This paper presents two experimental schemes, graded cyclic loading and unloading, and variable lower limit cyclic loading and unloading, to investigate the energy evolution and acoustic emission characteristics of rocks under different cyclic loading and unloading paths. The experiments were conducted using a WAW-300B microcomputer-controlled hydraulic servo universal testing machine and an AMSY-6 acoustic emission testing instrument. The evolution characteristics of both the acoustic emission ring count and energy count during the loading process were monitored in real-time, and the energy evolution and damage status of the rocks in each cycle were inferred from the stress–strain curve. The results show that: (1) under both types of cyclic loading and unloading paths, the elastic energy, dissipative energy, and total energy of the rocks are positively correlated with the number of cycles; (2) through comparative analysis of the energy dissipation rate and storage rate, it is concluded that the gradual accumulation of dissipative energy ultimately leads to rock failure; (3) based on the energy dissipation method, the study reveals that rock damage is more severe under the variable lower limit cyclic loading and unloading path; (4) under both types of cyclic loading and unloading, the acoustic emission ring count exhibits the Kaiser effect, and Felicity is negatively correlated with the number of cycles. This holds significance in comprehending the behavior of rock deterioration and forecasting its state of destruction.

In order to investigate the compaction characteristics of graded crushed stone under repeated utilization, it is necessary to improve the utilization rate of road recycling crushed stone and maintain its strength and stability during recycling. In the present study, repeated compaction characteristic curves of graded crushed stone were developed using repeated compaction and screening of the graded crushed stone. The correlations between the fractal dimension of particle size distribution and repeated compaction times, water content, and dry density were analyzed. The experimental results indicate that both the maximum dry density and the optimal water content increase as the repeated compaction times increase. The fractal dimension of the particle size distribution of the graded crushed stone used in this test is 2.33 to 2.57. The obtained results show that as the fractal dimension increases, the maximum dry density of the graded crushed stone increases. At a constant repeated compaction time, the fractal dimension of the particle size distribution of graded crushed stone increased and then decreased as the water content increased. In summary, the compaction performance of the structural layer of graded crushed stone can be tuned by adjusting the fractal dimension of the particle size distribution of the recycled pavement structural layer in practical applications. Moreover, the optimal graded materials can be prepared under the guidance of the fractal dimension, thereby achieving an optimized working performance of the recycled pavement structural layer.