Agrietamiento por fatiga top-down en pavimentos asfálticos.

Abstract

In recent years at an international level attention has been paid to a type of cracking in asphalt pavements associated with loads and that in fact are generated by a fatigue mechanism that produces cracks that develop from the surface downwards, that is, the reverse process of conventional crocodile skin type fatigue. Precisely the objective of this work is to study said "top-down" type fatigue cracking phenomenon through the analysis of updated information and studies of particular cases of pavements on main roads, to make evaluations about the effect of the factors involved and methods prediction. To achieve this objective, the results of damage assessments on concessioned highways in the Guayas province of Ecuador, between 2000 and 2010, carried out using the PAVER system were analyzed. In the investigation, initially a review of the context in which this type of failure is developed is carried out, presenting the main causative agents: segregation of the aggregates, the aging of the asphalt, the traffic and the incidence of the tires themselves; in addition to a review of updated information on recent research. As a main result, relationships between the acting loads have been found, through the number of equivalent simple axles of 82 kN with the percentages of area deteriorated by top-down fatigue in the different tracks. The general trend line obtained presents a coefficient of determination R² of 74.7%. On the other hand, the comparison of these results with the permissible repetitions for this type of failure obtained with the prediction equation of AASHTO 2008, indicates that there are no coincidences between the two.