Asphalt Concrete Mixing Plant Heat Regeneration Technology

The paper mainly studies the Hot Central Plant Recycling (HCPR). The paper introduces two ways to removing the pavement: Ripping and Milling, and analyses the differences between them. In order to control the recycling HMA production, the paper introduces two ways to crushing the RAP: Dry crushing and Wet crushing, and introduces the typical equipments. Based on the analyses the differences between of them, the author recommend the dry crushing, and then suggest the crushed RAP size to 25～12mm,12～4.75mm,and less than 4.75mm, or 19～12mm and less than 12mm. Then the author introduces the management of the RAP stockpiles.The paper analyses a variety of HMA facility configurations that have been successfully used to include RAP in HMA and recommends the parallel-flow dryer drum is the best equipment to handling the RAP in an HMA facility, then discusses the key technologies, such as hot gas generator, the characteristics and the layout of the vanes, the exhaust gas secondary burning, hot material hopper, electrical equipment, and so on, to development the parallel-flow dryer drum.Based on the performance testing of the parallel-flow dryer drum and the asphalt pavement maintenance, the paper analyses the craft of the Hot Central Plant Recycling (HCPR), the author recommend the temperature of the gas, which entered the parallel-flow dryer drum should less than 430℃, and the max should not higher than 480℃, the temperature of the material which leave the drum should between 110 ℃ to 140℃, and the author analyze the dried temperature of aggregate, the mixing time, the temperature of the recycled HMA, and so on. In order to ensure the quality of the recycling HMA, the author suggest test the aggregate gradation, the water and the asphalt content the of RAP, the index of the asphalt reclaimed form the RAP, the gradation and the water of the new aggregate, the aggregate gradation and asphalt content of the recycled HMA, the index of the asphalt reclaimed form the recycled HMA, and so on, and then propose the flow of quality control. And then design some experimentation to validate the performance of the parallel-flow dryer drum.