Masonry structures account for a major portion of all buildings worldwide. Renowned for their long lifespans and structural redundancy, it is an increasingly familiar sight to see deteriorated masonry still in active use. However, due to its heterogeneous and brittle nature, failure modes can be sudden and impactful. Failure in masonry can take place via a myriad of mechanisms and can occur in all locations of a masonry structure. However, most current masonry modelling approaches limit failure to occurring only at the joints, which are often merged simplifications of the mortar joint and unit-mortar interface. In instances where failure is allowed to occur in the masonry units, the units themselves are simplified as elastic blocks, with minimal discretisation. Such approaches, although computationally efficient and helpful in approximations, overlook distinct failure modes including unit-mortar interface de-bonding, mortar crushing, brick spalling and brick crushing amongst others. To account for all major failure modes, while maintaining computational feasibility, the numerical technique known as particle-based Discrete Element Method (pbDEM), has shown potential and capability. To improve understanding of failure modes in small-scale masonry, this research utilised the pbDEM to simulate failure in a masonry core compression test, a popular physical test with limited structural damage. The method was validated against experimental data from literature and the results provide robust evidence to continue using this technique to tackle further problems relating to masonry.