Saskatchewan is experiencing significant increases in commercial truck traffic due to grain transportation rationalization, consolidation of the rural grain elevator system, rural economic diversification, and expansion of resource industries. Although increasing truck traffic has long-term implications for the primary pavement system, significant increases hold immediate implications for thin paved roads; many were not originally designed to accommodate heavily loaded commercial trucks. There is a clear need to strengthen many Saskatchewan thin pavements. However, conventional structural strengthening typically involves regrading and granular subbase-base overlay systems, often too expensive because of the cost associated with aggregate hauls and regrading. As a result, the Saskatchewan Department of Highways and Transportation is investigating the use of cold in-place recycling and full-depth cementitious stabilization to strengthen Saskatchewan thin pavements. To this end, industrial waste coproducts such as coal fly ash, bottom ash, and kiln dusts are being investigated as structural cementitious soil stabilizers. The results are presented from preconstruction site investigation methods, laboratory materials characterization, and in situ quality assurance test results. Field performance after 2 years shows cold in-place recycling and cementitious stabilization to be a technically and economically feasible solution for strengthening Saskatchewan thin paved roads built on clay-till subgrades.
Abstract