Elastic Properties and Damage Evolution Analysis for Lightweight Shale Ceramsite Concrete

The damage behavior of lightweight aggregate concrete (LWAC) is different from that of normal concrete and mesoscopic simulation has been an effective method to understand the damage and failure process of LWAC. It is important for the reliability of simulation to determine the mechanical properties of individual constituents for LWAC. A micromechanical model of LWAC was proposed by utilizing the nearest-surface distribution functions, the generalized self-consistent scheme and a two-phase spherical model. The prediction method of elastic properties for lightweight shale ceramsite concrete (LWSCC) and an inverse method of parameter for each phase were also proposed. Based on a damage constitutive and a 3D mesoscale model, the damage process of LWSCC was analyzed. Results show that the elastic modulus of ITZ is about 0.70 times that of the cement. The damage caused by compression occurs earlier, but the damage caused by tension finally leads to the failure of the sample under uniaxial compression. The inversion method of elastic properties and damage evolution equations are available to study the damage process of LWAC.