COMPARATIVE ANALYSIS OF CRACKING AND RUTTING CHARACTERISTICS OF ASPHALT MIXES

Idaho mixes are typically good against rutting. It adopted Superpave design method, which was developed through SHRP program in late 1990s. Superpave mixes are described as more drier mixes than Marshall mixes. It has well rutting resistance performance, but bad cracking resistance performance. In addition, using Recycled Asphalt Pavement (RAP) as alternatives for virgin material produces stiffer mixes. Recently, more attention is paid for utilizing laboratory performance assisting tests for mixture assessments for both rutting and cracking. This study evaluates two test protocols (AASHTO T24 and AASHTO T340) for rutting and three fracture tests protocols (AASHTO TP 124, ASTM D8044, and ASTM D6931) for assessing cracking resistance of asphalt mixes. Two rutting resistance indices ( Rut depth @8000 cycle and rut depth @20000 cycles) along with six fracture performance indices were included: Flexibility Index (FI), Fracture Energy (Gf), Cracking Resistance Index (CRI), strain energy release rate (Jc), and Indirect Tension Test Strength (IDTstrength). Indices were evaluated for potential for results variability, and sensitivity for binder content, binder grade, mix type, RAP materials and increment in recycle binder replacement (RBR%). It was found that, Hamburg Wheel Tracking Test (HWTT) and Flexibility Index (FI) was able to capture the most accurate sensitivity for rutting and cracking.masters, M.S., Civil Engineering -- University of Idaho - College of Graduate Studies, 2018-1