Stiffness Variability and Evolution of Cement-Bitumen Treated Materials in an Urban Rehabilitated Road

This study investigated the spatial variability of surface modulus in cement-bitumen treated materials during an urban pavement rehabilitation project in Québec, Canada. Lightweight Deflectometer (LWD) tests were conducted at 24, 48, and 72 h after compaction across nine sections (in total 48 points). Statistical analysis (Levene’s, Kruskal-Wallis, and Dunn) revealed significant heterogeneity at all curing times, with marked differences across and between sections. Although median surface modulus increased over time, variability also grew, reflecting non-uniform material behavior. Overall, the findings emphasize the need for strict quality control and continuous monitoring to ensure reliable performance in urban areas.