Advancing Field Aging Simulation Methods for Cantabro Abrasion Loss Testing

Abstract

Over the past several years, the asphalt industry has progressively increased efforts to evaluate mixtures after laboratory conditioning for the purpose of simulating field aging, and has also increased reliance on mixture testing. AASHTO T 401-22 describes Cantabro Mass Loss testing and has an appendix of field aging simulation protocols that can be used to estimate field aging by making use of compacted specimens. T 401-22 is one of the few methods to contain both a field aging simulation protocol and a mixture property index test. This paper uses roughly 1,000 tested specimens from forty-nine mixes (mostly dense-graded asphalt with minor amounts of stone-matrix asphalt) evaluated for up to four years of field aging in a hot and non-freeze climate alongside twenty-five different laboratory conditioning protocols. This paper’s objective is to provide information to improve T 401-22 by way of recommendations to update the appendix of conditioning protocols with more comprehensive assessments of their effectiveness in simulating field aging in a hot, non-freeze climate. The overarching recommendation of this work culminates with four protocols. Two of these protocols use only oven conditioning, whereas the remaining two protocols use a combination of stages exposing specimens to oxidation in ovens, moisture effects in hot water baths, and freeze–thaw cycling. The time required to administer the recommended protocols varies from approximately 6 to 28 days and they simulate between 1 and 5 years of field aging depending on the protocol selected.