This paper presents an investigation into the cracking susceptibility of concrete made with recycled concrete aggregates through two-dimensional numerical finite element simulations. Due to the limited experimental data on the performance of Recycled concrete Aggregate Concrete (RAC) in both compression and tension, a series of finite element simulations were performed on a RAC systems with a range of adhered mortar contents for a regular 100 mm RAC cube. The finite element simulation was performed for 0%, 2%, 4%, 10%, 20%, 50%, and 100% adhered mortar contents in order to examine the compressive and tensile behavior of the RAC cube under monotonic loading. Experimental image analysis was used to map the physical geometry of each materialto the finite element model. Loading conditions were prescribed as a strain deformation for the monotonic loading, and sequential crack initiation and crack propagation were also explored. Simulated compressive strengths decreased by 11% between 0% and 50% adhered mortar contents, simulated tensile strengths remained consistent across adhered mortar contents, and modulus of elasticity degraded with adhered mortar content. Both compressive and tensile stress-strain behaviors have showed a slight increase in strain at cracking with increasing adhered mortar content, highlighting an apparent deformability in RAC systems. Stress concentrations were observed near the adhered mortar and interfacial transition zone boundaries, which emphasizes the fact that the fracture path initiates within the new interfacial transition zone. be used as a replacement material to the natural aggregates, such that the adverse environmental effects can be minimized. Recycled concrete aggregate concrete (RAC) consists of five different materials that have unique mechanical properties. The five materials are natural aggregate, new interfacial transition zone, adhered mortar, old interfacial transition zone, and cement-paste matrix. A schematic diagram of an aggregate in the RAC system is shown in Figure 1. Although the response of each material is well understood, the composite RAC system is a complex heterogeneous material. In general, RAC has lower strength, lower elastic modulus, and higher peak strain compared to conventional concrete (Etxeberria et al. 2007). The adhered mortar consists of a highly porous cementitious material which makes it less strong (Malešev et al. 2010) than an ordinary mortar. This is due to the microcracks that are induced in the adhered mortars during the crushing operations (Padmini et al. 2009). RAC systems can achieve higher peak strains than ordinary concrete because a large volume of hardened adhered mortar exists in the RAC system (Liu et al. 2011). Peak strains can be higher in RAC systems compared to normal concrete systems due