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• The crack growth performance of cement-treated construction and demolition waste was characterized by Paris law. • A new model for predicting the fatigue damage growth of cement-treated construction and demolition waste was proposed. • The fatigue damage characteristic of cement-treated construction and demolition waste as a base layer was analyzed by FEM. • The stress-dependent characteristic of cement cement-treated construction and demolition waste was evaluated. Fatigue damages of cement-treated construction and demolition waste (CDW) aggregate base materials were predicted using a nonlinear elastic-damage model coupled with a finite element (FE) program. CDW with two different gradations (BC1 and BC2) and one control cement-treated base material using quarried aggregate (N1) were tested. Three-point bending strength and fatigue tests were conducted to obtain the fracture property of the three base materials and inputs of the proposed nonlinear elastic-damage model. Pavement structures with the three base layers were modelled by FE simulations, to evaluate the mechanical and cracking performance under three different vehicle load levels of 700 kPa, 840 kPa and 1050 kPa, respectively. The result of experiments shows that the BC1 with a skeleton-dense gradation has the highest fracture strength, which was followed by the N1, and is much higher than the BC2. In the FE simulations, the proposed nonlinear elastic-damage model can well reflect the damage evolution and modulus distribution of cement-treated base layers under vehicle loading. With the accumulation of vehicle loading cycles, the damage of base layers increases, and pavement structure with the BC2 base layer shows the fastest damage evolution. Besides, the stress-dependent modulus shows a non-uniform distribution in the base layers, presenting very high values at the surface and bottom of the base layer due to the high compressive stress and tensile stresses. [ABSTRACT FROM AUTHOR]

• The fatigue behavior of rocks is studied experimentally and theoretically. • A micromechanics-based model is developed to characterize the fatigue crack growth within rocks. • Theoretical model captures the classical three-stage damage evolution of rock fatigue. The present study investigates the fatigue behavior of granite and red sandstone under coupled static and cyclic loading. Experimental results reveals a three-stage evolution trend for the deformation modulus, Young's modulus, peak strain, residual strain, dissipated energy as a function of the absolute cycle. Acoustic emission (AE) rate also exhibits a three-phase stage, including the initial phase, uniform velocity phase, and accelerated phase. To explain the mechanical responses and fracture mechanisms related to rock fatigue, this study built a micromechanics-based damage model that adopts a modified Paris law and considers both the effect of static stress and stress amplitude. The theoretical model successfully reflects the effect of static loading history and reproduces the three-stage evolution of residual strain during rock fatigue. The SIF deduced by the theoretical model exhibits a distinct behavior: it initially decreases during the first few cycles, stabilizes at a lower value, and subsequently undergoes a significant increase as it approaches the final cycles. The internal cause behind the three-stage evolution of crack growth rate, AE rate, and mechanical properties is attributed to subcritical crack growth during cyclic loading. Finally, the theoretical model successfully characterizes the effect of static stress and stress amplitude of cyclic loads on fatigue damage evolution. [ABSTRACT FROM AUTHOR]