Chemical and Rheological Characterization of Wet and Dry Aging of SBS Copolymer Modified Asphalt Cements: Laboratory and Field Evaluation

摘要

An SBS copolymer modified asphalt cement (PG 76-22) was subjected to accelerated aging using multiple PAV operations in the absence and in the presence of water. A similar polymer modified asphalt cement composition was sampled from a road after up to seven years of service. The extent of oxidation and changes in the molecular mass of the asphalt cement components of aged samples were estimated from FTIR and GPC analyses. Dynamic viscoelastic properties were determined using a high torque instrument. A characteristic point of interest was the temperature at which tanδ became unitary at a frequency of 10rad/s. Oxidative aging in the presence of water promoted an increase in the carbonyl content of aged samples, primarily as acid groups, but the high humidity aging reduced the extent of asphalt hardening. A correlation between laboratory and field results was obtained.