Defects in Flexible Pavements: A Relationship Assessment of Defects for Low-Cost Pavement Management System

Abstract

Pavement maintenance has been a key concern for any pavement management authority. Countries are facing a severe challenge of funds in maintenance schemes, especially in developing countries. The existing pavement maintenance methods are goal-specific and lack integration of various indicators that are significant for any low-cost PMS. Thus, this paper aims to investigate the possible defects which may occur in flexible pavements. It also investigates the relationship between the different defects. A detailed literature review has been done for this research to identify all possible defects in flexible pavements and key features considered in any PMS. A questionnaire was designed to seek the expert’s opinion on the defects and their possible relationships to be considered for a low-cost PMS. The data was collected from 283 experts currently working in pavement management authorities and pavement maintenance schemes. Aggregated Mean Score, Box plotting and Chi-Square test are used to analyze the data. It is concluded that Bumps/Sags (3.17) are one of the major defects reported by the experts in pavements in Pakistan, followed by the fatigue cracks (3.07). Rutting (2.98) and rut depth (2.98) stand at third key defects reported in this study. Depression (2.96), potholes (2.76), longitudinal crack (2.69), edge crack (2.55), roughness (2.51) and deflection (2.50) are also regularly arising defects in pavement maintenance activities in Pakistan. The results are in the acceptance range of the three mentioned validation methods. The correlation test results show that most of the defects in structural, functional, safety and serviceability indicators reject the null hypothesis thus, there is a close relationship between these defects observed in the flexible pavements. In last stage, a PMS model is suggested to assist the road management authorities of developing countries to make low cost decision for effective pavement rehabilitation.