Coal-petroleum base composite modified asphalt preparation and environmentally friendly warm mix technology for its mixture

Objective Yunnan Province has made rapid progress in highway construction in recent years, with a large demand for road-building materials and a shortage of asphalt supply. The study investigates the application technology for asphalt pavement engineering, combining the local characteristics of rich mineral resources in Yunnan Province, and using local low-cost materials, e.g., coal tar pitch and waste rubber powder. Method First, coal-petroleum base asphalt mixture was made by using medium-temperature coal tar pitch and petroleum asphalt. Its road performance and heat storage stability were tested. Then, the mixture was modified with SBS/CR composite, and the road performance and heat storage stability were studied. Second, the measuring device was designed to investigate the key factors affecting asphalt fume emission amount. It simulated the influence of pavement construction conditions variation on fume emission. Finally, the warm mix technology was applied to lower the temperature during mixture production, mix and compaction, thereby reducing asphalt fume emission. The warm mix effects of different warm mix agents were studied. The influences of different warm mix agents on mixture road performances were explored. Result The road performance and heat storage stability of modified coal-petroleum mixture asphalt are obviously improved. Temperature is the main reason for the increase of fume emission of coal-petroleum base modified asphalt. Reducing the production and construction temperature and shortening storage time would effectively reduce the emission of toxic components in asphalt fume. Aspha-Min warm mix agent has the best cooling effect. Using zeolite as warm mix agent could prepare environmentally friendly coal-petroleum base medium-temperature composite modified asphalt mixture, which has good road performance. Conclusion For expanding the popularization and application of coal tar pitch materials in road engineering, the study result provides technical basis, which has certain practical significance for developing and utilizing local materials as road construction materials.