Statistical Analysis of the Tensile Strength of Cold Recycled Cement-Treated Materials and Its Influence on Pavement Design

The tensile behavior of cold recycled cement-treated mixtures (CRCTMs), typically produced through full-depth reclamation (FDR), is critical for pavement design. Since no universal design method exists, different tests are applied, leading to varying results. In this context, this study aimed (a) to statistically analyze the flexural tensile strength (FTS) and indirect tensile strength (ITS) of CRCTMs incorporating reclaimed asphalt pavement (RAP) and lateritic soil (LS); (b) to evaluate how using FTS or ITS influences the design of CRCTM layers. FTS and ITS tests were conducted with different cement (1–7%) and RAP (7–93%) contents at multiple curing times (3–28 days), and results were used for statistical and mechanistic analyses. Results showed that cement and RAP contents significantly increased FTS and ITS. RAP exhibited the strongest influence on ITS. This indicates that CRCTMs with similar materials benefit from higher RAP contents. Mechanistic analysis revealed that lower RAP contents require thicker pavement structures, suggesting that increasing RAP can reduce costs and environmental impacts. FTS was about 65% higher than ITS, but using ITS in design led to structures 1.7–3.3 times thicker for the same service life. These findings highlight the need for proper CRCTM characterization, with flexural tests recommended for more reliable and cost-effective pavement design.