ABSTRACT
Foam glass aggregates is a material produced from mixing and baking glass residues with a foaming agent at high temperatures. The resulting product is a lightweight and insulating material with limited mechanical characteristics, characterized by unconnected millimetric and micrometric alveoli. The production of foam glass aggregates can help to resolve the recycled glass management issue in some countries, while contributing to the need of light, insulating and draining materials in civil engineering. Foam glass aggregates can be used in numerous applications, among them within the flexible pavement layered systems as insulation layers. In cold regions, this technique helps controlling frost penetration in frost sensitive subgrade soils, 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 impacts of freezing and thawing on flexible pavements in northern countries are among the main causes of the ride quality and general condition deterioration. However, because of its intrinsic characteristic, the use of foam glass aggregates for pavement insulation requires a good assessment of the mechanical response and performance for adequate pavement design and performance, as well as for adequate mechanical protection of the insulation layer. A laboratory study was undertaken to document the resilient modulus and permanent deformation behaviour of three foam glass aggregates from different processes using test methods adapted from AASHTO T307 and EN13286-7. These tests allowed obtaining the essential material parameters to predict the non linear response of foam glass aggregates and quantify the stress dependency, as well as to predict the permanent deformation and the expected ranges of behaviour with respect to stress.
