Knowledge CentreTechnical Resources SearchConference PapersImpact of Effective Layer Thicknesses on the Structural Performance of In‐Service Roads

Impact of Effective Layer Thicknesses on the Structural Performance of In‐Service Roads


Over the in‐service life of a road, the structural layers are subjected to environmental effects such as freeze‐thaw, moisture migration and fines translation into the structural layers. These processes affect the mechanical properties of the layers and reduce the structural life cycle of a road. These effects are known to increase in areas of higher moisture susceptibility.
This study focuses on the use of a comprehensive field road condition data collection and post‐survey analysis integrated with non‐linear structural finite element modeling to assess the current moisture migration condition of an in‐service road structure, mechanistic materials characterization and numerical modeling was used to quantify the impact on the structural integrity of the road and the effective remaining layers.
Results from non‐linear finite element analysis and non‐destructive pavement condition data collection show that moisture infiltrated layers contribute to pavement deterioration as the effective layer thickness is reduced, therefore compromising structural integrity of the overall structure. The three‐dimensional structural model results show higher peak surface defections for the  compromised structures, as expected. Strains, both orthogonal and shear, also increased in the case of thinner effective layer thickness. This study shows three‐dimensional modeling calculated shear strains were found to yield a higher rate of increase as the road deteriorates. As well, the induced shear strains were found to be significantly higher than traditional orthogonal strains used to predict pavement performance. Therefore, true three‐dimensional modeling and non‐linear orthogonal materials characterization better captures shear strains state which is known to be the primary failure mechanism of road structural performance.

Conference Paper Details

Session title:
Testing and Modelling of Road and Embankment Materials
Soares, R.
Haichert, R.
Berthelot, C.