Paper ID#: 75

Paper Title: Fatigue Cracking and Deflection

Primary Author: O. Gutiérrez-Bolivar

Abstract Text : Traditionally deflection plays a very important role in Spain in the structural rehabilitation of pavements. Guidelines and specifications advocate the use of the deflection as the main factor for pavement structural rehabilitation projects. In the past the deflection measures were obtained by the Benkelman beam and nowadays by the deflectographs as Lacroix or Curviameter or Falling Weight Deflectometers. On the other hand fatigue is the main structural problem in the pavements of the network. As deflections are costly and slow to be obtained, only distress surveying is the method for evaluating the structural condition in the Pavement Management System for the National Road Network. Therefore the relation between deflections and fatigue is essential for justifying the use of distress surveying as the method for assigning rehabilitation action in the Pavement Management System. This paper will show the relations obtained between deflection and its curvature radius with fatigue cracking. For such a task the data of 6,000 km of road were considered. The deflection in 6,000 km ,measured each 5 m with the Curviameter along a part of the Network, was associated with the distress surveying. The study was divided for different types of pavements. Mean values and correlation coefficients show that a relation could be established between deflection and distresses. Although initially the rehabilitation actions for the PMS were conceived using a panel of experts, these results justify the assumptions that were made using experience and intuition.