Resumen de Efecto del envejecimiento y de la acción del agua en la fisuración de las mezclas asfálticas
Asphalt mixtures cracking is one of the most common deterioration mechanisms in flexible pavements. This phenomenon is due to both the application of loads and the degradation of the material as a result of its exposure to environmental conditions.
The main factors affecting the mixtures durability are ageing and the action of water. This is the reason why analyzing the cracking resistance of mixtures subjected to moisture damage, aged and subjected to moisture damage after ageing becomes a key factor in the prevention of pavement damage and failure.
The objective of this thesis was precisely to study the effect of ageing, the action of water and temperature in the mixtures cracking. To this end, two different tests were used: a direct tensile test (Fénix) and a strain sweep cyclic test (EBADE). Both were applied on unconditioned mixtures, aged mixtures, mixtures subjected to moisture damage and aged mixtures subjected to moisture damage.
Results show the great influence of ageing and test temperature on the cracking behavior of mixtures, especially when they combine with one another, while the effect of the action of water has less influence for the studied conditions. Thus, the applicability of Fénix and EBADE tests in the study and design of asphalt pavement materials is highlighted.
A new methodology was proposed to estimate the fatigue laws of mixtures based on the EBADE test results. This allows the effect of different variables (ageing, test temperature or binder type and content) to be studied on the asphalt mixtures fatigue life. Otherwise (from the classic time sweep tests), it would require too much time.
Finally, the introduction of rest periods in cyclic tests for the study of fatigue cracking of mixtures shows the importance of the sequence of applied loads in mixtures fatigue life, as well as the different behavior of mixtures depending on their stiffness.
