Assessment of mechanical and thermal properties of foam glass aggregates for use in pavements

In cold regions, differential winter heaving and bearing capacity loss during spring, induced by seasonal temperature variations, lead to several types of damages on the road networks. Deterioration of the ride quality, cracking of the asphalt concrete layer and increasing rutting and pothole's formation are likely to occur. In prevention, the use of thermal insulation layer is increasingly common in order to limit the frost penetration in frost sensitive subgrade soil, thus reducing the associated damages and rehabilitation costs. In Quebec and Canada, extruded polystyrene is widely used for pavement insulation. However, new alternative materials are now available, including foam glass aggregates (FGAs) made from recycled glass of various origins, which is characterized by a very low thermal conductivity and density. FGAs can be considered as a lightweight and insulating granular material and has been used in road construction in Europe for the last 50 years. This type of materials has also a great potential to help the recycling industry to face the challenges associated with the valorisation of glass, as 90 000 tons of glass are dumped or buried every year in Québec. A cooperative research project was initiated in Quebec to optimize the characteristics of this material. Laboratory tests were performed to document the physical properties, as well as the mechanical and thermal properties. Indoor laboratory heavy vehicle simulator tests were performed to study the performance of a pavement structure insulated with FGAs. Test sections were also built to monitor the long-term thermal and mechanical response of pavement structures with FGAs in comparison with sections built with polystyrene panels or sections without insulation. The paper presents a summary of the main findings regarding the most relevant engineering parameters and observations that were obtained from the laboratory tests and field trials.

Author: 
Ghafari, N., Segui, P., Bilodeau, J-P., Côté, J., Doré, G.
Session title: 
Testing and Modelling of Road and Embankment Materials (S)
Year: 
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