COMPARATIVE ANALYSIS OF OVERLAY THICKNESS USING THE ASPHALT INSTITUTE’S AND MEPDG WITH KENLAYER

Abstract

The Mechanistic-Empirical Pavement Design Guide (MEPDG) is widely regarded as the current state of the art in mechanistic-empirical pavement analysis and design. The guide offers a comprehensive set of procedures for determining overlay thickness, a crucial aspect of pavement design. The objective of this study is to investigate the differences that arise when designing overlay thickness using two distinct methods: the Asphalt Institute's mechanistic-empirical and the MEPDG. This study utilized KENLAYER software, which enables stress and strain analysis by modeling the nonlinear elastic pavement structure. Accordingly, the Asphalt Institute method solely relies on alligator cracking and rut depth as its failure indicators, while the MEPDG encompasses several additional criteria that serve as determinants for evaluating the performance of pavement structure. The subject of this study is flexible pavement situated on a road located in West Java, Indonesia. Following this, a falling weight deflectometer (FWD) test was conducted to obtain the deflection characteristics of the road. This paper provides a detailed explanation of overlay thickness calculation processes employed in both the Asphalt Institute's mechanistic-empirical and the MEPDG method. The Asphalt Institute Method resulted in a slightly thicker overlay of 30 cm, while the MEPDG method produced a thickness of 25 cm. To adapt and apply MEPDG effectively in Indonesia, adaptations such as employing Weigh-In-Motion data for load spectra and conducting local calibration are necessary.