Dynamic Mechanical Response of Full-Structure Reclaimed Pavement under Special Working Conditions

This study focuses on full-structure recycled pavement (B) supplemented by conventional cold recycled pavement (A). A three-dimensional finite element model of pavement structure was established using numerical simulation, and the mechanical responses of different pavement structural layers under moving loads were analyzed under three working conditions: normal condition, low-speed heavy load, and high-speed light load. Parametric sensitivity of B was evaluated via orthogonal design. Both structures exhibit a "compression-tension-compression" strain cycle with abrupt changes. B shows larger strain amplitudes, indicating greater transient loading sensitivity. Semi-rigid layer stress curves show a "single-peak pulse", but B displays high-frequency fluctuations, reflecting uneven stress transfer. Compared to A, B shows 5.76-fold and 5.22-fold increases in transverse and longitudinal stress peaks, with 7% and 12% increases in shear stress and deflection, suggesting greater susceptibility to cracking and rutting. Under low-speed heavy-load versus high-speed light-load, B exhibits exponential increases in peak strain, shear stress, and deflection. Semi-rigid layer stress peaks increase by approximately 51.5%, demonstrating that load governs tensile stress while loading rate induces fluctuations. ANOVA reveals that B's shear stress is sensitive to upper base layer modulus and thickness (p < 0.05), while deflection is sensitive to both base layer thicknesses (p < 0.01).