Mechanical Behavior of Pavement Structures Containing Foam Glass Aggregates Insulation Layer: Laboratory and In Situ Study

摘要

The use of thermal insulation layers in flexible pavement structures increases the durability of the pavement and decreases the maintenance and rehabilitation costs. Indeed, this technique limits frost penetration in the frost-sensitive subgrade soil, thus reducing the impact of freezing and thawing cycles responsible for the winter differential heaving and the spring bearing capacity loss experienced on the road network. The impact of climate change on pavement performance can result in rolling comfort deterioration. However, because of its intrinsic characteristic, a thermal insulation layer is typically weak from a mechanical perspective. Therefore, for an adequate design, a compromise needs to be made between mechanical and thermal characteristics. In Quebec and the rest of Canada, extruded polystyrene is the recommended material for pavement insulation. New alternative materials are becoming available, among others foam glass aggregates made from recycled glass of various origins, which are lightweight granular materials. This study presents the mechanical performance assessment of a foam glass aggregate layer based on three levels of experimentation, from the laboratory to in situ flexible pavement structures in cold regions conditions. The results presented were obtained using the resilient modulus test, the response of an indoor experimental pavement tested with a heavy vehicle simulator, as well as using falling weight deflectometer (FWD) measurements taken on an experimental test track, which is composed of a standard section without insulation and two insulated sections. The results indicate that foam glass aggregate layers have interesting mechanical properties.