NB/SH/T 0978-2019 in English

Technical Background of the Standard

This standard is modified to adopt ASTM D7226-11. The main technical differences include: deleting non-SI units, adjusting the structure description, and using the corresponding Chinese standard to replace the ASTM reference document. It is suitable for rotating paddle viscometer to measure the apparent viscosity of emulsified asphalt in the range of 30-1500 mPa·s.

Core Test Methods

Key Instrument Parameters

Analysis of key points of operation

1. Preheating requirements: Instrument preheating ≥ 30 minutes, constant temperature water bath needs to be opened 10 minutes in advance
2. Sample loading specifications: The sample cup is filled to the mark line, and the paddle is fully immersed and friction-free
3. Data reading: Record the displayed value after stabilization for 5 minutes, and adjust the speed if the range is exceeded

Precision control

Repeatability requirements: ≤22% at 25℃, ≤64% at 50℃ (relative difference). Comparison data from a laboratory showed that the CV value of anionic emulsified asphalt measured three times was 2.3%, which is better than the standard requirement.

Project Implementation Suggestions

• Temperature sensitivity: Viscosity decreases by about 15-20% for every 5°C increase in temperature, so strict temperature control is required
• Sample processing: Test immediately after stirring to prevent segregation
• Equipment calibration: It is recommended to perform range verification with standard silicone oil every month