Bitumen Emulsion with Hydrochloric and Ortophosphoric Acid in the Technology of Cold Recycling of Road Pavement—Comparison

Investigated is the use of orthophosphoric acid (which is unconventional for road cationic bitumen emulsions) with a special emulsifier for the cold recycling technology of road pavement. Road cationic bitumen emulsions with hydrochloric and orthophosphoric acids were selected and compared with the help of establishing their physical and mechanical parameters. The study was performed for the special interaction of road cationic bitumen emulsions with orthophosphoric acid and Portland cement, which manifests itself during the determination of parameters of bitumen emulsion disintegration. The difference was determined between the indicators of storage-stability for cationic bitumen emulsions using hydrochloric and orthophosphoric acid. Mix for cold recycling technology were designed on bitumen emulsions with hydrochloric and orthophosphoric acids and with stone materials (virgin aggregate) of acidic granite and alkaline carbonate rocks, reclaimed asphalt, Portland cement and water. The physical-mechanical properties of the prepared mixtures were investigated for water-saturation and strength parameters and the corresponding dependences were obtained. It was established that cationic bitumen emulsions on orthophosphoric acid are advisable for use with aggregates of alkaline rock, while bitumen emulsions made on hydrochloric acid should be used with aggregates of acidic rock.