Hydraulic Mortars in the Imperial Residence

Abstract

Supply and management of water on the Palatine Hill in Rome played an immanent role for settlements, especially for maintenance of the imperial palace. In the presented project fountains, reservoirs and supply pipes were analysed. Most of them can be dated back to Domitian’s building program and were remodeled at least until the 4th century AD Many fountains were provided with multiple layers of hydraulic mortar. 55 samples were examined including several scientific methods, such as polarized light microscopy, XRD/DTA or sieve analysis. In general most of the samples show a very similar composition. This demonstrates the homogeneity of the building material and the continuity of mortar technology that was used over centuries for different purposes at the imperial workshops on the Palatine: Low-fired crushed ceramics, maybe wasters from the imperial brickyards, and volcanic‚ ‘Pozzolane Rosse’ sands quarried near Rome were constantly used until at least the 3rd century AD In addition two different types of mortar, used in different areas and at different periods, could be identified. This homogeneity and partial correlation between microscopically established groupings and archaeological categories prevent reliable chronological conclusions.