Control of recycling dosage: Too much recycling agent will soften and oil the asphalt; too little will not effectively improve the aging condition of the asphalt, reducing the durability of the repaved pavement. It will also reduce the adhesion between the recycled asphalt and aggregate particles, causing problems such as segregation during paving and difficulty in compaction. So, what are the key points of quality control in asphalt hot recycling technology?

1. Due to the uneven gradation and asphalt content of the actual pavement, timely on-site adjustments are necessary. Generally, if the asphalt mixture is dull or gray, the amount of recycling agent or asphalt used is less; if the asphalt mixture is too bright and sticky, the amount of recycling agent or asphalt used is too much.
2. Control of fresh asphalt mixture. The amount of asphalt added to the new asphalt mixture should be the sum of the amount of asphalt added to the old pavement material and the amount of asphalt added to the new asphalt mixture. When adjusting the gradation of the new mixture, the newly added aggregate should have a coarse size to compensate for the coarse aggregate damage caused by the old material's load.
3. Temperature control of the mixture. Excessive heating temperature will cause asphalt aging and reduce recycling efficiency; low-temperature recycling agents have difficulty bonding with old asphalt and will not achieve the recycling effect. If the construction temperature is too low, problems such as mixture segregation, difficulty in compaction, and poor interlayer bonding will occur. The heating rate should be adjusted according to the weather, temperature, and wind force.
4. The thickness of the recycled pavement must maintain sufficient uniformity. This not only affects the smoothness but also the accuracy of the recycling agent and asphalt dosage, affecting the construction quality. To ensure the quality of longitudinal joints, the heating width is generally 10-20cm wider than the rake width, making the longitudinal joints dense and not loose. Recycled asphalt mixtures have high stiffness and a fast cooling rate.
5. Asphalt pavements will develop various degrees of defects during use, affecting normal vehicle traffic and hindering the development of the transportation economy. The application of hot recycling technology can repair various defects, improve the stability and firmness of the pavement, and achieve good maintenance results. Therefore, it is necessary to master the key points of this technology in detail, control the details, and extend the service life of the road.
6. Recycling heating is the primary issue in asphalt hot recycling technology. Whether in-plant or on-site recycling, the recycled materials need to be heated. The heating temperature of the recycled material, the choice of heating method, and the rationality of the heating structure all have a significant impact on the stability of the finished product and the reliability and continuity of equipment operation. Heating recycled asphalt plays a crucial role in plant-mixed asphalt recycling technology.
7. Therefore, the success or failure of plant-mixed asphalt hot recycling technology depends to a certain extent on proper heating. Adhesion issues are a byproduct of plant-mixed asphalt hot recycling technology. From the moment the temperature of the recycled asphalt rises, adhesion problems constrain the entire production process. This is evident in drying drums, temporary storage units, recycled material metering units, chutes, etc. Adhesion problems are ubiquitous.
8. Adhesion is related to both the inherent physical properties of the recycled asphalt and its heating temperature. After repeated heating, the mechanism and chemical composition of the asphalt change, and coupled with dust pollution from the mixing plant, its adhesion characteristics become more prominent. Solving the adhesion problem of waste asphalt helps improve the overall level of plant-mixed asphalt hot recycling technology.