Statistics and Visual Logic Approach for Detecting Causal Factor of Distress in Flexible Pavement

Civil Department, Helmand University, Helmand, Afghanistan

deformation, disintegration, and surface defects. For this study, a section of road in Lashkargah City was selected as a study section. In the study area, the maintenance of pavement is limited to overlay and performing maintenance without adequately defining the causes of distress. Therefore, the objective of this study is to collect the inventory data of the study road section from Sola intersection to Bost intersection and the relative causes of these distresses. For this purpose, data on distress severity and possible causes in each 50 m distance interval of each bound has been collected and finally, the possible causes for each distress were investigated. Nine distresses were detected in the study section, Among the nine distresses longitudinal cracks, transverse cracks, rutting, alligator cracks, and patches were common while raveling, polishing, shoving, and potholes were rare. The analysis of the result shows that the considerable difference in the value of longitudinal cracks, transverse cracks, rutting, alligator, and polishing for each chainage, suggests that there was considerable inconsistency in construction material and structural strength of the layers. Raveling and potholes were seen locally, it seems to be due to local faults in the asphalt layer and drainage problems respectively. Patches were extruded or settled regarding the pavement surface, it seems that there was a significant inaccuracy in patch thicknesses, or the road was opened to traffic before the setting time of the patches.