Recycled aggregate concrete (RAC), a promising alternative for mitigating negative effects of construction and demolition waste (CDW), demonstrates significant material heterogeneity that poses challenges for its widespread structural application. Moreover, existing mesoscale modelling approaches frequently struggle to accurately represent the multiphase heterogeneity of RAC. Nevertheless, the Lattice Discrete Particle Model (LDPM) has proved to be a robust and versatile computational approach for simulating fracture in concrete, standing for its capability to capture the heterogeneity while keeping computational efficiency. Given the limited application of LDPM for simulating mechanical behaviors of RAC, this study presents a preliminary investigation towards mesoscale parameter calibration and macroscale validation. LDPM parameters are calibrated by fitting numerical results from compression and direct tension tests to experimental data, while splitting tension tests are used for validation. The results indicate that LDPM provides a great capacity for capturing the mechanical behavior of RAC, laying a solid foundation for further mesoscale modelling investigations of RAC.