Influence of Aggregate-Binder Adhesion on Fatigue Life of Asphalt Mixtures.

Autor: Lucas Júnior, Jorge Luiz Oliveira, Babadopulos, Lucas Feitosa de Albuquerque Lima, Soares, Jorge Barbosa
Zdroj: Journal of Testing & Evaluation; Jan2020, Vol. 48 Issue 1, p150-160, 11p
Abstrakt: The adhesiveness between aggregate and asphalt binder is believed to affect the life cycle of asphalt pavements, mainly in the presence of water. One of the most common asphalt pavement distresses is fatigue cracking. The objective of this article is to investigate the relationship between adhesion properties and fatigue life of asphalt mixtures. The asphalt bond strength test was used to measure adhesion (pull-off tensile strength) at two different moisture conditioning states: unconditioned (or dry) and conditioned in distilled water for 24 h at 40°C. The test consists of measuring the pull-off pressure required to break an aggregate-binder interface, called the pull-off tensile strength. For the fatigue damage characterization of the mixtures, controlled crosshead sinusoidal tension-compression tests were used, associated with the Simplified Viscoelastic Continuum Damage modeling protocol. Four asphalt mixtures were investigated. They share the same aggregate gradation but differ in aggregate source (two different sources) and the presence or absence of an anti-stripping agent. The mixture with pure asphalt binder showed higher values of pull-off tensile strength than mixtures with asphalt binder doped by an anti-stripping agent. However, the analysis of the pull-off tensile strength ratio (comparison between unconditioned and moisture-conditioned specimens) showed that the addition of anti-stripping agent provided significant moisture damage resistance in the aggregate-binder interface. Results also show that mixtures with asphalt binder modified by anti-stripping agent had higher simulated fatigue life than mixtures with pure asphalt binder. Excellent correlations were obtained between the strain amplitude required to obtain a given @ Nf (strain amplitude @ Nf) with pull-off tensile strength, which confirms that the fatigue life of asphalt mixtures is related to the adhesion between aggregate and asphalt binder. [ABSTRACT FROM AUTHOR]
Databáze: Supplemental Index