Publikace (přehled)

Fatigue cracking is one of the most important phenomena connected to durability of asphalt pavements. The fatigue resistance of asphalt pavements depends on many factors such as asphalt mixture composition and binder properties. Also temperature of asphalt pavement is important, what is directly related to viscoelastic nature of the bituminous binder. The fatigue cracks may occur within the bitumen (cohesive cracking) or at the bitumen-aggregate interface (adhesion cracking). The cohesive cracking resistance can be evaluated by bitumen testing. The Linear Amplitude Sweep (LAS) test has recently been proposed for fatigue characterization of bituminous binders. The LAS test is performed acc. to AASHTO TP 101 standard. This procedure is based on viscoelastic continuum damage approach to predict binder fatigue life as a function of strain level in the pavement. In the research fatigue performance of three types of binders: paving grade, typically polymer modified and highly polymer modified were evaluated. Tests were performed using the LAS method at temperatures: 5 °C, 10 °C, 20 °C, on samples after RTFOT+PAV aging. Obtained results have shown that each group of binders behave in different way which is connected to its internal network or lack of it. Finally, the best fatigue properties have been presented by highly modified bitumen (HiMA). The paper presents description of the LAS method, test results containing comparison of fatigue characteristics of used binders and conclusions.