Recycled Asphalt Pavement: Study of High-RAP Asphalt Mixtures on Minnesota County Roads

摘要: This report summarizes lessons learned about the field performance of local roads containing Recycled Asphalt Pavement (RAP) and associated laboratory work with asphalt activation as well design testing high-RAP bituminous mixtures.Transverse cracking Minnesota county highways averaging 20-26% RAP was improved when PG 52-34 binder selected over 58-28 or other grades.Testing in plant settings showed that coarse aggregates from mixing achieved a more uniform coating were subjected to less abrasion than those mixing. Low temperature mixture designs up 55% RAP, new-to-total cement ratios low 43%, found indirect tensile test (IDT) creep stiffness increased along content. IDT critical results addition significantly temperature, predicting crack resistance. Semi-circular bend fracture lowered energy toughness mixtures, highest contents had most reduced performance.