Mechanistic Characterization of Superpave Asphalt Mixes in Costa Rica

This paper presents an investigation of the dynamic modulus, fatigue properties, and static creep of ten different Superpave mixes used in Costa Rica. The mechanistic properties were compared with empirical properties and also with equivalent Marshall Mix designs. The effect of the volumetric properties on the mechanistic and empirical properties was investigated. It was found that resilient modulus has a high correlation with Indirect Tensile strength yet it is not a good estimator for dynamic modulus. Effective binder content was found to correlate with the fatigue resistance. Asphalt Pavement Analyser (APA) results are highly influenced by the air voids of the specimens, whereas the benefits of using gap-graded gradations (e.g., SMA) is not reflected by the APA results. The paper shows that the tensile strength ratio (AASHTO T183 test) is highly sensitive to gradation and it fails to quantify moisture effects.