The fine clay content in reclaimed powder significantly influences the mechanical properties of cement-based materials. To promote the resource utilization of reclaimed powder in road engineering, using the methylene blue (MB) value as an indicator to evaluate the fine clay content of reclaimed powder, the influence of the MB value and proportion of reclaimed powder on the mechanical strength of cement-stabilized macadam was analyzed; fitting equations for the relationship between reclaimed powder proportion and mechanical strength were constructed; the required MB value and optimal proportion of reclaimed powder were clarified; the impact of MB value variation on mechanical strength under optimal proportion conditions was evaluated; and with mechanical strength consistency as the principle, equivalence analysis between reclaimed powder proportion and cement content was conducted. The results indicate that when the MB value of reclaimed powder is less than 5.0 g/kg, the MB value has no obvious influence on the mechanical strength of cement-stabilized macadam. With increasing reclaimed powder content, both the compressive strength and splitting tensile strength of cement-stabilized macadam first increase and then decrease, reaching peak values at reclaimed powder contents of 3.0–4.0% and 5.0–5.5%, respectively. As cement content increases, the strength-enhancing effect of reclaimed powder weakens. The MB value of reclaimed powder should be less than 5.0 g/kg with a content of 4%. When cement content is 3–4%, based on mechanical strength equivalence, a reclaimed powder content of 4% can replace at least 0.4–0.5% of cement content.

To investigate the rutting resistance of Large Stone Asphalt Mixture (nominal maximum aggregate size of 53 mm, abbreviated as LSAM-50), this study evaluated the effects of temperature, load, and their interaction on the rutting performance of LSAM-50 through large-thickness rutting tests. It analyzed the characteristics of rutting deformation under varying thermal and loading conditions, established a permanent deformation-temperature-load dependency model, and explored the correlations between permanent deformation and high-temperature evaluation indicators. The findings indicate that the temperature-load interaction fundamentally alters the load-transfer mechanism between the viscoelastic matrix and coarse aggregates within LSAM-50, thereby activating the interlocking effect of its thick structural skeleton. The dynamic stability undergoes a pronounced reduction as temperature or load increases, peaking at a degradation rate of 40–57% within the 40–50 °C interval. Furthermore, the rutting deformation of the LSAM-50 mixture demonstrates significant temperature and load dependency; as the number of loading cycles increases, the deformation exhibits an initial rapid escalation before reaching a plateau. During temperature elevation and load escalation, the rutting deformation increases in a step-wise manner. Notably, the preliminary application of low temperatures and light loads imparts a substantial “training” effect on the material’s rutting resistance. Once the mixture is wheel-tracked to densification under high temperatures or heavy loads, negligible new deformation is generated during the subsequent cooling or unloading phases. Specifically, upon the initial unloading from 1.1 MPa to 0.9 MPa, the incremental deformation is merely 0.04 mm; upon further unloading to 0.7 MPa, the additional deformation approaches 0 mm. The established permanent deformation-temperature-load dependency model for LSAM-50 yields a high predictive correlation of 96%. Moreover, the permanent deformation exhibits robust linear relationships with 1-h rutting depth (R² = 0.95), compressive strength (R² = 0.91), and shear strength (R² = 0.97). These indicators can thus facilitate the rapid and precise estimation of permanent pavement deformation.