Relationship between rutting, roughness and resilient modulus of flexible expressway pavement

Abstract

The study was conducted to investigate the relationship between rutting, roughness and resilient modulus of flexible expressway pavement. The evaluation was conducted at Shah Alam Expressway from km 17.90 to km 52.20. The expressway consisted of three lanes for each bound (slow, middle and fast lanes). The scanner vehicle was used to evaluate the roughness and rutting of the entire test section and the roughness value was given in the International Roughness Index (IRI). While, the resilient modulus values for bituminous layer (E1), road base (E2) and subgrade (E3) were determined by Falling Weight Deflectometer (FWD). IRI and rutting values show that the expressway was in a good to satisfactory condition. In term of resilient modulus, most of the E1 and E2 layers were in the sound to satisfactory condition except 20.1% and 32.1% of the slow lane section was in poor condition, respectively. Resilient modulus of E3 for the entire section was in the sound to satisfactory condition. As a conclusion, the fast lane shows a better condition compares to the middle and slow lanes. In addition, poor correlation was found between rutting, roughness and resilient modulus respectively.