construction testing equipment


Reflux Extractor


4000 Grams

Minimum Order Quantity


Product Description - Reflux Extractor

What is Reflux Extraction?

Reflux Extractor is the most economical method for determining the asphalt content of asphalt mixtures. The hot plates generate solvent vapor that flows around and through the sample contained in two wire mesh cones lined with filter paper. The reflux solvent that condenses in the water-cooled condenser is repeatedly filtered through the sample until the bitumen is removed.

The simple device Reflux Extractor, which works on the same principle, consists of a cylindrical glass container containing two metallic cones made of stainless steel mesh and a metallic condenser above the container. Comes complete with 100 filter papers and wire gauge, heating plate.

Capacity of Reflux Extractor is 4,000 grams.

Note: An additional cylindrical glass jar can be provided at an additional cost.

Reflux Extractor includes hot plate, extraction vessel, two mesh cones with bow handles, copper condenser with water inlet/outlet tubes, filter paper, insulating pads and instructions.

The characteristics of Reflux Extraction:

  • An economical option for determining asphalt content in asphalt mixes
  • Capacity of 4,000 grams
  • All-in-one solution with the necessary elements for the procedure

Standards of Reflux Extractor: ASTM D 2172- AASHTO T 164

Reflux Extraction Procedure:

Test Description for  Reflux Extractor:

This method involves the quantitative determination of bitumen in hot paving mixes and paving samples.

Test application This method can be used to quantitatively determine bitumen in HMA samples and pavement for specification acceptance, service evaluation, inspection and survey.

Units of measurement The bitumen content is expressed as a percentage by mass of moisture-free asphalt.

Test Procedure for  Reflux Extractor:

Determine the moisture content of the mixture according to the test method. Dry and determine the mass of a sheet of filter paper for each frame to be used. Fold each paper to its diameter, bend the ends and spread them out to form a suitable size for the metal cones to fit. Determine the mass of each frame with its filter paper insert to the nearest 0.5 g. Record the mass and identify each image by its number. Place the test part on the board. If two frames are used, split the test part evenly between the two.

The top of the test coupon should be below the top of the backing paper. Determine the mass of each structure loaded separately to the nearest 0.5 g. Consider the dough again. Pour the solvent into the glass cylinder and place the bottom frame inside. The solvent level must be below the top of the bottom frame. If two frames are used, insert the top frame into the bottom frame and place its tabs in the holes at the top of the bottom frame. Place the glass cylinder on the heating plate. Cover the condenser. Run a smooth, steady flow of cold water through the condenser. 

Adjust the temperature of the hot plate so that the solvent boils slightly and a steady stream of condensed solvent flows through the standard test procedure manual.

 If necessary, adjust the hot plate temperature to maintain the solvent flow rate necessary to keep the test portions at the tips completely covered with condensed solvent. Make sure that no condensed solvent drips onto the filter cones. Continue backtracking until the solvent coming out of the lower cones is a light straw color. At this point, turn off the hotplate and let the unit cool down while the water passes through the condenser. When boiling has stopped and the cylinder is cool enough to handle, turn off the condenser and remove it from the cylinder.

Results and calculations  done in Reflux Extractor:

Calculations Calculate the percentage of bitumen in the test portion as follows:

Bitumen content in % = [(w1 – w2)-(w3-w4) / w1-w2] x 100

Where: W1 = test plug ground

 W2 = mass of water in the test portion

 W3 = mass of extracted mineral aggregate

 W4 = mass of the mineral in the extract

Calibrations, corrections, repeatability

The amount of asphalt extracted should be adjusted for the following: Extraction error required due to loss of fines through the filter and absorption of asphalt into the aggregate. Moisture correction required because moisture in the mix is extracted as a bituminous binder.

The standard deviation for a single laboratory was 0.18%. Therefore, the results of two tests performed correctly must be reported by the same operator should not differ by more than 0.52%. The multi-laboratory standard deviation has been found to be 0.29%. Therefore, the results of two properly conducted tests from two different laboratories on samples from the same batch should not differ by more than 0.81%.

Reflux Extractor should be cleaned frequently to prevent testing errors.

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