Bitumen Extraction Test – Procedure ASTM D 2172

Bitumen Extraction Test – Procedure

The penetration test, flash and fire point test, and softening point test have been utilized to ascertain the quality and durability of bitumen. The bitumen extraction test is now being carried out to determine the percentage of bitumen present in bituminous concrete.

What is a Bitumen Extraction Test?

The bitumen extraction test, as per ASTM D 2172, is a method used to assess the amount of bitumen binder used in asphaltic pavement through the cold dissolver technique. After the pavement work is finished, a specific bitumen sample is collected and analyzed to determine the quality of the binder.

Why Bitumen Extraction Test required?

The percentage of bitumen used plays a crucial role in determining the quality, durability, and strength of the asphaltic pavement. Therefore, it is imperative to ascertain this value in order to assess the pavement’s quality.

Apparatus required for Bitumen Extraction Test

  • Centrifuge Extractor
  • Weighing Machine
  • 500 g bitumen sample (min)
  • Filter paper (New)
  • Benzene ( C6H6 )
  • Measuring Jar
  • Tray

Test Bitumen Extraction Test Procedure

  • Measure 1000g of bitumen sample (A) and place it in the cup of the centrifuge.
  • Weigh the filter paper and label it as (C).
  • Fill the cup with benzene (dissolver) up to the top of the sample to ensure thorough soaking.
  • The benzene will help separate the aggregates and bitumen.
  • Cover the sample with the filter paper in the centrifuge apparatus. Position a beaker at the outlet of the centrifuge to collect the extracted sample.
  • Allow the solvent to dissolve the bitumen and other asphaltic pavement ingredients for up to 3 to 5mins .
  • Gradually increase the speed of the centrifuge machine to 3600 revolutions per minute.
  • The entire amount of bitumen and benzene will fully drain into the beaker.
  • Add more benzene into the cup and repeat the process.
  • Continue running the centrifuge until the bitumen extraction is finished.
  • The extracted material will appear as a light straw color.
  • Weigh the extracted material as B.
  • Remove the filter paper,
  • Finally, weigh the dried filter paper as D.

The examination ought to be carried out with a minimum of three specimens, and the mean figure represents the proportion of bitumen employed in the road surface.

Calculation For Bitumen Extraction Test

The percentage of bitumen = (A-B+(D-C)))/A*100

A- Weight of Sample before Extraction

B- Weight of Sample After Extraction

C – Weight of Filter Paper before Extraction

D – Weight of Filter Paper After Extraction

Bitumen Extraction Test Format


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