Since COS current design methods do not directly incorporate stabilization materials, this study used a three dimensional non-linear orthotropic computational road structure model to measure the performance of pavement structure stabilized base course layers. The objective of this project was to investigate the effects of cement stabilization for granular material and subgrade soil, within a typical City of Saskatoon road structure. The cross section used in this study was a typical City of Saskatoon local road structure, composed of 45 mm hot mix asphalt concrete (HMAC) on 225 mm granular base, built directly on top of in situ subgrade. The cross section was analysed with two percent cement stabilization added to the granular base layer and three percent cement stabilization added to the top 300 mm of the in situ subgrade. Gyratory compaction and triaxial frequency sweep analysis of the materials were conducted at realistic field state conditions to determine the mechanistic material constitutive properties used in the structural road model. The cement stabilized granular base layer examined in the study showed improved shear strain and horizontal strain behaviour when compared to the unstabilized granular base layer. This improvement confirms that cement stabilization of granular base materials has an enhanced primary response. This study demonstrated that COS pavement designs are highly dependent on subgrade type and condition state and that cement stabilization of subgrade materials can improve the structural primary response of the subgrade layer.
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