Main features:

　　The instrument introduces American rotary compaction technology. It requires no fixed installation—simply push it forward with your hand to start operating. Powered by mains electricity, the compaction chamber is fully enclosed and equipped with a high-precision angle-measuring system as well as an integrated demolding system. Once compacted, the HMA specimens are directly ejected from the mold within the instrument. The instrument is controlled by a highly integrated industrial computer; operators only need to input the appropriate compaction parameters and place the prepared mold into the compaction chamber. To initiate the compaction test, simply press the “START” button. Once the “START” button is pressed, the computer system automatically executes the program, applying the specified rotation angle and pressure. When the specimen reaches the predetermined number of rotations or specified height, the test automatically concludes. After leveling the specimen, the pressure is released, and the operator removes the mold’s top cover. Then, by pressing the “RAM UP” button, the specimen is ejected from the mold. This integrated demolding feature makes both the testing process and specimen removal remarkably easy. In 2009, this instrument successfully passed the department’s evaluation and certification for rotary compaction equipment as well as the nationwide comparative testing for rotary compaction machines.

Operating Procedures for the DF-20 Type Hand-Pushed Rotary Compactor for Asphalt Mixtures

1. Place the instrument on a level and stable surface, and adjust the leveling feet underneath the device to ensure it is perfectly horizontal. The leveling feet must not be left unsupported.

2. Plug the device’s power cord into a 220V power outlet.

3. Power on and preheat the equipment 30 minutes in advance.

4. Press the Enter key to enter the “Function Selection” menu, select “Test Mode,” and then press the Enter key again.

5. Apply petroleum jelly to the areas of the instrument and test mold that will come into contact with asphalt. Select the appropriate test mold diameter and set the “number of rotations” or “compaction height.”

6. Push the mold containing the prepared specimen into the compaction frame, tighten the handle, and securely fasten the top cover onto the mold.

7. Close the safety door. Once the “Machine Ready” indicator light turns on, click the “START” button to begin automatic rotation and compaction. The instrument will display in real time the specimen’s compaction pressure, rotation angle, specimen height, number of compaction cycles, and other relevant parameters. When compaction is complete, the instrument will prompt the operator to remove the top cover. Then, press the “UP” button, and the instrument will automatically eject the specimen. Use the specimen holder to carefully remove the specimen. If the “Machine Ready” indicator light does not turn on, check the pressure cap on the mold, the safety door, or try pressing the “DOWN” button.

8. Remove the specimen, take off the paper discs from the top and bottom of the specimen, wipe the base plate of the mold clean, and then return it to its original position.

9. Press the “DOWN” key, and the die head will automatically reset.

10. After the test is completed, wipe dry the instrument and the test mold bucket.