GB/T 4507-2014 Standard Test Method for Softening Point of Bitumen Ring-and-Ball Apparatus

AI-translated method card — human verification pending. This is not an official translation of the standard. Unclear source values remain unverified; check the original standard and product certificate before use.

Card type: Test method

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

• Standard number: GB/T 4507-2014
• Chinese name: Standard Test Method for Softening Point of Bitumen Ring-and-Ball Apparatus
• English name: Standard test method for softening point of bitumen—Ring-and-ball apparatus
• Replacement relationship: replaces GB/T 4507—1999; previous versions are GB/T 4507—1984, GB/T 4507—1999
• Adoption relationship: modified adoption using the redrafting method of ASTM D36-09 "Standard Test Method for Softening Point of Bitumen"
• Publication/implementation: published on 2014-02-19, implemented on 2014-06-01
• Custodianship: National Technical Committee for Standardization of Petroleum Products and Lubricants, Subcommittee on Petroleum Asphalt (SAC/TC 280/SC 4)

2. Scope of application and non-applicability

• This standard specifies a method for determining the softening point of bitumen by the ring-and-ball apparatus.
• It is applicable to the determination of the softening point of bituminous materials by the ring-and-ball apparatus; the softening point range determined is 30 ℃～157 ℃ (the source text source-text extraction writes "30CC～-157CC", requires confirmation against the source standard (source-text extraction)).
• Note: Applicable bituminous materials include petroleum asphalt, coal tar pitch, emulsified asphalt or modified emulsified asphalt residue, modified asphalt, natural asphalt that can melt into a fluid upon heating without changing its properties, special asphalt, and asphalt materials recovered from asphalt mixtures, etc.
• Not applicable: no explicit non-applicability clause is provided in the available source.

3. Method principle

Two horizontal asphalt discs placed in shoulder or conical brass rings are heated in a heating medium at a certain rate, with a steel ball placed on each asphalt disc. The reported softening point is the average of the temperatures at which the two steel balls placed on the asphalt fall a distance of 25 mm when the specimen softens.

4. Reagents and materials (purity / preparation)

• 5.2.1 Heating medium
  • 5.2.1.1 Freshly boiled distilled water.
  • 5.2.1.2 Glycerol.
• 5.2.2 Release agent: prepared by weight from two parts glycerol and one part talc; this release agent is suitable for asphalt materials with 30 ℃～157 ℃ (the source text source-text extraction writes "30CC~157C", requires confirmation against the source standard (source-text extraction)).
• Purity: not provided in the available source.

5. Apparatus and equipment

• 5.1.1 Rings: two brass shoulder rings or conical rings, dimensions and specifications are shown in Figure 1a) and Figure 1b).
• 5.1.2 Support plate: flat and smooth brass plate or ceramic tile, dimensions approximately 50 mm×75 mm.
• 5.1.3 Balls: two steel balls with a diameter of 9.5 mm, each with a mass of 3.50 g±0.05 g.
• 5.1.4 Ball centering guides: two, used to center the steel balls on the specimen; general shape and dimensions are shown in Figure 1c).
• 5.1.5 Bath: a heatable glass container with an inner diameter of not less than 85 mm and a depth from the heated bottom of not less than 120 mm.
• 5.1.6 Ring support and assembly: one brass support used to support two rings in a horizontal position; shape and dimensions are shown in Figure 1d), and the installation diagram is shown in Figure 1e). The bottom of the shoulder rings on the support is at a distance of 25 mm from the upper surface of the lower support plate, and the lower surface of the lower support plate is at a distance of 16 mm±3 mm from the bottom of the bath.
• 5.1.7 Knife: for cutting asphalt.
• 5.1.8 Thermometer
  • 5.1.8.1 Shall comply with the technical requirements for thermometer GB-42 in GB/T 514, that is, a total-immersion thermometer with a temperature measurement range of 30 ℃～180 ℃ and a minimum scale division of 0.5 ℃. This thermometer shall not be replaced by other thermometers; other temperature-measuring devices that meet the same accuracy, minimum displayed temperature, and error requirements may be used instead.
  • 5.1.8.2 A suitable thermometer or suitable temperature-measuring device shall be suspended on the support as shown in Figure 1e), so that the bottom of the mercury bulb or the temperature measurement point is level with the bottom of the ring, with a distance within 13 mm, but not touching the ring or the support.

6. Recommended operating conditions

• 8.1 Select one of the following heating media and a thermometer or temperature-measuring device suitable for the expected softening point.
  • 8.1.1 Freshly boiled distilled water is suitable for asphalt with a softening point of 30 ℃～80 ℃; the initial heating medium temperature shall be 5 ℃±1 ℃.
  • 8.1.2 Glycerol is suitable for asphalt with a softening point of 80 ℃～157 ℃; the initial heating medium temperature shall be 30 ℃±1 ℃.
  • 8.1.3 For arbitration, all asphalts with a softening point lower than 80 ℃ shall be tested in a water bath, while asphalt materials with a softening point of 80 ℃～157 ℃ shall be tested in a glycerol bath. For arbitration, the corresponding thermometer specified in the standard shall be used. Alternatively, the above may be decided jointly by the buyer and seller.
• 8.5 Heat from the bottom of the bath so that the temperature rises at a constant rate of 5 ℃/min. To prevent the influence of drafts, a protective device may be used if necessary. During the test, the average heating rate shall not be taken; however, after 3 min, the heating rate shall reach 5 ℃/min±0.5 ℃/min. If the temperature rise rate exceeds this specified range, the test is invalid.

