A novel peridynamics modelling of cemented granular materials

Cemented granular materials (CGMs) are multi-phase materials consisting of a skeleton of solid particles and a cement phase completely or partially filling the voids among the particles. Although CGMs have been increasingly used in geotechnical applications, their mechanical behaviour has not been clearly understood yet. Peridynamics is a numerical method that can accurately simulate the damage/failure process in solid materials only based on inherent material properties. However, it has limited capability for modelling complicated materials like CGMs. In this paper, a novel peridynamics model is developed to remove the restrictions and investigate the mechanical behaviours of CGMs with different volume fractions of cementitious phase. The irregularly shaped particles are created based on X-ray scanning of rock particles. Key mechanical phenomena including inter-particle frictional contact, distribution of cement bonds and cement clogs between particles are considered in the model. The simulation results in this paper are supported by experimental tests, showing that the mechanical parameters of CGMs vary significantly with change in the cement volume fraction. For a small cement volume fraction up to 2%, pure cement bonds control the overall behaviour of CGMs. From 2 to 12%, the bulk behaviour of cement clogs affects CGMs, and after 12%, cement bonds and clogs with defects control the behaviour of CGMs. This peridynamics model is capable of modelling the unconfined compressive strength and Young’s modulus of CGMs under a large variation of cement ratios.