the 3th decimal place) as the test result for the relative density of the test sample. If the two results exceed the repeatability requirement, the test is invalid and shall be retested.
• 13.2 Report of density: if the relative density meets the repeatability requirement, the value obtained according to formula (2) (accurate to 0.001 g/cm³) is taken as the density of the test sample at 25 ℃.

12. Referenced Documents

• GB/T 11147 Sampling method for petroleum asphalt (Chapter 2, Chapter 7).

13. Source and verification

This page is an AI translation of the available Chinese method card. Human verification is pending. It is not an official translation of the standard. Check the source standard and product certificate before use.

14. Quick Reference for Questions and Answers