7. Sampling and specimen preparation

• 6 Sampling: obtain a representative sample in accordance with GB/T 11147.
• 7.1 The heating time of the sample shall be as short as possible on the basis of not affecting the properties of the sample and ensuring sufficient flow of the sample. For petroleum asphalt, modified asphalt, natural asphalt, and emulsified asphalt residue, the heating temperature shall not exceed the expected asphalt softening point by 110 ℃. For coal tar pitch samples, the heating temperature shall not exceed the expected coal tar pitch softening point by 55 ℃.
• 7.2 If the sample is an emulsified asphalt residue or polymer-modified emulsified asphalt residue obtained by the methods of SH/T 0099.4, SH/T 0099.16, NB/SH/T 0890, its hot residue may be stirred uniformly and then directly poured into the test mold. If the test is repeated, the sample shall not be reheated; a fresh sample shall be used to prepare the specimen in a clean container.
• 7.3 If the estimated softening point is between 120 ℃～157 ℃, the brass rings and support plate shall be preheated to 80 ℃～100 ℃, and then the brass rings shall be placed on the support plate coated with release agent. Otherwise, the asphalt specimen may completely detach from the brass rings.
• 7.4 Pour a slight excess of asphalt specimen into each ring and allow the specimen to cool at room temperature for at least 30 min. For samples that are softer at room temperature, the specimen shall be cooled in an environment at a temperature above the expected softening point by 10 ℃ for 30 min. The time from the start of pouring the specimen to the completion of the test shall not exceed 240 min.
• 7.5 After the specimen has cooled, use a slightly heated knife or scraper to cleanly remove excess asphalt so that each disc is full and flush with the top of the ring.

8. Analytical procedure

• 8.2 Place the apparatus in a fume hood and set up two specimen rings and ball centering guides, insert the thermometer into the appropriate position, fill the bath with heating medium, and place each apparatus in the proper position. Use tweezers to place the steel balls at the bottom of the bath so that they reach the same initial temperature as the other parts of the support.
• 8.3 If necessary, place the bath in ice water, or carefully heat and maintain an appropriate initial bath temperature for 15 min, and place the apparatus in the proper position, taking care not to contaminate the bath liquid.
• 8.4 Again use tweezers to pick up the steel balls from the bottom of the bath and place them in the centering guides.
• 8.5 Heat from the bottom of the bath so that the temperature rises at a constant rate of 5 ℃/min (see Section 6 for details).
• 8.6 When the steel ball wrapped in asphalt touches the lower support plate, record the temperature displayed by the thermometer for each. It is not necessary to correct the immersed portion of the thermometer. Take the average of the two temperatures as the softening point of the asphalt material. When the softening point is between 30 ℃～157 ℃, if the difference between the two temperatures exceeds 1 ℃, repeat the test.

9. Qualitative and quantitative and calculation formulas

• 9.1 Because the determination of softening point is a conditional test method, for a given asphalt specimen, when the softening point is slightly higher than 80 ℃, the softening point determined in a water bath is lower than that determined in a glycerol bath.
• 9.2 When the softening point is higher than 80 ℃, the change from a water bath to a glycerol bath is discontinuous. The lowest reported softening point of asphalt in a glycerol bath may be 84.5 ℃, while the lowest softening point of coal tar pitch may be 82 ℃. When the softening point in a glycerol bath is lower than these values, the softening point in the water bath shall be converted to 80 ℃ or lower, and this shall be noted in the report.
  • 9.2.1 When converting the softening point from a glycerol bath to a water bath, the correction value for petroleum asphalt is −4.5 ℃, and for coal tar pitch is −2.0 ℃. The use of this correction value can only roughly indicate the level of the softening point; to obtain an accurate softening point, the test shall be repeated in a water bath.
  • 9.2.2 In any case, if the average softening point of petroleum asphalt measured in a glycerol bath is 80.0 ℃ or lower, or the average softening point of coal tar pitch is 77.5 ℃ or lower, the test shall be repeated in a water bath.
• 9.3 When converting a softening point slightly higher than 80 ℃ in a water bath to a softening point in a glycerol bath, the correction value for petroleum asphalt is +4.5 ℃, and the correction value for coal tar pitch is +2.0 ℃. The use of this correction value can only roughly indicate the level of the softening point; to obtain an accurate softening point, the test shall be repeated in a glycerol bath. In any case, if the average of two measured temperatures in a water bath is 85.0 ℃ or higher, the test shall be repeated in a glycerol bath.
• Calculation formula: not provided in the available source (the average of the two temperatures is taken as the softening point, see 8.6, 10.1).

10. Precision

• 11.1 Repeatability: In the same laboratory, by the same operator using the same equipment, following the same test method, and within a short period of time, the absolute difference between two test results obtained from independent tests on the same test object shall not exceed the value in Table 1.
• 11.2 Reproducibility: In different laboratories, by different operators using different equipment, following the same test method, the absolute difference between two test results obtained from independent tests on the same test object shall not exceed the value in Table 1.
• Table 1 Precision requirement data table

11. Report

• 10.1 Take the average of the two results as the test result.
• 10.2 When reporting the test results, also report the type of heating medium used in the bath.

12. Referenced documents

• GB/T 514 Technical conditions for glass liquid thermometers for petroleum product testing
• GB/T 11147 Sampling method for petroleum asphalt
• SH/T 0099.4 Determination method for evaporated residue content of emulsified asphalt
• SH/T 0099.16 Determination method for residue content of emulsified asphalt (low-temperature vacuum distillation method)
• NB/SH/T 0890 Test method for low-temperature evaporation recovery of emulsified asphalt residue

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 Q&A