Detailed rigid particle models (PM) that take directly into consideration the physical mechanisms and the influence of the material aggregate structure have gained relevance and have been shown to be able to predict, evaluate and understand cracking phenomena in concrete. A 3D rigid PM model is adopted that includes in an approximate way the polyhedral particle shape but keeps the simplicity and the reduced computational costs of rigid spherical particle models [1]. In order to apply the 3D rigid PM model to reinforced concrete an explicit formulation for the reinforcement model is presented similar to that adopted in 2D [2]. The reinforcement bar is discretized through several rigid bar cylindrical segments that interact with each other at the bar ends, where the reinforcement elastic and strength properties are lumped. With the adopted approach, the reinforcement bar model and the bar discretization required for contact purposes with the surrounding concrete, represented by spherical particles, are made independent. The 3D PM model enhanced with reinforcement capabilities is evaluated using known three-point bending tests on reinforced concrete beams without stirrups. It is shown that the reinforced PM model can reproduce the expected final crack pattern, the crack propagation and the load displacement response observed experimentally. The reinforced PM model is also validated against known shear transfer tests due to dowel action. The reinforced PM model is shown to be able to predict the influence of the dowel stiffness and the localized fracture in the vicinity of the initial crack. REFERENCES [1] M. Candeias, N. Monteiro Azevedo, N. and M.L. Farinha. 3D Particle Model for the Study of Rock Fracture Based on Voronoi Diagrams of Granular Structure, Geotecnia, 143:171-197, 2018 (in Portuguese). [2] N. Monteiro Azevedo, J. Lemos, J. and J. Almeida. A discrete particle model for reinforced concrete fracture analysis, Structural Engineering and Mechanics, 36 (3):343-361, 2010.