Applicability of the light-weight deflectometer (LWD) to assess the quality of cement-bitumen-treated materials (CBTM) in the Canadian context

Cement-bitumen treated materials (CBTM) are obtained following full-depth reclamation, and are considered one of the best solutions for pavement rehabilitation from a technical, economic and environmental point of view. Due to the addition of binders and water, CBTM requires time to achieve sufficient strength before reopening to traffic and overlaying with hot mix asphalt. In addition, quality control (QC) is very important to achieve a durable pavement structure. Many agencies in Canada do not have QC specifications or requirements, which limits the use of CBTM. In this paper, the suitability of using the Light-Weight Deflectometer (LWD) for QC purposes in the Canadian context was investigated. Overall, LWD test results showed good reliability for evaluating the stiffening rate of CBTM over time in the Canadian context. Results highlighted that stiffening rate became significant from 4 hours after construction and that traditional laboratory/field measurements were highly variable from one site to another.