Hadrianic Concrete, a Roman Archetype: archaeometric characterization of the construction materials in the Mausoleum of Hadrian, Rome.

The Romans established a strong dominion on the Mediterranean region, extending to further boundaries, with their capital at Rome. They were renowned for their architectural and engineering skills, commended even today. This thesis analyses and characterizes the ancient roman mortars that were used by the Roman Emperor Hadrian in 2nd century AD in the city of Rome. The case study for the analysis is the Mausoleum of Hadrian in Rome. Samples were collected from the core and load bearing members of the structure. The construction techniques and building materials advocated by Hadrian is an important topic of discussion, since centuries. The high-quality mortars and concrete making up the skeleton of the historical structure give great insight into the reasons for such structural stability across multiple centuries. An archaeometry analysis and characterization, with a multi-analytical approach has been adopted to evaluate the provenance of construction material, the mortar recipes adopted and the construction chronology. The dissertation has been divided into two distinct parts. The first part focuses on the background study on the history of Rome during Hadrian’s reign; geology of Rome, with focus on the Alban Hills; and literature on mortar technology and chemistry. The second part highlights the results and discussion of the multi-analytical, archaeometric methods adopted for the building samples. Several qualitative and quantitative methods were implemented for mineral characterization of the bulk samples (mortars and the aggregate), as well as of the separated binder fraction for selected samples. A mineralogical clustering for the mortars was obtained with the help of multiple methods, such as X-Ray Powder Diffraction (XRPD), Optical Microscopy (OM), X-Ray Fluorescence (XRF) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS). The Gravimetric Liquid Separation was used for analysing the binder fraction of mortars, and Optical Microscopy (OM) and X-Ray Fluorescence (XRF) was used for analysing the stone fragments in the concrete. The combined interpretation of the results obtained indicate the reaction processes and the original mortar and concrete recipes prepared for the Mausoleum, as well as the provenance of the raw materials used for its construction.