A framework for determining the optimal moisture content of high-speed railway-graded aggregate materials based on the lab vibration compaction method

•A novel quality assessment method from physical and mechanical perspectives was proposed.•The HRGA with CMC possesses desirable strength and load-bearing capacity.•The graded and water abrasion features of HRGA significantly affect the CMC.•The CMC of the HRGA can be reliably and accurately predicated using the PSO-ANN model.