Asphalt mixtures must be produced in a heating device and cannot be created through manual or cold mixing methods. This ensures that the asphalt is properly heated and evenly distributed throughout the aggregate, resulting in a high-quality mixture.
When setting up an asphalt mixing plant, several key requirements must be met to ensure efficiency and quality:
- The location should have good access for transporting raw materials, ensuring they are dry, clean, and free from contamination.
- Sufficient power, water, and heat supply must be available to support continuous operations.
- Asphalt storage should be organized in labeled, sealed tanks to prevent degradation and contamination.
- Mineral materials such as crushed stone, sand, and fines should be stored on a hard, level surface and kept separate to avoid mixing. Mineral powder should also be protected from moisture and rain.
Hot mix asphalt is typically produced using either an intermittent or continuous mixing machine. Continuous mixers should be equipped with automatic feeding systems that adjust according to the design mix, monitoring moisture levels in the aggregates and adjusting feed ratios accordingly. The asphalt dosage and mixing speed should also be controlled to maintain consistency.
Intermittent mixers, on the other hand, should have automatic data recording equipment that prints out critical information such as the amount of asphalt used, the quantities of each mineral material, and the mixing temperature. This helps in maintaining quality control and traceability.
In addition to mechanical specifications, the mixing time should be determined through trial batches to ensure full coating of the aggregate by the asphalt. For standard batch mixers, the mixing time per batch should be between 30 to 50 seconds, with a minimum dry mixing time of 5 seconds. The vibrating screen used for secondary screening of hot aggregates should be selected based on the desired gradation and adjusted according to the material's flowability and the vibrator’s performance.
A well-mixed asphalt blend should be uniform, with no uncoated particles, clumping, or segregation of coarse and fine materials. The final mixture temperature must meet national standards to ensure proper compaction and long-term durability.
Electric Nose Hair Trimmer,2 In 1 Eyebrow Hair Trimmer,Protable Nose Hair Trimmer,3 In One Trimming Hair
ZHEJIANG SHENGFA ELECTRIC APPLIAMNCES CO.,LTD , https://www.sfelectricappliances.com