The Abson Recovery Apparatus for Asphalt Mixtures is a laboratory device used to recover asphalt binder from solvent-extracted mixtures. It efficiently separates and recovers bitumen from aggregates, enabling accurate binder analysis for quality control and performance testing in asphalt laboratories.

Abson Recovery Apparatus for Asphalt Mixtures

Model:TD726-1

I. Product Introduction
The Asphalt Mixture Binder Recovery Apparatus (Abson Method) is mainly used for recovering asphalt binder from petroleum asphalt mixtures. The equipment performs solvent extraction on asphalt pavement or asphalt mixtures and subsequently removes the solvent effectively, while minimizing any alteration to the original properties of the asphalt, thereby obtaining representative recovered asphalt samples.

The recovered asphalt can be used to evaluate the aging condition of asphalt, analyze pavement damage causes, and provide a basis for the mix design of recycled asphalt mixtures. In addition, various physical properties and chemical compositions of the recovered asphalt can be tested as required.

II.Reference or Applicable Standards

JTG 3410, ASTM D5404, ASTM D1856, EN 12697-3, AASHTO T164, AASHTO T170

III. Instrument and Material Requirements

1.TD726-1 Asphalt Mixture Binder Recovery Apparatus

2.Vent tube: rubber hose with a minimum length of 180 mm, outer diameter of 6 mm, and a bulb end with an outer diameter of 10 mm. It has six staggered side holes with an approximate diameter of 1.5 mm.

3.Solvent: trichloroethylene, industrial grade.

4.Others: crucible with handle, beakers, etc.

IV. Test Procedure and Method

4.1 Preparation

4.1.1 Prepare asphalt mixture samples. The sample size should be estimated to obtain 80–120 g of recovered asphalt binder per test. If the required amount is insufficient for testing, multiple recoveries may be carried out and then combined. For field-cored asphalt mixture samples, they should first be air-dried using a fan to remove moisture, then heated in a microwave oven or drying oven until reaching a loose state. The heating temperature should be controlled at 105°C ± 5°C, and the time from the start of heating to the loose condition should be 35 min ± 5 min.

4.1.2 According to T 0722 of this specification, extract the asphalt mixture using the centrifugal method until the extract becomes clear and transparent.

4.1.3 Transfer the asphalt extract solution into centrifuge tubes in batches and remove mineral filler using high-speed centrifugal separation. Apply a relative centrifugal force of not less than 770 × g for no less than 30 minutes.

4.1.4 Take a portion of the clean extract and filter it through filter paper using a vacuum filtration device. While applying vacuum, rinse the filter paper with fresh trichloroethylene solution. Carefully check whether any mineral particles remain on the filter paper to verify the effectiveness of the high-speed centrifugation process. If a vacuum filtration device is not available, a muffle furnace or other high-temperature equipment may be used to heat the extract, and the residue after combustion can be weighed to determine whether fine mineral particles remain. If impurities are still present, repeat step 4.1.3 and extend the separation time until no mineral particles are detected in the extract.

4.2 Test Procedure

4.2.1 Pour the entire extract solution (350–400 mL) into a clean 500 mL distillation flask. Rinse the container with a small amount of solvent and add the rinse solution into the same flask.

4.2.2 Assemble the distillation system as shown in Figure T0726-1, including the distillation flask, condenser, thermometer, flow meter, vent tube, and solvent recovery conical flask. Ensure that the end bulb of the vent tube is above the liquid level. Place the distillation flask in an electric heating mantle. Connect the vent tube with the flow meter and CO₂ gas cylinder. Before introducing gas, clamp the rubber tubing to prevent flow. The tip of the thermometer bulb should be positioned 10 mm from the top of the vent tube. The lower part of the flask neck should be immersed in the oil bath to prevent solvent vapor from condensing and dripping back into the upper section.

4.2.3 Start heating the flask and introduce CO₂ gas into the solution. The gas flow should be adjusted so that the solution gently boils and circulates. Alternatively, during initial heating, immerse the lower 2–4 cm of the flask in the oil bath to prevent vigorous boiling.

4.2.4 Adjust the heating temperature. The oil bath temperature is generally set at 155–165°C until trichloroethylene begins to distill in droplets.

4.2.5 When trichloroethylene starts to distill dropwise, increase the CO₂ flow rate to 1400 mL/min ± 50 mL/min and set the oil bath temperature to 165–175°C, maintaining the internal flask temperature at 160–166°C.

4.2.6 Continue heating for 15 minutes while maintaining CO₂ flow. If solvent droplets appear in the condenser or on the inner wall of the flask, continue CO₂ purging until distillation stops. Then continue CO₂ flow for an additional 5 minutes to remove residual solvent vapor from the flask walls. The heating temperature must remain unchanged during this process.

4.2.7 At the end of distillation, stop heating and CO₂ flow. While still hot, pour the recovered asphalt binder into a container. Proceed immediately with testing of the recovered binder (reheating is not permitted). The total time from extraction to completion of recovery shall not exceed 8 hours.

4.2.8 Conduct tests on the recovered asphalt binder, including viscosity, penetration, softening point, and compositional analysis. The test methods shall be the same as those used for original asphalt.

V. Test Report

The report shall clearly state the recovery method used and comprehensively present all measured properties of the recovered asphalt binder.