A variety of heritage structures worldwide are constructed using dry-joint masonry blocks. The structural
integrity of such structures strongly relies on the mechanical properties of the contact interface between the
blocks, which include the frictional properties, the interface stiffness and the interface damping. Among
them, the interface damping has attracted less attention in the scientific literature, while it plays an essential
role in the global response of these assemblies when subjected to earthquakes. To this end, this paper
presents a thorough experimental characterisation campaign on dry-joint limestone blocks focusing on the
interface damping. More specifically, two distinct types of energy dissipation are identified and characterised
using an equivalent viscous damping representation: (i) the hysteretic and (ii) the vibration damping. In this
work, the hysteretic energy losses are experimentally quantified after joint closure tests, and the vibration
damping is measured through ambient vibration tests on dry-joint assemblies. The results show different
damping ratios for the various types of damping and a rather constant response with respect to normal stress
at the interface.