Assessing Moisture-Induced Fatigue Cracking in Asphalt Mixtures

One of the primary concerns in asphalt pavements is fatigue cracking of the surface course, which is influenced by both climatic and traffic factors, along with constituent properties. This chapter aims to assess alterations in the fatigue life of asphalt mixtures due to moisture-induced damage. Three mixtures were investigated: a baseline mixture utilizing acidic aggregates and a 50/70 neat binder (M1), a mix containing an amine-based anti-stripping additive (M2), and a third mixture containing hydrated lime among the aggregates (M3). The testing methods encompassed dry–wet evaluations, utilizing Indirect Tensile Strength (ITS), Dynamic Modulus, and Tension–Compression Fatigue tests. The findings suggest that the ITS ratio provides accurate insights into the reduction in fatigue life observed across different parameters and the effectiveness of various additives in mitigating the distress. A noteworthy observation is that testing conducted without moisture may lead to an overestimation of fatigue life for the materials under consideration.