Efficient preparation and characterization of calcium alginate-attapulgite composite capsules for asphalt self-healing

Calcium alginate capsules encapsulating rejuvenator are a promising self-healing technology for asphalt pavement, but the high cost and low preparation efficiency of cannot meet requirements application. This research proposed an efficient method preparing low-cost calcium using industrial sodium self-developed reaction kettle. To enhance strength assure survival in mixture, attapulgite was incorporated different proportions to form composite shell capsules, their microstructure, thermal stability, mechanical strength, release behavior were investigated. It found that prepared with 2.0 wt% solution ratio 1:1 had clear multi-cavity structure, sufficient use mixture. The within mixture can gradually inside wheel tracking test. test result showed 82.67% significantly soften binder when they suffered 115,200 cycles compression loading (equivalent 7 years traffic on medium grade pavement), indicating rapid crack-healing property pavement during service life.