Mortars characterization of Olisipo late Roman wall

Abstract

Since 2009 the City Hall of Lisbon has sponsored the study and valorization of the “Cerca Velha” (Old Rampart) of Lisbon, Portugal. The archaeological excavations done allowed checking the layout of the medieval Wall back to Roman times. These interventions enabled a partial mapping of the late Roman Olisipo’s defensive wall correlated with the end of the 3rd and the beginning of the 4th century CE. This work presents the characterization of those construction materials in order to pursue an interpretation for standard construction technologies and to clarify the sources of raw materials used, as well as to identify potential degradation factors. The methodology used involves a comprehensive use of mechanical, physical, chemical, mineralogical and microstructural techniques. The results obtained contributed to increase the knowledge of the ancestral techniques in a perspective of conservation and restoration of historical and architectural heritage.