Analysis of Perpetual Pavement Experiment Sections in China

Abstract

The rapidly growing highway infrastructure in China has led to the need for long-lasting, high-performing pavement structures. Historically, under frequent extremely heavy loads, expressways in Shandong Province that use pozzolana-treated base have needed to be fully rehabilitated after only 5 to 8 years. In 2005, a full-scale experiment was initiated to develop a better understanding of how these pavements behave under load and to explore perpetual pavement concepts. Five sections were constructed on a new expressway near Binzhou, Shandong Province, China. Three sections were designed as full-depth asphalt pavements that use perpetual pavement concepts, while the other two sections followed more-conventional Chinese designs. The original designs developed in 2004 used the best available information but did not represent in situ properties, climate, or traffic. Now that the sections have been used for 5 years, valuable data sets have become available to conduct an analysis of the as-built sections. This paper documents the relevant input parameters and analysis conducted by using PerRoad, a probabilistic mechanistic–empirical pavement analysis program. Surveyed thicknesses, material properties derived from backcalculation, and load spectra from an on-site weigh-in-motion system were entered into PerRoad, from which probabilistic distributions of pavement response were generated. Both full-bond and full-slip interfacial conditions were modeled. Tensile strain data showed the unlikeliness that any of the sections will experience bottom-up fatigue cracking. Compressive stress in the pozzolana-treated base could be contributing to distress, and stress distributions are proposed to control cracking in the pozzolana-treated material. Interface conditions also appear to be critical.