The Energy Dissipation Mechanism and Damage Constitutive Model of Roof–CPB–Floor (RCF) Layered Composite Materials

The stability of composite material that is composed roof rock, cemented paste backfill (CPB), and floor rock has an important impact on safe mining within metal mines. In order to explore the mechanical properties, acoustic emission (AE), energy dissipation, damage evolution roof–CPB–floor (RCF) layered materials, uniaxial compression (loading rate 0.02 mm/min) AE tests RCF materials with different CPB height ratios were performed. test results show that: (1) compressive strength (UCS) elastic modulus (ER) lower than those or higher CPB. With increase in CPB’s ratio from 0.2 0.7, UCS ER decreased 18.42 MPa 10.08 3.15 GPa 1.79 GPa, respectively, peak strain first 0.695 0.510 then increased 0.595. as a polynomial function ER. (2) ring count slowly, rapidly, finally maintained high-speed increase. cumulative at point ratio. dissipation showed UE accumulated slowly first, dissipated UD increased, almost linearly. UT, UE, UD, UE–UT UD–UT decreasing trend, UE–UD increasing trend (3) Two constitutive models established based principle. process can be divided into three stages: slow accumulation stage, stable growth rapid stage.