Critical pavement response analysis of low-volume pavements considering nonlinear behavior of materials

Abstract

An empirical approach is used to design low-volume pavements in many countries, including India. These types of pavements are made up mainly of an unbound granular material layer over a subgrade with a thin asphalt surface. Accurate modeling of the granular material is essential to better correlate the identified mechanistic responses with pavement performance. It is known that unbound materials are nonlinear and have a stress-dependent resilient modulus. Therefore, the stress dependency of unbound materials should be considered to accurately estimate true pavement responses. Suitable codes written in finite element (FE) analysis software were used to model the nonlinearity of unbound granular layers. A three-dimensional FE was developed and analyzed. It was observed that the pavement responses obtained from the three-dimensional FE analysis carried out for typical low-volume pavements, with the nonlinear characteristics of unbound pavement materials taken into account, differed by 34% to 44% from those obtained with linear analysis.