Investigation of Small Samples for Characterization of Linear Viscoelastic Properties and Fatigue Performance of Asphalt Mixtures

Abstract

More robust methods for predicting the performance of asphalt mixtures in the field have been established in recent years. However, the tests carried out to obtain the data generally make use of samples compacted in the laboratory with diameters that make it impossible to extract samples from field layers. This problem can be solved with the use of small samples with a diameter smaller than the compaction thicknesses used in the field. Although characterization tests of asphalt mixtures with small samples have already been performed in the literature, few studies have been carried out, thus denoting the need for more tests for a larger number of mixtures. This research aims to verify the behavior of smaller samples (38×110 mm) and to evaluate if they can provide the same linear viscoelastic (LVE) analyzed from the master curves and the rheological Model 2S2P1D (two springs, two parabolic elements, and one dashpot), the same fatigue characterization, and the same performance over time results for fatigue damage by pavement simulation in FlexPAVE software. The observation of LVE domain suggests a great consistency between the results obtained for the two test geometries. The same was observed for fatigue analysis based in the simplified viscoelastic continuum damage (S-VECD) model. The accumulated fatigue damage curves along the traffic and the cracked area (CA%) prediction obtained by FlexPAVE showed that the characterization by standard and small samples lead to concordant results. The small-scale specimen geometry tested in this research is an accurate and alternative method to full-size samples, with the ability to characterize the LVE behavior, the fatigue phenomenon, and performance simulations in the context of forensic analysis or other investigations that require the use of samples extracted from pavements in field.